Microstrip transition millimeter wave tunable resonant equalizer
By introducing a microstrip transition structure and absorbing material into the waveguide equalizer, the problems of assembly error, complex debugging and reflection loss of traditional waveguide equalizers are solved, achieving higher equalization accuracy and a simplified debugging process, which is suitable for 5G communication and satellite navigation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEISHITONG ELECTRONIC TECH (SHANGHAI) CO LTD
- Filing Date
- 2025-05-14
- Publication Date
- 2026-06-02
AI Technical Summary
Traditional waveguide equalizers suffer from problems such as sensitivity to assembly errors, complex debugging, high reflection loss, and low equalization accuracy, making it difficult to achieve effective equalization of complex gain curves within a limited equalization bandwidth.
A microstrip transition millimeter-wave tunable resonant equalizer was designed. By setting a coupling hole between the transmission waveguide and the main resonant cavity, connecting the auxiliary resonant cavity, and using a microstrip probe transition structure, with built-in absorbing material and tuning screws, the VSWR and frequency band adjustment are optimized.
It effectively solves problems such as sensitivity to assembly errors, complex debugging, and high reflection loss, achieving higher equalization accuracy and a simpler debugging process, and is suitable for millimeter-wave systems such as 5G communication and satellite navigation.
Smart Images
Figure CN224318684U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of electronic information technology, and in particular to a microstrip transition millimeter-wave tunable resonant equalizer. Background Technology
[0002] In the current microwave and millimeter-wave fields, most devices use solid-state power amplifier chips to increase the gain of the entire system. However, the gain of a chip varies within its corresponding frequency band, and different chips have different gain curves. The losses of cables and connectors during transmission also vary within the frequency band. All of these factors can lead to a deterioration in the gain flatness of the device, thus affecting the overall RF performance. To compensate for the losses during transmission and the differences in the gain of the chips themselves, an equalizer needs to be added to the device.
[0003] Equalizers can be categorized into active and passive equalizers based on whether they require external power. Active equalizers are more complex in design, and the presence of a gain unit can lead to instability in the equalization process. Passive equalizers can be classified into waveguide, coaxial, and microstrip equalizers based on their equalization method. Waveguide equalizers are widely used due to their high power handling capacity and adjustability.
[0004] In existing technologies, refer to Figure 1 A typical waveguide equalizer consists of a resonant cavity, a coupling aperture, and a transmission waveguide. Thin-film resistors or absorbing materials are placed within the resonant cavity to absorb and dissipate the energy coupled in. Using traditional waveguide equalizers for power equalization inevitably introduces four main problems:
[0005] 1. Processing and assembly issues: Traditional waveguide equalizers typically place a thin-film resistor substrate or absorbing material in the center of the cavity. However, assembly errors can occur when assembling the thin-film resistor substrate or absorbing material, causing it to deviate from the original simulation preset position, resulting in degraded performance. Moreover, processing errors of the cavity itself can also alter the performance of the equalizer.
[0006] 2. Debugging Issues: Waveguide equalizers are prone to debugging problems. If a thin-film resistor substrate is used, it requires repeated replacement of substrates with different resistance values for debugging, and each reassembly of the substrate consumes considerable time and cost. If absorbing materials are used, the dimensional accuracy and shape of manually cut absorbing materials are difficult to achieve ideal results, requiring repeated opening and re-attaching of the absorbing material. Furthermore, the adhesive residue left on the cavity after removing the absorbing material can also affect performance, necessitating repeated wiping of the cavity with alcohol each time the absorbing material is replaced. These issues further complicate the debugging process.
[0007] 3. Reflection problem: Ordinary waveguide equalizers usually have a large return loss, which will affect the VSWR and other indicators of the entire link, resulting in a decrease in overall performance.
