A new coupler with reconfigurable coupling coefficient based on HMCSIW

Abstract

The present invention provides a novel HMCSIW-based coupler with reconfigurable coupling coefficient, comprising a dielectric substrate, a first metal layer and a second metal layer on the upper and lower surfaces of the dielectric substrate. The first metal layer comprises two symmetrically arranged metal patches, each metal patch comprising a half-mode comb-line substrate integrated waveguide, a trapezoidal transition region and a quarter-circular arc-shaped microstrip line. The two ends of the half-mode comb-line substrate integrated waveguide are respectively connected to the trapezoidal transition region, and the ends of the trapezoidal transition region are respectively connected to the arc-shaped microstrip line. The first metal layer is provided with a plurality of U-shaped groove pairs and coupling coefficient reconstruction components, the U-shaped groove pairs comprising an upper U-shaped groove and a lower U-shaped groove. A gap is provided between the open edges of the two half-mode comb-line substrate integrated waveguides, and the coupling coefficient reconstruction component is provided in the gap. The present invention can achieve the change of the coupling coefficient and switch between multiple coupling coefficients without changing the size of the coupler.

Description

Technical Field

[0001] The invention relates to a novel HMCSIW-based coupler with reconfigurable coupling coefficient, belonging to the technical field of communications. Background Art

[0002] Substrate integrated waveguide (SIW) technology has attracted the attention of many scholars due to its low cost and planarity. SIW-based integrated circuits have been widely used in wireless communication systems. However, due to the presence of metal through-holes, additional RF chokes are required when accessing active devices loaded on the SIW. As an extension of SIW research, comb-line-like substrate integrated waveguide (CSIW) uses a set of quarter-wavelength microstrip open-circuit stubs instead of metal through-holes to form an equivalent electric wall to confine electromagnetic waves in the waveguide. Since the top and bottom metal layers in CSIW are independent, the input and output ports can be isolated from the ground layer to facilitate integration with active devices. Due to the use of a set of quarter-wavelength microstrip open-circuit stubs, CSIW-based devices are generally larger than similar SIW devices.

[0003] To meet the development needs of miniaturization, a half-mode combline-like substrate integrated waveguide (HMCSIW) was proposed. HMCSIW halves the size of a CSIW circuit, and its longitudinal open edges offer a natural advantage for direct integration with active devices.

[0004] In wireless communication systems, couplers are essential components of transceivers or phased array antennas. The paper "Jin H, Zhu Z, Cheng R. Novel broadband coupler based on corrugated half-mode substrate integrated waveguide [J]. IEICE Electronics Express, 2015: 12.20150896." DOI: https: / / doi.org / 10.1587 / elex.12.20150896) proposes a broadband coupler based on HMCSIWs, in which coupling occurs at the equivalent magnetic wall between two parallel HMCSIWs. However, with this structure, the coupling coefficient can only be altered by changing the dimensions. Specifically, the coupling coefficient is modified by varying the distance between the two parallel half-mode combline-like substrate integrated waveguides (HMCSIWs).

[0005] Previous research on combline-like SIB-based couplers has failed to demonstrate digitally tunable coupling coefficients. Therefore, research on digitally tunable coupling coefficients is of great significance. The aforementioned issues are crucial for designing combline-like SIB-based couplers. Summary of the Invention

[0006] The purpose of the present invention is to provide a new type of reconfigurable coupling coefficient coupler based on HMCSIW to solve the problem in the prior art that the coupling coefficient needs to be changed by changing the coupler size under the existing structural design, which makes it difficult to regulate the coupling coefficient.

[0007] The technical solution of the present invention is:

[0008] A novel HMCSIW-based coupler with reconfigurable coupling coefficient includes a dielectric substrate, a first metal layer on the upper and lower surfaces of the dielectric substrate, and a second metal layer. The first metal layer includes two symmetrically arranged metal patches, each of which includes a half-mode comb-line substrate integrated waveguide, a trapezoidal transition region, and a quarter-circular arc microstrip line. The two ends of the half-mode comb-line substrate integrated waveguide are respectively connected to the trapezoidal transition region, and the ends of the trapezoidal transition region are respectively connected to the arc microstrip line. The first metal layer is provided with a plurality of U-shaped groove pairs and coupling coefficient reconstruction components. The U-shaped groove pairs include an upper U-shaped groove and a lower U-shaped groove. The upper U-shaped groove and the lower U-shaped groove are respectively symmetrically arranged between the open edges of the two half-mode comb-line substrate integrated waveguides. A gap is provided between the open edges of the two half-mode comb-line substrate integrated waveguides, and a coupling coefficient reconstruction component is provided in the gap.

