A tuner with a filter

Abstract

The present invention relates to the fields of waveguides, coaxial cavity filters, and low-noise blocks (LNBs), and discloses a low-noise block with a filter, including: a low-noise block body having a first housing in which a circuit board is provided; and a waveguide filter disposed back-to-back with the low-noise block body, the waveguide filter having a second housing, and a filtering cavity of the waveguide filter being formed inside the second housing; the first housing and the second housing are integrally formed. By integrally disposing the waveguide filter and the low-noise block body back-to-back, the present invention simplifies the engineering installation steps, can avoid problems such as flange misalignment and contact gaps in cascade installation, improves the system performance index, is beneficial to reducing the installation space of the waveguide filter, and for satellite earth stations using the backfeed method, can avoid the situation where it is even impossible to use a waveguide filter to suppress 5G interference due to space constraints.

Description

Technical Field

[0001] The present invention relates to the fields of waveguides, coaxial cavity filters, and low-noise block downconverters (LNBs), and more particularly, to an LNB with a filter. Background Art

[0002] 3.4 - 3.6 GHz and 4.8 - 4.9 GHz are one of the planned frequency bands for the fifth-generation mobile communication (5G). The operating frequency of the LNB (low-noise amplifier + frequency converter) used in satellite earth stations in the C band is generally 3.4 - 4.2 GHz. Therefore, 5G signals (3.4 - 3.6 GHz) will also be received and amplified by the LNB, which is extremely likely to cause the LNB power to saturate, resulting in the receiver being unable to demodulate. Comprehensive measures such as installing a waveguide filter for the earth station, geographical isolation, installing a shielding net, reducing the transmission power of 5G base stations, and adjusting the maximum radiation direction of 5G base station antennas can be taken to mitigate or eliminate interference. The most economical and effective way is to install a waveguide filter between the feed and the LNB to suppress 5G signals in the 3.4 - 3.6 GHz frequency band.

[0003] The waveguide filter is implemented in a metal coaxial cavity manner, with a designed passband of 3.7 - 4.2 GHz, which can ensure low transmission loss while having strong suppression of 5G signals. Both the input and output interfaces of the filter are waveguide standard flange interfaces, where the input port is connected to the feed and the output port is connected to the LNB.

[0004] Adopting this solution, the waveguide filter and the LNB are two independent modules. Installing the waveguide filter has high requirements for the operation of engineering installers, requiring the two flange surfaces to be precisely aligned (as shown in Figure 1 ). If the installation is misaligned or there are gaps, it is easy to cause poor system performance and waterproof hazards. On the other hand, for satellite earth stations using the front-feed method, the feed and the LNB are installed at the focus of the parabolic antenna through a three-legged bracket. If a waveguide filter is installed on this basis, it will inevitably increase the supporting weight of the three-legged bracket. At the same time, too many components increase the wind resistance area and will block part of the satellite signal reception, affecting system performance and safety. Especially in the case of dual polarization, two waveguide filters and two LNBs need to be installed on the bracket, and the impact is more prominent. For satellite earth stations using the back-feed method, it is often impossible to install a waveguide filter due to space limitations.

[0005] This patent provides an integrated design solution for the waveguide filter and the LNB, which can well solve the above problems. Summary of the Invention

[0006] The present invention aims to overcome at least one defect (shortcoming) of the above-mentioned prior art, and provides a feedhorn with a filter, which is used to solve the technical problems of 5G interfering with the reception of satellite earth stations and the difficult installation or even impossible installation of waveguide filters.

[0007] The technical solution adopted by the present invention is a feedhorn with a filter, including

[0008] a feedhorn body, the feedhorn body having a first housing; and

[0009] a waveguide filter, the waveguide filter being arranged back-to-back with the feedhorn body, the waveguide filter having a second housing, and a filtering cavity of the waveguide filter being formed inside the second housing;

[0010] The first housing and the second housing are integrally formed.

[0011] The present invention provides an integrated design solution for the waveguide filter and the feedhorn. The second housing of the waveguide filter and the second housing of the feedhorn body are integrally formed. The filtering cavity of the waveguide filter is formed by the internal space surrounded by the second housing. Compared with the conventional separation solution of the filter and the feedhorn, the engineering installation steps are simplified, the problems of flange misalignment and contact gap in cascade installation can be avoided, and the system performance index can be improved. The waveguide filter and the feedhorn body are arranged back-to-back, which is beneficial to reducing the installation space of the waveguide filter. For satellite earth stations using the back-feed method, the situation where it is impossible to use a waveguide filter to suppress 5G interference due to limited space can be avoided.

[0012] To ensure the intensity of the received signal, the first housing and the second housing have a common bottom plate. A circuit board is provided in the first housing. The waveguide filter is provided with a port resonator column located in the filtering cavity. The port resonator column is connected to the circuit board through a pin passing through the bottom plate, and a capacitive coupling is formed between the pin and the port resonator column.

[0013] In the present invention, the waveguide filter can be implemented in a metal coaxial cavity manner and through cross-coupling technology, the signal received by the waveguide filter is capacitively coupled through the port resonator column in the filter cavity to the pin electrically connected to the high-frequency head circuit board, thereby realizing the transmission of the signal from the waveguide filter to the high-frequency head body. When the passband insertion loss is required to be ≤0.5 dB, it is easy to achieve a relatively high out-of-band rejection, and the received 5G interference signal can be well suppressed at the input end, avoiding entering the subsequent receiver processing module, which not only eliminates the 5G interference but also helps to ensure the strength of the received signal. Among them, the port resonator column can be processed from a metal material, generally copper or steel, and can also be processed from graphite, carbon fiber, carbon black, activated carbon, diamond, graphene, carbon nanotube and their derived inorganic non-metallic materials or polymer materials, and the surface is plated with silver, copper, gold, zinc, tin, nickel, chromium, etc. and their alloys, such as the resonator columns disclosed in Chinese patents with publication numbers CN106654499A and CN205603496U. The pin is generally a wire plated with silver, gold, etc. on the surface, or can also be a metal wire such as silver or gold.

