Waveguide pin diode digital phase shifter with adjustable phase shift range and phase shift step
By designing the waveguide PIN diode digital phase shifter as an independent module and inserting metal sheets between adjacent units, adjusting the unit spacing and step size, the problem of increased reflection coefficient in the prior art is solved, achieving a low-loss and low-cost phase shifter design.
Patent Information
- Application Number
- CN202511293331.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-11
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2045-09-11
AI Technical Summary
Existing waveguide PIN diode digital phase shifters suffer from increased reflection coefficients due to manufacturing errors after cascading multiple phase shifting units. This makes it difficult to adjust the unit spacing and step value, increasing design cycle and cost.
The phase-shifting unit is designed as an independent module. By adjusting the number of modules and inserting metal sheets of different thicknesses between adjacent units, the phase-shifting range and step can be adjusted to compensate for processing errors. A detachable circuit board structure is adopted to reduce the reflection coefficient and insertion loss.
This invention achieves a digital phase shifter with low reflection coefficient and low insertion loss, reducing design cycle and manufacturing cost, and improving the flexibility and adaptability of the phase shifter.
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Figure CN120824525B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of high-power microwave PIN diode phase-shifting, and particularly relates to a waveguide PIN diode digital phase shifter with adjustable phase-shifting range and phase-shifting step. BACKGROUND
[0002] As a key device for phase control in microwave systems, phase shifters are widely used in various microwave systems, such as radars, phased arrays, mode couplings, power combinations, communications, etc. Traditional phase shifters mainly include waveguide phase shifters applied to high-power systems, ferrite phase shifters, and semiconductor phase shifters applied to low-power systems. The semiconductor phase shifter has advantages of fast response, high precision, high stability, etc., and is widely used in the field of communication. The waveguide phase shifter does not contain dielectric and metal pins, and thus has high power capacity and is widely used in high-power microwave systems, such as high-power phased array antennas, high-energy particle accelerators, etc. The waveguide phase shifter changes the phase of the output signal by mechanically adjusting the microwave transmission length, and the response time is long, usually in the order of milliseconds or even seconds. The ferrite phase shifter also has a power capacity in the order of megawatts, and the phase of the transmission signal is controlled by changing the bias field of the ferrite material through the current, and the response time is also above the order of milliseconds. Therefore, in order to combine the advantages of fast response of the semiconductor phase shifter and high power capacity of the waveguide phase shifter, a waveguide PIN diode phase shifter combining the PIN diode phase shifter and the waveguide structure is developed. This design is to insert a traditional microstrip phase shift circuit board into a rectangular waveguide, control the bias state of the PIN diode through an external circuit, change the equivalent impedance of the PIN diode in the waveguide transmission line, and thus make the phase of the transmission signal change.
[0003] In order to improve the power capacity of the waveguide PIN diode phase shifter, the microstrip circuit is inserted along the narrow side of the waveguide, and is placed as far as possible from the place where the field strength is large in the center of the waveguide, i.e., in the weak field area, so that the phase shift amount that can be achieved by a single microstrip circuit is usually low. In order to achieve large-angle phase shifting, a plurality of microstrip circuits are generally cascaded. For example, a 0~360° waveguide PIN diode digital phase shifter with 24 phase shift circuit units has been reported, which starts from 0 and has 32 states with a step of 11.25°, and the spacing between the phase shift units is about one-quarter of the waveguide wavelength. However, in the method of realizing digital phase shifting by cascading a plurality of phase shift units, after overall processing, there is usually a size error, which will cause the frequency offset of the reflection coefficient curve, and further increase the reflection coefficient. The spacing between the cascaded units generally cannot be optimized and modified after overall processing, and there is a risk of rework. Similarly, if a digital phase shifter with different step values is needed, the parameters of the installed circuit board need to be adjusted and redesigned. However, after the parameters of the circuit board are modified, the spacing between the circuit units also needs to be re-optimized, which requires modification and design of the entire digital phase shifter for reprocessing, thereby increasing the design cycle and processing cost.
