CN117097313A

CN117097313A - Radio frequency signal isolating switch, device, communication system and method

Info

Publication number: CN117097313A
Application number: CN202310047000.6A
Authority: CN
Inventors: 张北江; 赵陆文
Original assignee: Nanjing Younitai Information Technology Co ltd
Current assignee: Nanjing Younitai Information Technology Co ltd
Priority date: 2023-01-31
Filing date: 2023-01-31
Publication date: 2023-11-21

Abstract

The invention discloses a radio frequency signal isolating switch, which comprises a first controlled switch and an auxiliary signal generator, wherein the first controlled switch comprises a first connecting end, a second connecting end, a first public connecting end and a first controlled connecting end; the first connecting end is used for inputting a controlled radio frequency signal, the auxiliary signal generator is used for generating an auxiliary signal and is electrically connected with the second connecting end, and the first controlled connecting end is used for inputting a control signal; the control signals are two different state signals, and respectively control the first controlled switch to be connected (disconnected) between the first connecting end and the first common connecting end, and simultaneously control the second connecting end to be disconnected (connected) between the second connecting end and the first common connecting end. The switch can solve the problem that the back-end receiving equipment can still receive the controlled radio frequency signal because the controlled radio frequency signal cannot be completely disconnected to generate leakage residues, and has the advantages of low cost, easiness in implementation and wide application range. Radio frequency signal isolation devices, communication systems, and methods are also disclosed.

Description

Radio frequency signal isolating switch, device, communication system and method

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a radio frequency signal isolation switch, a device, a communication system, and a method.

Background

In the communication fields of satellite communication, satellite positioning navigation, mobile communication and the like, an antenna and a receiving device usually exist in a split mode, as shown in fig. 1, an active antenna for GNSS (GlobalNavigation Satellite System ) and a navigation time service device exist in a split mode, and are connected with each other through a radio frequency cable.

In practical application, the radio frequency signal received by the antenna is usually a normal signal transmitted by a satellite or a corresponding transmitting terminal, but there are malicious interference signals or deception signals, and the malicious signals are similar to the normal signal in frequency band range, frequency spectrum characteristics, power and other aspects, even the power is larger than the normal signal, and when the malicious signals are received together with the normal signal by the antenna, the normal signal is possibly suppressed or replaced by the normal signal, and the normal signal is received by a receiving device at the rear end, so that the abnormal signal received by the receiving device at the rear end is caused, and errors of positioning navigation, time-of-reception, information receiving and the like occur, thereby causing adverse effects.

Therefore, it is necessary to detect the rf signal received by the antenna, for example, to detect whether the rf signal is interfered or deceptively, and if so, it is necessary to turn off the rf signal through the rf switch to avoid the receiving device at the back end from receiving the rf signal.

However, the transmission characteristics of the rf signal are different from those of the dc signal, and the rf switch cannot be completely disconnected from the rf signal, and a small portion of the rf signal is leaked and transmitted to the back end. Therefore, we measure the turn-off characteristics of the radio frequency switch by using the isolation (or called turn-off loss), and generally, the larger the isolation or turn-off loss is, the better the turn-off characteristics of the radio frequency switch are.

Under the existing condition, as shown in fig. 1, the GNSS active antenna and the navigation time service device are usually installed and constructed, and a radio frequency isolation device based on a radio frequency switch is required to be additionally installed on the basis, but the reality is that: first, high turn-off losses (greater than 100 dB) are difficult to achieve, and are costly, with the isolation of ordinary rf switches not being large enough (e.g., less than 60 dB); secondly, even if the radio frequency isolation device can realize the turn-off loss of more than 100dB, the output port or joint of the active antenna is adjacent to the input port or joint of the navigation time service equipment in space, and radio frequency leakage exists in the radio frequency cable joint connecting the active antenna and the navigation time service equipment, the radio frequency signal which is turned off can be transmitted to the receiving equipment to be received due to the radio frequency leakage. Most of the current solutions focus on improving the turn-off loss, and cannot solve the problem of radio frequency leakage of the radio frequency cable connector due to space proximity.

Disclosure of Invention

The invention mainly solves the technical problems that in the prior art, radio frequency signals cannot be completely turned off and joints are leaked, so that the rear-end receiving equipment erroneously receives the radio frequency signals with interference.

In order to solve the technical problems, the technical scheme adopted by the invention is to provide a radio frequency signal isolating switch, which comprises a first controlled switch and an auxiliary signal generator, wherein the first controlled switch comprises a first connecting end, a second connecting end, a first public connecting end and a first controlled connecting end; the first connecting end is used for inputting a controlled radio frequency signal, the auxiliary signal generator is used for generating an auxiliary signal and is electrically connected with the second connecting end, and the first controlled connecting end is used for inputting a control signal; the control signal is a first state signal, and the first controlled switch is connected with the first connecting end and the first public connecting end, and is disconnected between the second connecting end and the first public connecting end; and if the control signal is a second state signal, the first controlled switch is connected with the second connecting end and the first common connecting end, and meanwhile, the first connecting end and the first common connecting end are disconnected.

Preferably, the auxiliary signal comprises a noise signal, a single frequency signal, a plurality of frequency signals or a carrier modulated signal.

