JPS5824201A - Helical filter - Google Patents

Abstract

PURPOSE:To improve the precision of a coupling part and to reduce variance in characteristics, by constituting coupling elements with low input and output impedance in spiral printed patterns for tuning elements with extremely high impedance. CONSTITUTION:In a shield case 12 which has a partition plate 11 with a coupling window 10, coiled tuning elements 14 and 14' connected electrically in parallel to variable capacitors 13 and 13' are arranged, and a printed board 15 is coupled with the case 12. On the surface of this board 15, spiral patterns 16 and 16' constituting the tuning elements 14 and 14' partially are formed and on the reverse surface, strip lines 17 and 17' are formed as input and output lead- out lines. Then, the case 12 and board 15 are combined together. At the same time, tips of the tuning elements 14 and 14' are inserted into center holes 18 and 18' of the spiral patterns 16 and 16' and soldered, allowing the spiral pattern 16 and 16' and tuning elements 14 and 14' to tune to a passing band in one body. Consequently, the precision of the coupling part is improved and variance in characteristics is reduced.

Description

[Detailed description of the invention] Honshu @ Mori to the Pope of 1m Lufilter - Compiled.

Conventionally) MaHFw and UH: Helicashi filters are layered as band overpass filters for f buds. @ζO^ritical filters are multi-layered as shown in Figure 1 and Figure 2. With a number of C-Kkn &! 2 pieces) Os
[Made in a bell bowl 4 having 1, 4) Okacho Koko 1
, 1'0 Jinrikikikai-Uta and Yuurikisokaill-yo1Hinyu$
It is connected to the input terminal 8 and the output terminal 9 via 97.7'.

Such a helical filter is required to have high selectivity and low pass loss. In order to satisfy this requirement, conventionally the input/output coupling section has been adjusted and the amount of coupling between the tuning elements has been adjusted to 1111. The reason why this adjustment is necessary is that there are variations in precision when manufacturing helical filters, and the position of the input/output coupling part 5.6 is determined by the position of the matching tuning element 1, 1' on the coil wound with the wire. This is because the variation is large because of the shape. The present invention was devised to solve this problem.

According to the present invention, in a helical filter consisting of a plurality of coil-type tuning elements and their shielding boxes, the spiral pattern forming a part of the tuning element, the input coupling part, and the output coupling part are connected to a printed circuit board. It is characterized by being constructed by.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 3 shows an exploded perspective view of the fabric. In this embodiment, a shield case 12 has a partition plate 11 provided with a coupling window 10.
Coil-shaped tuning elements 14 and 14' which are electrically connected in parallel to the A maco 71m11m' and the A mako 71m11m' are arranged in the shield case 13, and the printed circuit board 1 [111
are combined・This pre-wound putter/1 @,
1@' is formed, and lip lines 17 and 17' are formed on the back side 1i1 as an input force. And shield case l Tomi and Pudding)! 1115 is identified as 0. At the same time, the pre-tip is inserted and soldered,
The spiral pattern and the tuning element are integrally tuned to the pass band.The nine embodiments formed in this way are designed to tune the high frequency signal within the pass band injected from the input trigger 11. resonates in the spiral pattern 1- and the tuning circuit of the tuning element 14, and the rust 91
An excess of 1G is transmitted to the output side tuning path through the spiral pattern 111'Th and the tuning element 14', and is outputted from the output terminal 17'.

As described above, the helical filter of the present invention dramatically improves the accuracy of the coupling part compared to the conventional one by configuring the coupling element of low impedance as a spiral printed pattern for the tuning element of extremely high impedance. Therefore, the variation in characteristics is also small.

Furthermore, as can be seen from FIG. 3, the helical filter of the present invention is integrated with the printed board, so as shown in FIG. It also has the advantage of being able to implement

[Brief explanation of drawings]

Figure 1 is a perspective view of an example of a conventional helical filter, Figure 2 is a perspective view of an example of a conventional helical filter.
The figure is a top view, FIG. 3 is an exploded perspective view of a helical filter according to an embodiment of the present invention, FIG. 4 is a plan view of its printed circuit board, and FIG. 5 is a helical filter of the present invention 1 mounted on a printed board. state [Explanatory diagram shown 0 10... Combined window, 11... Partition plate, 1
2...Shield case, Im, 1r--Pa = ty. 14, 14'----Mlljllll, III---
21')! II, 1g, 1g'-1... Spiral Ap-
11-One-man power extraction line, 1γ-...Output extraction-
, tS---- to acoustical filter. Patent applicant Fujitsu Ik Takemeisha Patent application attorney Attorney! Hon robenbashi ryo value ne no benhoshi 1) Fist male bentoshi yamaguchi yoshi 1 fig. 2 fig. 4 fig. 5 q

Claims (1)

[Claims] In the 701111 box to 1 to 9 filter, the vortex IIk-shaped pattern that becomes part of the tuning element, the input coupling part, and the output clamp are formed. ＞To make a substitute image of the thing composed by a board ★
Lufilta.