Electrically tunable coupling and electrically tunable bandpass filter between low-frequency high-power resonators

Abstract

The present invention discloses an electrically adjustable coupling between low-frequency and high-power resonators and an electrically adjustable bandpass filter with electrically adjustable coupling between low-frequency and high-power resonators. The electrically adjustable coupling between low-frequency resonators includes an outer conductor, a coupling rod, and a dielectric support. A groove is provided on the top of the outer conductor, and a finger-shaped spring made of beryllium bronze is installed in the groove. The coupling rod extends into the cavity from the groove and makes elastic short-circuit contact with the finger-shaped spring. A hollow hole is provided at the corresponding dielectric support so that the coupling rod can penetrate deep into the cavity. The high-power electrically adjustable bandpass filter is composed of an input interface, an output interface, and two or more electrically tuned units with electrically adjustable coupling between resonant cavities connected in sequence. It not only realizes the electrically changing frequency and bandwidth of the bandpass filter, but also can meet the requirements of miniaturization, wide tuning frequency range, and high power in the ultra-low frequency band.

Description

Technical Field

[0001] The invention relates to an electrically adjustable coupling and an electrically adjustable bandpass filter between low-frequency resonators, in particular to an electrically adjustable coupling and an electrically adjustable bandpass filter between low-frequency high-power resonators, belonging to the technical field of microwave filters. Background Art

[0002] The coupling between resonators achieved by traditional methods is a fixed coupling structure. Since the coupling structure is fixed, after the electric frequency change, the corresponding coupling amount changes, causing the coupling bandwidth to change, and the absolute bandwidth is inconsistent, especially when used in the low frequency band, the absolute bandwidth changes greatly. At present, there is a demand for high-power bandpass filters that can work at low frequencies, change frequencies electrically, and withstand power of more than a few kilowatts while being able to change bandwidth electrically.

[0003] In the prior art, the Chinese utility model patent with patent number CN201420764841.5 discloses "a VHF band high-power electrically tunable filter", in which the resonator has a corresponding transmission mechanism and capacitor loading, and the frequency is changed by the number of rotation steps relative to the zero point position, but the coupling between the resonant cavities is fixed, and the bandwidth cannot be changed. In addition, the electrically tunable filter is huge in size and weight and cannot be flexibly installed. The Chinese utility model patent with patent number CN20101220548993.2 discloses "a low-frequency band broadband high-power bandpass filter", which adopts a comb line structure, and its frequency and bandwidth are fixed.

[0004] In the prior art, a Chinese invention patent with patent number CN201410745975.7 discloses "a low-frequency, high-power resonator and an electrically tunable band-stop filter", inventing a low-frequency, high-power resonator and an electrically tunable band-stop filter with a low-frequency, high-power resonator, which realizes electrically adjustable frequency change, but does not have the function of electrically controlled bandwidth adjustment, and does not have the function of a bandpass filter. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides an electrically tunable coupling and an electrically tunable bandpass filter between low-frequency and high-power resonators, which realizes an electrically tunable bandpass filter with electrically controlled adjustable bandwidth while electrically changing the frequency in the low-frequency band.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] An electrically adjustable coupling between low-frequency high-power resonators, comprising an outer conductor 2 and a plurality of inner conductors 3, wherein the inner conductors 3 are arranged in parallel in the outer conductor 2 to form a high-power resonator, each high-power resonator is connected in series, a signal path is formed between each high-power resonator and an adjacent high-power resonator, and a coupling part for adjusting a signal coupling value is provided in each signal path;

[0008] The coupling part includes a coupling rod 6 and a transmission mechanism 12. An opening is provided at the top of the outer conductor 2 corresponding to the coupling rod 6. The coupling rod 6 extends into the signal path through the opening. The coupling rod 6 is in conductive contact with the outer conductor 2. The transmission mechanism 12 is provided above the coupling rod 6. The transmission mechanism 12 drives the coupling rod 6 to move up and down.

