Miniaturized wideband digital phase shifter

Abstract

The application provides a miniaturized wideband digital phase shifter, comprising a first dielectric layer, a metal ground layer, a second dielectric layer, a resonator unit and a transmission structure; the first dielectric layer, the metal ground layer and the second dielectric layer are sequentially laminated; the resonator unit comprises at least one first low-impedance transmission line arranged on the first dielectric layer, at least one second low-impedance transmission line arranged on the second dielectric layer and a radio frequency switch, the first low-impedance transmission line and the second low-impedance transmission line are different in shape and partially coincide in projection; the transmission structure comprises a coupler and a 50-ohm transmission line, the radio frequency switch is connected between the coupler and the corresponding first low-impedance transmission line, and the port of the radio frequency switch is connected with the first low-impedance transmission line and the second low-impedance transmission line at the corresponding positions. The scheme can greatly reduce the size of the phase shifter, reduce the circuit area, select different phase paths by switching the radio frequency switch, reduce the cascade series under the demand of multiple phases and wide phase shifting range, and reduce the system insertion loss.

Description

Technical Field

[0001] This invention belongs to the field of radio frequency microwave devices, and particularly relates to a miniaturized broadband digital phase shifter. Background Technology

[0002] Phase shifters are key functional components in phased array antennas, radar communication systems, satellite communications, wireless transceiver front-ends, and beamforming networks. Their main function is to introduce controllable phase delay during radio frequency signal transmission, thereby enabling functions such as beam scanning, phase compensation, signal synthesis, and pattern control.

[0003] With the rapid development of 5G mobile communication, satellite communication, millimeter-wave communication, radar detection, and integrated air-space-ground networks, intelligent sensing and communication integration, and high-capacity wireless transmission technologies for 6G mobile communication, radio frequency (RF) front-end systems are evolving towards higher frequencies, larger bandwidths, more channels, higher integration, and lower power consumption. As a key phase control device in the RF microwave front-end, the performance of the phase shifter directly affects the system's beam pointing accuracy, scanning range, sidelobe level, link gain, and overall operating efficiency. Digital phase shifters typically control different transmission paths or different equivalent circuit states through switching devices, thereby achieving discrete phase switching. Compared to analog phase shifters, digital phase shifters have advantages such as simpler control methods, clearer phase states, easier integration with digital control circuits, and better repeatability. Therefore, they are widely used in phased array antennas, 5G / 6G base station RF front-ends, satellite communication terminals, low-Earth orbit satellite phased array antennas, and millimeter-wave transceiver components. As communication systems continue to operate at higher frequencies, signal bandwidths increase, and the number of array channels grows, digital phase shifters not only need to achieve accurate phase control, but also need to possess comprehensive performance characteristics such as miniaturization, broadband, low insertion loss, good port matching, and amplitude consistency.

[0004] However, digital phase shifters in related technologies often employ cascaded multiple phase shift units, resulting in a relatively large phase modulation structure, high losses, and narrow phase shift bandwidth. Furthermore, with the increasing demands for miniaturization, broadband, and wide phase shift range from 5G millimeter-wave communication, future 6G broadband communication, and satellite internet terminals, the existing digital phase shifter structures are struggling to meet these requirements. Summary of the Invention

[0005] This invention provides a miniaturized broadband digital phase shifter that can greatly simplify circuit complexity and reduce system size, and better meet the miniaturization requirements of future communications.

