JP2533706Y2 - Dielectric resonator type band stop filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a dielectric resonator type band rejection filter, and more particularly, to a dielectric resonator type of a dielectric resonator used in a microwave communication device. It relates to a band rejection filter.

[Prior art] Conventionally, this type of dielectric resonator type band rejection filter has a dielectric resonator on a stripline substrate in a cut-off waveguide of a metal housing, and has a quarter-wavelength in the strip conductor direction. In order to provide coupling between each dielectric resonator and the transmission line at an odd multiple of 1/4 wavelength and a predetermined size of external Q to provide coupling between transmission lines, a constant distance in the height direction of the fixed stop conductor The dielectric resonator is juxtaposed to the strip conductor.

2 (a) and 2 (b) are a front view and a cross-sectional view of a conventional dielectric resonator type band rejection filter. In this figure, a dielectric resonator 3 is attached by a support 7 through a metal housing 1 for coupling with a strip line 6. 3 (a) and 3 (b) show a front view and a cross-sectional view of a dielectric band-pass filter. 3 (a) and 3 (b), the dielectric resonator 3 is fixed on a metal plate and coupled to the antenna 8. In this case, since the external Q can be changed by changing the distance between the antenna 8 and the dielectric resonator 3, the metal plate 4 can be constituted by a simple flat plate.

[Problems to be solved by the invention]

Since the above-mentioned conventional dielectric resonator type band rejection filter uses a strip line as a transmission line in the cut-off waveguide, a strip conductor is required to obtain a coupling amount in which the external Q is about 100 to 300. And the distance between the dielectric resonator and
It is necessary to set it at about 2 mm, the dielectric resonator is very close to the ground side of the strip line, and it is higher than the set resonance frequency of the dielectric resonator when configuring a normal band reject filter.
The frequency is about 100MHz lower in the 4GHz band. For this reason, there is a disadvantage that the internal dimensions of the metal housing, which has been optimally designed for the band rejection filter, must be changed. Also, a counterbore for dropping the dielectric resonator support base should be provided on the metal housing side to bring the dielectric resonator closer to the strip conductor, and the dielectric resonator must be mounted on the support for positioning. In addition, there is a disadvantage that the number of processed parts is large and expensive.

The object of the present invention is to eliminate the above-mentioned drawbacks and to replace the transmission line in the cut-off waveguide from a stripline to a triplate line, so that a metal housing and a dielectric resonator having the same shape as the band-pass filter can be obtained. It is an object of the present invention to provide an inexpensive dielectric resonance type band rejection filter which can be used and can greatly reduce the number of parts and processing.

[Means for solving the problem]

The dielectric resonance type band rejection filter according to the present invention is a dielectric resonator type band rejection filter including a metal housing and at least one dielectric resonator built in the metal housing. A metal plate that forms a distributed constant line for transmitting a signal and electromagnetically coupling with the dielectric resonator to give a desired frequency characteristic is formed by metal plates above and below the metal housing. It is configured with a tri-plate structure for sandwiching.

〔Example〕

Next, the present invention will be described with reference to the drawings. First
FIG. 1A is a front view of an embodiment of the present invention, and FIG. 1B is a cross-sectional view.

The metal housing 1 becomes a cut-off waveguide in the used frequency band, and becomes a transmission line inside at an odd multiple of 1/4 wavelength along the triplate line 2 as a coupling circuit of the cut-off waveguide and the dielectric resonator. Thus, the dielectric resonator 3 is positioned and attached to the metal plate 4 with high precision by an adhesive method. This triplate configuration has a configuration in which a triplate line 2 of a metal plate is sandwiched between upper and lower metal plates of a metal housing. With this configuration, since the dielectric resonator and the transmission line are all spatially coupled, an external Q having a predetermined size can be easily obtained. Therefore,
Since one side of the strip conductor is provided on the dielectric substrate as in a conventional microstrip line, the external Q is reduced. Therefore, the distance between the strip conductor and the dielectric resonator must be extremely close to obtain a predetermined value. Disappears. Both ends of the triplate line 2 are connected to the coaxial connector 5. This band reject filter is a 1/4 wavelength coupling type,
The dielectric resonators 3 are coupled with each other at an odd multiple of 1/4 wavelength in the transmission line direction. The dielectric resonator 3 operates as a band rejection filter by obtaining a predetermined external Q according to the distance from the triplate line 2. FIG. 2 (a) is a front view of a conventional dielectric resonator type band rejection filter, and FIG. 2 (b) is a cross-sectional view. As is apparent from a comparison between the conventional example shown in FIGS. 2A and 2B and the present invention shown in FIGS. 1A and 1B, the dielectric resonator 3 is moved from the metal plate 4 to the band. The band can be separated at the same interval as when the filter is configured, and the band rejection filter can be configured without affecting the shapes of the metal housing 1 and the dielectric resonator 3.

[Effect of the invention]

As described above, according to the present invention, the metal casing and the dielectric resonator having the same shape as the band-pass filter can be used by replacing the transmission line in the cut-off waveguide from the strip line to the triplate line. In addition, the number of parts and processing can be reduced, and an inexpensive dielectric resonator type band rejection filter can be provided.

[Brief description of the drawings]

1 (a) is a front view of one embodiment of the present invention, FIG. 1 (b) is a cross-sectional view of one embodiment of the present invention, and FIG. 2 (a) is a conventional dielectric resonator band stop. FIG. 2 (b) is a cross-sectional view of FIG. 2 (a). Fig. 3 (a)
FIG. 3B is a front view of a dielectric resonator bandpass filter, and FIG.
1 is a cross-sectional view of a dielectric resonator type bandpass filter. DESCRIPTION OF SYMBOLS 1 ... Metal housing, 2 ... Triplate line, 3 ... Dielectric resonator, 4 ... Metal plate, 5 ... Coaxial connector, 6 ... Stripline board, 7 ... Support, 8
……antenna.

Claims (1)

(57) [Scope of request for utility model registration] 1. A dielectric resonator type band rejection filter comprising a metal housing and at least one dielectric resonator built in the metal housing, wherein the dielectric resonator is adhered to the metal housing. A metal plate forming a distributed constant line for transmitting a signal and electromagnetically coupling with the dielectric resonator to give a desired frequency characteristic is sandwiched between upper and lower metal plates of the metal housing. And a dielectric resonator type band rejection filter.