[0009] Preferably, a tuning rod 7 is inserted into each inner conductor 3 , and the top end of the tuning rod 7 is located above the outer conductor 2 . Each tuning rod 7 is linearly driven by a transmission mechanism 12 disposed on the outer conductor 2 .

[0010] Preferably, two radio frequency interfaces are provided on the outer conductor 2, and the two radio frequency interfaces are connected to the inner conductors 3 located at two ends in a one-to-one correspondence.

[0011] Preferably, the coupling rod 6 is a hollow metal round rod.

[0012] Preferably, electrical coupling is achieved between every two adjacent high-power resonators through a coupling portion.

[0013] Preferably, an annular groove is formed on the outer conductor at the connection between the tuning rod 7 and the outer conductor 2 and at the connection between the coupling rod 6 and the outer conductor 2, and a finger-shaped spring 9 made of beryllium bronze is installed in each annular groove, and the finger-shaped spring 9 is in elastic short-circuit contact with the outer conductor;

[0014] Preferably, it also includes a dielectric support plate, which is horizontally placed inside the outer conductor 2, and the inner conductor 3 is inserted into the dielectric support plate, and the bottom end of the inner conductor 3 is short-circuited with the outer conductor.

[0015] Preferably, the outer walls of the inner conductors 3 of the adjacent resonant cavities are provided with hollow spiral grooves.

[0016] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is:

[0017] 1. Compared with the existing prior art, the present invention realizes the miniaturization and lightness of the VHF band high-power filter in terms of volume, reduces the volume by at least 40%, saves space, and can be flexibly assembled at the required position of the system.

[0018] 2. The present invention uses electrically tunable coupling between two or more electrically tunable resonators, and the cavity bandpass filter realized on this basis can not only electrically control the frequency change but also electrically control the bandwidth in the low frequency band, thereby expanding the application range of the bandpass filter.

[0019] 3. The present invention adopts the electrically adjustable coupling between resonators, and the bandwidth can be adjusted and changed, which adapts to the requirements of radio frequency signals of various systems, reduces the product types of electrically adjustable filters, and achieves multiple uses of one picture.

[0020] 4. The present invention adopts an electrically controlled mechanical adjustment method of independently adjusting the coupling between resonant cavities to change the working bandwidth of the filter, and achieves better filtering characteristics through the mutual cooperation of electrically adjusted frequency change and electrically controlled bandwidth adjustment.

[0021] 5. The electrically tunable coupling between the electrically tunable resonators and the electrically tunable bandpass filter adopted in the present invention, and their design method and structural form can also be applicable to low-power designs, and the structural design can have a variety of forms, such as a straight line or folded into a square, which is flexible and diverse according to system requirements and optimizes the occupied space.

[0022] 6. The electrically tunable coupling and electrically tunable bandpass filter between the electrically tunable resonators used in the present invention also represent a technological advancement in that the band-stop filter in the prior art can only attenuate a known, single interference signal, and serves as a path for all signals other than this single frequency; whereas the bandpass filter used allows signals of a specific frequency band to pass through, while shielding similar or unknown interference frequencies and signals of other frequency bands, thereby effectively improving the anti-interference capability of communication equipment.

[0023] 7. Compared with the band-stop filter and the prior art, the electrically tunable coupling between electrically tunable resonators and the electrically tunable bandpass filter adopted in the present invention have technical progress in that the present invention integrates the electrically tunable coupling between electrically tunable resonators and the electrically tunable resonator in series, simplifies various connectors, and transforms the unchangeable inter-cavity coupling into an intelligently adjustable one. It has a compact structure, optimized performance, and the system can be flexibly placed according to the use space. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention;

[0025] Figure 2 is a structural cross-sectional view of embodiment 1 of the present invention;

[0026] Figure 3 This is a schematic diagram of Example 2.

