CN113253220A - Radar passive calibrator with variable polarization and insensitive attitude - Google Patents
Radar passive calibrator with variable polarization and insensitive attitude Download PDFInfo
- Publication number
- CN113253220A CN113253220A CN202110754430.2A CN202110754430A CN113253220A CN 113253220 A CN113253220 A CN 113253220A CN 202110754430 A CN202110754430 A CN 202110754430A CN 113253220 A CN113253220 A CN 113253220A
- Authority
- CN
- China
- Prior art keywords
- dragon
- polarization
- radar
- lens
- attitude
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/40—Means for monitoring or calibrating
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Aerials With Secondary Devices (AREA)
Abstract
The invention provides a polarization-variable and attitude-insensitive radar passive calibrator, which comprises a dragon wave lens and a reflecting plate unit arranged on one side of the dragon wave lens, wherein the reflecting plate unit comprises a plurality of reflecting plates and a reflecting plate switching mechanism; the curvature of each reflecting plate is matched with that of the dragon wave lens, and the reflecting plates can be attached to the dragon wave lens; the reflecting plate switching mechanism is connected with each reflecting plate and can switch different reflecting plates to be close to the dragon wave lens. The reflecting plate switching mechanism can switch different reflecting plates, the reflecting plates are attached to the dragon wave lens, the curvatures of the reflecting plates and the dragon wave lens are matched, and the combination of the reflecting plates and the dragon wave lens can realize that the polarization of the calibrator is variable, the attitude of the calibrator is insensitive, and the cross section area of the calibrator is large.
Description
Technical Field
The invention belongs to the technical field of radar measurement, and relates to a radar passive calibrator with variable polarization and insensitive attitude.
Background
Polarization is another important physical parameter of electromagnetic waves besides amplitude, phase and frequency, and characterizes the vector characteristics of electromagnetic waves. Micro physical attribute information such as the attitude, the size, the structure, the material and the like of the target can be inverted by utilizing the polarization information, and the method has a qualitative improvement effect on the detection, the identification and the classification of the target. The polarized radar can acquire complete information of target scattering in the electromagnetic sense, and is a research hotspot in the world at present. With the advent of a series of high performance polarization radars and the widespread use of polarization information, polarization radars are advancing into the "precision measurement" stage. In order to meet the requirement of radar polarization precision measurement, the polarization precision calibration of the radar is required.
The radar polarization calibration refers to calibration of errors of hardware equipment of a radar system, and specifically refers to a technology of calibrating unknown error parameters of the radar system by means of measuring a calibration body with known polarization scattering characteristics or injecting a calibration signal into the radar system, and correcting and compensating by using a corresponding polarization calibration algorithm. The reflected echoes of polarized radar are called polarization scattering matrix, which is a complex matrix with the size of 2 x 2, and can characterize the homopolar and cross-polarization components.
Radar calibrators may be divided into active calibrators and passive calibrators depending on whether they are active or not. Compared with an active calibrator, the passive calibrator has the advantages of miniaturization, lightness, portability, flexible arrangement and the like, and is suitable for more radar calibration scenes. RCS (Radar Cross Section) is a basic parameter for measuring the level of the reflected echo of the Radar calibrator, and the larger the value of RCS is, the wider the scene is applicable to the calibrator. Polarization is variable and attitude is insensitive, which is also a basic requirement of a polarization radar calibrator, otherwise, if the polarization of the calibrator is too sensitive to attitude, the polarization state cannot be accurately measured, and radar polarization calibration cannot be realized. How to realize large radar scattering cross section, variable polarization and insensitive attitude is always a difficult problem of polarization calibrator design. Typical passive collimators include metal spheres, corner reflectors, dragon lenses, etc. where the cross-polarization component of the metal sphere and the dragon lens is zero, the corner reflectors are too sensitive to pose and are generally difficult to use directly for polarization alignment.