[0009] Furthermore, the coupling coefficient reconstruction component includes a plurality of PIN diodes, a plurality of first capacitors and a plurality of second capacitors. The PIN diodes are symmetrically arranged at the gap, and the PIN diodes are respectively arranged between the upper U-shaped groove and the lower U-shaped groove. The first capacitors are respectively provided on both sides of the upper U-shaped groove, and the second capacitors are respectively provided on both sides of the lower U-shaped groove. One end of the PIN diode is connected to both sides of the upper U-shaped groove through the first capacitor, and the other end of the PIN diode is connected to both sides of the lower U-shaped groove through the second capacitor.

[0010] Furthermore, the PIN diodes of the coupling coefficient reconstruction component are arranged at gaps every quarter of the working wavelength.

[0011] Furthermore, the inner sides of the two half-mode comb-line-like substrate integrated waveguides are arranged in parallel.

[0012] Furthermore, the impedance of the arc-shaped microstrip line and the trapezoidal transition region are both 50 ohms.

[0013] Furthermore, in the two symmetrically arranged metal patches, the ends of the arcuate microstrip lines of the upper metal patch respectively form a coupling port and an isolation port, and the ends of the arcuate microstrip lines of the lower metal patch respectively form an input port and a through port.

[0014] Furthermore, the coupling coefficient is adjusted by controlling the on-off of the PIN diode of the coupling coefficient reconstruction component through DC bias.

[0015] Furthermore, the coupling coefficient adjustment process of the new HMCSIW-based coupler with reconfigurable coupling coefficient is as follows: by increasing the number of PIN diodes in the coupling coefficient reconstruction component that are turned on, the energy transfer is enhanced and the coupling coefficient is increased; by reducing the number of PIN diodes in the coupling coefficient reconstruction component that are turned on, the energy transfer is weakened and the coupling coefficient is reduced.

[0016] The beneficial effects of the present invention are:

[0017] First, this new HMCSIW-based coupler with reconfigurable coupling coefficient can change the coupling coefficient, enabling switching between multiple coupling coefficients without changing the coupler dimensions. This achieves the reconfigurable coupling coefficient performance of a combline-like substrate integrated waveguide while maintaining the coupler's performance in all states.

[0018] 2. The present invention uses capacitors to connect the PIN diodes and the half-mode combline substrate integrated waveguide HMCSIW on both sides, thereby isolating the voltage that provides DC bias to the PIN diodes. In this way, the on and off of each PIN diode can be controlled individually, and flexible switching between multiple coupling coefficients can be achieved without changing the size of the coupler.

[0019] 3. This new HMCSIW-based coupler with reconfigurable coupling coefficient can achieve digital control of the coupling coefficient by controlling the number of PIN diodes between the two HMCSIWs that are turned on or off. Experimental verification shows that the phase is stable, and the working bandwidth, reflection coefficient and isolation in each state perform well. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 1 is a schematic structural diagram of a novel coupler with reconfigurable coupling coefficient based on HMCSIW according to an embodiment of the present invention;

[0021] Figure 2 2 is a schematic structural diagram of a half-mode comb-line substrate integrated waveguide and a coupling coefficient reconstruction component in an embodiment;

[0022] Figure 3 1. It is a schematic diagram of S-parameter and phase difference simulation of a specific example of a comb-line substrate integrated waveguide reconfigurable coupler in an embodiment when 0 diodes are turned on;

[0023] Figure 4 1 is a schematic diagram of S-parameter and phase difference simulation of a specific example of a comb-line substrate integrated waveguide reconfigurable coupler according to an embodiment when one diode is turned on;

[0024] Figure 51. It is a schematic diagram of S-parameter and phase difference simulation of a specific example of a comb-line substrate integrated waveguide reconfigurable coupler in an embodiment when two diodes are turned on;