[0014] Since there is a direct current passing through the connection between the circuit board and the pin in the high-frequency head body, it is necessary to ensure that the pin is not grounded. Therefore, the coupling of the signal between the waveguide filter and the high-frequency head body must be capacitive coupling. Specifically, the capacitive coupling between the pin and the port resonator column can be realized through the following two schemes:

[0015] The first scheme: A first sleeve is sleeved outside the port resonator column, and a first insulating medium is provided between the first sleeve and the port resonator column, and the first sleeve is electrically connected to the pin;

[0016] The second scheme: A second sleeve is sleeved outside the pin, and a second insulating medium is provided between the second sleeve and the port resonator column, and the second sleeve is electrically connected to the port resonator column.

[0017] Among them, the first sleeve and / or the second sleeve can be made of metal materials such as silver, copper, gold, zinc, tin, nickel, chromium, etc. plated on the surface. The first insulating medium and / or the second insulating medium can be formed by gases such as air, or can also be made of solid materials. To accurately position the first sleeve and / or the second sleeve, it is preferred to use the first insulating medium and / or the second insulating medium made of solid materials. More importantly, the solid first insulating medium and / or the second insulating medium play a role in preventing direct current grounding short circuit, and the solid material can adopt polytetrafluoroethylene material or other insulating materials.

[0018] The positional and connection relationships between the port resonance post and the pin are closely related to the port coupling bandwidth. The port coupling bandwidth can be adjusted according to the passband bandwidth of waveguide filters of different models (the passband of the waveguide filter described in this patent is 3700 MHz to 4200 MHz, with a total bandwidth of 500 MHz). To facilitate the adjustment of the port coupling bandwidth, the above two schemes can be improved as follows.

[0019] For the first scheme, the first sleeve and the pin can be directly electrically connected or indirectly electrically connected through a first tap wire.

[0020] When the first sleeve and the pin are directly electrically connected, the pin can be electrically connected to the first sleeve sleeved outside the port resonance post by bending. The connection position between the pin and the first sleeve is related to the coupling bandwidth; the diameter of the pin is related to the coupling bandwidth; the distance between the port resonance post and the pin is related to the coupling bandwidth. The port coupling bandwidth can be adjusted in the following ways:

[0021] 1. Increase the height of the pin bending point and / or the height of the electrical connection (welding) between the pin and the port resonance post (relative to the bottom of the filter cavity), the port coupling bandwidth becomes wider, and vice versa;

[0022] 2. Increase the diameter of the pin, the port coupling bandwidth becomes wider, and vice versa;

[0023] 3. When the height of the pin bending point and the height of the electrical connection between the pin and the port resonance post remain unchanged, the closer the port resonance post is to the pin, the wider the port coupling bandwidth. On the contrary, the farther the distance, the narrower the port coupling bandwidth.

[0024] When the first sleeve and the pin are electrically connected through a first tap wire, the connection position between the first tap wire and the pin and / or the first sleeve is related to the coupling bandwidth; the diameter of the first tap wire is related to the coupling bandwidth; the distance between the port resonance post and the pin is related to the coupling bandwidth. The port coupling bandwidth can be adjusted in the following ways:

[0025] 1. Increase the height of the electrical connection (welding) between the first tap wire and the pin and / or the first sleeve (relative to the bottom of the filter cavity), the port coupling bandwidth becomes wider, and vice versa; increasing the length of the first sleeve cannot effectively increase the port coupling bandwidth;

[0026] 2. Increase the diameter of the first tap wire, the port coupling bandwidth becomes wider, and vice versa;

[0027] 3. When the height of the first tap wire remains unchanged, the closer the port resonance post is to the pin, the wider the port coupling bandwidth. On the contrary, the farther the distance, the narrower the port coupling bandwidth.

[0028] For the second solution, the second sleeve and the port resonator column are electrically connected through a second tap wire. In this case, the connection positions of the second tap wire with the port resonator column and / or the second sleeve are related to the coupling bandwidth; the diameter of the second tap wire is related to the coupling bandwidth; the distance between the port resonator column and the pin is related to the coupling bandwidth. The port coupling bandwidth can be adjusted in the following ways:

[0029] 1. Increase the height (relative to the bottom of the filter cavity) of the electrical connection (welding) between the second tap wire and the port resonator column and / or the second sleeve, and the port coupling bandwidth becomes wider; conversely, it becomes narrower.

[0030] 2. Increase the diameter of the second tap wire, and the port coupling bandwidth becomes wider; conversely, it becomes narrower.

[0031] 3. When the height of the second tap wire remains unchanged, the closer the port resonator column is to the pin, the wider the port coupling bandwidth; on the contrary, the farther the distance, the narrower the port coupling bandwidth.

[0032] Among them, the first tap wire and / or the second tap wire are generally wires with a silver or gold plating on the surface, or can be silver, gold and other metal wires. Their shapes are not limited to the wire form, and can also be in the form of flakes.

[0033] The pin is positioned in the waveguide filter through a support medium. To prevent the pin from sliding up and down, there is an interference fit between the support medium and the pin.

[0034] According to the diameter of the pin, the diameter of the support medium can be adjusted so that the transmission impedance is 50Ω. To facilitate the adjustment of the diameter of the support medium, the support medium is detachably connected to the bottom plate, which is convenient for removing the support medium to change its diameter by replacement, grinding, etc., so as to achieve the purpose of adjusting the transmission impedance. The bottom plate is provided with a limiting structure that cooperates with the support medium, and the limiting structure is used to limit the support medium. Specifically, the axial section of the support medium is a "convex" character structure, and it is installed through the installation hole provided on the bottom plate. The installation hole is provided with a stepped limiting groove, which can prevent the support medium from slipping into the filter cavity.

[0035] During the assembly process of the pin, it not only needs to be accurately positioned and fixed, but also electrically connected to the circuit board. To facilitate the completion of the assembly work and improve the assembly efficiency, small holes are provided on the circuit board, and the pin passes through the small holes and is electrically connected to the circuit board. The diameter of the small hole is slightly larger than the diameter of the pin, so that the pin can pass through the middle. Solder pads are provided on the circuit board, and the pin and the circuit board are welded together through the solder pads. In this way, signals can be coupled from the waveguide filter to the high-frequency head body on the back.