Disclosure of Invention
The invention provides a radar passive calibrator with variable polarization and insensitive attitude, which aims to solve the problems that the polarization of the existing radar calibrator is not variable, or the polarization is variable but the attitude is sensitive, a radar calibration method is not suitable for a larger far field condition, the operation is not flexible enough and the like. Compared with the existing radar calibrator, the radar calibrator has the advantages of wide application range and flexibility and maneuverability.
In order to solve the technical problems, the technical scheme provided by the invention is as follows:
a radar passive calibrator with variable polarization and insensitive attitude comprises a dragon wave lens and a reflecting plate unit arranged on one side of the dragon wave lens, wherein the reflecting plate unit comprises a plurality of reflecting plates and a reflecting plate switching mechanism; the curvature of each reflecting plate is matched with that of the dragon wave lens, and the reflecting plates can be attached to the dragon wave lens; the reflecting plate switching mechanism is connected with each reflecting plate and can switch different reflecting plates to be close to the dragon wave lens. The reflecting plate switching mechanism can switch different reflecting plates to be attached to the dragon wave lens, the reflecting plates are matched with the curvature of the dragon wave lens, and the combination of the reflecting plates and the dragon wave lens can realize that the polarization of the calibrator is variable, the attitude of the calibrator is insensitive, and the cross section area of the calibrator is large.
As a preferable scheme of the invention, the dragon wave lens and the reflecting plate unit are both carried on an aerial maneuvering platform. The control of the radar passive calibrator to be in a radar far-field position can be realized by utilizing the aerial maneuvering platform. The aerial maneuvering platform is like an unmanned plane.
According to the preferred scheme of the invention, the dragon wave lens is connected with a dragon wave lens supporting mechanism, and the dragon wave lens is mounted on the aerial maneuvering platform through the dragon wave lens supporting mechanism.
As a preferable aspect of the present invention, the dragon lens support mechanism is a dragon lens support rod. Furthermore, the dragon wave lens supporting rod can also be set to be a telescopic rod. Or the dragon wave lens supporting rod is formed by connecting more than one connecting rods through middle joints, and part of the connecting rods are telescopic connecting rods.
In a preferred embodiment of the present invention, the reflector unit is connected to a reflector unit supporting mechanism, and the reflector unit is mounted on the aerial mobile platform by the reflector unit supporting mechanism.
As a preferable aspect of the present invention, the reflecting plate unit supporting mechanism is a link supporting mechanism, the link supporting mechanism is formed by connecting more than one link with each other through an intermediate joint, wherein the link directly connected to the aerial mobile platform and the link directly connected to the reflecting plate unit are telescopic links, and the telescopic links drive the reflecting plate unit to move away from or approach to the dragon wave lens. Specifically, the connecting rod supporting mechanism comprises a first connecting rod and a second connecting rod, the first connecting rod and the second connecting rod are telescopic connecting rods, and the first connecting rod and the second connecting rod are connected together through a middle joint. The first connecting rod is used for connecting the reflecting plate unit, and the second connecting rod is used for connecting the aerial maneuvering platform.
According to the preferable scheme of the invention, the reflecting plate switching mechanism comprises an installation plate, a rotary joint and a plurality of radial support plates, the rotary joint is installed at the end of the first connecting rod, the installation plate is installed on the rotary joint, the rotary joint is provided with a rotary motor, the rotary joint is driven to rotate through the rotary motor, the installation plate is radially connected with the plurality of radial support plates, angles between adjacent radial support plates are equal, a reflecting plate is supported between free ends of adjacent radial support plates, and the rotary motor drives the installation plate to rotate through the rotary joint so as to realize that different reflecting plates are switched to be close to the dragon wave lens.
In a preferred embodiment of the present invention, the dragon lens is spherical, includes a plurality of dielectric layers from inside to outside, and has successively smaller relative dielectric constants.
As a preferred scheme of the invention, each reflecting plate comprises a plurality of active frequency selective surface reflecting units distributed in an array. Active frequency selective surface reflection units and distribution conditions adopted on each reflecting plate can be different from each other, radar scattering sectional area adjustment can be realized by switching different reflecting plates, and polarization change can also be realized.