[0025] Figure 6 1. It is a schematic diagram of S-parameter and phase difference simulation of a specific example of a comb-line substrate integrated waveguide reconfigurable coupler in an embodiment when three diodes are turned on;

[0026] Figure 7 1. It is a schematic diagram of S-parameter and phase difference simulation of a specific example of a comb-line substrate integrated waveguide reconfigurable coupler in an embodiment when four diodes are turned on;

[0027] Figure 8 1. It is a schematic diagram of S-parameter and phase difference simulation of a specific example of a comb-line substrate integrated waveguide reconfigurable coupler in an embodiment when five diodes are turned on;

[0028] Figure 9 1 is a schematic diagram illustrating S parameters and phase differences of a specific example of a comb-line substrate integrated waveguide reconfigurable coupler in six cases;

[0029] Wherein: 1- dielectric substrate, 2- first metal layer, 3- gap, 4- U-shaped groove pair, 5- coupling coefficient reconstruction component;

[0030] 21-half-mode comb-line substrate integrated waveguide, 22-trapezoidal transition region, 23-arc-shaped microstrip line;

[0031] 41-upper U-shaped groove, 42-lower U-shaped groove;

[0032] 51-PIN diode, 52-first capacitor, 53-second capacitor. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] Example

[0035] A new type of coupler with reconfigurable coupling coefficient based on HMCSIW, such as Figure 1, comprising a dielectric substrate 1, wherein a first metal layer 2 and a second metal layer are respectively provided on the upper and lower surfaces of the dielectric substrate 1, the first metal layer 2 comprises two symmetrically arranged metal patches, each metal patch comprises a half-mode comb-line substrate integrated waveguide 21, a trapezoidal transition region 22 and a quarter-circle arc-shaped microstrip line 23, the two ends of the half-mode comb-line substrate integrated waveguide 21 are respectively connected to the trapezoidal transition region 22, and the ends of the trapezoidal transition region 22 are respectively connected to the arc-shaped microstrip line 23, the first metal layer 2 is provided with a plurality of U-shaped groove pairs 4 and a coupling coefficient reconstruction component 5, the U-shaped groove pair 4 comprises an upper U-shaped groove 41 and a lower U-shaped groove 42, the upper U-shaped groove 41 and the lower U-shaped groove 42 are respectively symmetrically arranged between the open edges of the two half-mode comb-line substrate integrated waveguides 21, a gap 3 is provided between the open edges of the two half-mode comb-line substrate integrated waveguides 21, and a coupling coefficient reconstruction component 5 is provided at the gap 3.

[0036] This new HMCSIW-based coupler with reconfigurable coupling coefficients can change the coupling coefficient without changing the coupler size and can switch between multiple coupling coefficients. This achieves the reconfigurable coupling coefficient performance of a combline-like substrate integrated waveguide while maintaining the coupler's performance in all states.

[0037] like Figure 2 The coupling coefficient reconstruction component 5 includes a plurality of PIN diodes 51, a plurality of first capacitors 52, and a plurality of second capacitors 53. The PIN diodes 51 are centrally symmetrically arranged at the gap 3, and the PIN diodes 51 are respectively arranged between the upper U-shaped groove 41 and the lower U-shaped groove 42. The first capacitors 52 are respectively provided on both sides of the upper U-shaped groove 41, and the second capacitors 53 are respectively provided on both sides of the lower U-shaped groove 42. One end of the PIN diode 51 is connected to both sides of the upper U-shaped groove 41 through the first capacitor 52, and the other end of the PIN diode 51 is connected to both sides of the lower U-shaped groove 42 through the second capacitor 53.

[0038] In the coupling coefficient reconstruction component 5, first capacitors 52 are located on either side of the upper U-shaped groove 41, and second capacitors 53 are located on either side of the lower U-shaped groove 42 to prevent DC short circuits. The coupling coefficient is adjusted by controlling the on / off state of the PIN diode 51 in the coupling coefficient reconstruction component 5 through DC bias. This enables digital control of the coupling coefficient and flexible switching of the coupling coefficient.

