WO2019109735A1

WO2019109735A1 - Waveguide filter having adjustable bandwidth

Info

Publication number: WO2019109735A1
Application number: PCT/CN2018/110560
Authority: WO
Inventors: 谢瑞华; 王旭
Original assignee: 罗森伯格技术（昆山）有限公司
Priority date: 2017-12-05
Filing date: 2018-10-17
Publication date: 2019-06-13
Also published as: CN208062225U

Abstract

Disclosed is a waveguide filter having an adjustable bandwidth, comprising: a cavity; an input end and an output end arranged at the cavity; and at least three coupling windows. A first dielectric rod capable of bandwidth adjustment is provided in each coupling window. A distance to which the first dielectric rod is inserted into a resonant cavity is adjustable. At least three first dielectric rods are driven by the same driving device. The present invention employs a transmission mechanism to synchronously control bandwidth adjustment for multiple coupling windows, such that the number of required driving motors is reduced, thereby greatly reducing costs of a filter, simplifying the structure of the filter, increasing adjustment precision, and reducing size and weight of the filter.

Description

Waveguide filter with adjustable bandwidth

Technical field

The utility model relates to a passive device filter, in particular to a waveguide filter with adjustable bandwidth.

Background technique

In the field of communication, filters are widely used as a frequency selection device. Among them, waveguide filters have important functions in frequency selection, frequency division and isolation signals in modern microwave communication, satellite communication, radar and remote sensing telemetry technologies. The performance of the system directly affects the quality of the system. The waveguide filter generally adopts a cavity structure, and a cavity can be equivalent to an inductance parallel capacitor to form a resonance level to achieve a filtering function. The bandwidth of the traditional waveguide filter is fixed and unadjustable. The designed bandwidth is determined at the factory and cannot meet the special conditions. The tunable filter is born.

With the rapid development of passive device technology, a motor-driven tunable waveguide filter is widely used to control the depth of the waveguide coupling window by controlling the forward and reverse of the stepping motor, thereby achieving the purpose of adjusting the bandwidth. The control is convenient and the precision is high.

Conventional tunable bandwidth waveguide filters usually have micromotors mounted on the tuning of each waveguide coupling window. This motor is used to control the depth of each tuned into the waveguide coupling window to achieve adjustable waveguide filter bandwidth. However, it is clear that as the number of filter stages increases, the same number of motors are required for control, and the number of motors is large, so that the cost of the tunable filter is drastically increased, the volume is large, the weight is large, and at the same time, due to each waveguide coupling window The bandwidth is greatly affected by the snail. In order to accurately control the position and depth of each snail, the accuracy of the motor is very high, resulting in high cost of the filter.

Utility model content

The purpose of the utility model is to overcome the defects of the prior art and provide a waveguide filter with adjustable bandwidth with high reliability and low cost.

In order to achieve the above object, the present invention provides the following technical solution: a waveguide filter with adjustable bandwidth, including a cavity, an input end, an output end, and at least three coupling windows disposed on the cavity, a coupling window is formed between adjacent two resonant cavities, between the input end and a resonant cavity connected to the input end, and between the output end and a resonant cavity connected to the output end, The bandwidth-adjusting waveguide filter further includes a plurality of first dielectric rods extending into the coupling window to function as an adjustment bandwidth, the length of the first dielectric rod extending into the coupling window is adjustable, and at least three of the first The dielectric rod is driven by the first drive.

Preferably, the adjustable bandwidth waveguide filter further includes a plurality of second dielectric rods extending into the resonant cavity for frequency modulation, and the length of the second dielectric rod extending into the resonant cavity is adjustable, at least two The second dielectric rod is driven by the first drive or by a second drive.

Preferably, the first and second driving devices each comprise a motor and a transmission mechanism, the motor drives the transmission mechanism, and the first dielectric rod and the second dielectric rod are connected to the transmission mechanism of the first driving device. Or the first dielectric rod is connected to the transmission mechanism of the first driving device, and the second dielectric rod is connected to the transmission mechanism of the second driving device.