[0006] To solve the above-mentioned technical problems, the present invention provides a miniaturized broadband digital phase shifter, comprising a first dielectric layer, a metal ground layer, a second dielectric layer, a resonator unit, and a transmission structure. The first dielectric layer, the metal ground layer, and the second dielectric layer are sequentially stacked to form a composite dielectric substrate; The resonator unit includes at least one first low-impedance transmission line disposed on the side of the first dielectric layer away from the metal ground layer, at least one second low-impedance transmission line disposed on the side of the second dielectric layer away from the metal ground layer, and a radio frequency switch. In the direction perpendicular to the metal ground layer, the projection shapes of the first low-impedance transmission line and the second low-impedance transmission line are different and the projections at least partially overlap. Both the first low-impedance transmission line and the second low-impedance transmission line are connected to the metal ground layer. The transmission structure includes two couplers located at both ends of the first low-impedance transmission line and a 50-ohm transmission line connected to the end of the coupler. The RF switch is connected between the coupler and the corresponding first low-impedance transmission line. The port of the RF switch is connected to the first low-impedance transmission line and the second low-impedance transmission line at the corresponding position. The RF switch is used to switch the state in which the coupler connects to the first low-impedance transmission line and the second low-impedance transmission line.

[0007] Furthermore, the resonator unit includes two spaced-apart first low-impedance transmission lines and two spaced-apart second low-impedance transmission lines. Both the first and second low-impedance transmission lines include a transmission body and a short-circuit stub connected to one side of the transmission body and extending outward. Both the first and second low-impedance transmission lines are connected to the ports of the RF switch through their respective two ends of the transmission body, and are grounded to the metal ground layer through the center of the end edge of the short-circuit stub.

[0008] Furthermore, the positions of the two first low-impedance transmission lines and the two second low-impedance transmission lines correspond one-to-one; the transmission body of the first low-impedance transmission line is rectangular, and the transmission body of the corresponding second low-impedance transmission line is also rectangular.

[0009] Furthermore, one of the first low-impedance transmission lines has a transmission body length of 27.6 mm and a width of 4 mm, and its short-circuit branch is rectangular, with a length of 12 mm and a width of 3.5 mm; the other of the first low-impedance transmission lines has a transmission body length of 22.2 mm and a width of 4 mm, and its short-circuit branch is rectangular, with a length of 6 mm and a width of 8.5 mm. One of the second low-impedance transmission lines has a transmission body length of 24.6 mm and a width of 1.2 mm, and its short-circuit branch is rectangular, with a length of 12 mm and a width of 2.4 mm; the other of the second low-impedance transmission lines has a transmission body length of 25 mm and a width of 1.2 mm, and its short-circuit branch is rectangular, with a length of 9.4 mm and a width of 2.7 mm.

[0010] Furthermore, the operating frequency band of the miniaturized broadband digital phase shifter is 2.4-3.3 GHz.

[0011] Furthermore, the coupler includes a high-impedance transmission line connected to the RF switch and a coupling transmission line spaced apart from the high-impedance transmission line, the end of which is connected to the corresponding 50-ohm transmission line. The coupling transmission line is provided in two parts, forming a fork structure, and the two coupling transmission lines are respectively arranged at intervals on both sides of the high impedance transmission line; or, the coupling transmission line is provided in one part, arranged at intervals on one side of the high impedance transmission line.

[0012] Furthermore, the RF switch adopts a single-pole quad-throw RF switch integrated chip, the common terminal of the RF switch is connected to the end of the high-impedance transmission line, and the four switch ports of the RF switch are respectively connected to each of the first low-impedance transmission lines and each of the second low-impedance transmission lines. The switching port of the radio frequency switch is connected to the corresponding second low-impedance transmission line through a metal via, and the metal ground layer has a hole around the metal via.

[0013] Furthermore, each transmission path of the miniaturized broadband digital phase shifter is symmetrical about its central axis.

[0014] Furthermore, at least two resonator units are arranged sequentially, and each adjacent resonator unit is connected by a coupler.

[0015] Furthermore, it also includes a plurality of control endpoints disposed on the composite dielectric substrate, each of the control endpoints being connected to the control port of the radio frequency switch.