Preferably, the circuit further comprises a second controlled switch, wherein the second controlled switch comprises a third connecting end, a fourth connecting end, a second public connecting end and a second controlled connecting end, the second controlled connecting end is used for inputting the control signal, and the second public connecting end is electrically connected with the first connecting end of the first controlled switch; the control signal is a first state signal, the second controlled switch is connected with the third connecting end and the second common connecting end, and meanwhile, the fourth connecting end and the second common connecting end are disconnected; the control signal is a second state signal, the second controlled switch is connected with the fourth connecting end and the second common connecting end, and meanwhile, the third connecting end and the second common connecting end are disconnected.

Preferably, the auxiliary signal generator includes a noise generator, the noise generator includes a zener diode, the positive electrode of the noise generator is grounded, the negative electrode is electrically connected with one end of a first resistor and one end of a first capacitor, the other end of the first resistor is connected with a power supply, the other end of the first capacitor is electrically connected with the input end of a first amplifier, and the output end of the first amplifier outputs noise as the auxiliary signal.

Preferably, the auxiliary signal generator includes a noise generator, the noise generator includes a second resistor, one end of the second resistor is grounded, the other end of the second resistor is electrically connected with one end of a second capacitor, the other end of the second capacitor is electrically connected with an input end of a second amplifier, and an output end of the second amplifier outputs noise as the auxiliary signal.

Preferably, a filter is further connected in series to the output end of the second amplifier.

Preferably, the second amplifier includes two cascaded amplifier chips AT2659S, and the filter is a saw filter device SAFEB1G57KE0F00.

Preferably, the first controlled switch is a radio frequency switch chip HMC349AMS8G, and the first connection end, the second connection end, the first common connection end, and the first controlled connection end of the first controlled switch correspond to the first radio frequency input end, the second radio frequency input end, the radio frequency output end, and the control end of the radio frequency switch chip HMC349AMS8G, respectively.

Based on the same conception, the radio frequency signal isolation device comprises a signal branching device, a deception jamming detection module and the radio frequency signal isolation switch; the input end of the signal splitter is used for accessing a first radio frequency signal received and output by the antenna, the two output ends are respectively connected with the radio frequency signal input end of the radio frequency signal isolating switch and the input end of the deception jamming detection module, and the signal splitter is used for dividing the input first radio frequency signal into a controlled radio frequency signal and a second radio frequency signal which are respectively transmitted to the radio frequency signal isolating switch and the deception jamming detection module; the output end of the deception jamming detection module is electrically connected with the control end of the radio frequency signal isolating switch and is used for detecting whether a deception radio frequency signal or an jamming radio frequency signal exists in the second radio frequency signal or not and outputting a control signal to the control end of the radio frequency signal isolating switch according to a detection result; and the output end of the radio frequency signal isolating switch is connected with the controlled radio frequency signal output by the signal divider or connected with the auxiliary signal under the action of the control signal.

Based on the same conception, there is also provided a communication system comprising an antenna and a receiving device between which the aforementioned radio frequency signal isolation means are arranged.

Based on the same conception, the radio frequency signal isolation method also comprises the following steps:

the radio frequency signal isolating switch is arranged between the antenna and the receiving equipment, and a first radio frequency signal received and output by the antenna is separated into a controlled radio frequency signal and is sent to the radio frequency signal isolating switch; the radio frequency signal isolating switch is controlled to disconnect the controlled radio frequency signal and input an auxiliary signal to the receiving equipment; or the radio frequency signal isolating switch is controlled to switch on the controlled radio frequency signal, input the controlled radio frequency signal to the receiving equipment, and switch off the auxiliary signal input to the receiving equipment.

The beneficial effects of the invention are as follows: the invention discloses a radio frequency signal isolating switch, which comprises a first controlled switch and an auxiliary signal generator, wherein the first controlled switch comprises a first connecting end, a second connecting end, a first public connecting end and a first controlled connecting end; the first connecting end is used for inputting radio frequency signals, the auxiliary signal generator is used for generating auxiliary signals and is electrically connected with the second connecting end, and the first controlled connecting end is used for inputting control signals; the control signals are two different state signals, and respectively control the first controlled switch to be connected (disconnected) between the first connecting end and the first common connecting end, and simultaneously control the second connecting end to be disconnected (connected) between the second connecting end and the first common connecting end. The switch can be used for solving the problem that the rear-end receiving equipment can still receive the radio-frequency signal because the radio-frequency signal cannot be completely disconnected to generate leakage residues, and has the advantages of low cost, easiness in implementation and wide application range. Radio frequency signal isolation devices, communication systems, and methods are also disclosed.