Preferably, the transmission mechanism includes a driving screw and a sliding rod, the driving screw is driven by the motor, the sliding rod is screwed with the driving screw, and the sliding rod is along the Driving the screw rod, the first dielectric rod and the second dielectric rod are connected to the sliding rod of the first driving device; or the first dielectric rod is connected to the sliding rod of the first driving device, the second dielectric rod and the second driving The sliders of the device are connected.

Preferably, the transmission mechanism further includes a driven screw rod, the driven screw rod is disposed in parallel with the driving screw rod, and the sliding rod is fitted on the driven screw rod and along the driven wire The rod slides.

Preferably, the cavity is formed with a via having a number of first dielectric bars or a sum of the first dielectric bar and the second dielectric bar on a wall of the cavity near the side of the transmission mechanism, A first dielectric rod extends from the via into a corresponding coupling window, the second dielectric rod extending from the via into a corresponding resonant cavity.

Preferably, the adjustable bandwidth waveguide filter further includes a tuning screw extending into the coupling window and the resonant cavity, the first dielectric bar and the second dielectric bar being vertically disposed with the corresponding tuning screw .

Preferably, all of the first dielectric rod and the second dielectric rod are driven by the first driving device, or all of the first dielectric rods are driven by the first driving device, all of the second dielectric rods Both are driven by the second drive.

Preferably, the resonant cavity is a waveguide cavity, and the coupling window is a waveguide coupling window.

Preferably, the first dielectric rod and the second dielectric rod telescopically move in respective axial directions.

The utility model synchronously controls the bandwidth adjustment of a plurality of coupling windows by a transmission mechanism, so that each coupling window is simultaneously adjusted to a required bandwidth, and the solution solves the difficulty of installing the motor due to the space-small coupling window without space. Moreover, since the number of driving motors is reduced, the cost of the filter is greatly reduced, the structure of the filter is simplified, the adjustment accuracy and reliability are improved, and the volume and weight of the filter are reduced.

DRAWINGS

1 is a schematic structural view of Embodiment 1 of the present invention;

Figure 2 is a schematic structural view of Embodiment 2 of the present invention;

3 is a schematic structural view of Embodiment 3 of the present invention.

Reference mark:

1, cavity, 2, resonant cavity, 3, coupling window, 4, tuning screw, 5, the first dielectric rod, 6, the first motor, 7, the first transmission mechanism, 71, the first drive screw, 72, First driven screw, 73, first slider, 8, signal input terminal, 9, signal output terminal, 10, second dielectric rod, 11, second motor, 12, second transmission mechanism, 121, second The driving screw, 122, the second driven screw, 123, and the second sliding rod.

Detailed ways

The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention.

The waveguide filter with adjustable bandwidth disclosed by the utility model adopts a window dielectric rod to compensate the coupling between the waveguide resonators, and connects all the dielectric rods of the coupling window into one body, and drives the whole waveguide through a micro motor. The bandwidth of the filter changes.

Example 1

As shown in FIG. 1, the adjustable bandwidth waveguide filter of the first embodiment includes a cavity 1, a resonant cavity 2, a coupling window 3, a tuning screw 4, a first dielectric rod 5, a first driving device, and a signal input terminal 8. And the signal output end 9, the top surface of the cavity 1 has an opening, and the other sides are closed, and a cover plate (not shown) is attached to the top surface of the cavity 1 to form a closed cavity. At least two resonant cavities 2 are formed in the cavity, specifically a waveguide cavity structure, and three resonant cavity 2 structures are shown in the figure. In practice, the resonant cavity 2 may be a circular cavity or a rectangular cavity. A coupling window 3 is formed between two adjacent resonant cavities 2, between the input end 8 and the resonant cavity 2 connected to the input end 8, and between the output end 9 and the resonant cavity 2 connected to the output end 9, forming at least three The coupling window 3, in particular the waveguide coupling window structure, shows four coupling window 3 structures.