[0016] Compared with existing technologies, the miniaturized broadband digital phase shifter of this invention has the following advantages: The resonator unit of this solution includes a first low-impedance transmission line and a second low-impedance transmission line of different shapes, located on opposite sides of a composite dielectric substrate, with at least partial overlap in their thickness direction projections. An RF switch connects the first and second low-impedance transmission lines to a coupler, which in turn connects to a 50-ohm transmission line. By controlling the RF switch, the transmission path can be switched between the first and second low-impedance transmission lines, thus achieving phase adjustment. Furthermore, different transmission paths share a common coupler. This significantly reduces the size of the phase shifter and the circuit area. By switching between different phase paths via the RF switch, the number of cascaded stages can be reduced to meet the requirements of multi-phase and wide phase-shifting ranges, while also lowering system insertion loss. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the overall structure of the miniaturized broadband digital phase shifter in an embodiment of the present invention; Figure 2 This is a simplified schematic diagram of the structure of the miniaturized broadband digital phase shifter in this invention, which transfers the radio frequency switch inside the high- and low-impedance multimode resonator. The black part is the high- and low-impedance multimode resonator. Figure 3 This is a schematic diagram of the components outside the first dielectric layer of the miniaturized broadband digital phase shifter in an embodiment of the present invention; Figure 4 This is a schematic diagram of the components outside the second dielectric layer of the miniaturized broadband digital phase shifter in an embodiment of the present invention; Figure 5 This is a simplified cross-sectional view of the miniaturized broadband digital phase shifter in an embodiment of the present invention; Figure 6 This is a schematic diagram of the metal ground layer structure of the miniaturized broadband digital phase shifter in an embodiment of the present invention; Figure 7 This is a simplified structural diagram of a miniaturized broadband digital phase shifter with a short-circuit stub in an embodiment of the present invention, wherein the black part is a high- and low-impedance multimode resonator. Figure 8 These are the simulated return loss and insertion loss curves of the 2-bit digital phase shifter of the miniaturized broadband digital phase shifter in this embodiment of the invention. Figure 9 This is the 2-bit digital phase shifter phase curve of the miniaturized broadband digital phase shifter in this embodiment of the invention; Figure 10 This is a schematic diagram of the three-dimensional structure of a 4-bit miniaturized broadband digital phase shifter in an embodiment of the present invention; Figure 11 This is the simulated return loss curve of the 4-bit miniaturized broadband digital phase shifter in this embodiment of the invention; Figure 12 This is a simulated insertion loss curve of a 4-bit miniaturized broadband digital phase shifter in an embodiment of the present invention; Figure 13 This is a simulated phase curve of a 4-bit miniaturized broadband digital phase shifter in an embodiment of the present invention; Figure 14 This is a simulated phase error curve of a 4-bit miniaturized broadband digital phase shifter in an embodiment of the present invention; Figure 15 This is a three-dimensional structural schematic diagram of a miniaturized broadband digital phase shifter with a fan-shaped short-circuit branch in an embodiment of the present invention; Figure 16 This is a schematic diagram of the components outside the first dielectric layer of a miniaturized broadband digital phase shifter with a fan-shaped short-circuit branch in an embodiment of the present invention. Figure 17This is a schematic diagram of the components outside the second dielectric layer of a miniaturized broadband digital phase shifter with a fan-shaped short-circuit branch in an embodiment of the present invention.

[0018] In the accompanying drawings, the reference numerals indicate: 100. Metal via; 1. First dielectric layer; 2. Metal ground layer; 21. Hole; 3. Second dielectric layer; 41. First low-impedance transmission line; 42. Second low-impedance transmission line; 43. RF switch; 401. Transmission body; 402. Short-circuit stub; 51. Coupler; 52. 50-ohm transmission line; 511. High-impedance transmission line; 512. Coupled transmission line; 6. Control terminal. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] This invention provides some solutions for miniaturized broadband digital phase shifters. Typically, in engineering applications, the insertion loss of phase shifters is required to be infinitely close to 0 dB, which is also the theoretical standard. In other words, the miniaturized broadband digital phase shifter of this invention can operate normally within the passband frequency band under the required conditions, with the insertion loss within a reasonable range, while simultaneously achieving wide bandwidth and wide phase shift range operation.