[0004] Based on the above situation and considering the practical engineering design and application scenarios of digital phase shifters, a waveguide PIN diode digital phase shifter with adjustable cascade number and variable unit spacing is proposed. Each phase shifting unit is designed and fabricated as an independent waveguide module. Different numbers of waveguide modules are assembled according to the required phase shift angle, and metal sheets of different thicknesses are added between each waveguide module to dynamically adjust the spacing between the phase shifting circuit units, achieving low insertion loss and low reflection for each phase shift state. Simultaneously, the same waveguide structure can be used to install circuit units with different phase shift amounts, enabling the recycling of the waveguide structure and reducing design cycle and manufacturing costs. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention provides a waveguide PIN diode digital phase shifter with adjustable phase shift range and phase shift step. This invention allows for the cascading of different numbers of phase shift circuit waveguide unit modules according to actual application requirements to achieve digital phase shifters with different phase shift ranges. Furthermore, inserting metal sheets of different thicknesses between adjacent cascaded unit modules allows for dynamic adjustment of the unit spacing to regulate the matching relationship and achieve low reflection coefficient applications. In addition, the phase shift circuit board of this invention is detachable, allowing for the replacement of phase shift circuit boards with different phase shift amounts within the same waveguide structure to achieve digital phase shifters with different phase shift steps.
[0006] The technical solution adopted in this invention is as follows:
[0007] A waveguide PIN diode digital phase shifter with adjustable phase shift range and phase shift step includes: N cascaded phase shift circuit waveguide unit modules; the phase shift range is adjustable by adjusting the number of phase shift circuit waveguide unit modules.
[0008] The phase-shifting circuit waveguide unit module includes a straight waveguide, a phase-shifting circuit board, a circuit board fixing structure, and an SMA bias connector. The straight waveguide has waveguide flanges at both ends for fixed connection to adjacent phase-shifting circuit waveguide unit modules. The phase-shifting circuit board is detachably mounted within the straight waveguide via the circuit board fixing structure. The SMA bias connector is located on the narrow side of the straight waveguide and is fixed by two limiting screws. The coaxial inner conductor of the SMA bias connector passes through the waveguide wall and connects to the phase-shifting circuit board to provide a bias voltage. By installing phase-shifting circuit boards with different phase shift amounts, the phase shift step can be adjusted.
[0009] Furthermore, the waveguide PIN diode digital phase shifter also includes several metal sheets; the metal sheets are placed between two adjacent phase shifting circuit waveguide unit modules to increase the spacing.
[0010] Further, the length of the phase-shifting circuit waveguide unit module is a quarter waveguide wavelength; when the spacing between adjacent unit modules is an integer multiple of the quarter waveguide wavelength, the reflection coefficient and the insertion loss correspond to the lowest.
[0011] Further, the phase-shifting circuit waveguide unit module is cascaded, and the actual reflection coefficient is obtained through testing; the actual required spacing between adjacent phase-shifting circuit waveguide unit modules is calculated according to the actual reflection coefficient; and a metal sheet with a corresponding thickness is added according to the actual required spacing, so as to compensate for the reflection coefficient error caused by the processing error. N
[0012] Further, the circuit board fixing structure comprises two grooves and a metal pressing strip; the two grooves are respectively arranged on the inner walls of the two wide edges of the straight waveguide and extend inward from the waveguide flange end face; the metal pressing strip is matched with the grooves in shape and is used for limiting the phase-shifting circuit board placed in the grooves; the grooves, the phase-shifting circuit board and the metal pressing strip are provided with at least one through positioning screw hole, and the matched positioning screw is used for detachable installation.
[0013] Further, the waveguide flange is a planar waveguide flange or a waveguide airtight flange; the airtight flange can be used to realize the inflation or vacuumization of the waveguide interior, so as to improve the power capacity.
[0014] Further, the phase-shifting circuit board is a linear phase-shifting circuit board loaded with two PIN diodes, a current-limiting resistor, a bias circuit, a loading line and two sections of branch lines; the PIN diodes are respectively welded on the two sections of branch lines; the current-limiting resistor is welded on the bias circuit; one end of the bias circuit is directly connected with the loading line, and the other end is connected with the coaxial inner conductor of the SMA bias connector; the two sections of branch lines are connected in parallel at the two ends of the loading line, and the other ends of the branch lines extend to the edges of the dielectric board, so as to realize the electrical interconnection with the straight waveguide.