Each of the resonant cavity 2 and each of the coupling windows 3 is provided with a tuning screw 4, and each of the coupling windows 3 is provided with a plurality of first dielectric rods 5 extending into the coupling window 3 to adjust the bandwidth, the first medium The rod 4 is used to achieve fine-tuning or perturbation of the bandwidth by varying the length of the coupling window 3.

The first driving device drives the plurality of first dielectric rods 5 through a driving motor. Compared with the conventional driving window 3, the driving motor of the present invention is significantly reduced in number and the cost is significantly reduced.

When the adjustable bandwidth waveguide filter is in operation, the signal enters from the waveguide input terminal 8, passes through the three resonant cavities 2 in sequence, and filters out the unwanted frequency components outside the resonant frequency of the resonant cavity 2, and the useful signal in the band is The waveguide output 9 leaves. When it is necessary to adjust and change the useful bandwidth, the first dielectric rod 5 is changed by the rotation of the motor to change its length into the coupling window 3, so that the perturbation changes the bandwidth of the four coupling windows 3, and the useful signal passband of the output terminal 9 It changes accordingly, thereby realizing the adjustable bandwidth of the waveguide filter.

Specifically, the first driving device includes a first motor 6 and a first transmission mechanism 7, and the first transmission mechanism 7 includes a first driving screw 71, a first driven screw 72, and a first sliding rod 73. The outer surface of the first driving screw 71 is a threaded structure, the first driving screw 71 is axially connected to the output shaft of the first motor 6, and the first driving screw 71 is at the first Rotating under the driving of the motor 6, the first driven screw 72 is disposed in parallel with the first driving screw 71, and the first sliding rod 73 is a rod-shaped structure adjacent to the first driving screw 71 One end is provided with a threaded hole to be screwed to the first driving screw 71, and the other end is sleeved on the outer side of the first driven screw 72, and the first driven screw 72 is Slide the connection. Thus, when the first motor 6 is in operation, the first driving screw 71 is rotated, and the first sliding rod 73 moves up and down along the first driving screw 71 and the first driven screw 72.

One end of the first dielectric rod 5 is connected to the first sliding rod 73, and the other end thereof passes through a through hole in the sidewall of the cavity and extends into the corresponding coupling window 3 to form a medium perturbation structure. It is noted that the through hole is formed on a side of the cavity 1 adjacent to the first transmission mechanism 7, and the diameter of the through hole can ensure that the first dielectric rod 5 can move freely along its axial direction. The number is identical to the number of the first dielectric rods 5. In Embodiment 1, the first dielectric rod 5 is placed perpendicularly to its corresponding tuning screw 4, and of course, the first dielectric rod 5 and the tuning screw 4 may alternatively be placed at a nearly vertical angle. The selection of the dielectric material also follows the above comprehensive principle, so that the filter insertion loss is not seriously affected when the bandwidth is adjusted over a large bandwidth.

In the first embodiment, all the first dielectric rods 5 are connected to the first driving device (specifically, the first sliding rod 73), so as to realize the overall translation of the filter passband; alternatively, the first motor may also be used. 6 drives a portion of the first dielectric rod 5, and the other first dielectric rods 5 are driven by an additional motor.

In the first embodiment, the driving screw is driven to rotate by a certain angle, and the first dielectric rod 5 sleeved on the screw will penetrate into the corresponding coupling window 3 for a certain length at the same time, and the bandwidth of the waveguide filter can be adjusted.

Example 2

As shown in FIG. 2, the waveguide of the adjustable bandwidth of the second embodiment further includes a plurality of second dielectric rods 10 extending into the resonant cavity for frequency modulation, each of the resonant cavities. The second dielectric rod 10 is disposed within the second dielectric rod 10 for achieving fine tuning or perturbation of the resonant frequency by variations in the length of the resonant cavity 2.

In the second embodiment, the second dielectric rod 10 shares a driving device with the first dielectric rod 5, that is, is also driven by the first driving device, and the first driving device drives the plurality of first dielectric rods 5 and the first by a driving motor 61. The two dielectric rods 10 have significantly reduced the number of driving motors used in the present invention, and each of the conventional resonant cavities 2 and each of the coupling windows 3 must be equipped with one driving motor, and the cost is significantly reduced.