[0021] In this embodiment, combined with Figure 1-2 The miniaturized broadband digital phase shifter includes a first dielectric layer 1, a metal ground layer 2, a second dielectric layer 3, a resonator unit, and a transmission structure; the first dielectric layer 1, the metal ground layer 2, and the second dielectric layer 3 are sequentially stacked to form a composite dielectric substrate; the resonator unit includes at least one first low-impedance transmission line 41 disposed on the side of the first dielectric layer 1 away from the metal ground layer 2, at least one second low-impedance transmission line 42 disposed on the side of the second dielectric layer 3 away from the metal ground layer 2, and an RF switch 43. In the direction perpendicular to the metal ground layer 2, the projected shapes of the first low-impedance transmission line 41 and the second low-impedance transmission line 42 are different and... The projections at least partially overlap, and both the first low-impedance transmission line 41 and the second low-impedance transmission line 42 are connected to the metal ground layer 2. The transmission structure includes two couplers 51 located at both ends of the first low-impedance transmission line 41 and a 50-ohm transmission line 52 connected to the end of the coupler 51. An RF switch 43 is connected between the coupler 51 and the corresponding first low-impedance transmission line 41. The port of the RF switch 43 is connected to the first low-impedance transmission line 41 and the second low-impedance transmission line 42 at the corresponding position. The RF switch 43 is used to switch the state of the coupler 51 connected to the first low-impedance transmission line 41 and the second low-impedance transmission line 42.

[0022] The resonator unit of this solution includes a first low-impedance transmission line 41 and a second low-impedance transmission line 42 with different shapes, located on opposite sides of the composite dielectric substrate, with at least partial overlap in their thickness direction projections. An RF switch 43 connects the first low-impedance transmission line 41, the second low-impedance transmission line 42, and a coupler 51. The coupler 51 connects to the 50-ohm transmission line 52. By controlling the RF switch 43, the transmission path can be switched between the first low-impedance transmission line 41 and the second low-impedance transmission line 42, thereby achieving phase adjustment. Furthermore, the coupler 51 is shared between different transmission paths. This significantly reduces the size of the phase shifter and the circuit area. By switching between different phase paths using the RF switch 43, the number of cascaded stages can be reduced under multi-phase, wide-phase-shifting-range requirements, while also lowering system insertion loss.

[0023] Furthermore, combined Figure 1 , Figure 3-7 The resonator unit includes two spaced-apart first low-impedance transmission lines 41 and two spaced-apart second low-impedance transmission lines 42. Both the first low-impedance transmission lines 41 and 42 include a transmission body 401 and a short-circuit stub 402 connected to one side of the transmission body 401 and extending outward. The first low-impedance transmission lines 41 and 42 are connected to the ports of the RF switch 43 through the corresponding two ends of the transmission body 401, and are grounded to the metal ground layer 2 through the center of the end edge of the short-circuit stub 402. Specifically, the center of the end edge of the short-circuit stub 402 is connected to the metal ground layer 2 through a metal via 100. In this scheme, the two first low-impedance transmission lines 41 and the two second low-impedance transmission lines 42 correspond one-to-one and at least partially overlap in the thickness direction, which can greatly save space and reduce the size of the device. Furthermore, the structural shape and size of each low-impedance transmission line are different, thus providing four different transmission paths. By controlling the RF switch 43, four different phase adjustments can be achieved, thereby realizing a four-way multimode resonator. Adding a short-circuit stub 402 to the multimode resonator can also improve the degree of freedom of the phase slope adjustment of the phase shifter and increase the operating bandwidth of the phase shifter.