Compared with the prior art, the invention has the advantages that:
the invention provides a radar passive calibrator with variable polarization and insensitive attitude. The polarized radar passive calibrator is formed by the combination of a dragon wave lens and a reflecting plate unit. The dragon wave lens can realize a larger radar scattering sectional area, and the radar scattering sectional area is not greatly changed under the condition of a wider incidence angle, namely the posture is insensitive. The reflecting plate unit is attached to the dragon wave lens by switching different reflecting plates, and the AFSS reflecting unit adopted on the reflecting plate has the functions of transmission and reflection and can be switched to realize the adjustment of the radar scattering sectional area, and the polarization can be changed. The radar passive calibrator is carried by an aerial maneuvering platform, so that the position information of the radar passive calibrator is accurately known and is not interfered by ground clutter.
The radar passive calibrator provided by the invention has the advantages of variable polarization, insensitive attitude, high system integration level due to the carrying of an aerial maneuvering platform, high precision, miniaturization, easiness in operation and the like, and can be flexibly applied to the calibration of the polarized radar.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments or the prior art of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for the ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic structural diagram of an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a passive calibrator for a polarization radar carried by an unmanned aerial vehicle according to an embodiment of the present invention.
Reference numbers in the figures:
100. a Dragon wave lens; 101. a dragon lens support mechanism; 200. a reflection plate unit; 201. a reflective plate; 202. a first link; 203. a second link; 204. mounting a plate; 205. a rotary joint; 206. a rotating electric machine; 207. a radial support plate; 300. an aerial mobile platform.
The objects, features, and advantages of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
For the purpose of promoting a clear understanding of the objects, aspects and advantages of the embodiments of the invention, reference will now be made to the drawings and detailed description, wherein there are shown in the drawings and described in detail, various modifications of the embodiments described herein, and other embodiments of the invention will be apparent to those skilled in the art. The exemplary embodiments of the present invention and the description thereof are provided to explain the present invention and not to limit the present invention.
Referring to fig. 1, the present embodiment provides a polarization-variable and attitude-insensitive radar passive etalon, which includes a dragon lens 100 and a reflector unit 200 disposed on one side of the dragon lens 100, wherein the dragon lens 100 and the reflector unit 200 are both mounted on an airborne mobile platform 300. Referring to fig. 2, controlling a radar passive aligner to a radar far field position may be accomplished using an airborne mobile platform 300.
The reflection plate unit 200 includes a plurality of reflection plates 201 and a reflection plate switching mechanism; the curvature of each reflecting plate 201 is matched with that of the dragon wave lens 100, and the reflecting plates can be attached to the dragon wave lens 100; the reflecting plate switching mechanism is connected to each reflecting plate 201, and can switch different reflecting plates 201 to come close to the dragon wave lens 100. The dragon wave lens 100 can converge the incident electromagnetic wave with a specific wavelength to a certain point on the spherical surface. Similarly, it can reflect the electromagnetic wave back along the original direction, so its radar scattering cross section is much larger than its physical cross section. The lunula lens 100 is spherical, and includes a plurality of dielectric layers from inside to outside, and the relative dielectric constants of the dielectric layers become smaller in sequence. The dragon wave lens 100 can realize a larger radar scattering sectional area, and the radar scattering sectional area is not greatly changed under the condition of a wider incidence angle, namely the posture is insensitive. The reflecting plate switching mechanism can switch different reflecting plates 201, the reflecting plates 201 are attached to the dragon wave lens 100, the curvatures of the reflecting plates 201 and the dragon wave lens 100 are matched, and the combination of the two can realize that the polarization of the calibrator is variable, the attitude of the calibrator is insensitive, and the cross section area of the calibrator is large.
Each reflector plate 201 includes a plurality of Active Frequency Selective Surface (AFSS) reflector units distributed in an array. These reflection units not only have transmission and reflection functions and can be switched to achieve radar scattering cross-sectional area adjustment, but also can achieve polarization variability.