[0036] The waveguide filter in the present invention is implemented by means of a metal coaxial cavity. Signals are transmitted in a sealed cavity, and the surface of the cavity can be silver-plated. Therefore, the transmission loss is smaller, and the power capacity that can be tolerated is larger. Combining cross-coupling technology, it is easier to achieve higher out-of-band rejection. The second housing is provided with a waveguide input port communicating with the filtering cavity, and the first housing is provided with an F-type output port electrically connected to the circuit board. The satellite signal is input through the waveguide input port, and the waveguide-to-coaxial conversion is completed at the port, and then filtered through the metal coaxial cavity. The signal is then connected to the circuit board in the LNB body by means of capacitive coupling of the resonant posts at the end port of the cavity filter, and finally output from the F-type output port electrically connected to the circuit board. The designed passband of the waveguide filter is 3.7 - 4.2 GHz, the insertion loss within the passband is ≤0.5 dB, the suppression degree for the 3.4 - 3.6 GHz frequency band is ≥65 dB, and the suppression degree for the 4.8 - 4.9 GHz frequency band is ≥80 dB. It can well suppress the received 5G interference signals at the input end and prevent them from entering the subsequent receiver processing module.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] 1. The waveguide filter suppresses 5G signals in the 3.4 - 3.6 GHz frequency band by more than 65 dB, and can well eliminate the interference problem of 5G base stations to satellite earth stations. At the same time, the small insertion loss of the waveguide filter ensures the strength of the received signal.

[0039] 2. The integrated design of the waveguide filter and the LNB significantly shortens the overall length of the waveguide filter and the LNB, and improves the integration of the earth station. This design method is not limited to the integrated LNB design in the C band, and can be extended to the LNB design in other bands such as the Ku band.

[0040] 3. Reduce the devices on the parabolic antenna mounting bracket, reduce the supporting weight of the mounting bracket, and is conducive to improving the system reliability. Reducing the number of devices is beneficial to reducing the wind resistance coefficient and improving the system stability and safety.

[0041] 4. Compared with the conventional scheme of separating the filter and the LNB, the engineering installation steps are simplified, and problems such as flange misalignment and contact gap in cascade installation can be avoided, and the system performance indicators are improved. Description of the Drawings

[0042] Figure 1 is a schematic structural diagram of the prior art scheme of separating the waveguide filter and the LNB.

[0043] Figure 2 is a schematic structural diagram of the LNB with a filter.

[0044] Figure 3 is an exploded view of the LNB with a filter.

[0045] Figure 4 It is a partial cross-sectional view of the RF tuner with a filter in Embodiment 1.

[0046] Figure 5 It is Figure 4 the sectional view taken along line A-A in

[0047] Figure 6 It is Figure 5 the enlarged view of part B in

[0048] Figure 7 It is a partial cross-sectional view of the RF tuner with a filter in Embodiment 2.

[0049] Figure 8 It is Figure 7 the sectional view taken along line C-C in

[0050] Figure 9 It is Figure 8 the enlarged view of part D in

[0051] Figure 10 It is a partial cross-sectional view of the RF tuner with a filter in Embodiment 3.

[0052] Figure 11 It is Figure 10 the sectional view taken along line E-E in

[0053] Figure 12 It is Figure 11 the enlarged view of part F in

[0054] Figure 13 It is a schematic diagram of the circuit board in Embodiment 3.

[0055] Explanation of reference numerals: RF tuner body 100, circuit board 110, pad 111, shielding cover 120, F-shaped output port 130, waveguide filter 200, port resonance column 210, pin 220, supporting medium 221, first tap wire 231, second tap wire 232, first sleeve 241, second sleeve 242, filtering cavity 250, waveguide input port 260, waterproof groove 261, first insulating medium 271, second insulating medium 272, first housing 301, second housing 302, first waterproof cover plate 310, second waterproof cover plate 320, bottom plate 330, mounting hole 331. Detailed implementation manners

[0056] The drawings of the present invention are only for illustrative purposes and should not be construed as a limitation of the present invention. For better illustration of the following embodiments, some components in the drawings are omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0057] Embodiment 1

[0058] This embodiment provides a tuner with a filter, which is used to solve the technical problems of 5G interfering with the reception of satellite earth stations and the difficult or even impossible installation of waveguide filters. As Figures 2 - 3 shown, the tuner with a filter adopts an overall double-sided layout, including a tuner body 100 and a waveguide filter 200 arranged back to back. The tuner body 100 has a first housing 301, and the waveguide filter 200 has a second housing 302. The first housing 301 and the second housing 302 are integrally formed, and there is a shared bottom plate 330 between them. This bottom plate 330 forms the interface of the double-sided layout. One side of the interface is the tuner body 100, and the other side is the waveguide filter 200.

[0059] Among them, back to back means that the back surface of the tuner body 100 is attached to the back surface of the waveguide filter 200, and they are back to back with each other; for example Figure 2 shown, the back surface of the tuner body 100 refers to Figure 2 the surface of the tuner body 100 facing downwards in Figure 2 , and the back surface of the waveguide filter 200 refers to Figure 2 the surface of the waveguide filter 200 facing upwards in

[0060] As Figure 3 shown, the tuner body 100 mainly includes a circuit board 110 positioned and connected to the bottom plate 330 and a shielding cover 120 covering the circuit board 110. The circuit board 110 and the shielding cover 120 are both arranged in the first housing 301, and an F-type output port electrically connecting the circuit board 110 is provided on one side of the first housing 301.

[0061] As Figures 4 - 5 shown, the waveguide filter 200 is implemented in a metal coaxial cavity manner, with a designed passband of 3.7 - 4.2 GHz, an insertion loss ≤ 0.5 dB within the passband, a suppression degree of ≥ 65 dB for the 3.4 - 3.6 GHz frequency band, and a suppression degree of ≥ 80 dB for the 4.8 - 4.9 GHz frequency band. It can well suppress the received 5G interference signal at the input end and prevent it from entering the subsequent receiver processing module.