One end of the second dielectric rod 10 is connected to the first sliding rod 73, and the other end thereof passes through a through hole in the sidewall of the cavity and extends into the corresponding resonant cavity 2 to form a medium perturbation structure, which needs to be explained. Yes, the via hole is also formed on a side of the cavity 1 near the first transmission mechanism 7, and the diameter of the via hole can ensure that the second dielectric rod 10 can move freely along its axial direction, The number is identical to the number of the second dielectric rods 10. Considering the change of the Q value of the resonator and the size of the frequency tunable range, and the structural feasibility, the solution uses the second dielectric rod 10 to be placed perpendicular to the corresponding tuning screw 3, of course, as an optional second medium. The rod 10 and the tuning screw 3 can also be placed at a nearly vertical angle. The selection of dielectric materials also follows the above comprehensive principle, so that when tuning in a large frequency range, the Q value of the resonant cavity is limitedly reduced, and the insertion loss of the filter is not seriously affected.

In the second embodiment, all the first dielectric rods 5 and all the second dielectric rods 10 are connected to the first driving device (specifically, the first sliding rod 73) to realize the overall translation of the filter passband; It is also possible that the first motor 6 drives a portion of the first and/or second dielectric rods, and the other dielectric rods are driven by an additional motor.

In the second embodiment, the driving motor drives the driving screw to rotate at a certain angle, and the first dielectric rod 5 sleeved on the screw will penetrate into the corresponding coupling window 3 for a certain length at the same time, and the bandwidth of the tunable waveguide filter; and the second medium The rod 10 will simultaneously penetrate into the corresponding cavity 2 for a certain length, and the resonant frequency of the tunable waveguide filter will be reduced to a certain frequency point.

Example 3

As shown in FIG. 3, different from the above embodiment 2, the second dielectric rod 10 of the third embodiment is driven by another second driving device, that is, the two dielectric devices respectively correspond to the first dielectric rod 5 and the Two dielectric rods 10 are driven.

The structure of the second driving device is the same as that of the first driving device, and includes a second motor 11 and a second transmission mechanism 12, and the second transmission mechanism 12 includes a second driving screw 121 and a second driven screw 122. And the second sliding rod 123, the outer surface of the second driving screw 121 is a threaded structure, and the second driving screw 121 is axially connected to the output shaft of the second motor 11, the second driving screw 121 is rotated by the second motor 11, the second driven screw 122 is disposed in parallel with the second driving screw 121, and the second sliding rod 123 is a rod-shaped structure, which is close to the One end of the second driving screw 121 is provided with a threaded hole to be screwed to the second driving screw 121, and the other end of the second driving screw 121 is sleeved on the outer side of the second driven screw 122, and the first The second driven screw 122 is slidably connected. Thus, when the second motor 11 is in operation, the second driving screw 121 is rotated, and the second sliding rod 123 is moved up and down along the second driving screw 121 and the second driven screw 122. The second dielectric rod 10 is connected at one end to the second sliding rod 123, and the other end thereof passes through a through hole in the sidewall of the cavity and extends into the corresponding resonant cavity 2 to form a dielectric perturbation structure.

In the third embodiment, all the first dielectric rods 5 are connected to the first driving device (specifically, the first sliding rod 73), and all the second dielectric rods 10 are connected to the second driving device (specifically and secondly). The sliding rod 123) is connected to realize the overall translation of the filter passband; alternatively, the first motor 6 may drive a portion of the first dielectric rod 5, and the other first dielectric rods 5 are driven by an additional motor, similarly, The second motor 11 drives a portion of the second dielectric rod 10, and the other second dielectric rods 10 are driven by an additional motor.

In the third embodiment, the two driving motors are driven to rotate the respective driving screws by a certain angle, and a driving motor drives the first dielectric rod 5 sleeved on the first driving screw 71 to penetrate into the corresponding coupling window to a certain length at the same time. The bandwidth of the waveguide filter is adjusted; another driving medium drives the second dielectric rod 10 sleeved on the second driving screw 121 to simultaneously penetrate into the corresponding cavity 2 for a certain length, tunable the frequency of the waveguide filter.