The dragon wave lens 100 is connected with a dragon wave lens supporting mechanism 101, and the dragon wave lens 100 is installed on the aerial maneuvering platform 300 through the dragon wave lens supporting mechanism 101. The support mechanism 101 of the embodiment shown in fig. 1 is a support rod for a lens. Furthermore, the dragon wave lens supporting rod can also be set to be a telescopic rod.
In this embodiment, the reflection plate unit 200 is connected to a reflection plate unit supporting mechanism, and the reflection plate unit 200 is mounted on the aerial mobile platform 300 through the reflection plate unit supporting mechanism. The reflecting plate unit supporting mechanism is a connecting rod supporting mechanism, the connecting rod supporting mechanism comprises a first connecting rod 202 and a second connecting rod 203, the first connecting rod 202 and the second connecting rod 203 are both telescopic connecting rods, and the first connecting rod 202 and the second connecting rod 203 are connected together through a middle joint. The first link 202 is used to connect the reflective panel unit and the second link 203 is used to connect the aerial mobile platform.
The reflecting plate switching mechanism comprises a mounting plate 204, a rotary joint 205 and a plurality of radial support plates 207, wherein the rotary joint 205 is mounted at the end of the first connecting rod 203, the mounting plate 204 is mounted on the rotary joint 205, the rotary joint 205 is provided with a rotary motor 206, the rotary joint 205 is driven to rotate by the rotary motor 206, and the rotary motor 206 drives the mounting plate 204 to rotate by the rotary joint 205. The mounting plate 204 is radially connected with a plurality of radial support plates 207, the angles between adjacent radial support plates 207 are equal, and a reflection plate 201 is supported between the free ends of adjacent radial support plates 207. The rotating motor 206 drives the mounting plate 204 to rotate through the rotating joint 205, so that different reflecting plates 201 are switched to be close to the dragon wave lens 100, and the combination switching of the different reflecting plates and the dragon wave lens 100 is realized.
When the reflective plates 201 need to be switched each time, the first connecting rod 202 is shortened to make the reflective plate unit 200 far away from the dragon wave lens 100, then the reflective plate unit 200 is rotated to realize the switching of the reflective plates 201 on the reflective plate unit, and finally the first connecting rod 202 is extended to make the corresponding reflective plate 201 adhere to the dragon wave lens 100. Due to different combinations of the dragon wave lens 100 and the reflecting plate 201, the designed radar calibrator can realize the functions of variable echo polarization and insensitive attitude.
In order to improve the precision of the radar calibrator, the equipment of the invention selects materials with smaller radar scattering cross section and lighter material, such as carbon fiber, as far as possible without using metal.
For a clearer explanation, fig. 2 shows a structural schematic diagram of an airborne maneuvering platform 300 carrying a polarized radar passive calibrator provided by the invention. The unmanned aerial vehicle is used as the aerial maneuvering platform 300 of the polarization radar calibrator provided by the invention, so that the polarization radar calibrator is not interfered by ground clutter when radar calibration is carried out, and the radar calibration precision is improved. The scheme also has the advantages of miniaturization, high flexibility, easy operation and the like.
According to the relative relation between the radar wavelength and the size of the calibrator, the radar scattering cross section of the target can be described by dividing the target into three regions. Typically, the etalon is relatively large in size, and operates in the radar scattering optical zone relative to the radar wavelength. The radar scattering optics zone needs to meet
Wherein
Is the radius of the dragon wave lens,
is the radar wavelength. The radar scattering cross section area of the metal ball with the same size as the dragon wave lens is
The radar scattering cross section area of the Dragon wave lens is
. Then for the X-band radar (
) In other words, then only
. Is not to take
Then the radar scattering cross section area of the metal ball is 0.0314m2And the radar scattering cross section area of the dragon wave lens is 0.6981 m2Is 22.2 times of the metal ball. It can be demonstrated that the radar scattering cross-sectional area of a lunge lens is much larger than its physical cross-section. As the collimator size increases, the radar scattering cross-sectional area of the dragon lens relative to the metal sphere increases by a greater factor. In addition, the half-power angle of the dragon wave lens is larger than 120 degrees, so that the radar scattering sectional area of the dragon wave lens is not greatly changed under the condition of a wider incidence angle, namely the posture is insensitive.