[0008] 4. Equalization accuracy issue: The equalization waveform formed by a typical waveguide equalizer in the frequency band is generally relatively flat, making it difficult to effectively equalize the gain curve with steep increases and decreases. That is, it is difficult to successfully equalize complex gain curves within the limited equalization bandwidth to ensure that the flatness meets the required specifications. Utility Model Content
[0009] To address the shortcomings of existing technologies, the purpose of this invention is to provide a microstrip transition millimeter-wave tunable resonant equalizer, which effectively solves the problems of traditional waveguide equalizers, such as sensitivity to assembly errors, complex debugging, high reflection loss, and low equalization accuracy. It has important application value in millimeter-wave systems such as 5G communication and satellite navigation.
[0010] The above-mentioned utility model objective is achieved through the following technical solution:
[0011] A microstrip transition millimeter-wave tunable resonant equalizer includes a transmission waveguide and a main resonant cavity. The sidewall of the transmission waveguide has several coupling holes, and the main resonant cavity is energy-coupled to the transmission waveguide through the coupling holes. The device also includes an auxiliary resonant cavity and a microstrip probe transition structure. The auxiliary resonant cavity is connected to the main resonant cavity through the microstrip probe transition structure. The auxiliary resonant cavity is provided with absorbing material and a tuning screw.
[0012] As a further technical solution of this utility model: an inverted triangular impedance adjustment area is provided at the top of the auxiliary resonant cavity, and the inverted triangular impedance adjustment area affects the absorption of the equalization unit by reducing the impedance of the resonant cavity.
[0013] As a further technical solution of this utility model: the microstrip probe transition structure is provided with a transition microstrip, which is used to transmit electromagnetic energy from the main resonant cavity to the auxiliary resonant cavity.
[0014] As a further technical solution of this utility model: the tuning screw is made of PTFE material, its thread accuracy grade is 6H, and the maximum adjustment stroke is 20%-30% of the cavity height.
[0015] As a further technical solution of this utility model: the absorbing material is a silicon carbide composite material with a thickness of 0.5-1.2 mm and a surface roughness Ra≤0.8 μm.
[0016] As a further technical solution of this utility model: the width of the coupling hole is adjustable in the range of 1 / 8λ-1 / 4λ, where λ is the center wavelength of the working frequency band.
[0017] As a further technical solution of this utility model: the volume ratio of the main resonant cavity to the auxiliary resonant cavity is 1:0.8-1.2, and the difference in the cavity Q value is controlled within ±15%.
[0018] As a further technical solution of this utility model: the inner surface of the transmission waveguide is plated with a silver-nickel alloy coating, and the surface roughness Ra≤0.05μm.
[0019] In summary, this utility model has at least one of the following beneficial technical effects:
[0020] 1. This utility model discloses a microstrip transition millimeter-wave tunable resonant equalizer, which includes a transmission waveguide, a main resonant cavity, and an auxiliary resonant cavity, connected by a microstrip probe transition structure. The main resonant cavity has a coupling aperture, and the auxiliary resonant cavity has an inverted triangular impedance adjustment area. The auxiliary resonant cavity contains absorbing material and is equipped with a tuning screw. Through the frequency selection function of the microstrip probe, the adjustment of the coupling aperture width, and the control of the tuning screw depth, the standing wave ratio (VSWR) optimization and precise frequency band adjustment are achieved. This utility model effectively solves the problems of traditional waveguide equalizers, such as sensitivity to assembly errors, complex debugging, high reflection loss, and low equalization accuracy, and has important application value in millimeter-wave systems such as 5G communication and satellite navigation.
[0021] 2. The equalization system composed of the equalization units with the above structure in this utility model not only effectively solves the common processing and assembly problems of waveguide equalizers, but also effectively optimizes the debugging process by adding tuning screws. Furthermore, the addition of a microstrip transition optimizes the VSWR. The combined effect of multiple parameters enables it to equalize relatively complex gain curves. This provides a new approach for microwave and millimeter-wave broadband equalizers.