[0015] Further, the SMA bias connector is a standard SMA connector or a standard airtight SMA connector; the bias state of the PIN diode is controlled by changing the external bias voltage; the airtight SMA connector can be used to realize the inflation or vacuumization of the waveguide interior, so as to improve the power capacity.
[0016] Compared with the prior art, the present application has the following beneficial effects:
[0017] (1) In the present application, the phase-shifting unit of the waveguide PIN diode digital phase shifter is designed as an independent module, different numbers of phase-shifting circuit waveguide unit modules can be selected according to the actual application of the microwave system to the phase shift amount, and the digital phase shifter with different phase shift ranges can be realized.
[0018] (2) The metal sheet with different thickness is added between the adjacent phase shift circuit waveguide unit modules in the application, the spacing between the modules can be adjusted to match the best, the reflection coefficient error caused by the processing size error is compensated, the low reflection coefficient and low insertion loss application is realized, and the rework probability is reduced.
[0019] (3) The phase shift circuit waveguide unit module in the application designs a detachable phase shift circuit board structure, the phase shift circuit board can be conveniently and quickly replaced, the phase shift circuit with different phase shift amounts is installed in the same waveguide structure, and the phase shift amount of a single module is variable. The same waveguide structure is used to realize the digital phase shifter with different step values, and the overall design cycle and processing cost can be reduced. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 It is a waveguide PIN diode digital phase shifter structure diagram with adjustable phase shift range and phase shift step of the application;
[0021] Figure 2 It is a phase shift circuit waveguide unit module structure diagram of the application;
[0022] Figure 3 It is a phase shift circuit board structure and SMA joint structure diagram of the application;
[0023] Figure 4 It is a circuit board fixing structure diagram of the application;
[0024] Figure 5 It is a metal sheet structure diagram of the application;
[0025] Figure 6 It is the S parameter of a 2-bit digital phase shifter with a phase shift range of 0-90° and a step of 22.5° in the embodiment of the application;
[0026] Figure 7 It is a phase shift curve of a 2-bit digital phase shifter with a phase shift range of 0-90° and a step of 22.5° in the embodiment of the application.
[0027] Wherein: 1, phase shift circuit waveguide unit module; 1-1, straight waveguide with flange; 1-2, phase shift circuit board; 1-2-1, loading line; 1-2-2, branch line; 1-2-3, current limiting resistor; 1-2-4, bias circuit; 1-2-5, PIN diode; 1-3, SMA joint; 1-4, circuit board fixing structure; 1-4-1, groove; 1-4-2, positioning screw hole; 1-4-3, metal pressing strip; 2, metal sheet. DETAILED DESCRIPTION
[0028] In order to more clearly illustrate the purpose, features and advantages of the application, the application will be further described in detail below with reference to the drawings and specific embodiments.
[0029] The embodiment provides a waveguide PIN diode digital phase shifter with variable phase shift range and phase shift step, which operates in an S wave band, and the phase shift steps are 11.25° and 22.5° respectively, and the phase shift ranges are 0-90° and 0-180° respectively.
[0030] As shown in Figure 1 and Figure 2 , the phase shifter comprises a plurality of phase shift circuit waveguide unit modules with a phase shift of 22.5° which are sequentially connected in cascade; the phase shift range is adjusted from 0-90° to 0-180° by adjusting the number of phase shift circuit waveguide unit modules to be 4 and 8 respectively.
[0031] The phase shift circuit waveguide unit module comprises a straight waveguide, a phase shift circuit board, a circuit board fixing structure and an SMA bias joint, as shown in Figure 2 ; wherein the straight waveguide adopts a BJ26 type waveguide, and both ends are provided with a planar waveguide flange for fixed connection with adjacent phase shift circuit waveguide unit modules; the phase shift circuit board is detachably mounted in the straight waveguide through the circuit board fixing structure; the SMA bias joint is arranged at the narrow edge of the straight waveguide and is fixed by two limiting screws, and the inner coaxial conductor penetrates the waveguide wall and is connected with the phase shift circuit board to provide a bias voltage; different phase shift circuit boards with different phase shifts are installed to realize adjustable phase shift step.