Drawings

Fig. 1 is a schematic diagram showing a split connection between an antenna and a receiving device in the prior art;

FIG. 2 is a schematic diagram of an embodiment of a RF signal isolation switch according to the present invention;

FIG. 3 is a schematic diagram of the signal and noise power transmission variation principle according to an embodiment of the prior art;

FIG. 4 is a schematic diagram of the principle of signal and noise power transmission variation of an embodiment of the RF signal isolation switch according to the present invention;

FIG. 5 is a schematic diagram of another embodiment of a RF signal isolation switch according to the invention;

FIG. 6 is a schematic diagram of an embodiment of an auxiliary signal generator in a RF signal-isolation switch according to the present invention;

FIG. 7 is a schematic diagram of another embodiment of an auxiliary signal generator in a radio frequency signal isolation switch according to the present invention;

FIG. 8 is a schematic circuit diagram of an embodiment of an auxiliary signal generator in a radio frequency signal isolation switch according to the present invention;

FIG. 9 is a schematic circuit diagram of one embodiment of a controlled switch in a radio frequency signal isolation switch according to the present invention;

FIG. 10 is a schematic diagram illustrating the composition of an embodiment of a radio frequency signal isolation device and communication system in accordance with the present invention;

fig. 11 is a schematic circuit diagram of an embodiment of a signal splitter in a radio frequency signal isolation device according to the present invention.

Detailed Description

In order that the invention may be readily understood, a more particular description thereof will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used in this specification includes any and all combinations of one or more of the associated listed items.

As shown in fig. 2, an embodiment of a radio frequency signal isolation switch according to the present invention includes a first controlled switch 1 and an auxiliary signal generator 2, where the first controlled switch 1 includes a first connection terminal 11, a second connection terminal 12, a first common connection terminal 13, and a first controlled connection terminal 14, the first connection terminal 11 is used for inputting a controlled radio frequency signal, the first common connection terminal 13 is used for outputting a signal, and the auxiliary signal generator 2 is used for generating an auxiliary signal and electrically connected to the second connection terminal 12, and the first controlled connection terminal 14 is used for inputting a control signal.

Here, the controlled radio frequency signal refers to a radio frequency signal received by the antenna to be transmitted to the receiving device at the back end, but the radio frequency signal needs to be controlled to be turned off or on during the transmission, and is referred to as a controlled radio frequency signal. The reason is that the radio frequency signal may be mixed with an interference or deception signal or is the interference or deception signal, so that detection and identification are usually required, on-off control is performed, and the situation that effective off control cannot be performed after the interference or deception signal exists, so that the rear-end receiving device receives wrong information is avoided. Optionally, the auxiliary signal generator 2 is configured to generate an auxiliary signal, where the auxiliary signal includes noise, a single frequency signal, multiple frequency signals, or a carrier modulated signal. The frequency range of the auxiliary signal is usually the same as or equivalent to the frequency range of the input controlled rf signal, and the power of the auxiliary signal is usually close to the power of the controlled rf signal, and is significantly larger than the power of the residual controlled rf signal which still leaks a small amount after the controlled rf signal is turned off, that is, the power of the residual controlled rf signal which leaks due to incomplete turn-off after the first controlled switch turns off the input controlled rf signal is lower than the power of the auxiliary signal.

When the control signal is a first state signal (e.g. 5v high voltage), the first controlled switch 1 is connected to the first connection terminal 11 and the first common connection terminal 13, and is disconnected between the second connection terminal 12 and the first common connection terminal 13; when the control signal is a second state signal (e.g. 0v low voltage), the first controlled switch 1 is connected to the second connection terminal 12 and the first common connection terminal 13, and is disconnected between the first connection terminal 11 and the first common connection terminal 13.

Here, the first state signal and the second state signal correspond to two different states representing the control signal, for example, the first state signal is a high voltage signal and the second state signal is a low voltage signal, or may be two different digital control signals, so as to distinguish between different controls of the first controlled switch 1.

When the control signal is the first status signal, since the first connection terminal 11 is connected to the first common connection terminal 13, the controlled rf signal inputted from the first connection terminal 11 is outputted through the first common connection terminal 13, and since the second connection terminal 12 is disconnected from the first common connection terminal 13, the auxiliary signal generated by the auxiliary signal generator 2 is not inputted to the first common connection terminal 13, and does not interfere with the controlled rf signal from the first connection terminal 11. Further, after the second connection terminal 12 is disconnected from the first common connection terminal 13, even if the auxiliary signal is disconnected and then is spatially coupled, a small amount of leakage will be induced by the first common connection terminal 13, but the controlled radio frequency signal is still unaffected, and the back-end receiving device is not affected to normally receive the controlled radio frequency signal. Therefore, the power of the auxiliary signal cannot normally be set too high, avoiding normal reception of the controlled radio frequency signal under normal conditions. Alternatively, the auxiliary signal generator 2 is always in operation, and even if the second connection 12 is disconnected from the first common connection 13, the auxiliary signal generator 2 is not affected to generate an output auxiliary signal, but the auxiliary signal is not connected to the first common connection 13.

Optionally, the auxiliary signal generator 2 is also electrically connected to the first controlled connection terminal 14 and receives the control signal, and when the control signal is a first state signal, the auxiliary signal generator 2 stops working and no auxiliary signal is output, so as to ensure that no auxiliary signal is generated in this state; when the control signal is the second state signal, the auxiliary signal generator 2 starts to operate, and then the output auxiliary signal is generated. The auxiliary signal generator 2 thus only works when the first common connection 13 is connected in, whereas the auxiliary signal generator 2 stops when disconnected from the first common connection 13. Therefore, the interference of the leaked auxiliary signal on the controlled radio frequency signal during normal operation can be avoided, and the energy consumption can be saved.