[0062] As Figure 6As shown in the figure, a filtering cavity 250 of the waveguide filter 200 is formed inside the second housing 302, and a waveguide input port 260 communicating with the filtering cavity 250 is provided on one side of the second housing 302. The waveguide filter 200 is provided with a port resonance post 210 located in the filtering cavity 250. The port resonance post 210 is connected to the circuit board 110 through a pin 220 passing through the bottom plate 330, and there is a capacitive coupling between the pin 220 and the port resonance post 210. Among them, the port resonance post 210 can be processed from a metal material, which is generally copper or steel, and the surface is treated with silver plating, gold plating, zinc plating, tin plating, nickel plating, chromium plating, etc. It can also be processed from graphite, carbon fiber, carbon black, activated carbon, diamond, graphene, carbon nanotubes and their derived inorganic non-metallic materials or polymer materials, and the surface is plated with silver, copper, gold, zinc, tin, nickel, chromium and their alloys, such as the resonance posts disclosed in Chinese patents with publication numbers CN106654499A and CN205603496U. The pin 220 is generally a wire with silver plating, gold plating, etc. on the surface, and can also be a metal wire such as silver or gold.

[0063] There is a capacitive coupling between the waveguide filter 200 and the high-frequency head body 100. In this way, it can prevent the pin 220 from being grounded due to the passage of direct current at the connection between the circuit board 110 and the pin 220 in the high-frequency head body 100. Specifically, a first sleeve 241 is sleeved outside the port resonance post 210, and a first insulating medium 271 is provided between the first sleeve 241 and the port resonance post 210, and the first sleeve 241 is electrically connected to the pin 220. Specifically, the pin 220 can be electrically connected to the first sleeve 241 sleeved outside the port resonance post 210 by bending. Among them, the first sleeve 241 can be made of metal materials such as silver plating, copper plating, gold plating, zinc plating, tin plating, nickel plating, chromium plating on the surface. The first insulating medium 271 can be formed by gases such as air, or can be made of solid materials. In order to accurately position the first sleeve 241, it is preferably made of a solid material for the first insulating medium 271. More importantly, the solid first insulating medium 271 plays a role in preventing direct current grounding short circuit, and the solid material can adopt polytetrafluoroethylene material or other insulating materials.

[0064] The positional relationship and connection relationship between the port resonance post 210 and the pin 220 are closely related to the port coupling bandwidth. At this time, the connection position between the pin 220 and the first sleeve 241 is related to the coupling bandwidth; the diameter of the pin 220 is related to the coupling bandwidth; the distance between the port resonance post 210 and the pin 220 is related to the coupling bandwidth. The port coupling bandwidth can be adjusted according to the passband bandwidth of different models of waveguide filters 200 (the passband of the waveguide filter 200 described in this embodiment is 3700 MHz to 4200 MHz, with a total bandwidth of 500 MHz). The specific changes are:

[0065] 1. Increasing the height of the bending point of the pin 220 and / or the height of the electrical connection (welding) between the pin 220 and the port resonance post 210 (relative to the bottom of the filter cavity 250) will widen the port coupling bandwidth, and vice versa;

[0066] 2. Increasing the diameter of the pin 220 will widen the port coupling bandwidth, and vice versa;

[0067] 3. When the height of the bending point of the pin 220 and the height of the electrical connection between the pin 220 and the port resonance post 210 remain unchanged, the closer the port resonance post 210 is to the pin 220, the wider the port coupling bandwidth. On the contrary, the farther the distance, the narrower the port coupling bandwidth.

[0068] The pin 220 is positioned in the waveguide filter 200 through a support medium 221. To prevent the pin 220 from sliding up and down, an interference fit is provided between the support medium 221 and the pin 220.

[0069] According to the size of the diameter of the pin 220, the diameter of the support medium 221 can be adjusted so that the transmission impedance is 50Ω. To facilitate the adjustment of the diameter of the support medium 221, the support medium 221 is detachably connected to the bottom plate 330, which is convenient for removing the support medium 221 to change its diameter by replacement, grinding, etc., so as to achieve the purpose of adjusting the transmission impedance. The bottom plate 330 is provided with a limiting structure that cooperates with the support medium 221, and the limiting structure is used to limit the support medium 221. Specifically, the axial section of the support medium 221 is a "convex" character structure, and it is installed through the mounting hole 331 provided on the bottom plate 330. The mounting hole 331 is provided with a limiting groove in a stepped structure, which can prevent the support medium 221 from slipping into the filter cavity 250.

[0070] During the assembly process of the pin 220, it not only needs to be accurately positioned and fixed, but also electrically connected to the circuit board 110. To facilitate the completion of the assembly operation and improve the assembly efficiency, small holes are provided on the circuit board 110, and the pin 220 passes through the small holes to be electrically connected to the circuit board 110. The diameter of the small holes is slightly larger than the diameter of the pin 220, so that the pin 220 can pass through the middle. Solder pads 111 are provided on the circuit board 110, and the pin 220 and the circuit board 110 are welded together through the solder pads 111. In this way, signals can be coupled from the waveguide filter 200 to the high-frequency head body 100 on the back.

[0071] On one side of the interface, the first housing 301 is provided with a first opening leading to the high-frequency head body 100, and on the other side of the interface, the second housing 302 is provided with a second opening leading to the waveguide filter 200. The first opening is sealed by a first waterproof cover plate 310 and waterproofed with a rubber ring. The second opening is sealed by a second waterproof cover plate 320 and waterproofed with a rubber ring. The F-type output port can be waterproofed by dispensing glue. The waveguide input port 260 can adopt a waveguide standard flange with a waterproof groove 261 (a waterproof rubber ring is placed in the waterproof groove 261). The overall waterproof level of the high-frequency head with a filter meets IP66 and can meet the use requirements in outdoor environments.

[0072] In this embodiment, the satellite signal is input from the waveguide input port 260, the waveguide-to-coaxial conversion is completed at the port, and then filtered through the metal coaxial cavity. The signal is then connected to the circuit board 110 in the high-frequency head body 100 through the port resonator 210 of the waveguide filter 200, and finally output from the F-type output port electrically connected to the circuit board.