[0032] The length of the phase shift circuit waveguide unit module is set to be one quarter of the waveguide wavelength, and in the embodiment, the length is 24 mm; when the spacing between adjacent unit modules is an integer multiple of one quarter of the waveguide wavelength, the reflection coefficient and the insertion loss correspond to the lowest.
[0033] The waveguide PIN diode digital phase shifter further comprises a plurality of metal sheets with a thickness of 1 mm, which are consistent in shape with the cross section of the planar waveguide flange, as shown in Figure 5 ; the metal sheets are placed between adjacent two phase shift circuit waveguide unit modules to increase the spacing and realize adjustment of the reflection coefficient.
[0034] The circuit board fixing structure comprises two grooves and a metal pressing strip, as shown in Figure 4 ; the two grooves are respectively arranged in the inner walls of the two wide edges of the straight waveguide and extend inward from the waveguide flange end face, the extension length is 15 mm, the depth is 4.3 mm, and the width is 28 mm; the shape of the metal pressing strip is matched with the grooves, and the metal pressing strip is used for limiting the phase shift circuit board placed in the grooves; the grooves, the phase shift circuit board and the metal pressing strip are provided with three through positioning screw holes with a diameter of 1.8 mm, and the positioning screw holes are detachably mounted through matched positioning screws.
[0035] The phase shift circuit board, as shown in Figure 3As shown, for loading linear phase shift circuit board, containing dielectric substrate, and set on the two PIN diodes, current limiting resistor, bias circuit, loading line, two sections of branch microstrip line on the base plate; wherein, the dielectric substrate adopts Rogers 4350B, thickness 0.508 mm, width is 28 mm, length is 51.8 mm; The PIN diode is welded on the two sections of branch microstrip line respectively, and the reverse bias capacitor of PIN diode is 0.15 pF; The current limiting resistor is welded on the bias circuit, and the resistance is 100 Ω; One end of the bias circuit is directly connected with the loading line, and the other end is connected with the coaxial inner conductor of the SMA bias connector, and the line width of the bias circuit is 1 mm; Two sections of the branch microstrip line are connected in parallel at both ends of the loading line, and the other end of the branch microstrip line extends to the edge of the dielectric plate to realize electrical interconnection with the straight waveguide, wherein the size of the branch line is 17.2*3 mm 2 , the end is bent 90° and extends to the edge of the dielectric substrate, and the line width of the bent part is 2 mm; The size of the loading line is 38*8 mm 2 .
[0036] The SMA bias connector, as shown in Figure 3 , is a standard SMA connector; The bias state of PIN diode is controlled by changing the external bias voltage.
[0037] Four phase shift circuit waveguide unit modules are cascaded, when the bias state of the phase shift circuit waveguide unit module changes, 2-bit digital phase shift can be realized, and the phase shift state has four, which are 22.5°, 45°, 67.5° and 90°, and the S parameter and phase shift curve of the four phase shift states are shown in Figure 6 and Figure 7 , the reflection coefficient is lower than-10 dB at 2.5 GHz, and the insertion loss is lower than 0.8 dB.
[0038] The actual reflection coefficient is obtained by testing, and the actual required spacing between adjacent phase shift circuit waveguide unit modules is calculated according to the actual reflection coefficient; According to the actual required spacing, the metal sheet with corresponding thickness is added, so as to compensate the reflection coefficient error caused by actual processing error.
[0039] The 4 phase shift circuit waveguide unit modules are cascaded to adjust 8 phase shift circuit waveguide unit modules, so that a 3-bit digital phase shifter with a phase shift range of 0-180° and a step of 22.5° is obtained. According to the quarter wavelength characteristic of the unit spacing, the optimal unit spacing of the 3-bit digital phase shifter is obtained by simulation optimization, which is 27 mm. Under the condition of the spacing, the reflection coefficient of the S parameter of each phase shift state is less than-10 dB at 2.5 GHz, and the insertion loss is less than 0.77 dB. The optimal unit spacing of the 3-bit digital phase shifter with 8 unit modules is 27 mm, which is longer than the length of the phase shift circuit waveguide unit module of 24 mm. Therefore, in practical application, 3 metal sheets of 0.5 mm are cascaded between each two waveguide unit modules to increase the unit spacing to 27 mm, so as to improve the matching relationship between the unit modules and reduce the reflection coefficient of each step phase shift state.