[0024] It should be understood that in some embodiments, three, four, five, etc., first low-impedance transmission lines 41 and second low-impedance transmission lines 42 can be provided on both sides of the composite dielectric substrate. Furthermore, the structure, shape, and size of the low-impedance transmission lines can be adaptively designed as needed, thus enabling more phase adjustment paths to be achieved through a single resonator unit. In some embodiments, the composite dielectric substrate can also be configured with a multi-layer structure. For example, at least two spaced metal ground layers 2 can be provided inside the composite dielectric substrate. The resonator unit can also include extended low-impedance transmission lines disposed between adjacent metal ground layers 2. The extended low-impedance transmission lines at least partially overlap with the projections of the first low-impedance transmission lines 41 and second low-impedance transmission lines 42 in the thickness direction, and the extended low-impedance transmission lines also connect to the RF switch 43. Thus, three, four, five, etc., low-impedance transmission lines can be provided in the same height direction within the same region of the composite dielectric substrate, further increasing the integration density and the number of phase adjustment transmission paths.

[0025] Furthermore, the positions of the two first low-impedance transmission lines 41 and the two second low-impedance transmission lines 42 correspond one-to-one. The transmission body 401 of one first low-impedance transmission line 41 is rectangular, and it has extension lines at both ends on one side for connecting to the RF switch 43, with a first rectangular gap between the extension lines. The corresponding transmission body 401 of the second low-impedance transmission line 42 is also rectangular, and it also has extension lines at both ends on one side for connecting to the RF switch 43, with a second rectangular gap between the extension lines. The dimensions of the first rectangular gap and the second rectangular gap are different; specifically, the height of the first rectangular gap is greater than the height of the second rectangular gap. The transmission body 401 of the other first low-impedance transmission line 41 is rectangular, and the transmission body 401 of the corresponding second low-impedance transmission line 42 is also rectangular. Specifically, in this embodiment, each transmission path of the miniaturized broadband digital phase shifter is symmetrical about its central axis, and each low-impedance transmission line is also symmetrical about its central axis. Therefore, the first rectangular gap is located at the center of the edge of the transmission body 401 of the corresponding first low-impedance transmission line 41, and the second rectangular gap is located at the center of the edge of the transmission body 401 of the corresponding second low-impedance transmission line 42. The rectangular notch and the spacing between the low-impedance transmission lines on the same side can be used for the arrangement of the RF switch 43, while reducing interference between adjacent low-impedance transmission lines. Since the transmission body 401 has different lengths, the extension line can facilitate the electrical connection between the corresponding transmission body 401 and the RF switch 43. Understandably, the extension line can be bent appropriately so that its end is aligned with the port of the RF switch 43 to be connected.

[0026] Furthermore, in this application, the low-impedance transmission line is maintained at 1 / 4 electrical length. Specifically, in this embodiment, the transmission body 401 of the first low-impedance transmission line 41 corresponding to the first rectangular notch is 27.6 mm long and 4 mm wide, and its short-circuit branch 402 is rectangular, with a length of 12 mm and a width of 3.5 mm; the transmission body 401 of the other first low-impedance transmission line 41 is 22.2 mm long and 4 mm wide, and its short-circuit branch 402 is rectangular, with a length of 6 mm and a width of 8.5 mm; the transmission body 401 of the second low-impedance transmission line 42 corresponding to the second rectangular notch is 24.6 mm long and 1.2 mm wide, and its short-circuit branch 402 is rectangular, with a length of 12 mm and a width of 2.4 mm; the transmission body 401 of the other second low-impedance transmission line 42 is 25 mm long and 1.2 mm wide, and its short-circuit branch 402 is rectangular, with a length of 9.4 mm and a width of 2.7 mm.

[0027] Combination Figure 8-9 The aforementioned miniaturized broadband digital phase shifter exhibits good transmission characteristics in the 2.4-3.3 GHz operating frequency band, achieving 2-bit phase shift from 0° to 360°. It also demonstrates good phase flatness and low insertion loss throughout the entire frequency band, indicating the feasibility of the electrical broadband digital phase shifter design method.