[0039] like Figure 1The top surface of the dielectric substrate 1 is a first metal layer 2. This layer 2 includes two parallel half-mode comb-line rectangles, two pairs of trapezoidal transition regions 22, and two pairs of quarter-arc arc microstrip lines 23. The ends of the arc microstrip lines 23 form four ports: port 1 is the input port, port 2 is the through port, port 3 is the coupled port, and port 4 is the isolated port. The two half-mode comb-line substrate integrated waveguides 21 (HMCSIW) are connected by several coupling coefficient reconstruction components 5. The bottom surface of the dielectric substrate 1 is a second metal layer, serving as the ground plane of the waveguide.

[0040] like Figure 2 The several PIN diodes 51 of the coupling coefficient reconstruction component 5 are placed symmetrically between the two half-mode comb-line substrate integrated waveguides 21HMCSIW. At the open edge of the half-mode comb-line substrate integrated waveguide 21HMCSIW at the corresponding position of the PIN diode 51, a U-shaped groove is opened with the PIN diode 51 as the center, namely the upper U-shaped groove 41 and the lower U-shaped groove 42, and the first capacitor 52 and the second capacitor 53 are placed on the left and right sides of each U-shaped groove. Each PIN diode 51 is then connected to the half-mode comb-line substrate integrated waveguide 21HMCSIW through the two capacitors on the left and right sides of the upper U-shaped groove 41 and the lower U-shaped groove 42, so as to achieve the purpose of individually controlling each PIN diode 51.

[0041] This novel HMCSIW-based coupler with reconfigurable coupling coefficient features two half-mode combline-like substrate integrated waveguides (SIWs) 21 arranged parallel to each other. PIN diodes 51 are loaded at intervals of a quarter of the operating wavelength in the gap 3 between the two SSIWs 21. The impedance of the curved microstrip line 23 and the trapezoidal transition region 22 are both 50 ohms. The dielectric substrate 1 can be made of Rogers 5880 material with a thickness of 0.508 mm. The length of the half-mode comb-line substrate integrated waveguide 21 of the first metal layer 2 is 30 mm, and the width is 8.7 mm. The length of the open branch line is 5.5 mm, and the width is 1 mm. The distance between two adjacent branch lines is 0.6 mm. The lower bottom of the trapezoidal transition zone 22 is 4.8 mm, and the upper bottom is 1.5 mm. The spacing between the open edges of the two half-mode comb-line substrate integrated waveguides 21 HMCSIW is 0.9 mm. The bottom gap width of the upper U-shaped groove 41 and the lower U-shaped groove 42 is 0.3 mm. The left and right side gap widths of the upper U-shaped groove 41 and the lower U-shaped groove 42 are 0.6 mm. The side length of the upper U-shaped groove 41 and the lower U-shaped groove 42 is 1.4 mm. The spacing between two adjacent PIN diodes 51 is 4.6 mm. The model of the PIN diode 51 can both be MADP-000907-14020. The first capacitor 52 and the second capacitor 53 can both be 30 pF.

[0042] In this novel HMCSIW-based coupler with reconfigurable coupling coefficient, the spacing and side length of the two rectangular patches of the half-mode combline-like substrate integrated waveguide 21HMCSIW in the first metal layer 2 can be determined according to design specifications. The loading position and number of the PIN diodes 51 in the coupling coefficient reconstruction component 5 can also be determined according to design specifications. The first capacitor 52 of the coupling coefficient reconstruction component 5 and the spacing between the first capacitor 52 and the half-mode combline-like substrate integrated waveguide 21HMCSIW can also be determined according to design specifications.

[0043] The operating principle of this new HMCSIW-based coupler with reconfigurable coupling coefficient is described as follows: A number of quarter-circuited branch lines replace metal cylinders, forming an electric barrier between the first metal layer 2 and the second metal layer, confining the electromagnetic field and forming a SIW resonant cavity. A half-mode combline substrate integrated waveguide 21 (HMCSIW) is half of a CSIW, with an open edge that radiates the electric field outward. The open edges of two half-mode combline substrate integrated waveguides 21 (HMCSIW) are placed opposite and parallel to each other, achieving electromagnetic coupling and energy transfer. This new HMCSIW-based coupler with reconfigurable coupling coefficient is fed through a quarter-arc arc microstrip line 23 and a trapezoidal transition region 22 to achieve impedance matching. The PIN diodes 51 of the coupling coefficient reconstruction component 5 are placed symmetrically between the inner open edges of the two half-mode combline substrate integrated waveguides 21 (HMCSIW). By controlling the number of PIN diodes 51 that are turned on or off, energy transfer is strengthened or weakened, digitally controlling the change in the coupling coefficient.