[0027] Among them, 1-RF interface, 2-outer conductor, 3-inner conductor, 4-dielectric support plate, 5-low-frequency high-power resonant cavity, 6-coupling rod, 7-tuning rod, 8-groove, 9-finger-shaped reed, 10-zero return switch, 11-linear motor, and 12-transmission mechanism. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0029] Embodiment 1: An electrically adjustable coupling between low-frequency high-power resonators, comprising an outer conductor 2 and a plurality of inner conductors 3, wherein the inner conductors 3 are arranged in parallel in the outer conductor 2 to form a high-power resonator, and the electrical signals of the high-power resonators form a series relationship, and a signal path is formed between each high-power resonator and an adjacent high-power resonator, and a coupling part for adjusting the signal coupling value is provided in each signal path, and the electrically adjustable coupling is realized between each two adjacent high-power resonators through the coupling part;

[0030] The coupling part includes a coupling rod 6 and a transmission mechanism 12. An opening is provided at the top of the outer conductor 2 corresponding to the coupling rod 6. The coupling rod 6 extends into the signal path through the opening. The coupling rod 6 is a hollow metal round rod. The coupling rod 6 is in conductive contact with the outer conductor 2. The transmission mechanism 12 is arranged above the coupling rod 6. The transmission mechanism 12 drives the coupling rod 6 to move up and down. The transmission mechanism 12 is a combination of a transmission rod body and an end cap mounted on the top of the coupling rod.

[0031] like Figure 1 As shown, a tuning rod 7 is inserted into the inner conductor 3 , and the top end of the tuning rod 7 is located above the outer conductor 2 . Each tuning rod 7 is linearly driven by a transmission mechanism 12 arranged on the outer conductor 2 .

[0032] Annular grooves are provided on the outer conductor at the connection between the tuning rod 7 and the outer conductor 2 and at the connection between the coupling rod 6 and the outer conductor 2. A finger-shaped spring 9 made of beryllium bronze is installed in each annular groove. The finger-shaped spring 9 is in elastic short-circuit contact with the outer conductor.

[0033] To ensure smooth signal transmission, two radio frequency interfaces are provided on the outer conductor 2, and the two radio frequency interfaces are connected to the inner conductors 3 at both ends in a one-to-one correspondence.

[0034] It also includes a dielectric support plate 4, which is horizontally placed inside the outer conductor 2, and the inner conductor 3 is inserted into the dielectric support plate. A low-frequency high-power resonance cavity is formed between the dielectric support plate 4 and the top wall of the outer conductor. The bottom of the low-frequency high-power resonance cavity is connected to the signal path through a common port, and the inner conductor 3 is connected to the low-frequency high-power resonance cavity through a top opening. The coupling rod is directly opposite to the common port.

[0035] In order to ensure the electrical performance, the outer wall of the inner conductor 3 of the adjacent resonant cavity is provided with a hollow spiral groove, and the bottom end of the inner conductor 3 is short-circuited with the outer conductor.

[0036] Embodiment 2:

[0037] like Figure 3As shown, a high-power electrically tunable bandpass filter with the low-frequency high-power resonator and electrically tunable coupling between resonators described in Example 1 is composed of an input interface, an output interface, and two or more electrically tunable resonators. The coupling structure between two adjacent resonators is electrically tunable coupling, and the outer walls of the inner conductors 3 of the adjacent resonant cavities are provided with hollow spiral grooves.