For the embodiment shown in fig. 2, when the control signal is the second status signal, since the second connection 12 is connected to the first common connection 13, the auxiliary signal generated by the auxiliary signal generator 2 is input to the first common connection 13 through the second connection 12, and thus the main auxiliary signal is output through the first common connection 13. The type of auxiliary signal is usually different from the signal characteristics of the controlled rf signal input by the first connection terminal 11, so that the auxiliary signal is easily recognized by the receiving device after being output through the first common connection terminal 13, without causing reception error information.

Therefore, even after the first connection terminal 11 is disconnected from the first common connection terminal 13, there is still a leakage of the controlled rf signal inputted from the first connection terminal 11 to the first common connection terminal 13, which is called a residual controlled rf signal, and if the residual controlled rf signal is still large, it can be normally received after being transmitted to the receiving apparatus, but when there is a malicious spoofing signal in the residual controlled rf signal, such reception will be undesirable. When the auxiliary signal is added in the invention, the residual controlled radio frequency signal is suppressed, the signal-to-noise ratio of the residual controlled radio frequency signal relative to the auxiliary signal is obviously reduced, or the auxiliary signal is used for replacing the residual controlled radio frequency signal to be a main signal entering the receiving device, so that after the receiving device at the back end receives the auxiliary signal, the information is difficult to demodulate from the residual controlled radio frequency signal because the signal-to-noise ratio between the residual controlled radio frequency signal and the auxiliary signal is greatly reduced, or the auxiliary signal is identified because the auxiliary signal has obvious carrier characteristics (such as a specific single frequency or a plurality of frequencies), or the auxiliary signal can be received by the receiving device to demodulate the information, the received auxiliary signal is identified, and the influence of the deception signal mixed in the residual controlled radio frequency signal is avoided.

In this regard, the technical effects of the embodiment of fig. 2 will be further described in connection with further quantitative example comparative analysis of fig. 3 and 4.

In fig. 3, a controlled rf signal inductively received by an antenna X11 passes through a low noise amplifier X12, then passes through a filter X13 to select a controlled rf signal within a corresponding frequency band range, and then passes through a rf switch X14 to perform switch controllable transmission.

The amplifier X12 and the filter X13 are generally disposed adjacent to the antenna X11 or disposed inside the antenna X11, and then the output controlled rf signal is transmitted to the receiving device through the rf cable, and the rf switch X14 is disposed on the rf channel connected to the rf cable. The characteristic parameters and signal transmission characteristics of the respective devices are given in table 1 below:

table 1 table of radio frequency transmission characteristics

Based on fig. 3 and table 1, the controlled radio frequency signal power C inductively received by the antenna is-110 dBm, the corresponding noise spectral density n0 is-174 dBm/Hz, which is the thermal noise of the antenna, which is also the thermal noise of other electronic devices, which is a general characteristic of thermal noise. Correspondingly, after passing through the amplifier, the amplification gain of the amplifier is +40dB, so that the power of the controlled radio frequency signal output by the amplifier is-110+40= -70dBm, and the noise spectral density is-174+40= -134dBm/Hz; after passing through the filter, the attenuation of the filter is-25 dB, so that the power of the controlled radio frequency signal output by the filter is-70-25= -95dBm, and the noise spectral density is-134-25= -159dBm/Hz; through the rf switch, the rf switch will not generate attenuation or gain when turned on, and thus corresponds to 0dB, while when the rf switch is turned off, the corresponding isolation or turn-off loss is-60 dB, so that in the case of the rf switch being turned off, there will be a residual controlled rf signal output, the corresponding residual controlled rf signal power is-95-60= -155dBm, but for the noise spectral density, it is not-159-60= -219dBm/Hz, but-174 dBm/Hz, which is determined by the characteristics of the thermal noise itself and is not affected by the turn-off loss of the rf switch, because this is already the value of the power spectral density corresponding to the thermal noise, which is a constant value.

Thus, with the radio frequency switch turned off, the output residual controlled radio frequency signal power C is-155 dBm, the noise spectral density n0 is-174 dBm/Hz, and the corresponding signal-to-noise ratio C/n0=19 dBm. The residual controlled radio frequency signal corresponding to the signal-to-noise ratio value enters the receiving device and can still be normally received by the receiving device, because, for example, the receiving device is a navigation time service device, and the corresponding navigation module generally has higher receiving sensitivity. After the radio frequency switch is turned off, although the power of the signal reaching the navigation module is reduced, the gain of the receiving channel is increased by an automatic gain control loop in the navigation module, so that the received signal still exceeds the tracking threshold, and the reception of the residual controlled radio frequency signal is difficult to thoroughly cut off. This is a consequence of the low isolation or switching losses of the radio frequency switch.

