CN105428765A - A metal resonator filter with a low-frequency null embedded in a slotted metal plate - Google Patents

Abstract

The invention discloses a metal resonant cavity filter with a low-frequency zero point and an embedded slotted metal plate, which comprises a metal resonant cavity, a probe and an SMA head, wherein the metal resonant cavity is embedded with the metal plate, and the metal plate is provided with a slot line. The invention controls the multimode of the filter and the position of the transmission zero point by adjusting the position and the size of the metal plate and the slot line on the metal plate, and the band-pass filter designed by the invention has the advantages of small volume, simple structure, easy processing, good performance and the like, and can meet the requirements of a communication system.

Description

A metal resonator filter with a low-frequency null embedded in a slotted metal plate

technical field

The invention relates to an in-line metal cavity filter, in particular to a metal resonant cavity filter with a low-frequency zero point embedded with a slotted metal plate.

Background technique

Microwave filter is an indispensable device in the transmitting and receiving ends of modern communication systems. It separates signals, allowing useful signals to pass through without attenuation as much as possible, and suppressing useless signals from passing through with as much attenuation as possible. With the development of wireless communication technology, the frequency band between signals becomes narrower and narrower, which puts forward higher requirements on the specification and reliability of filters. Rectangular cavity filters have high application value due to their high frequency selectivity, low insertion loss, large power capacity, and stable performance. Many scholars have studied the multi-mode passband generated by the cavity filter. By adjusting the coupling between resonators to change the separation of multi-modes, generate transmission zeros, and further improve the bandpass performance.

Contents of the invention

In order to overcome the shortcomings and deficiencies of the prior art, the present invention provides a metal resonant cavity filter with a low-frequency zero point embedded with a slotted metal plate.

The purpose of the present invention is to propose a cavity filter that can generate multiple transmission poles and transmission zeros. In a rectangular metal resonant cavity, a metal plate is embedded, and groove lines are opened on the metal plate. By adjusting the metal plate And the position and size of the groove line on the metal plate to control the position of the transmission pole and transmission zero of the filter.

The present invention adopts following technical scheme:

A metal resonant cavity filter with a low-frequency zero point embedded with a slotted metal plate, including a probe and an SMA head, and a metal resonant cavity, the metal resonant cavity is embedded with a metal plate, and a slot is opened on the metal plate Wire.

The groove line is specifically a rectangle.

Specifically, there are three groove lines, one of which is located at the center line in the length direction of the metal plate, and the other two are symmetrical about the center line in the length direction of the metal plate.

The probe and the SMA probe are welded together, specifically two groups, respectively located at both ends of the metal resonant cavity for power feeding.

The length of the slot line located at the midline in the length direction of the metal plate is longer than the other two slot lines.

The metal resonant cavity and the metal plate have a rectangular structure.

Beneficial effects of the present invention:

(1) The present invention can meet the characteristics of miniaturization, high selectivity, high Q value, simple design and processing;

(2) The structure volume of the present invention is small, and the problem of large volume of the rectangular cavity filter is improved;

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the side view of Fig. 1;

Fig. 3 is the top view of Fig. 1;

FIG. 4 is an electromagnetic simulation curve corresponding to frequency according to an embodiment of the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example

A metal resonant cavity filter embedded with a slotted metal plate with a low-frequency zero point, comprising a metal resonant cavity 3 , and a metal plate 1 embedded in the metal resonant cavity 3 , and a grooved line 2 is opened on the metal plate 1 .

As shown in Figure 1-Figure 3, the metal resonator is a rectangular structure, its length is about 1/2 wavelength of the working center frequency, and its width is about 1/4 wavelength of the center frequency. The metal plate is embedded in the metal resonator. And it is connected with the front and rear inner walls of the metal resonant cavity.

There are groove lines on the metal plate. In this embodiment, there are three groove lines, and the three groove lines are all rectangular. One of the groove lines is located on the center line in the length direction of the metal plate, and its length is equal to the width of the metal plate. The positions of the other two groove lines are symmetrical with respect to the center line in the length direction of the metal plate, and are located on both sides of the center line, and the length of the groove line located on the center line is greater than the length of the other two groove lines.

This embodiment also includes a probe 4 and an SMA head 5, the probe and the SMA probe are welded together, the two sides of the metal resonator are provided with the probe and the SMA head, and the probe is connected to the metal plate for feeding Electricity.

Both the metal plate and the metal resonant cavity are made of metal materials, preferably gold and silver.

The processing of the present embodiment is as follows:

Cut the metal resonant cavity into upper and lower cavity, and metal plate;

Grooves and threads for fixing screws and small holes for connecting probes are cut in the metal plate;

On the lower chamber, a threaded hole for fixing the SMA connector is made near each input and output port, a thread for fixing the screw and a groove for fixing the metal plate are made on the wall of the cavity, and a hole for accommodating the probe is made at the input and output ports. the lower half of the hole;

On the upper chamber, a threaded hole for fixing the SMA connector is opened near each input and output port, and a threaded hole corresponding to the fixing screw is opened on the cavity wall of the upper cavity, and a hole is opened on the input and output cavity wall. out the upper half of the through-hole that accommodates the probe;

Finally, weld the SMA head and the probe, insert the metal plate into the groove of the lower cavity, weld the probe to the metal plate, fix the SMA head on the metal cavity with screws, cover the metal upper cavity, and use Screws fix the upper cavity, metal plate and lower cavity, and finally carry out the test.

As shown in Figure 4, the simulation diagram shows that the proposed filter structure can introduce transmission zeros in the upper and lower cut-off bands, and generate transmission poles in the passband.

The invention mainly uses the metal plate embedded in the metal cavity to control the transmission pole and zero point, and controls the input coupling and the coupling between modes by adjusting the length of the probe (the size of the metal plate) and the size and position of the slot line on the metal plate. Control and improve filter performance by adjusting the overall size of the metal cavity, etc.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the embodiment, and any other changes, modifications, substitutions and combinations made without departing from the spirit and principle of the present invention , simplification, all should be equivalent replacement methods, and are all included in the protection scope of the present invention.

Claims (6)

1. A metal resonator filter with a low-frequency zero embedded slotted metal plate, including a probe and an SMA head, is characterized in that it also includes a metal resonator, and the metal resonator is embedded with a metal plate, the metal resonator The metal plate is slotted. 2 . The metal resonator filter according to claim 1 , wherein the groove line is specifically rectangular. 3 . 3. The metal resonator filter according to claim 1, wherein there are three groove lines, one of which is located at the center line in the length direction of the metal plate, and the other two are about the center line in the length direction of the metal plate symmetry. 4. The metal resonant cavity filter according to claim 1, wherein the probe and the SMA probe are welded together, specifically two groups, respectively located at both ends of the metal resonant cavity for power feeding. 5 . The metal resonator filter according to claim 3 , wherein the length of the slot line located at the midline in the length direction of the metal plate is longer than the other two slot lines. 5 . 6 . The metal resonator filter according to claim 1 , wherein the metal resonator and the metal plate have a rectangular structure.