[0040] The length of the loading line in the phase shift circuit board is shortened to 31 mm, and the rest of the size and structure remains unchanged. Under this condition, the phase shift amount of a single phase shift circuit waveguide unit module is reduced to 11.25°, that is, the step value is 11.25°. The length of the waveguide unit module is still 24 mm, the size of the circuit board remains unchanged, and the size of the fixed structure of the circuit board also remains unchanged. Installing the phase shift circuit board with a step of 11.25° and cascading 8 units can realize a 3-bit digital phase shifter with a phase shift range of 0-90° and a step of 11.25°, realizing the change of the phase shift step from 22.5° to 11.25°.
Claims
1. A waveguide PIN diode digital phase shifter with a phase shifting range and phase shifting step adjustable, characterized in that, The application relates to a phase-shifting circuit waveguide unit module, which comprises the following steps: The phase-shifting circuit waveguide unit module comprises a straight waveguide, a phase-shifting circuit board, a circuit board fixing structure and an SMA biasing connector; two waveguide flanges are arranged at the two ends of the straight waveguide and used for fixed connection with adjacent phase-shifting circuit waveguide unit modules; the phase-shifting circuit board is detachably installed in the straight waveguide through the circuit board fixing structure; the SMA biasing connector is arranged at the narrow side of the straight waveguide and fixed by two limiting screws; the coaxial inner conductor of the SMA biasing connector penetrates through the waveguide wall and is connected with the phase-shifting circuit board and used for providing a bias voltage; different phase-shifting circuit boards with different phase-shifting amounts are installed to realize phase-shifting step adjustment. The length of the phase-shifting circuit waveguide unit module is one quarter of the waveguide wavelength. Will N The phase-shifting circuit waveguide unit modules are cascaded, and the actual reflection coefficient is obtained by testing. The actual required spacing between adjacent phase-shifting circuit waveguide unit modules is calculated based on the actual reflection coefficient. A metal sheet of corresponding thickness is added according to the actual required spacing to compensate for the reflection coefficient error caused by processing error.
2. A waveguide PIN diode digital phase shifter with a phase shifting range and phase shifting step adjustable as claimed in claim 1, characterized in that, The circuit board fixing structure comprises two grooves and a metal pressing strip; the two grooves are arranged in the inner walls of the two wide sides of the straight waveguide and extend inward from the waveguide flange end face; the shape of the metal pressing strip is matched with the grooves and used for limiting the phase-shifting circuit board placed in the grooves; the grooves, the phase-shifting circuit board and the metal pressing strip are provided with at least one through positioning screw hole, and matched positioning screws are used for detachable installation.
3. A waveguide PIN diode digital phase shifter with a phase shifting range and phase shifting step adjustable as claimed in claim 2, characterized in that, The waveguide flange is a plane waveguide flange or a waveguide airtight flange.
4. A waveguide PIN diode digital phase shifter with a phase shifting range and phase shifting step adjustable as claimed in claim 3, characterized in that, The phase-shifting circuit board is a linear phase-shifting circuit board, which comprises a dielectric substrate, two PIN diodes, a current-limiting resistor, a biasing circuit, a loading line and two branch lines arranged on the dielectric substrate.
5. A waveguide PIN diode digital phase shifter with a phase shifting range and phase shifting step adjustable as claimed in claim 4, characterized in that, The two PIN diodes are welded on the two branch lines respectively; the current-limiting resistor is welded on the biasing circuit; one end of the biasing circuit is directly connected with the loading line, and the other end is connected with the coaxial inner conductor of the SMA biasing connector; the two branch lines are connected in parallel at the two ends of the loading line, and the other ends of the branch lines extend to the edges of the dielectric board to realize electrical interconnection with the straight waveguide. The SMA biasing connector is a standard SMA connector or a standard airtight SMA connector; the biasing state of the PIN diode is controlled by changing the external bias voltage.
6. A waveguide PIN diode digital phase shifter with a phase shifting range and phase shifting step adjustable as claimed in claim 5, characterized in that,
Citation Information
Patent Citations
Phase shifter based on waveguide transmission line
CN223023570U
Velocity modulation electron tube apparatus
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