For example, the positioning navigation modules ATGM336H-5N and ATGM332D-5N manufactured by micro-electronics Inc. of Hangzhou, shanghai mobile telecommunication technology Co., ltd, L76KB-A58, and VG7669T160N0SA manufactured by Shenzhen, wo, technology Co., ltd, have a tracking sensitivity of-162 dBm, which is significantly lower than-155 dBm, so that the residual controlled RF signal can be tracked. Based on the thermal noise spectral density n0 being-174 dBm/Hz, the threshold signal-to-noise ratio of these modules is 12 dBm, whereas the resulting signal-to-noise ratio C/n0=19 dBm, above which the threshold signal-to-noise ratio is 12 dBm, thus also indicating that the residual controlled radio frequency signal can be received normally by these modules.

On the basis of the embodiment shown in fig. 3, fig. 4 is an application example of the example of fig. 2, in which a noise generator X141 (an implementation of the aforementioned auxiliary signal generator) is added, and the generated noise is input to the radio frequency switch X14. Table 2 below is a table of radio frequency transmission characteristics based on table 1.

Table 2 table of radio frequency transmission characteristics

The main differences between tables 1 and 2 are: the power C of the controlled radio frequency signal induced by the antenna becomes-90 dBm, the noise output by the noise generator X141 is increased after the radio frequency switch X14 is turned off, the power spectrum density n0 of the noise is-134 dBm/Hz corresponding to the auxiliary signal generated by the auxiliary signal generator in fig. 2, so that the power C of the residual controlled radio frequency signal output by the radio frequency switch is-135 dBm under the condition that the radio frequency switch is turned off, and the corresponding signal-to-noise ratio C/n0= -1dBHz, obviously, the signal-to-noise ratio is obviously reduced compared with the output signal-to-noise ratio 19dBHz in the embodiment corresponding to fig. 3 and table 1, and the information can be demodulated from the residual controlled radio frequency signal after the receiving equipment can not be caused. And, the antenna in table 2 induces rf signal power of-90 dBm, which is significantly greater than the corresponding-110 dBm in table 1, if it is still-110 dBm, the signal-to-noise ratio C/n0 of the output will be less than-21 dBm, and the receiving device at the back end will be less able to demodulate the information from the residual controlled rf signal. Obviously, the embodiment shown in fig. 4 uses the rf signal isolation switch shown in fig. 2, so that the blocking suppression of the residual controlled rf signal can be obviously performed, thereby preventing the residual controlled rf signal from being normally received by the receiving device at the back end.

Thus, in the present invention, after the controlled rf signal is turned off, the ratio of the power of the residual controlled rf signal (or referred to as the leaked controlled rf signal) to the power of the auxiliary signal, or the ratio of the power of the residual controlled rf signal to the power spectral density of the auxiliary noise signal, is lower than the threshold signal-to-noise ratio of the rear-end receiving device (where the threshold signal-to-noise ratio includes the ratio of the two signal powers or the ratio of the signal power to the noise power spectral density). As in the foregoing table 2, the ratio of the power of the residual controlled rf signal to the power spectral density of the auxiliary generated noise signal is-1 dBHz, which is significantly lower than the threshold signal-to-noise ratio of 12dBHz of the positioning and navigation modules ATGM336H-5N and ATGM332D-5N, so that these receiving devices at the rear end cannot normally receive the residual controlled rf signal, i.e. cannot demodulate and recover the information modulated therein from the residual controlled rf signal.

Another embodiment is further presented in fig. 5, based on the embodiment shown in fig. 2. The first controlled switch 1 and the auxiliary signal generator 2 have the same composition as the embodiment shown in fig. 2, and are not described herein. Fig. 5 further includes a second controlled switch 3, where the second controlled switch 3 includes a third connection terminal 31, a fourth connection terminal 32, a second common connection terminal 33, and a second controlled connection terminal 34, the third connection terminal 31 is used for inputting a controlled radio frequency signal, the second controlled connection terminal 34 is used for inputting the control signal, and the second common connection terminal 33 is electrically connected with the first connection terminal 11. Preferably, the fourth connection 32 may be connected to a matching load, such as a resistor having an impedance of 50 ohms.

When the control signal is a first state signal, the second controlled switch is connected to the third connection terminal 31 and the second common connection terminal 33, and is disconnected between the fourth connection terminal 32 and the second common connection terminal 33; when the control signal is a second state signal, the second controlled switch is connected to the fourth connection terminal 32 and the second common connection terminal 33, and is disconnected between the third connection terminal 31 and the second common connection terminal 33. The control of the first controlled switch by the control signal is as described in the previous embodiment of fig. 2.

It is obvious that in fig. 5, a second controlled switch is added at the previous stage of the first controlled switch, by adding the second controlled switch, the isolation degree or switching loss caused by the radio frequency switch can be further increased, for example, the corresponding loss after the first controlled switch is turned off is 60dB, the loss after the second controlled switch is turned off is also 60dB, and then after the two switches are cascaded, the turn-off loss of 120dB can be caused to the input controlled radio frequency signal after the two switches are turned off. And the two controlled switches are simultaneously controlled by the control signal, so that the controlled actions can be synchronously performed under the action of the control signal, and the consistency of the switch control is ensured.