[0028] In some embodiments, combined with Figure 15-17 The short-circuit stubs 402 of the first low-impedance transmission line 41 and the second low-impedance transmission line 42 can both be configured as fan-shaped, and the arc edge of the fan-shaped section faces away from the corresponding transmission body 401.

[0029] It is understood that the shape of the transmission body 401 and the shape of the short-circuit branch 402 are not limited to the above-mentioned schemes. For example, the transmission body 401 can be a square, pentagon, circle, etc., and the shape of the short-circuit branch 402 can be a triangle, semi-circular, T-shaped, etc., which can be adjusted according to the actual situation.

[0030] Furthermore, combined Figure 3 and Figure 16 Coupler 51 includes a high-impedance transmission line 511 connected to RF switch 43 and a coupling transmission line 512 spaced apart from the high-impedance transmission line 511. The end of the coupling transmission line 512 is connected to a corresponding 50-ohm transmission line 52. Two coupling transmission lines 512 are provided, forming a fork structure, and the two coupling transmission lines 512 are respectively spaced apart on both sides of the high-impedance transmission line 511; or, a single coupling transmission line 512 is provided, spaced apart on one side of the high-impedance transmission line 511. Coupler 51 can be shared by multiple first low-impedance transmission lines 41 and multiple second low-impedance transmission lines 42, reducing the use of coupling structures, thereby reducing device size and losses.

[0031] Furthermore, combined Figure 1 and Figure 3 The RF switch 43 adopts a single-pole quad-throw RF switch integrated chip. The common terminal of the RF switch 43 is connected to the end of the high-impedance transmission line 511. The four switch ports of the RF switch 43 are respectively connected to each first low-impedance transmission line 41 and each second low-impedance transmission line 42. The switch ports of the RF switch 43 are connected to the corresponding second low-impedance transmission line 42 through a metal via 100. The metal ground layer 2 is provided with a hole 21 around the metal via 100 to prevent short circuit.

[0032] Specifically, in this embodiment, the RF switch 43 uses the ADRF5040 manufactured by Analog Devices, which is a single-pole quad-throw RF switch with high isolation, low insertion loss, and wide bandwidth characteristics, covering the operating frequency band of 9kHz-12GHz. An RF switch 43 is respectively set at both ends of the first low-impedance transmission line 41, and the RF switch 43 is set between the two first low-impedance transmission lines 41. The two switch ports of the RF switch 43 are respectively connected to the ends of the two first low-impedance transmission lines 41, and the other two switch ports of the RF switch 43 are respectively connected to the ends of the two second low-impedance transmission lines 42 through metal vias 100. In this way, the RF switch 43 is directly set between the high and low impedance transmission lines inside the multimode resonator, so that multiple transmission paths can share the coupling structure, which greatly simplifies the circuit complexity, reduces the size of the system, and reduces the system insertion loss. In practical use, the state of the input port (V1, V2) of the RF switch 43 integrated chip is controlled. When (V1, V2) = (0,0), (V1, V2) = (0, 1), (V1, V2) = (1, 0), and (V1, V2) = (1, 1), the RF switch 43 integrated chip connects ports 1, 2, 3, and 4 of the RF switch 43 respectively. Among them, the same numbered ports of the two RF switches 43 are connected to the same low-impedance transmission line. In this way, the low-impedance transmission lines of different multimode resonators can be connected to the high-impedance transmission line 511. By selecting the appropriate transmission path, the switching of four phase states can be realized.

[0033] In some implementations, switches can be placed between different low-impedance transmission lines to allow them to be connected in series or parallel. Thus, even with only four types of low-impedance transmission lines, more than four phase selections can be achieved. For example, switches can be placed between two first low-impedance transmission lines 41 and between two second low-impedance transmission lines 42. These switches are used for parallel connection between adjacent low-impedance transmission lines, such as two first low-impedance transmission lines 41 in parallel, two second low-impedance transmission lines 42 in parallel, or a first low-impedance transmission line 41 in parallel with a second low-impedance transmission line 42 whose projection in the thickness direction overlaps with it. This provides four additional parallel connection methods. Understandably, three or four low-impedance transmission lines can also be connected in parallel, or any two, three, or four in series, or a combination of series and parallel connections, as long as more phase selections can be achieved; no limitation is imposed here.