[0044] The coupling coefficient adjustment process of this new HMCSIW-based coupler with reconfigurable coupling coefficient is as follows: by increasing the number of PIN diodes 51 of the coupling coefficient reconstruction component 5 that are turned on, the energy transfer is enhanced and the coupling coefficient is increased; by reducing the number of PIN diodes 51 of the coupling coefficient reconstruction component 5 that are turned on, the energy transfer is weakened and the coupling coefficient is reduced.

[0045] This new type of HMCSIW-based coupler with reconfigurable coupling coefficient can isolate the DC bias voltage for the PIN diode 51 by connecting the PIN diode 51 and the half-mode comb-line substrate integrated waveguide 21HMCSIW on both sides with a capacitor. In this way, the on and off of each PIN diode 51 can be controlled individually, and flexible switching between multiple coupling coefficients can be achieved without changing the size of the coupler.

[0046] This new HMCSIW-based coupler with reconfigurable coupling coefficient can achieve digital control of the coupling coefficient by controlling the number of PIN diodes 51 that are turned on or off between two half-mode comb-line substrate integrated waveguides 21HMCSIW. Experimental verification shows that the phase is stable, and the working bandwidth, reflection coefficient and isolation in each state perform well.

[0047] This new HMCSIW-based coupler with reconfigurable coupling coefficient achieves excellent coupling performance. Compared to other types of SIW reconfigurable couplers, the present invention exhibits superior isolation and reflection coefficient performance across both the operating bandwidth and operating frequency range. Furthermore, it has a simple structure and is easy to manufacture.

[0048] The specific example of the novel HMCSIW-based coupler with reconfigurable coupling coefficient in the embodiment is verified by experimental simulation as follows:

[0049] This novel HMCSIW-based coupler with reconfigurable coupling coefficients uses a coupling coefficient reconstruction component 5 composed of five PIN diodes 51, ten first capacitors 52, and ten second capacitors 53. PIN diodes 51 are loaded at intervals of a quarter of the operating wavelength in the gap 3 between two half-mode combline substrate integrated waveguides 21. The five PIN diodes 51 are numbered A, B, C, D, and E from left to right. Bias voltages are used to control the conduction or discontinuation of the five PIN diodes 51. If a PIN diode 51 is on, the number is set to 1; if it is off, the number is set to 0. This allows for different combinations, but the degree of coupling depends only on the number of PIN diodes 51 that are on, not the position of the PIN diodes 51 that are on. However, the position of the PIN diodes 51 that are on can affect the phase difference.

[0050] After simulation optimization, the following six combinations are obtained, corresponding to the change in the number of 5 PIN diodes 51 turned on from 0 to 5. When 0 diodes are turned on, A, B, C, D, and E are 0, 0, 0, 0, 0, respectively; when 1 diode is turned on, A, B, C, D, and E are 0, 0, 1, 0, 0, respectively; when 2 diodes are turned on, A, B, C, D, and E are 0, 1, 1, 0, 0, respectively; when 3 diodes are turned on, A, B, C, D, and E are 0, 1, 1, 1, 0, respectively; when 4 diodes are turned on, A, B, C, D, and E are 1, 1, 1, 1, 0, respectively; when 5 diodes are turned on, A, B, C, D, and E are 1, 1, 1, 1, 1, respectively.

[0051] The simulation results of the novel HMCSIW-based coupler with reconfigurable coupling coefficient are as follows: Figure 3-Figure 8 ,from Figures 3 to 8 The following are the S parameter and phase difference simulation diagrams when the number of diodes turned on ranges from 0 to 5. Figures 3 to 8It can be seen from the results that the simulation bandwidth of this new type of reconfigurable coupling coefficient coupler based on HMCSIW in these six states is 10.9GHz-12.1GHz. Within this bandwidth, the reflection coefficient S11 and the isolation coefficient S41 are both less than -15dB, the phase difference is (87.5±2.5)deg, and the coupling coefficients are 14dB, 10dB, 7.5dB, 6dB, 4.5dB, and 3.5dB, respectively.