Alternatively, for the auxiliary signal generator, a noise generator may be used, and the corresponding embodiment of the noise generator is shown in fig. 6, where the noise generator includes a zener diode 22, the positive terminal of which is grounded, the negative terminal of which is electrically connected to one end of the first resistor 21 and one end of the first capacitor 23, the other end of the first resistor is connected to the power Vcc, the other end of the first capacitor 23 is electrically connected to the input end of the first amplifier 24, and the output end of the first amplifier 24 outputs noise as the auxiliary signal.

Preferably, the output of the first amplifier 24 is further connected to a first filter 25, such as a watch filter, and the first filter 25 outputs noise. The noise generated at the cathode of the zener diode 22 is input to the first amplifier 24 through the first capacitive coupling for amplification, for example, the amplification gain is 20dB, the output power of the noise is adjusted according to the requirement, and the first filter 25 is used for filtering and selecting the noise output in different frequency ranges, where the frequency ranges overlap with the frequency range of the input controlled radio frequency signal.

In the noise generator, the voltage stabilizing tube generates noise with larger output power, so that the requirement on the amplification gain of the first amplifier is not high, for example, a gain of 20dB is enough.

Alternatively, as shown in fig. 7, the embodiment of the noise generator may further include a second resistor 26, one end of which is grounded, and the other end of which is electrically connected to one end of a second capacitor 27, and the other end of the second capacitor 27 is electrically connected to the input end of a second amplifier 28, and the output end of the second amplifier 28 outputs noise as the auxiliary signal.

Preferably, an inductor may be connected in series between the second capacitor 27 and the input of the second amplifier 28.

Preferably, the output of the second amplifier 28 is connected to a second filter 29, such as a watch filter, and the second filter 29 outputs noise. The noise generated by the second resistor 26 is coupled to the second amplifier 28 via the second capacitor 27 for amplifying, for example, the gain is 40dB, the output power of the noise is adjusted according to the requirement, and the second filter 29 is used for filtering and selecting the noise output in different frequency ranges, where the frequency ranges overlap with the frequency range of the input controlled radio frequency signal.

The noise generator generates noise with smaller output power by the resistor, so that the amplification gain of the first amplifier is required to be higher, for example, 40 dB.

For the embodiment shown in fig. 7, fig. 8 shows a specific implementation circuit, which includes a first amplifying chip U240, the type of the amplifying chip is AT2659S, a noise generating source is formed by a third resistor R240 and a third capacitor C240, one end of the third resistor R240 is grounded, and is also grounded GND together with pins 2 and 3 of the first amplifying chip U240, the other end of the third resistor R240 is connected to one end of the third capacitor C240, and the other end of the third capacitor C240 is connected to an input pin, i.e. pin 1, of the first amplifying chip U240 after being connected in series with the first inductor L240. The 5 and 6 pins of the first amplifying chip U240 are connected to a power source, such as a +3v power source, and the 4 pins of the output pin of the first amplifying chip U240 output noise amplified by gain. For example, the amplification gain of the first amplification chip U240 is 20dB.

Preferably, in order to improve the amplification gain, a second amplification chip U241 is further connected in series to the subsequent stage of the first amplification chip U240, and the model is also the AT2659S chip. The output pin of the first amplifying chip U240 is connected in series with the fourth capacitor C243 and the second inductor L241 in sequence, and then connected to the input pin of the second amplifying chip U241. Similarly, pins 2 and 3 of the second amplifying chip U241 are commonly grounded GND, pins 5 and 6 are connected to a power supply, and pins 4 are the output pins, i.e., pins 4 output noise after gain amplification again. Thus, through two-stage amplification, 40dB of gain amplification can be performed on noise.

Preferably, the output pin of the second amplifying chip U241 is further electrically connected to the filter device F240, and the model is SAFEB1G57KE0F00, connected to the input pin 1 of the device, and output from the output pin 4 after being filtered. The aforementioned first filter 25 and second filter 29 may each be a device SAFEB1G57KE0F00.

In connection with the embodiment shown in fig. 2, fig. 9 is a corresponding implementation circuit, where the circuit includes a radio frequency switch chip U230 serving as a controllable switch, where the type of the radio frequency switch chip U230 is preferably HMC349AMS8G, and includes a first radio frequency input terminal RF1 and a second radio frequency input terminal RF2, corresponding to the 5 th pin and the 8 th pin of the chip HMC349AMS8G, respectively, a radio frequency output terminal RFC, corresponding to the 3 rd pin of the chip HMC349AMS8G, a control terminal C corresponds to the 2 nd pin AMS of the chip HMC349AMS8G, and an enable terminal EN corresponds to the 4 th pin of the chip HMC349AMS8G, where the pins are grounded. The 1 st pin is connected with a power supply, and the 6 th pin and the 7 th pin are grounded.

Through the radio frequency switch chip, when the control end C is high voltage, the radio frequency output end RFC is connected with the first radio frequency input end RF1 and is used for inputting a controlled radio frequency signal, and is disconnected with the second radio frequency input end RF 2; when the control terminal C is at a low voltage, the radio frequency output terminal RFC is disconnected from the first radio frequency input terminal RF1 and simultaneously connected with the second radio frequency input terminal RF2, so as to input an auxiliary signal.