[0073] The integrated design solution of the waveguide filter 200 and the high-frequency head provided in this embodiment. The waveguide filter 200 is implemented in a metal coaxial cavity manner and through cross-coupling technology, the signal received by the waveguide filter 200 is capacitively coupled to the pin 220 electrically connected to the high-frequency head circuit board 110 through the port resonator 210 in the filter cavity 250, thereby realizing the transmission of the signal from the waveguide filter 200 to the high-frequency head body 100. When the passband insertion loss is required to be ≤0.5 dB, it is easy to achieve a relatively high out-of-band rejection, and it can well suppress the received 5G interference signal at the input end, avoiding entering the subsequent receiver processing module, eliminating 5G interference and being beneficial to ensuring the strength of the received signal. The second housing 302 of the waveguide filter 200 and the first housing 301 of the high-frequency head body 100 are integrally formed. The filter cavity of the waveguide filter is formed by the internal space surrounded by the second housing. Compared with the conventional solution of separating the filter and the high-frequency head, it simplifies the engineering installation steps, can avoid problems such as flange misalignment and contact gaps in cascade installation, and improves the system performance index. The waveguide filter 200 and the high-frequency head body 100 are arranged back to back, which is beneficial to reducing the installation space of the waveguide filter 200. For satellite earth stations using the back-feed method, it can avoid the situation where it is impossible to use the waveguide filter 200 to suppress 5G interference due to space limitations.

[0074] Embodiment 2

[0075] This embodiment provides a high-frequency head with a filter to solve the technical problems of 5G interference with satellite earth station reception and difficult or even impossible installation of waveguide filters. As Figures 2 - 3As shown in the figure, the overall layout of the RF head with a filter is a double-sided layout, including an RF head body 100 and a waveguide filter 200 arranged back-to-back. The RF head body 100 has a first housing 301, and the waveguide filter 200 has a second housing 302. The first housing 301 and the second housing 302 are integrally formed, and there is a shared bottom plate 330 between them. This bottom plate 330 forms the interface for the double-sided layout. One side of the interface is the RF head body 100, and the other side is the waveguide filter 200.

[0076] Among them, "back-to-back" means that the back surface of the RF head body 100 is attached to the back surface of the waveguide filter 200, and they are back-to-back with each other; for example Figure 2 As shown in the figure, the back surface of the RF head body 100 refers to Figure 2 the surface of the RF head body 100 facing downward in the figure, and the back surface of the waveguide filter 200 refers to Figure 2 the surface of the waveguide filter 200 facing upward in the figure. It can be understood that Figure 2 the directions in the figure are only for example and do not limit the scope of this embodiment.

[0077] As Figure 3 shown in the figure, the RF head body 100 mainly includes a circuit board 110 positioned and connected to the bottom plate 330 and a shielding cover 120 covering the circuit board 110. The circuit board 110 and the shielding cover 120 are both arranged in the first housing 301. An F-type output port for electrically connecting the circuit board 110 is provided on one side of the first housing 301.

[0078] As Figures 7 - 8 shown in the figure, the waveguide filter 200 is implemented in a metal coaxial cavity manner. The designed passband is 3.7 - 4.2 GHz, the insertion loss within the passband is ≤ 0.5 dB, the suppression ratio for the 3.4 - 3.6 GHz frequency band is ≥ 65 dB, and the suppression ratio for the 4.8 - 4.9 GHz frequency band is ≥ 80 dB. It can well suppress the received 5G interference signals at the input end and prevent them from entering the subsequent receiver processing module.

[0079] As Figure 9As shown, a filtering cavity 250 of the waveguide filter 200 is formed inside the second housing 302, and a waveguide input port 260 communicating with the filtering cavity 250 is provided on one side of the second housing 302. The waveguide filter 200 is provided with a port resonance post 210 located in the filtering cavity 250. The port resonance post 210 is connected to the circuit board 110 through a pin 220 passing through the bottom plate 330, and there is a capacitive coupling between the pin 220 and the port resonance post 210. Among them, the port resonance post 210 can be processed from a metal material, which is generally copper or steel, and the surface is treated with silver plating, gold plating, zinc plating, tin plating, nickel plating, chromium plating, etc. It can also be processed from inorganic non-metallic materials or polymer materials such as graphite, carbon fiber, carbon black, activated carbon, diamond, graphene, carbon nanotubes and their derivatives, and the surface is plated with silver, copper, gold, zinc, tin, nickel, chromium, etc. and their alloys, such as the resonance posts disclosed in Chinese patents with publication numbers CN106654499A and CN205603496U. The pin 220 is generally a wire with silver plating, gold plating, etc. on the surface, and can also be a metal wire such as silver or gold.

[0080] There is a capacitive coupling between the waveguide filter 200 and the high-frequency head body 100. In this way, it can prevent the pin 220 from being grounded due to the passage of direct current at the connection between the circuit board 110 and the pin 220 in the high-frequency head body 100. Specifically, a first sleeve 241 is sleeved outside the port resonance post 210, and a first insulating medium 271 is provided between the first sleeve 241 and the port resonance post 210. The first sleeve 241 is electrically connected to the pin 220. Among them, the first sleeve 241 is made of metal materials such as silver plating, copper plating, gold plating, zinc plating, tin plating, nickel plating, chromium plating on the surface. The first insulating medium 271 can be formed by gases such as air, or can be made of solid materials. To accurately position the first sleeve 241, it is preferably made of a solid material for the first insulating medium 271. More importantly, the solid first insulating medium 271 plays a role in preventing direct current grounding short circuit, and the solid material can adopt polytetrafluoroethylene material or other insulating materials.