[0034] Furthermore, in some embodiments, combined with Figure 10 At least two resonator units can be sequentially arranged, and adjacent resonator units are connected through coupler 51. The miniaturized broadband digital phase shifter also includes multiple control endpoints 6 disposed on a composite dielectric substrate, each control endpoint 6 connected to the control port of the RF switch 43. Specifically, this solution is a 4-bit broadband digital phase shifter, which achieves multiple phase states through cascading, and the control port of the RF switch 43 integrated chip is brought out, allowing different phase shift states to be switched by inputting different control signals. Figure 11-14 The structure exhibits good transmission characteristics in the operating frequency band of 2.4-3.3 GHz, and the insertion loss is within a reasonable range. Compared with the aforementioned scheme, it has more phase states. The simulated return loss of each phase state is basically below -10dB, and the insertion loss is above -4.3dB. The phase flatness is good, which shows the feasibility of the design method of the broadband digital phase shifter.

[0035] In this scheme, short-circuit stubs 402 are connected to all low-impedance transmission lines. The length and width of the short-circuit stubs 402 can be designed and changed to adjust the phase slope of the phase shifter, thereby realizing a wide-band phase shift function. It can operate in the 2.4GHz-3.3GHz frequency band and has a small physical size and a wide phase shift bandwidth under a wide range (0°-360°) phase shift and multi-phase conditions.

[0036] Based on the above solution, compared with the prior art, the present invention has the following advantages: Compared with traditional high and low impedance multimode resonant digital phase shifters, this invention moves the RF switch 43 from outside the multimode resonator to between the high and low impedance transmission lines inside the multimode resonator, allowing multiple transmission paths to share the coupling structure, which greatly simplifies the circuit complexity, reduces the system size, and lowers the system insertion loss.

[0037] Traditional multi-bit digital phase shifters use a main transmission line and a reference transmission line pair for each bit, and multiple bits are cascaded, resulting in a large system size. This invention uses a single-pole quad-throw RF switch integrated chip to form one reference transmission line and three main transmission lines, reducing the number of cascade stages in the multi-bit digital phase shifter, greatly reducing the system size, and at the same time reducing the system insertion loss.

[0038] Compared with traditional high and low impedance multimode resonant digital phase shifters, this invention designs a parallel short-circuit stub 402 on the high and low impedance multimode resonator, which improves the freedom of phase slope adjustment of the phase shifter, increases the phase shift bandwidth of the digital phase shifter, and uses a multilayer board to connect four resonators in parallel, making full use of the space of multilayer stacking and further reducing the circuit area.

[0039] Compared to the bulky waveguide phase shifter, this solution, based on a dielectric substrate, is a miniaturized broadband digital phase shifter with advantages such as mature processing technology, low cost, easy integration with switching devices and bias networks, and suitability for mass production. Therefore, it has high application value in mobile communication, satellite communication, and radar systems.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A miniaturized wideband digital phase shifter, characterized in that, It includes a first dielectric layer, a metallic ground layer, a second dielectric layer, a resonator unit, and a transmission structure; The first dielectric layer, the metal ground layer, and the second dielectric layer are sequentially stacked to form a composite dielectric substrate; The resonator unit includes at least one first low-impedance transmission line disposed on the side of the first dielectric layer away from the metal ground layer, at least one second low-impedance transmission line disposed on the side of the second dielectric layer away from the metal ground layer, and a radio frequency switch. In the direction perpendicular to the metal ground layer, the projection shapes of the first low-impedance transmission line and the second low-impedance transmission line are different and the projections at least partially overlap. Both the first low-impedance transmission line and the second low-impedance transmission line are connected to the metal ground layer. The transmission structure includes two couplers located at both ends of the first low-impedance transmission line and a 50-ohm transmission line connected to the end of the coupler. The RF switch is connected between the coupler and the corresponding first low-impedance transmission line. The port of the RF switch is connected to the first low-impedance transmission line and the second low-impedance transmission line at the corresponding position. The RF switch is used to switch the state in which the coupler connects to the first low-impedance transmission line and the second low-impedance transmission line.