In connection with the embodiment shown in fig. 8, the second RF input terminal RF2 in fig. 9 is electrically connected to the output pin of the second amplifying chip U241 in fig. 8, or the second RF input terminal RF2 in fig. 9 is electrically connected to the output pin of the RF switch chip U230 in fig. 8, for switching in the noise signal generated in the embodiment of fig. 8.

Further, based on the same inventive concept, fig. 10 shows a radio frequency signal isolation device A1, which includes a radio frequency signal isolation switch a11, a signal splitter a12 and a fraud detection module a13 described in the foregoing embodiments; the input end of the signal splitter A12 is used for accessing a first radio frequency signal received and output from the antenna, the two output ends are respectively connected with the radio frequency signal input end of the radio frequency signal isolating switch A11 and the input end of the deception jamming detection module A13, and the signal splitter A12 is used for dividing the input first radio frequency signal into a controlled radio frequency signal and a second radio frequency signal and respectively transmitting the controlled radio frequency signal and the second radio frequency signal to the radio frequency signal isolating switch A11 and the deception jamming detection module A13. It can be seen that the controlled rf signal and the second rf signal are split from the first rf signal, so that the two rf signals are identical to the first rf signal in terms of signal composition, bandwidth, etc., and the main difference is that the power is half that of the first rf signal. Therefore, in practical application, the first rf signal is first power-amplified and then split.

The spoofing interference detection module a13 is configured to perform spoofing interference detection on the input second radio frequency signal, which is equivalent to detecting whether the first radio frequency signal received by the antenna has a spoofing radio frequency signal or an interfering radio frequency signal, and output a control signal to a control end of the radio frequency signal isolation switch a11 according to a detection result.

The output end of the radio frequency signal isolating switch A11 is connected with the controlled radio frequency signal from the signal splitter A12 or connected with the auxiliary signal under the action of the control signal.

The input end of the rf signal isolation switch a11 corresponds to the first connection end of the first controlled switch in fig. 2 or the third connection end of the second controlled switch in fig. 5, and is used for inputting the controlled rf signal from the signal splitter a 12. The control end of the rf signal isolation switch a11 corresponds to the first controlled connection end of the first controlled switch in fig. 2, or corresponds to the first controlled connection end of the first controlled switch and the second controlled connection end of the second controlled switch in fig. 5, and is used for controlling the connection relationship inside the rf signal isolation switch. The output end of the rf signal isolation switch a11 corresponds to the first common connection end of the first controlled switch in fig. 2, or corresponds to the first common connection end of the first controlled switch in fig. 5, and is configured to output a controlled rf signal or an auxiliary signal.

Fig. 11 shows a specific implementation of the signal splitter a12 in fig. 10, where the signal splitter a12 corresponds to the chip SP-2g1+, and the 5 th pin is the input terminal S, the 1 st pin and the 3 rd pin are two split output terminals P1 and P2, respectively, and the other pins are all used for grounding.

Based on the same concept, based on the illustration of fig. 10, the present invention also provides a communication system, which includes an antenna B1 and a receiving device C1, between which a radio frequency signal isolation device A1 is connected. The composition of the rf signal isolation device A1 is as described above.

Based on the same conception, the invention also provides a radio frequency signal isolation method, namely the radio frequency signal isolation switch is arranged between the antenna and the receiving equipment, and a first radio frequency signal received and output by the antenna is separated into a path of controlled radio frequency signal and the radio frequency signal isolation switch; the radio frequency signal isolating switch is controlled to disconnect the controlled radio frequency signal and input an auxiliary signal to the receiving equipment; or the radio frequency signal isolating switch is controlled to switch on the controlled radio frequency signal, input the controlled radio frequency signal to the receiving equipment, and switch off the auxiliary signal input to the receiving equipment.

After the controlled radio frequency signal is disconnected, the ratio of the power of the residual controlled radio frequency signal transmitted to the receiving device due to leakage to the power of the auxiliary signal or the ratio of the power of the residual controlled radio frequency signal to the power spectral density of the auxiliary generated noise signal is smaller than the threshold signal-to-noise ratio of the receiving device. I.e. the auxiliary signal is sufficient to reduce the signal-to-noise ratio of the leaked residual controlled radio frequency signal such that the receiving device avoids receiving the leaked residual controlled radio frequency signal.

Further, the method further comprises the steps of separating a path of second radio frequency signal from the first radio frequency signal received and output by the antenna, detecting the second radio frequency signal, controlling the radio frequency signal isolating switch to disconnect the controlled radio frequency signal when detecting that the second radio frequency signal contains a deception signal or an interference signal, and inputting an auxiliary signal to the receiving equipment; and if the second radio frequency signal does not contain a deception signal or an interference signal, controlling the radio frequency signal isolating switch to switch on a controlled radio frequency signal to the receiving equipment and switch off the auxiliary signal.

The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent structural changes made by the present invention and the accompanying drawings, or direct or indirect application in other related technical fields, are included in the scope of the present invention.