[0081] The positional relationship and connection relationship between the port resonance post 210 and the pin 220 are closely related to the port coupling bandwidth. The port coupling bandwidth can be adjusted according to the passband bandwidth of different models of the waveguide filter 200 (the passband of the waveguide filter 200 described in this embodiment is 3700 MHz to 4200 MHz, with a total bandwidth of 500 MHz). To facilitate the adjustment of the port coupling bandwidth, the first sleeve 241 and the pin 220 are electrically connected through a first tap wire 231. Specifically, one end of the first tap wire 231 is welded to the pin 220, and the other end is welded to the first sleeve 241 or connected by screws. Among them, the first tap wire 231 is generally a wire with silver plating, gold plating, etc. on the surface, and can also be a metal wire such as silver or gold. Its shape is not limited to the wire form, and can also be in the form of a sheet.

[0082] At this time, the connection position of the first tap line 231 with the pin 220 and / or the first sleeve 241 is related to the coupling bandwidth; the diameter of the first tap line 231 is related to the coupling bandwidth; the distance between the port resonance post 210 and the pin 220 is related to the coupling bandwidth. Adjusting the soldering position of the second tap line can adjust the coupling bandwidth. The specific changes are as follows:

[0083] 1. Increasing the height (the height relative to the bottom of the filter cavity 250) of the electrical connection (soldering) between the first tap line 231 and the pin 220 and / or the first sleeve 241 will widen the port coupling bandwidth, and vice versa; increasing the length of the first sleeve 241 cannot effectively increase the port coupling bandwidth;

[0084] 2. Increasing the diameter of the first tap line 231 will widen the port coupling bandwidth, and vice versa;

[0085] 3. When the height of the first tap line 231 remains unchanged, the closer the port resonance post 210 is to the pin 220, the wider the port coupling bandwidth. On the contrary, the farther the distance, the narrower the port coupling bandwidth.

[0086] The pin 220 is positioned in the waveguide filter 200 through a support medium 221. To prevent the pin 220 from sliding up and down, an interference fit is provided between the support medium 221 and the pin 220.

[0087] According to the size of the diameter of the pin 220, the diameter of the support medium 221 can be adjusted so that the transmission impedance is 50Ω. To facilitate the adjustment of the diameter of the support medium 221, the support medium 221 is detachably connected to the bottom plate 330, which is convenient for removing the support medium 221 to change its diameter by replacement, grinding, etc., so as to achieve the purpose of adjusting the transmission impedance. The bottom plate 330 is provided with a limiting structure that cooperates with the support medium 221, and the limiting structure is used to limit the support medium 221. Specifically, the axial cross-section of the support medium 221 is a "convex" character structure, and it is installed through an installation hole 331 provided on the bottom plate 330. The installation hole 331 is provided with a stepped limiting groove, which can prevent the support medium 221 from slipping into the filter cavity 250.

[0088] During the assembly process of the pin 220, it not only needs to be accurately positioned and fixed, but also needs to be electrically connected to the circuit board 110. To facilitate the completion of the assembly operation and improve the assembly efficiency, small holes are provided on the circuit board 110, and the pin 220 passes through the small holes to be electrically connected to the circuit board 110. The diameter of the small holes is slightly larger than the diameter of the pin 220, so that the pin 220 can pass through the middle. A solder pad 111 is provided on the circuit board 110, and the pin 220 and the circuit board 110 are soldered together through the solder pad 111. In this way, signals can be coupled from the waveguide filter 200 to the high-frequency head body 100 on the back.

[0089] On one side of the interface, the first housing 301 is provided with a first opening leading to the headend body 100. On the other side of the interface, the second housing 302 is provided with a second opening leading to the waveguide filter 200. The first opening is sealed by a first waterproof cover plate 310 and waterproofed with a rubber seal. The second opening is sealed by a second waterproof cover plate 320 and waterproofed with a rubber seal. The F-type output port can be waterproofed by dispensing glue. The waveguide input port 260 can adopt a waveguide standard flange with a waterproof groove 261 (a waterproof rubber seal is placed in the waterproof groove 261). The overall waterproof grade of the headend with a filter meets IP66, which can meet the use requirements in outdoor environments.

[0090] In this embodiment, the satellite signal is input from the waveguide input port 260, and the waveguide-to-coaxial conversion is completed at the port. Then, it is filtered through the metal coaxial cavity. The signal is then connected to the circuit board 110 in the headend body 100 through the port resonator 210 of the waveguide filter 200, and finally output from the F-type output port electrically connected to the circuit board.

[0091] The integrated design solution of the waveguide filter 200 and the headend provided in this embodiment. The waveguide filter 200 is implemented in a metal coaxial cavity manner and through cross-coupling technology. The signal received by the waveguide filter 200 is capacitively coupled to the pin 220 electrically connected to the headend circuit board 110 through the port resonator 210 in the filter cavity 250, thereby realizing the transmission of the signal from the waveguide filter 200 to the headend body 100. When the passband insertion loss is required to be ≤0.5 dB, it is easy to achieve a relatively high out-of-band rejection, and it can well suppress the received 5G interference signal at the input end, avoiding entering the subsequent receiver processing module, which not only eliminates the 5G interference but also helps to ensure the strength of the received signal. The second housing 302 of the waveguide filter 200 and the first housing 301 of the headend body 100 are integrally formed. The filter cavity of the waveguide filter is formed by the internal space surrounded by the second housing. Compared with the conventional solution where the filter and the headend are separated, it simplifies the engineering installation steps, can avoid problems such as flange misalignment and contact gaps in cascade installation, and improves the system performance indicators. The waveguide filter 200 and the headend body 100 are arranged back-to-back, which is beneficial to reducing the installation space of the waveguide filter 200. For satellite earth stations using the backfeed method, it can avoid the situation where it is even impossible to use the waveguide filter 200 to suppress 5G interference due to space limitations.

[0092] Embodiment 3

[0093] This embodiment provides a headend with a filter, which is used to solve the technical problems of 5G interference with the reception of satellite earth stations and the difficult or even impossible installation of waveguide filters. As Figures 2 - 3As shown, the overall layout of the tuner with a filter is a double-sided layout, including a tuner body 100 and a waveguide filter 200 arranged back-to-back. The tuner body 100 has a first housing 301, and the waveguide filter 200 has a second housing 302. The first housing 301 and the second housing 302 are integrally formed, and there is a shared bottom plate 330 between them. The bottom plate 330 forms the interface for the double-sided layout. On one side of the interface is the tuner body 100, and on the other side is the waveguide filter 200.