[0022] 3. This invention adds a resonant cavity connected to the original single resonant cavity, using a microstrip probe as a transition at the connection point to reduce return loss, thereby lowering reflectivity, optimizing standing waves, and solving reflection problems. Using a microstrip probe as a transition allows for better control of the equalization frequency, reducing frequency shifts caused by machining errors in the cavity and coupling holes, thus solving machining and assembly problems. Adding a tuning screw to the equalization cavity allows for fine-tuning by controlling the screw's insertion length, reducing the number of times the cover needs to be opened during debugging and solving debugging problems. By controlling all parameters of the equalization process, the equalizer's amplitude and bandwidth can achieve the goal of equalizing complex curves, solving the equalization accuracy problem. Attached Figure Description
[0023] Figure 1This is a schematic diagram of the overall structure of a traditional waveguide equalizer in the background technology of this utility model.
[0024] Figure 2 This is a schematic diagram of the overall structure of this utility model.
[0025] Figure 3 This is the equivalent circuit diagram of this utility model.
[0026] Figure 4 This utility model presents a schematic diagram of a structure in which multiple equalizers are installed on a transmission waveguide.
[0027] Figure 5 The figure shows the simulation results of this utility model.
[0028] Figure reference numerals: 1. Transmission waveguide; 2. Main resonant cavity; 3. Coupler hole; 4. Auxiliary resonant cavity; 41. Absorbing material; 42. Tuning screw; 43. Inverted triangular impedance adjustment region; 5. Microstrip probe transition structure; 51. Transition microstrip. Detailed Implementation
[0029] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0030] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0032] Example 1:
[0033] Reference Figure 2 This invention discloses a microstrip transition millimeter-wave tunable resonant equalizer, comprising a transmission waveguide 1 and a main resonant cavity 2. The sidewall of the transmission waveguide 1 has several coupling holes 3 (see...). Figure 4 The main resonant cavity 2 is coupled to the transmission waveguide 1 through the coupling hole 3. It also includes an auxiliary resonant cavity 4 and a microstrip probe transition structure 5. The auxiliary resonant cavity 4 is connected to the main resonant cavity 2 through the microstrip probe transition structure 5. The auxiliary resonant cavity 4 is provided with a wave-absorbing material 41 and a tuning screw 42.
[0034] An inverted triangular impedance adjustment region 43 is provided at the top of the auxiliary resonant cavity 4. The inverted triangular impedance adjustment region 43 affects the absorption of the equalization unit by reducing the impedance of the resonant cavity. A transition microstrip 51 is provided in the microstrip probe transition structure 5. The transition microstrip 51 is used to transfer electromagnetic energy from the main resonant cavity 2 to the auxiliary resonant cavity 4.
[0035] This invention adds a resonant cavity connected to the original single resonant cavity, using a microstrip probe as a transition at the connection point to reduce return loss, thereby lowering reflectivity, optimizing standing waves, and solving reflection problems. Using a microstrip probe as a transition allows for better control of the equalization frequency, reducing frequency shifts caused by machining errors in the cavity and coupling hole 3, thus solving machining and assembly problems. A tuning screw 42 is added to the equalization cavity, allowing for fine-tuning by controlling the screw's insertion length, reducing the number of times the cover needs to be opened during debugging and solving debugging problems. By controlling all parameters of the equalization process, the equalizer's amplitude and bandwidth can achieve the goal of equalizing complex curves, solving the equalization accuracy problem.
[0036] Reference Figure 3 In typical waveguide equalizers using aperture coupling, when microwaves propagate through waveguide 1, some energy is coupled into the waveguide resonant cavity via the coupling aperture 3 during transmission. This energy is then absorbed by the substrate with a thin-film resistor or the absorbing material 41 placed inside the resonant cavity, thus achieving a gain reduction equalization effect. The entire equalization unit can be equivalent to an RLC circuit, where the coupling aperture 3 is approximately equal to the inductance Lm, the entire cavity is equivalent to the capacitance C, the energy-dissipating thin-film resistor or the absorbing material 41 is equivalent to the resistance Rr, and the transmission waveguide 1 is equivalent to Y0. Based on this, this invention adds a cavity section, which is connected to the original resonant cavity via a transition microstrip 51. The absorbing material 41 and tuning screw 42 are added to this cavity. The resulting equalization unit has a general shape as shown in the figure. Figure 2 As shown.