In an embodiment of the present invention, 1 example of a dragon wave lens design is provided as follows: the dragon wave lens 100 is a multilayer layered dielectric sphere, and the relative dielectric constant of the outer layer of the sphere is the same as or close to that of air, and the dielectric constant is larger towards the center of the sphere. The dragon wave lens can be designed with different layers and dielectric constants according to different working frequency bands and purposes. The dragon wave lens in the embodiment is composed of 3 layers of media and outer air, and the reflectivity and the thickness of the 3 layers of media are 1.4 cm, 1.34 cm, 1.22 cm, 3.40cm, 1.83cm and 2.01cm respectively from inside to outside.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
Claims (10)
1. A radar passive calibrator with variable polarization and insensitive attitude is characterized by comprising a dragon wave lens and a reflecting plate unit arranged on one side of the dragon wave lens, wherein the reflecting plate unit comprises a plurality of reflecting plates and a reflecting plate switching mechanism; the curvature of each reflecting plate is matched with that of the dragon wave lens, and the reflecting plates can be attached to the dragon wave lens; the reflecting plate switching mechanism is connected with each reflecting plate and can switch different reflecting plates to be close to the dragon wave lens.
2. The radar passive calibrator with variable polarization and insensitivity to attitude of claim 1, wherein the dragon lens and the reflector unit are mounted on an aerial maneuvering platform, and the aerial maneuvering platform is used for controlling the radar passive calibrator to be in a radar far-field position.
3. The polarization-variable attitude-insensitive radar passive etalon of claim 2 wherein a dragon lens support mechanism is connected to the dragon lens, through which the dragon lens is mounted to an airborne mobile platform.
4. The polarization variable and attitude insensitive radar passive etalon of claim 3, wherein the dragon lens support mechanism is a dragon lens support bar.
5. The polarization-variable and attitude-insensitive radar passive calibrator according to any one of claims 2 to 4, wherein a reflector plate unit support mechanism is connected to the reflector plate unit, by which the reflector plate unit is mounted to an airborne motorized platform.
6. The polarization-variable attitude-insensitive radar passive etalon of claim 5 wherein the reflecting plate unit supporting mechanism is a link supporting mechanism formed by connecting more than one link to each other through an intermediate joint, wherein the link directly connected to the airborne motorized platform and the link directly connected to the reflecting plate unit are telescopic links, and the reflecting plate unit is driven away from or close to the dragon lens by the telescopic links.
7. The polarization-variable and attitude-insensitive radar passive etalon of claim 6 wherein the linkage support mechanism comprises a first linkage and a second linkage, the first linkage and the second linkage each being telescopic linkages, the first linkage and the second linkage being connected together by an intermediate joint, the first linkage being for connection to the reflective plate unit and the second linkage being for connection to an aerial mobile platform.
8. The polarization-variable and attitude-insensitive radar passive calibrator as claimed in claim 7, wherein the reflector plate switching mechanism includes a mounting plate, a rotary joint and a plurality of radial support plates, the rotary joint is mounted at an end of the first connecting rod, the mounting plate is mounted on the rotary joint, the rotary joint is provided with a rotary motor, the rotary joint is driven to rotate by the rotary motor, the mounting plate is radially connected with the plurality of radial support plates, angles between adjacent radial support plates are equal, a reflector plate is supported between free ends of adjacent radial support plates, and the rotary motor drives the mounting plate to rotate by the rotary joint so as to switch different reflector plates to be close to the dragon wave lens.
9. The radar passive calibrator with variable polarization and insensitivity to attitude according to claim 1, wherein the dragon lens is spherical, and comprises a plurality of dielectric layers from inside to outside, and the relative dielectric constants thereof become smaller in sequence.