Since the utility model removes most of the high-precision micro-motors, leaving only one or two micro-motors, the cost is significantly reduced, and the application is more advantageous and the reliability is higher in today's increasingly severe suppression requirements and an increase in the number of resonant cavities. In addition, since the adjustable stroke of the dielectric rod is significantly larger than the stroke of the conventional tuning, the accuracy requirement of the motor is significantly reduced; furthermore, since the bandwidth is adjusted by the dielectric rod, the intermodulation is not deteriorated due to the tight contact surface.

The technical content and the technical features of the present invention have been disclosed as above. However, those skilled in the art can still make various substitutions and modifications without departing from the spirit of the present invention based on the teachings and disclosures of the present invention. Therefore, the present invention protects the present invention. The scope of the invention is not limited by the scope of the invention, and the invention is intended to cover various alternatives and modifications without departing from the invention.

Claims

An adjustable bandwidth waveguide filter includes a cavity, an input end, an output end, and at least three coupling windows disposed on the cavity, the coupling window being formed between two adjacent resonant cavities, The input end is connected between the resonant cavity connected to the input end and the output end and the resonant cavity connected to the output end, wherein the adjustable bandwidth waveguide filter further comprises a plurality of A first dielectric rod extending into the coupling window to adjust the bandwidth, the length of the first dielectric rod extending into the coupling window is adjustable, and at least three of the first dielectric rods are driven by the first driving device.
The adjustable bandwidth waveguide filter according to claim 1, wherein the adjustable bandwidth waveguide filter further comprises a plurality of second dielectric rods extending into the resonant cavity for frequency modulation, the second medium The length of the rod extending into the cavity is adjustable, and at least two of the second dielectric rods are driven by the first drive or by a second drive.
The adjustable bandwidth waveguide filter according to claim 2, wherein said first and second driving means each comprise a motor and a transmission mechanism, said motor driving said transmission mechanism to move said first medium Both the rod and the second dielectric rod are connected to the transmission mechanism of the first driving device; or the first dielectric rod is connected to the transmission mechanism of the first driving device, and the second dielectric rod is connected to the transmission mechanism of the second driving device.
The adjustable bandwidth waveguide filter according to claim 3, wherein said transmission mechanism comprises a drive screw and a slide rod, said drive screw being driven by said motor, said slide rod and The driving screw is screwed, the sliding rod moves along the driving screw, and the first dielectric rod and the second dielectric rod are both connected to the sliding rod of the first driving device; or the first dielectric rod and the first A sliding rod of a driving device is connected, and a second dielectric rod is connected to the sliding rod of the second driving device.
The adjustable bandwidth waveguide filter according to claim 4, wherein the transmission mechanism further comprises a driven screw, the driven screw is disposed in parallel with the driving screw, and the sliding rod set On the driven screw and sliding along the driven screw.
The adjustable bandwidth waveguide filter according to claim 3, wherein the cavity is formed on the wall of the cavity near the side of the transmission mechanism to have the same number of first dielectric bars or the first medium. a via having a sum of the number of bars and a second dielectric rod extending from the via into a corresponding coupling window, the second dielectric rod extending from the via to a corresponding resonant cavity Inside.
The adjustable bandwidth waveguide filter of claim 1 wherein said adjustable bandwidth waveguide filter further comprises a tuning screw extending into said coupling window and said resonant cavity, said first The dielectric rod and the second dielectric rod are disposed perpendicular to the corresponding tuning screw.
The adjustable bandwidth waveguide filter according to claim 2, wherein all of said first dielectric rod and said second dielectric rod are driven by said first driving means, or all of said first dielectric rods Driven by the first drive means, all of the second dielectric rods are driven by the second drive means.
The adjustable bandwidth waveguide filter of claim 1 wherein said resonant cavity is a waveguide cavity and said coupling window is a waveguide coupling window.
The variable bandwidth waveguide filter of claim 1 wherein said first dielectric rod and said second dielectric rod telescopically move in respective axial directions.