2. The miniaturized broadband digital phase shifter according to claim 1, characterized in that, The resonator unit includes two spaced-apart first low-impedance transmission lines and two spaced-apart second low-impedance transmission lines. Both the first and second low-impedance transmission lines include a transmission body and a short-circuit stub connected to one side of the transmission body and extending outward. Both the first and second low-impedance transmission lines are connected to the ports of the RF switch through the corresponding two ends of the transmission body, and are grounded to the metal ground layer through the center of the end edge of the short-circuit stub.

3. The miniaturized broadband digital phase shifter according to claim 2, characterized in that, The positions of the two first low-impedance transmission lines and the two second low-impedance transmission lines correspond one-to-one; the transmission body of the first low-impedance transmission line is rectangular, and the transmission body of the corresponding second low-impedance transmission line is rectangular.

4. The miniaturized broadband digital phase shifter according to claim 3, characterized in that, One of the first low-impedance transmission lines has a transmission body length of 27.6 mm and a width of 4 mm, and its short-circuit branch is rectangular, with a length of 12 mm and a width of 3.5 mm; the other of the first low-impedance transmission lines has a transmission body length of 22.2 mm and a width of 4 mm, and its short-circuit branch is rectangular, with a length of 6 mm and a width of 8.5 mm. One of the second low-impedance transmission lines has a transmission body length of 24.6 mm and a width of 1.2 mm, and its short-circuit branch is rectangular, with a length of 12 mm and a width of 2.4 mm; the other of the second low-impedance transmission lines has a transmission body length of 25 mm and a width of 1.2 mm, and its short-circuit branch is rectangular, with a length of 9.4 mm and a width of 2.7 mm.

5. The miniaturized broadband digital phase shifter according to claim 4, characterized in that, The miniaturized broadband digital phase shifter operates in the 2.4-3.3 GHz frequency band.

6. The miniaturized broadband digital phase shifter according to claim 2, characterized in that, The coupler includes a high-impedance transmission line connected to the radio frequency switch and a coupling transmission line spaced apart from the high-impedance transmission line, with the end of the coupling transmission line connected to the corresponding 50-ohm transmission line. The coupling transmission line is provided in two forms, forming a fork structure, with the two coupling transmission lines respectively spaced apart on both sides of the high impedance transmission line; or, the coupling transmission line is provided in one form, spaced apart on one side of the high impedance transmission line.

7. The miniaturized broadband digital phase shifter according to claim 6, characterized in that, The radio frequency switch uses a single-pole quad-throw radio frequency switch integrated chip. The common terminal of the radio frequency switch is connected to the end of the high-impedance transmission line, and the four switch ports of the radio frequency switch are respectively connected to each of the first low-impedance transmission lines and each of the second low-impedance transmission lines. The switching port of the radio frequency switch is connected to the corresponding second low-impedance transmission line through a metal via, and the metal ground layer has a hole around the metal via.

8. The miniaturized broadband digital phase shifter according to claim 1, characterized in that, The transmission paths of the miniaturized broadband digital phase shifter are symmetrical about its central axis.

9. The miniaturized broadband digital phase shifter according to any one of claims 1-8, characterized in that, At least two resonator units are arranged sequentially, and each adjacent resonator unit is connected by a coupler.

10. The miniaturized broadband digital phase shifter according to claim 9, characterized in that, It also includes a plurality of control endpoints disposed on the composite dielectric substrate, each of the control endpoints being connected to the control port of the radio frequency switch.

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