[0094] Among them, "back-to-back" means that the back surface of the tuner body 100 is in contact with the back surface of the waveguide filter 200, and they are back-to-back with each other; for example Figure 2 As shown, the back surface of the tuner body 100 refers to Figure 2 the surface of the tuner body 100 facing downwards in [reference], and the back surface of the waveguide filter 200 refers to Figure 2 the surface of the waveguide filter 200 facing upwards in [reference]. It can be understood that Figure 2 the directions in [reference] are only for example and do not limit the scope of this embodiment.

[0095] As Figure 3 shown, the tuner body 100 mainly includes a circuit board 110 (such as Figure 13 ) positioned and connected to the bottom plate 330 and a shielding cover 120 covering the circuit board 110. The circuit board 110 and the shielding cover 120 are both arranged in the first housing 301. An F-type output port for electrically connecting the circuit board 110 is provided on one side of the first housing 301.

[0096] As Figures 10 - 11 shown, the waveguide filter 200 is implemented in a metal coaxial cavity manner, with a designed passband of 3.7 - 4.2 GHz, an insertion loss ≤ 0.5 dB within the passband, a suppression degree ≥ 65 dB for the 3.4 - 3.6 GHz frequency band, and a suppression degree ≥ 80 dB for the 4.8 - 4.9 GHz frequency band. It can well suppress the received 5G interference signals at the input end and prevent them from entering the subsequent receiver processing module.

[0097] As Figure 12As shown, a filtering cavity 250 of the waveguide filter 200 is formed inside the second housing 302, and a waveguide input port 260 communicating with the filtering cavity 250 is provided on one side of the second housing 302. The waveguide filter 200 is provided with a port resonance post 210 located in the filtering cavity 250. The port resonance post 210 is connected to the circuit board 110 through a pin 220 passing through the bottom plate 330, and a capacitive coupling is formed between the pin 220 and the port resonance post 210. Among them, the port resonance post 210 can be processed from a metal material, which is generally copper or steel, and the surface is treated with silver plating, gold plating, zinc plating, tin plating, nickel plating, chromium plating, etc. It can also be processed from graphite, carbon fiber, carbon black, activated carbon, diamond, graphene, carbon nanotubes and their derived inorganic non-metallic materials or polymer materials, and the surface is plated with silver, copper, gold, zinc, tin, nickel, chromium, etc. and their alloys, such as the resonance posts disclosed in Chinese patents with publication numbers CN106654499A and CN205603496U. The pin 220 is generally a wire with a silver-plated or gold-plated surface, and can also be a metal wire such as silver or gold.

[0098] A capacitive coupling is formed between the waveguide filter 200 and the high-frequency head body 100. In this way, it is possible to prevent the pin 220 from being grounded due to the passage of a direct current at the connection between the circuit board 110 and the pin 220 in the high-frequency head body 100. Specifically, a second sleeve 242 is sleeved outside the pin 220, and a second insulating medium 272 is provided between the second sleeve 242 and the port resonance post 210. The second sleeve 242 is electrically connected to the port resonance post 210. Among them, the second sleeve 242 is a metal material plated with silver, copper, gold, zinc, tin, nickel, chromium, etc. on the surface. The second insulating medium 272 can be formed by a gas such as air, or can be made of a solid material. In order to accurately position the second sleeve 242, it is preferably made of a solid material for the second insulating medium 272. More importantly, the solid second insulating medium 272 plays a role in preventing direct current grounding short circuit, and the solid material can adopt polytetrafluoroethylene material or other insulating materials.

[0099] The positional relationship and connection relationship between the port resonance post 210 and the pin 220 are closely related to the port coupling bandwidth. The port coupling bandwidth can be adjusted according to the passband bandwidth of different models of the waveguide filter 200 (the passband of the waveguide filter 200 described in this embodiment is 3700 MHz to 4200 MHz, with a total bandwidth of 500 MHz). To facilitate the adjustment of the port coupling bandwidth, the second sleeve 242 and the port resonance post 210 are electrically connected through a second tap wire 232. Specifically, one end of the second tap wire 232 is welded or connected by a screw to the port resonance post 210, and the other end is welded or connected by a screw to the second sleeve 242. Among them, the second tap wire 232 is generally a wire with a silver-plated or gold-plated surface, and can also be a metal wire such as silver or gold. Its shape is not limited to the wire form, and can also be in the form of a sheet.

[0100] At this time, the connection position of the second tap line 232 with the port resonance column 210 and / or the second sleeve 242 is related to the coupling bandwidth; the diameter of the second tap line 232 is related to the coupling bandwidth; the distance between the port resonance column 210 and the pin 220 is related to the coupling bandwidth. Adjusting the welding position of the second tap line 232 can adjust the coupling bandwidth, and the specific changes are as follows:

[0101] 1. Increasing the height of the second tap line 232 welded to the port resonance column 210 and / or the second sleeve 242 (the height relative to the bottom of the filter cavity 250) will widen the port coupling bandwidth, and vice versa;

[0102] 2. Increasing the diameter of the second tap line 232 will widen the port coupling bandwidth, and vice versa;

[0103] 3. When the height of the second tap line 232 remains unchanged, the closer the port resonance column 210 is to the pin 220, the wider the port coupling bandwidth. On the contrary, the farther the distance, the narrower the port coupling bandwidth.

[0104] The pin 220 is positioned in the waveguide filter 200 through a support medium 221. To prevent the pin 220 from sliding up and down, an interference fit is provided between the support medium 221 and the pin 220.

[0105] According to the size of the diameter of the pin 220, the diameter of the support medium 221 can be adjusted so that the transmission impedance is 50 Ω. To facilitate the adjustment of the diameter of the support medium 221, the support medium 221 is detachably connected to the bottom plate 330, which is convenient for removing the support medium 221 to change its diameter by replacement, grinding, etc., so as to achieve the purpose of adjusting the transmission impedance. The bottom plate 330 is provided with a limiting structure that cooperates with the support medium 221, and the limiting structure is used to limit the support medium 221. Specifically, the axial cross-section of the support medium 221 is a "convex" character structure, and it is installed through a mounting hole 331 provided on the bottom plate 330. The mounting hole 331 is provided with a stepped limiting groove, which can prevent the support medium 221 from sliding into the filter cavity 250.

