JPS63252001A - Waveguide type filter - Google Patents

Abstract

PURPOSE:To obtain a filter of curved structure which has small deterioration in characteristics by providing optional-angle E- or H-surface curved structure for an optional susceptance element and a matching element provided to the curved part of the curved structure. CONSTITUTION:The waveguide type filter which uses an iris as the susceptance element is constituted having the H- or E-surface curved structure at the fitting position of an (i)th iris (i) and couples of irises are arranged at right angles to a fitting surface at specific intervals to adjacent couples of irises. Further, the prismatic matching element 2 is provided at an outside curved part and the couples of irises are fitted on the waveguide surface of this matching element 2. In this constitution, the electric length 2Bc is set to 0 by an adjusting and matching element 2 for the intervals of irises (i-1), (i) and (i+1) so as to compensate susceptance jBc due to the use of the curved structure instead of a straight structure and the resulting electric length 2DBc. Consequently, the waveguide type filter of curved structure which has small deterioration in performance is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of practical application] The present invention relates to a waveguide filter, and particularly to a waveguide filter having a curved structure.

[Conventional technology]

Traditionally, a waveguide filter has an internal iris.

Waveguide type filters having an intersecting linear structure in which susceptance elements such as metal posts and external cavity filters are appropriately arranged are widely used.

FIG. 3(a) shows an example in which a conventional waveguide filter with a linear structure is used as a polarization splitter in a communication device. This GI machine has 3 polarization demultiplexers. It is composed of a filter 4, a transmitter 5, and a receiver 6 with an @ wire structure, and are connected as shown in the figure.

[Problem that the invention seeks to solve]

In this communication device, since a waveguide type filter with a linear structure is used, it is often possible to prevent downsizing of the device. In addition, in order to miniaturize the device, the waveguide filter with the linear structure described above is
It is conceivable to use a structure with a surface or HH surface curve of 9, but simply using a structure with a curve of t) will not provide the desired electrical length and, therefore, will not provide the desired performance. Second
Figure-) is the equivalent circuit of a waveguide filter with a linear structure, ag
FIG. 2(b) shows an equivalent circuit of a waveguide filter in which the frame and the @ line structure of FIG. 2(a) are changed to an E-plane or UH-plane bent structure at the position of the i-th susceptance element. In the figure.

Indicates the optimal electrical length to obtain the desired characteristics. 5 equivalent susceptance elements c are generated in the curved structure, so that the equalized electrical length is 2Δθ. occurs, and the desired performance cannot be obtained.

The present invention has solved the above drawbacks. The purpose of the present invention is to provide a waveguide filter having a curved structure without deterioration in performance.

In order to achieve the above object, the waveguide filter of the present invention has the following features:
In a waveguide filter in which a plurality of susceptance elements are arranged so as to obtain desired characteristics, an E-plane or H-plane bending structure at an arbitrary angle in an arbitrary susceptance element part, and a curve of this bending structure. It is characterized by having a matching element provided in the 9th part.

〔Example〕

FIG. 1 is a perspective view showing an embodiment of a waveguide type filter according to the present invention, with a partially cut away portion entirely, and is an example in which an iris is used as a susceptance element. FIG. 1(a) shows an example of H-plane bending, and FIG. 11(b) shows an example of E-plane bending. This example has an H-plane or E-plane bending structure at the mounting position of the first iris (susceptance element) i, and the paired irises have a
and is arranged at a predetermined distance from an adjacent pair of irises. Furthermore, a triangular prism matching element 2 is provided at the outer bent portion: rL% A pair of irises i are attached to the waveguide surface of this matching element 2.

The linear structure is changed to a bent structure, and in addition, the susceptance jBcm generated by F is compensated for, and the alternating current length 2ΔBc (see Fig. 2(b)) is compensated for.Next, the iris i-1*
By adjusting the interval of 1 #s +1 and using the matching element 2, the electrical length Δ2Bc is set to 0. Figure 2 (
c) r1% This is an equivalent circuit of the waveguide filter shown in FIGS. 1(a) and 1(b). Adjust the spacing of the susceptance elements as described above and adjust the susceptance element to Fj(Bi'0B(H-Bm
)=jBi, that is, electrical length 2Δθ. = 0, and performance equivalent to the equivalent circuit of FIG. 2(a) is obtained. Figure 3 (b
) is an example in which the H-plane curved waveguide filter of the present invention is used as a polarization splitter in a communication device.

In the figure, 3 is a polarization splitter, 7 is a waveguide filter of the present invention, and 8
indicates a transceiver.

〔Effect of the invention〕

As described above, according to the present invention, miniaturization of the device cannot be prevented;
Moreover, a waveguide filter having the same performance as a linear waveguide filter can be obtained.

[Brief explanation of drawings]

Fig. 1(a) *Example of the H-plane curved waveguide type filter of the present invention, Fig. 1(b) l'! An example of the E-plane curved waveguide filter of the present invention, FIG. 2(a) is an equivalent circuit of a linear waveguide filter, and FIG. ) The equivalent circuit of a waveguide filter having a nine-track structure, Fig. 2(c)i The equivalent circuit of the waveguide filter of the present invention, Fig. 3(c) a) is an example in which a linear filter is used as a polarization demultiplexer in a communication device, and Figure 3Cb) is an example in which an uninvented waveguide filter is used in a polarization demultiplexer in a communication device. show. 1...Iris (susceptance element), 2...
...Matching element, 3...Polarization splitter, 4...
...@θ type filter. 5...Transmitter, 6...Receiver, 7...
...Waveguide, 8...Transmitter/receiver, 9...
...A waveguide type filter of the present invention. Agent: Patent Attorney Uchihara Ontsu′°・°ゝ. Figure (a) (b) 2nd @

Claims (1)

[Claims] In a waveguide filter in which a plurality of susceptance elements are arranged to obtain desired characteristics, an E plane at an arbitrary angle in an arbitrary susceptance element part has an H plane curved structure and a bent part of this curved structure. A waveguide type filter comprising: a matching element provided in the waveguide filter;