10. The polarization-variable and attitude-insensitive radar passive etalon of claim 1 wherein each reflector plate comprises a number of active frequency selective surface reflection units distributed in an array.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110754430.2A CN113253220A (en) | 2021-07-05 | 2021-07-05 | Radar passive calibrator with variable polarization and insensitive attitude |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110754430.2A CN113253220A (en) | 2021-07-05 | 2021-07-05 | Radar passive calibrator with variable polarization and insensitive attitude |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113253220A true CN113253220A (en) | 2021-08-13 |
Family
ID=77190648
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110754430.2A Pending CN113253220A (en) | 2021-07-05 | 2021-07-05 | Radar passive calibrator with variable polarization and insensitive attitude |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113253220A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113777561A (en) * | 2021-09-23 | 2021-12-10 | 广东福顺天际通信有限公司 | RCS reflector system capable of changing polarization characteristics |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111641047A (en) * | 2020-06-19 | 2020-09-08 | 中国人民解放军总参谋部第六十研究所 | Luneberg lens with variable RCS |
| CN111983741A (en) * | 2020-07-27 | 2020-11-24 | 南京航空航天大学 | RCS (radar cross section) controllable luneberg lens reflector based on active frequency selective surface |
| CN112698287A (en) * | 2021-03-24 | 2021-04-23 | 中国人民解放军国防科技大学 | Attitude-measurable and adjustable polarization radar passive calibrator and radar calibration method |
-
2021
- 2021-07-05 CN CN202110754430.2A patent/CN113253220A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111641047A (en) * | 2020-06-19 | 2020-09-08 | 中国人民解放军总参谋部第六十研究所 | Luneberg lens with variable RCS |
| CN111983741A (en) * | 2020-07-27 | 2020-11-24 | 南京航空航天大学 | RCS (radar cross section) controllable luneberg lens reflector based on active frequency selective surface |
| CN112698287A (en) * | 2021-03-24 | 2021-04-23 | 中国人民解放军国防科技大学 | Attitude-measurable and adjustable polarization radar passive calibrator and radar calibration method |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113777561A (en) * | 2021-09-23 | 2021-12-10 | 广东福顺天际通信有限公司 | RCS reflector system capable of changing polarization characteristics |
| CN113777561B (en) * | 2021-09-23 | 2022-11-11 | 广东福顺天际通信有限公司 | RCS reflector system capable of changing polarization characteristics |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7576701B2 (en) | Rotating screen dual reflector antenna | |
| US4477814A (en) | Dual mode radio frequency-infrared frequency system | |
| US4550319A (en) | Reflector antenna mounted in thermal distortion isolation | |
| US8743001B2 (en) | Mechanically steered reflector antenna | |
| US5162811A (en) | Paraboloidal reflector alignment system using laser fringe pattern | |
| US7133001B2 (en) | Inflatable-collapsible transreflector antenna | |
| US6307521B1 (en) | RF and IR bispectral window and reflector antenna arrangement including the same | |
| JP3270548B2 (en) | Wide-field fixed body alignment direction measurement array | |
| USRE43498E1 (en) | Adaptive reflector antenna and method of implementing the same | |
| CN108155483B (en) | Polarization tracking device | |
| US7411561B1 (en) | Gimbaled dragonian antenna | |
| CN112363157B (en) | Radar beacon and radar measurement system | |
| US6720936B1 (en) | Adaptive antenna system | |
| US3958246A (en) | Circular retrodirective array | |
| CN111981438A (en) | Super-surface lens corner reflector | |
| CN113253220A (en) | Radar passive calibrator with variable polarization and insensitive attitude | |
| US2549721A (en) | Antenna system of variable directivity and high resolution | |
| JP2007528027A (en) | Prism device and optical and radio frequency combined beam steering system | |
| US6747604B2 (en) | Steerable offset antenna with fixed feed source | |
| US3852765A (en) | Spherical double reflector antenna | |
| JP4536096B2 (en) | Antenna device | |
| US4558324A (en) | Multibeam lens antennas | |
| US8159410B2 (en) | Reflective antenna assembly | |
| US3331072A (en) | System and method for surveillance, tracking and communicating | |
| Ding et al. | Ka-band multibeam antenna for Chinasat-16 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210813 |
|
| RJ01 | Rejection of invention patent application after publication |