[0106] During the assembly process of the pin 220, it not only needs to be accurately positioned and fixed, but also needs to be electrically connected to the circuit board 110. To facilitate the completion of the assembly operation and improve the assembly efficiency, small holes are provided on the circuit board 110, and the pin 220 passes through the small holes to be electrically connected to the circuit board 110. The diameter of the small holes is slightly larger than the diameter of the pin 220, so that the pin 220 can pass through the middle. A solder pad 111 is provided on the circuit board 110, and the pin 220 and the circuit board 110 are welded together through the solder pad 111. In this way, signals can be coupled from the waveguide filter 200 to the high-frequency head body 100 on the back.

[0107] On one side of the interface, the first housing 301 is provided with a first opening leading to the high-frequency head body 100. On the other side of the interface, the second housing 302 is provided with a second opening leading to the waveguide filter 200. The first opening is sealed by a first waterproof cover plate 310 and waterproofed with a rubber seal. The second opening is sealed by a second waterproof cover plate 320 and waterproofed with a rubber seal. The F-type output port can be waterproofed by dispensing glue. The waveguide input port 260 can adopt a waveguide standard flange with a waterproof groove 261 (a waterproof rubber seal is placed in the waterproof groove 261). The overall waterproof level of the high-frequency head with the filter meets IP66, which can meet the use requirements in outdoor environments.

[0108] In this embodiment, the satellite signal is input from the waveguide input port 260, and the waveguide-to-coaxial conversion is completed at the port. Then, it is filtered through the metal coaxial cavity. The signal is then connected to the circuit board 110 in the high-frequency head body 100 through the port resonator 210 of the waveguide filter 200, and finally output from the F-type output port electrically connected to the circuit board.

[0109] The integrated design solution of the waveguide filter 200 and the high-frequency head provided in this embodiment. The waveguide filter 200 is implemented in a metal coaxial cavity manner and through cross-coupling technology. The signal received by the waveguide filter 200 is capacitively coupled to the pin 220 electrically connected to the high-frequency head circuit board 110 through the port resonator 210 in the filter cavity 250, thereby realizing the transmission of the signal from the waveguide filter 200 to the high-frequency head body 100. When the passband insertion loss is required to be ≤0.5 dB, it is easy to achieve a relatively high out-of-band rejection, and it can well suppress the received 5G interference signal at the input end, avoiding entering the subsequent receiver processing module, eliminating 5G interference and being beneficial to ensuring the strength of the received signal. The second housing 302 of the waveguide filter 200 and the first housing 301 of the high-frequency head body 100 are integrally formed. The filter cavity of the waveguide filter is formed by the internal space surrounded by the second housing. Compared with the conventional solution where the filter and the high-frequency head are separated, it simplifies the engineering installation steps, can avoid problems such as flange misalignment and contact gaps in cascade installation, and improves the system performance indicators. The waveguide filter 200 and the high-frequency head body 100 are arranged back-to-back, which is beneficial to reducing the installation space of the waveguide filter 200. For satellite earth stations using the back-feed method, it can avoid the situation where it is impossible to use the waveguide filter 200 to suppress 5G interference due to space limitations.

[0110] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solutions of the present invention, rather than limitations on the specific implementation manners of the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the claims of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A tuner with a filter, characterized in that, it includes a tuner body having a first housing; and a waveguide filter disposed back-to-back with the tuner body, the waveguide filter having a second housing, and a filtering cavity of the waveguide filter being formed inside the second housing; the first housing and the second housing are integrally formed, the first housing and the second housing have a common bottom plate, a circuit board is provided in the first housing, a port resonator post located in the filtering cavity is provided in the waveguide filter, the port resonator post is connected to the circuit board by a pin passing through the bottom plate, and capacitive coupling is provided between the pin and the port resonator post.

2. The tuner with a filter according to claim 1, characterized in that, a first sleeve is sleeved outside the port resonator post, and a first insulating medium is provided between the first sleeve and the port resonator post, and the first sleeve is electrically connected to the pin; alternatively, a second sleeve is sleeved outside the pin, and a second insulating medium is provided between the second sleeve and the port resonator post, and the second sleeve is electrically connected to the port resonator post.

3. The tuner with a filter according to claim 2, characterized in that, the first sleeve and the pin are electrically connected by a first tap wire.

4. The tuner with a filter according to claim 3, characterized in that, the connection position of the first tap wire with the pin and / or the first sleeve is related to the coupling bandwidth; the diameter of the first tap wire is related to the coupling bandwidth.

5. The tuner with a filter according to claim 2, characterized in that, the second sleeve and the port resonator post are electrically connected by a second tap wire.

6. The tuner with a filter according to claim 5, characterized in that, the connection position of the second tap wire with the port resonator post and / or the second sleeve is related to the coupling bandwidth; the diameter of the second tap wire is related to the coupling bandwidth.

7. The tuner with a filter according to claim 1, characterized in that, the distance between the port resonator post and the pin is related to the coupling bandwidth.

8. The tuner with a filter according to claim 1, characterized in that, the pin is positioned on the bottom plate through a support medium.

9. The tuner with a filter according to claim 8, characterized in that, an interference fit is provided between the support medium and the pin.

10. The tuner with a filter according to claim 8, characterized in that, the support medium is detachably connected to the bottom plate.

11. The tuner with a filter according to claim 8, characterized in that, the bottom plate is provided with a limiting structure cooperating with the support medium.

12. The tuner with a filter according to any one of claims 1 to 11, characterized in that, the insertion loss within the passband of the waveguide filter is ≤0.5 dB, the suppression degree for the 3.4 - 3.6 GHz frequency band is ≥65 dB, and the suppression degree for the 4.8 - 4.9 GHz frequency band is ≥80 dB.

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