[0037] The tuning screw 42 is made of PTFE with a thread accuracy grade of 6H and a maximum adjustment stroke of 20%-30% of the cavity height. The absorbing material 41 is a silicon carbide composite material with a thickness of 0.5-1.2 mm and a surface roughness Ra≤0.8 μm.
[0038] The width of coupling aperture 3 is adjustable from 1 / 8λ to 1 / 4λ, where λ is the center wavelength of the operating frequency band. The volume ratio of the main resonant cavity 2 to the auxiliary resonant cavity 4 is 1:0.8-1.2, and the difference in cavity Q-value is controlled within ±15%. The inner surface of the transmission waveguide 1 is plated with a silver-nickel alloy coating, and the surface roughness Ra ≤ 0.05 μm.
[0039] Compared to typical waveguide equalization units, Figure 2 The equalization unit in this design connects the original resonant cavity to the newly added resonant cavity by adding a microstrip waveguide transition structure. Electromagnetic energy is then transferred from the original resonant cavity to the newly added resonant cavity via the transition microstrip 51. An absorbing material 41 is placed within the newly added resonant cavity to absorb the electromagnetic energy. This equalization unit, based on this structure, exhibits lower return loss and a better standing wave ratio compared to conventional waveguide equalization units.
[0040] Furthermore, compared to typical waveguide equalization units, the equalization frequency of this equalization unit is jointly determined by the transition microstrip 51, the resonant cavity, and the coupling aperture 3. The equalization frequency can be affected by changing the width of the coupling aperture 3, the shape and size of the transition microstrip 51, and the size of the resonant cavity itself. The coupling aperture 3 first couples a certain bandwidth of energy into the resonant cavity, and the transition microstrip 51 further plays a frequency-selective role, transferring the energy to the resonant cavity with absorbing material 41, thereby controlling the frequency of the equalization unit. In addition, the size of the cavity itself also has a certain impact on the equalization frequency. The inverted triangle shape at the top of the resonant cavity mainly affects the absorption of the equalization unit by reducing the impedance of the resonant cavity. Furthermore, the amount of absorbing material 41 itself also affects the absorption of the equalization unit. The desired equalization unit can be obtained by adjusting the dimensions of the coupling aperture 3, the transition microstrip 51, the cavity and its inverted triangle, and the amount of absorbing material 41.
[0041] Although high-precision transition microstrip 51 was used for frequency selection to reduce processing and assembly errors, the processing tolerances of the cavity itself and the parameters of the absorbing material 41 differed from the simulation. It was difficult to achieve theoretical accuracy during cutting and placement, so the test results of the actual machined object still differed from the simulation results (such as frequency deviation and absorption differences). To reduce the number of times the cover was opened during debugging, a tuning screw 42 was added at the center of the cavity. By controlling the length of the tuning screw 42 extending into the cavity, the frequency and absorption of the machined object could be fine-tuned. This effectively reduced the number of times the cover was opened during debugging, greatly reducing the time consumed in the debugging process.
[0042] While this equalizer unit can already achieve precise equalization of complex gain curves within a bandwidth of several hundred megabits by changing many of the variables mentioned above, a single equalizer unit still struggles to equalize complex gain curves over a wider bandwidth. To obtain an equalizer capable of successfully equalizing complex curves, it is necessary to first analyze the gain curve, design equalizer units corresponding to each high-gain frequency of the curve, then cascade all the designed equalizer units for simulation, compare the cascaded simulation curve with the target curve, and fine-tune it using the previously mentioned variables to obtain the desired equalizer. The resulting equalizer has a better VSWR, higher equalization accuracy, and a simpler tuning process compared to typical waveguide equalizers.
