JPS6011481B2 - Microwave polarized bandpass filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a band-pass wave device in which the pass band exhibits flat or wavy characteristics and the stop band exhibits wavy characteristics in the microwave band.

Conventionally, wave transmitters widely used in the microwave band have been of the Butterworth type or Chebyshev type, which do not have an attenuation pole at a finite frequency.

An example is shown in FIG. FIG. 1 shows an interdigital type four-stage band wave device consisting of a weight body 1, coupling beams 11, 12, main wavelength resonators 21, 22, 23, 24, and input/output connectors 31, 32. This is what is shown.
Figure 2 shows the frequency characteristics of the pass-through attenuation of the filter shown in Figure 1. In order to increase the attenuation at a specific frequency, a band-stop filter is added to Figure 1. I needed to. Therefore, in recent years, microwave polarized band-pass wave filters with poles in the attenuation castle have been developed, which have the functions of both band-pass filters and band-stop filters.

SUMMARY OF THE INVENTION An object of the present invention is to provide a coaxial type microwave polarized bandpass wave generator which is easy to structure and electrically adjust. That is, the feature of the present invention is that in a coaxial band-pass wave device consisting of three or more resonators, two of the resonators are not substantially adjacent to each other. A transmission branch path for coupling is provided, and a coupling adjustment mechanism is provided for adjusting the coupling between the two resonators, thereby making it possible to set an attenuation pole at a finite frequency.

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 is a structural diagram of a four-stage polarized band-passing wave device according to an embodiment of the present invention. This embodiment is used as an antenna to couple the first resonator 21 and the fourth resonator 24 to the conventional wave transmitter shown in FIG. conductor rods 51, 52 and a conductor plate 41 that connects these conductor rods 51, 52, and 3 prevents the resonators 21, 22, 23, and 24 from being directly coupled to the conductor plate 41. The conductor plate 3 is insulated from the conductor threads 51 and 52 by an insulator. 61 is a coupling adjustment screw attached to the lid 2,
This coupling adjustment screw 61 varies the coupling between the first resonator 21 and the fourth resonator 24.

Most of the input signal A from the connector 31 is transmitted to the resonator 21
, 22, 23, and 24 and goes out through the connector 32 as an output B, but a part is coupled from the first resonator 21 to the conductor bar 51, passes through the conductor plate 41, and goes out as the output B.
It is coupled to the fourth resonator 24 via.

Signals passing through these two paths, that is, the resonators 21, 22,
If the signals passing through 23 and 24 and the signal passing through conductive plate 41 are made to have opposite phases to each other, an attenuation pole is produced at frequencies where the amplitudes are equal. The passage characteristic at this time is represented by the solid line in Fig. 4, and the coupling adjustment screw 61
By inserting , the passage characteristics change from a solid line to a dotted line to a dotted line. That is, the attenuation pole can be set to any frequency using the coupling adjustment screw 61. A plurality of such coupling adjustment screws 61 may be provided, and the conductor plate 4
A printed board may be used instead of 1. Further, the conductor plate 41 is set on the conductor plate 3 via an insulator, and the conductor rods 51,
52 can also be made into a screw structure so that it can be moved and the connection can be adjusted. FIG. 5 shows another embodiment of the present invention, in which parts corresponding to those in FIGS. 1 and 3 and parts common to each other are denoted by the same reference numerals.

FIG. 5 shows a case where a conductor plate 81 is provided to couple the first resonator 21 and the fourth resonator 24, and the resonators 22, 23 and the conductor plate bent into a convex shape are shown in FIG. This is to avoid stray coupling with 81. Reference numerals 91 and 92 are conveyor screws for holding the conductor plate 81 and changing its position.

By pulling up the conductor plate 81 using the dielectric screws 91 and 92, the transmission characteristics change from the solid line in FIG. 4 to the dotted line.
Changes to a dashed line. That is, the dielectric screws 91, 9
2 can be used to set the attenuation pole to any frequency. In addition"
In the above-mentioned embodiment, a case has been described in which a shunt is provided in an interdigital type bandpass filter, but the present invention can be applied to a commoline type bandpass filter. As explained above, according to the present invention, a shunt is provided in a conventional coaxial wave transmitter using a conductor or a conductive plate to couple resonators that are not substantially adjacent to each other, Furthermore, by providing a mechanism for adjusting this coupling, it is possible to obtain a polarized band-passing wave device in which the frequency of the attenuation pole can be arbitrarily set, and therefore manufacturing and electrical adjustment are simple.

Furthermore, if the present invention is used in a frequency conversion circuit, a band blocking filter can be omitted, and if used in a duplexer, the guard band can be narrowed to make effective use of frequencies. It is.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the structure of a conventional coaxial microwave wave transmitter, Fig. 2 is a diagram showing the frequency characteristics of the attenuation amount of the transducer shown in Fig. FIG. 4 is a diagram showing the frequency characteristics of the attenuation amount of the wave device shown in FIG. 3. FIG. 5 is a diagram showing another embodiment of the present invention. . The main reference symbols used in the figures are as follows.
1... Pyramid body, 2... Lid "3, 81, 41...
...Conductor plate, 11, 12...Coupling antenna, 21
, 22, 23, 24...1' gold skin long resonator, 31,
32... Input/output connector, 51, 52... Conductor plate,
61... Screw for coupling adjustment, 91, 92... Dielectric screw. Figure 1 Figure 2 Figure 3 Figure 5

Claims (1)

[Claims] 1. In a microwave polarized bandpass filter consisting of three or more resonators, the filter is provided to couple two resonators that are not substantially adjacent to each other among the resonators. A microwave polarized band-pass filter comprising: a transmission branch; and coupling adjustment means for adjusting the amount of coupling between the two resonators by changing the position of the transmission branch. vessel.