Claims

1. The radio frequency signal isolating switch is characterized by comprising a first controlled switch and an auxiliary signal generator, wherein the first controlled switch comprises a first connecting end, a second connecting end, a first common connecting end and a first controlled connecting end;

the first connecting end is used for inputting a controlled radio frequency signal, the auxiliary signal generator is used for generating an auxiliary signal and is electrically connected with the second connecting end, and the first controlled connecting end is used for inputting a control signal;

the control signal is a first state signal, and the first controlled switch is connected with the first connecting end and the first public connecting end, and is disconnected between the second connecting end and the first public connecting end; and if the control signal is a second state signal, the first controlled switch is connected with the second connecting end and the first common connecting end, and meanwhile, the first connecting end and the first common connecting end are disconnected.

2. The radio frequency signal isolation switch of claim 1, wherein the auxiliary signal comprises a noise signal, a single frequency signal, a plurality of frequency signals, or a carrier modulated signal.

3. The radio frequency signal isolation switch of claim 1, further comprising a second controlled switch comprising a third connection, a fourth connection, a second common connection, and a second controlled connection for inputting the control signal, the second common connection being electrically connected to the first connection of the first controlled switch;

the third connection end is used for inputting a controlled radio frequency signal, the control signal is a first state signal, the second controlled switch is connected with the third connection end and the second public connection end, and meanwhile, the fourth connection end and the second public connection end are disconnected; the control signal is a second state signal, the second controlled switch is connected with the fourth connecting end and the second common connecting end, and meanwhile, the third connecting end and the second common connecting end are disconnected.

4. The radio frequency signal isolation switch according to claim 1, wherein the auxiliary signal generator comprises a noise generator, the noise generator comprises a zener diode, the positive terminal of the noise generator is grounded, the negative terminal of the noise generator is electrically connected with one end of a first resistor and one end of a first capacitor, the other end of the first resistor is connected with a power supply, the other end of the first capacitor is electrically connected with the input end of a first amplifier, and the output end of the first amplifier outputs noise as the auxiliary signal.

5. The radio frequency signal isolation switch of claim 1, wherein said auxiliary signal generator comprises a noise generator comprising a second resistor having one end grounded and the other end electrically connected to one end of a second capacitor, the other end of said second capacitor being electrically connected to an input of a second amplifier, and an output of said second amplifier outputting noise as said auxiliary signal.

6. The radio frequency signal isolation switch of claim 5, further comprising a filter in series with the output of the second amplifier.

7. The radio frequency signal isolation switch of claim 6, wherein the second amplifier comprises two cascaded amplifier chips AT2659S, and the filter is a saw filter device SAFEB1G57KE0F00.

8. The radio frequency signal isolation switch of claim 1, wherein the first controlled switch is a radio frequency switch chip HMC349AMS8G, and the first connection, the second connection, the first common connection, and the first controlled connection of the first controlled switch correspond to a first radio frequency input, a second radio frequency input, a radio frequency output, and a control of the radio frequency switch chip HMC349AMS8G, respectively.

9. A radio frequency signal isolation device comprising a signal splitter, a fraud detection module and a radio frequency signal isolation switch according to any of claims 1 to 8;

the input end of the signal splitter is used for accessing a first radio frequency signal received and output by the antenna, the two output ends are respectively connected with the radio frequency signal input end of the radio frequency signal isolating switch and the input end of the deception jamming detection module, and the signal splitter is used for dividing the input first radio frequency signal into a controlled radio frequency signal and a second radio frequency signal which are respectively transmitted to the radio frequency signal isolating switch and the deception jamming detection module;

the output end of the deception jamming detection module is electrically connected with the control end of the radio frequency signal isolating switch and is used for detecting whether a deception radio frequency signal or an jamming radio frequency signal exists in the second radio frequency signal or not and outputting a control signal to the control end of the radio frequency signal isolating switch according to a detection result;

and the output end of the radio frequency signal isolating switch is connected with the controlled radio frequency signal output by the signal divider or connected with the auxiliary signal under the action of the control signal.

10. A communication system comprising an antenna and a receiving device, characterized in that the radio frequency signal isolation device of claim 9 is arranged between the antenna and the receiving device.

11. A method of isolating radio frequency signals, comprising the steps of:

the radio frequency signal isolating switch of any one of claims 1 to 8 is arranged between the antenna and the receiving equipment, and a path of controlled radio frequency signal is separated from the first radio frequency signal received and output by the antenna to the radio frequency signal isolating switch;

the radio frequency signal isolating switch is controlled to disconnect the controlled radio frequency signal and input an auxiliary signal to the receiving equipment;

or the radio frequency signal isolating switch is controlled to switch on the controlled radio frequency signal, input the controlled radio frequency signal to the receiving equipment, and switch off the auxiliary signal input to the receiving equipment.

12. The method for isolating radio frequency signals according to claim 11, further comprising the steps of receiving the outputted first radio frequency signal by an antenna, separating a second radio frequency signal, detecting the second radio frequency signal, and controlling the radio frequency signal isolating switch to disconnect the controlled radio frequency signal and inputting an auxiliary signal to the receiving device if the second radio frequency signal is detected to contain a spoofing signal or an interference signal;

and if the second radio frequency signal does not contain a deception signal or an interference signal, controlling the radio frequency signal isolating switch to switch on the controlled radio frequency signal to the receiving equipment and switch off the auxiliary signal.