[0043] The power equalizer structure proposed in this invention has been verified in simulation software. Figure 5 The simulation results of the equalizer are shown in the figure. It can be seen from the simulation results that the return loss of the equalizer designed in this paper is below -10. It can achieve equalization of different frequency bands in the wide range and can equalize relatively complex gain curves.
[0044] The implementation principle of this utility model is as follows: This utility model discloses a microstrip transition millimeter-wave tunable resonant equalizer, which includes a transmission waveguide 1, a main resonant cavity 2, and an auxiliary resonant cavity 4, the two cavities being connected by a microstrip probe transition structure 5. The main resonant cavity 2 is provided with a coupling hole 3, and the auxiliary resonant cavity 4 is provided with an inverted triangular impedance adjustment area 43. The auxiliary resonant cavity 4 has a built-in absorbing material 41 and is equipped with a tuning screw 42. Through the frequency selection function of the microstrip probe, the adjustment of the width of the coupling hole 3, and the depth control of the tuning screw 42, the standing wave ratio is optimized and the frequency band is precisely adjusted. This utility model effectively solves the problems of traditional waveguide equalizers, such as sensitivity to assembly errors, complex debugging, large reflection loss, and low equalization accuracy, and has important application value in millimeter-wave systems such as 5G communication and satellite navigation.
[0045] The embodiments described herein are preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape, and principle of this utility model should be included within the scope of protection of this utility model.
Claims
1. A microstrip transition millimeter-wave tunable resonant equalizer, comprising a transmission waveguide (1) and a main resonant cavity (2), wherein the sidewall of the transmission waveguide (1) is provided with a plurality of coupling holes (3), and the main resonant cavity (2) is energy coupled to the transmission waveguide (1) through the coupling holes (3), characterized in that, It also includes an auxiliary resonant cavity (4) and a microstrip probe transition structure (5). The auxiliary resonant cavity (4) is connected to the main resonant cavity (2) through the microstrip probe transition structure (5). The auxiliary resonant cavity (4) is provided with a microwave absorbing material (41) and a tuning screw (42).
2. The microstrip transition millimeter-wave tunable resonant equalizer according to claim 1, characterized in that, The top of the auxiliary resonant cavity (4) is provided with an inverted triangular impedance adjustment region (43), which affects the absorption of the equalization unit by reducing the impedance of the resonant cavity.
3. The microstrip transition millimeter-wave tunable resonant equalizer according to claim 1, characterized in that, The microstrip probe transition structure (5) is provided with a transition microstrip (51), which is used to transmit electromagnetic energy from the main resonant cavity (2) to the auxiliary resonant cavity (4).
4. A microstrip transition millimeter-wave tunable resonant equalizer according to claim 1, characterized in that, The tuning screw (42) is made of PTFE material, with a thread accuracy grade of 6H and a maximum adjustment stroke of 20%-30% of the cavity height.
5. A microstrip transition millimeter-wave tunable resonant equalizer according to claim 1, characterized in that, The microwave absorbing material (41) is a silicon carbide composite material with a thickness of 0.5-1.2 mm and a surface roughness Ra≤0.8 μm.
6. A microstrip transition millimeter-wave tunable resonant equalizer according to claim 1, characterized in that, The width of the coupling hole (3) is adjustable in the range of 1 / 8λ to 1 / 4λ, where λ is the center wavelength of the working frequency band.
7. A microstrip transition millimeter-wave tunable resonant equalizer according to claim 1, characterized in that, The volume ratio of the main resonant cavity (2) to the auxiliary resonant cavity (4) is 1:0.8-1.2, and the difference in the cavity Q value is controlled within ±15%.
8. A microstrip transition millimeter-wave tunable resonant equalizer according to claim 1, characterized in that, The inner surface of the transmission waveguide (1) is plated with a silver-nickel alloy coating with a surface roughness Ra≤0.05μm.