[0052] Figure 9 1 is a schematic diagram illustrating the S parameters and phase differences of a specific example of a comb-line substrate integrated waveguide reconfigurable coupler in six cases. Figure 9 It can be seen from the summary results that this new type of reconfigurable coupling coefficient coupler based on HMCSIW shows good coupling performance in all states. It can not only realize digital control of the coupling coefficient, but also has phase stability and simple structure. The working bandwidth, reflection coefficient and isolation in each state perform well.

[0053] The above embodiments are only for illustrating the technical concept of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made to the technical solution in accordance with the technical concept proposed by the present invention fall within the protection scope of the present invention.

Claims

1. A novel HMCSIW-based coupler with reconfigurable coupling coefficients, comprising a dielectric substrate, a first metal layer and a second metal layer on the upper and lower surfaces of the dielectric substrate, wherein the first metal layer comprises two symmetrically arranged metal patches, each of which comprises a half-mode comb-line substrate integrated waveguide, a trapezoidal transition region, and a quarter-circular arc-shaped microstrip line, wherein the two ends of the half-mode comb-line substrate integrated waveguide are respectively connected to the trapezoidal transition region, and the ends of the trapezoidal transition region are respectively connected to the arc-shaped microstrip line, and the first metal layer is provided with a plurality of U-shaped slot pairs and a coupling coefficient reconstruction component, wherein the U-shaped slot pairs comprise an upper U-shaped slot and a lower U-shaped slot, and the upper U-shaped slot and the lower U-shaped slot are respectively symmetrically arranged on the two half-mode comb-line substrate integrated waveguides. A gap is provided between the open edges of the comb-line substrate integrated waveguide and the open edges of the two half-mode comb-line substrate integrated waveguides, and a coupling coefficient reconstruction component is provided at the gap; the coupling coefficient reconstruction component includes a plurality of PIN diodes, a plurality of first capacitors and a plurality of second capacitors, the PIN diodes are centrally symmetrically arranged at the gap, and the PIN diodes are respectively arranged between the upper U-shaped groove and the lower U-shaped groove, the first capacitors are respectively provided on both sides of the upper U-shaped groove, and the second capacitors are respectively provided on both sides of the lower U-shaped groove, one end of the PIN diode is connected to both sides of the upper U-shaped groove through the first capacitor, and the other end of the PIN diode is connected to both sides of the lower U-shaped groove through the second capacitor.

2. The novel HMCSIW-based coupler with reconfigurable coupling coefficient according to claim 1, characterized in that: The PIN diodes of the coupling coefficient reconstruction component are arranged at gaps every quarter of the working wavelength.

3. The novel HMCSIW-based coupler with reconfigurable coupling coefficient according to claim 1 or 2, characterized in that: Two half-mode comb-line-like substrate integrated waveguides are arranged in parallel on the inner sides.

4. The novel HMCSIW-based coupler with reconfigurable coupling coefficient according to claim 1 or 2, characterized in that: The impedance of the arc-shaped microstrip line and the trapezoidal transition region are both 50 ohms.

5. The novel HMCSIW-based coupler with reconfigurable coupling coefficient according to claim 1 or 2, characterized in that: In the two symmetrically arranged metal patches, the ends of the arcuate microstrip lines of the upper metal patch respectively form a coupling port and an isolation port, and the ends of the arcuate microstrip lines of the lower metal patch respectively form an input port and a through port.

6. The novel HMCSIW-based coupler with reconfigurable coupling coefficient according to claim 1 or 2, characterized in that: The coupling coefficient is adjusted by controlling the on-off of the PIN diode of the coupling coefficient reconstruction component through DC bias.

7. The novel HMCSIW-based coupler with reconfigurable coupling coefficient according to claim 1 or 2, characterized in that: The coupling coefficient adjustment process of the new HMCSIW-based reconfigurable coupling coefficient coupler is as follows: by increasing the number of PIN diodes in the coupling coefficient reconstruction component that are turned on, the energy transfer is enhanced and the coupling coefficient is increased; by reducing the number of PIN diodes in the coupling coefficient reconstruction component that are turned on, the energy transfer is weakened and the coupling coefficient is reduced.

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