[0038] In the embodiment, N electrically tunable resonators are connected in parallel on the main transmission line, N is four, the electrically tunable coupling between the four electrically tunable resonators is M, M is three, and a four-cavity bandpass filter that can electrically control the change of the working frequency and electrically tunable bandwidth is realized, which is used to allow signals within a certain frequency band to pass through and suppress signals outside this frequency band. The electrically tunable bandpass filter includes input and output interfaces, seven drive circuits, and four electrically tunable resonators are connected through three electrically tunable coupling structures. The seven drive circuits use conventional technical means to control the rotation of seven corresponding linear motors respectively. After the system monitors the system to issue a command to change the working frequency and bandwidth of the bandpass filter, each electrically tunable resonator changes its own resonator frequency and absolute bandwidth according to the corresponding data table of pulses, center frequencies and absolute bandwidths stored on the monitoring board in the monitoring chassis. After the four electrically tunable resonators and three electrically tunable couplings change the working frequency and bandwidth respectively, the working frequency of the entire electrically tunable bandpass filter is changed. In this embodiment, the input and output are coaxial ports, and each electrically tunable resonator has screw holes on the bottom surface and the side of the transmission mechanism, and is installed inside the equipment cabinet with screws. The electrically adjustable bandpass filter achieves the effects of high power, electrically controlled frequency change and electrically controlled bandwidth adjustment, and is easy to use.

[0039] The operating mechanism of the present invention is described below:

[0040] Each transmission mechanism 12 moves back and forth in the vertical direction along the direction of the linear motor 11. First, the linear motor drives the coupling rod and the tuning rod to rise. When the upper return to zero switch 10 is triggered, it stops moving and starts to drive the coupling rod 6 and the tuning rod 7 to move downward, thereby changing the extension length of the tuning rod 7 in the inner conductor 3 and the coupling length of the coupling rod 6 between adjacent resonant cavities, thereby realizing electronically controlled frequency change and electronically controlled bandwidth modulation.

Claims

1. A high power bandpass filter with electrically adjustable coupling between low frequency high power resonators, characterized in that: It comprises an outer conductor (2) and a plurality of inner conductors (3), wherein the inner conductors (3) are arranged in parallel inside the outer conductor (2) to form a high-power resonator, each high-power resonator is connected in series, a signal path is formed between each high-power resonator and an adjacent high-power resonator, and a coupling portion for adjusting a signal coupling value is provided in each signal path; The coupling portion comprises a coupling rod (6) and a transmission mechanism (12); an opening is provided at the top of the outer conductor (2) corresponding to the coupling rod (6); the coupling rod (6) extends through the opening into the signal path; the coupling rod (6) is in conductive contact with the outer conductor (2); the transmission mechanism (12) is arranged above the coupling rod (6); the transmission mechanism (12) drives the coupling rod (6) to move up and down; the coupling rod (6) is a hollow metal round rod; A tuning rod (7) is inserted into each inner conductor (3), and the top end of the tuning rod (7) is located above the outer conductor (2). Each tuning rod (7) is linearly driven by a transmission mechanism (12) arranged on the outer conductor (2).

2. The high-power bandpass filter with electrically adjustable coupling between low-frequency high-power resonators according to claim 1, characterized in that: Two radio frequency interfaces are provided on the outer conductor (2), and the two radio frequency interfaces are connected to the inner conductors (3) located at two ends in a one-to-one correspondence.

3. The high-power bandpass filter with electrically adjustable coupling between low-frequency high-power resonators as claimed in claim 1, characterized in that: Electrically adjustable coupling is achieved between every two adjacent high-power resonators through a coupling part.

4. The high-power bandpass filter with electrically adjustable coupling between low-frequency high-power resonators as claimed in claim 1, characterized in that: Annular grooves are provided on the outer conductor at the connection points between the tuning rod (7) and the outer conductor (2) and the connection points between the coupling rod (6) and the outer conductor (2), and a finger-shaped spring (9) made of beryllium copper material is installed in each annular groove. The finger-shaped spring (9) is in elastic short-circuit contact with the outer conductor.

5. The high-power bandpass filter with electrically adjustable coupling between low-frequency high-power resonators according to claim 1, characterized in that: It also includes a dielectric support plate, which is horizontally arranged inside the outer conductor (2), and the inner conductor (3) is inserted into the dielectric support plate, and the bottom end of the inner conductor (3) is short-circuited with the outer conductor.

6. The high-power bandpass filter with electrically adjustable coupling between low-frequency high-power resonators according to claim 5, characterized in that: The outer wall of the inner conductor (3) is provided with a hollow spiral slot.

Images