Multiplexer and detector

Abstract

The present application provides a multiplexer and a detector, wherein the multiplexer includes a dielectric substrate, a connection structure, and a plurality of bandpass filters with different operating frequencies. A conductive film layer is provided on one side plane of the dielectric substrate, and the conductive film layer includes a signal line and a ground plate located on the side of the signal line. The connection structure is provided on the conductive film layer, and includes a main branch and a plurality of branches, wherein the main branch is respectively connected to the plurality of branches, and the main branch serves as an input port of the multiplexer. A plurality of bandpass filters with different operating frequencies are all connected to the signal line and the ground plate. Each bandpass filter includes a first port and a second port, wherein the first port is respectively connected to the corresponding branch, and the second port serves as an output port of the multiplexer. The signal line and the ground plate, the connection structure, and the bandpass filter can be located on the same side plane of the dielectric substrate, thereby reducing metal loss and radiation loss, and facilitating integration with other components of the detector.

Description

Technical Field

[0001] The present application relates to the field of superconducting devices, and in particular to a multiplexer and a detector. Background Art

[0002] In astronomical observation and imaging systems, high-sensitivity low-temperature superconducting detectors play an important role, especially in the higher-frequency millimeter-wave and terahertz bands. Currently, multiple detector pixel units are used to form a large-scale array, which can improve spatial resolution and field of view, and is conducive to improving system performance. The use of multi-color pixels can realize observations in multiple frequency bands at the same time, which is conducive to improving the utilization of millimeter-wave observation frequency bands and increasing millimeter-wave communication rates, which requires a multiplexer to achieve.

[0003] In the related art, the multiplexer adopts a quarter-wavelength terminal short-circuit microstrip structure, in which one side of the dielectric substrate of the structure is a metal conductor and the other side is a ground plane. The metal conductor is connected to the ground plane through a metal via. The process is complicated and is not conducive to the integration of the multiplexer and other components of the detector. In addition, the metal loss and radiation loss of the structure are large, resulting in reduced performance of the multiplexer. Summary of the invention

[0004] The present application provides a multiplexer and a detector to solve at least part of the problems in the related art.

[0005] On one hand, the present application provides a multiplexer, comprising:

[0006] A dielectric substrate, one side plane of which is provided with a conductive film layer, the conductive film layer includes a signal line and a ground plate located on the side of the signal line, and there is a gap between the signal line and the ground plate;

[0007] a connection structure, provided in the conductive film layer, comprising a main branch and a plurality of branches, wherein the main branch is respectively connected to the plurality of branches, and the main branch serves as an input port of the multiplexer; and

[0008] Multiple bandpass filters with different operating frequencies are all connected to the signal line and the ground plate. Each of the bandpass filters includes a first port and a second port. The first port is respectively connected to the corresponding branch, and the second port serves as the output port of the multiplexer.

[0009] Optionally, the multiple branches include a first branch and a second branch, the multiple bandpass filters with different operating frequencies include a first bandpass filter and a second bandpass filter, the first port of the first bandpass filter is connected to the first branch, and the first port of the second bandpass filter is connected to the second branch.

[0010] Optionally, the impedance of each branch matches the operating frequency of the corresponding bandpass filter, and does not match the operating frequencies of the bandpass filters corresponding to other branches.

[0011] Optionally, each of the bandpass filters includes a first resonance unit and a second resonance unit, the first resonance unit and the second resonance unit both generate zero points and poles, the first resonance unit and the second resonance unit are coupled and connected, and the frequency of the pole is between the frequencies of the zero points.

[0012] Optionally, the ground plane is provided on both sides of the signal line, the first resonance unit and the second resonance unit are connected to the signal line and the ground plane on both sides of the signal line, and the first resonance unit and the second resonance unit are symmetrically arranged with respect to the signal line.

[0013] Optionally, the first resonance unit and the second resonance unit are coupled and connected via the signal line; and / or

[0014] The first resonance unit and the second resonance unit are quasi-lumped resonance units.

[0015] Optionally, each of the bandpass filters includes two first resonance units and two second resonance units, wherein one of the first resonance units and one of the second resonance units are coupled to form a first coupling unit, another of the first resonance units and another of the second resonance units are coupled to form a second coupling unit, and the first coupling unit and the second coupling unit are coupled to each other through two of the first resonance units or two of the second resonance units; the first coupling unit and the second coupling unit are symmetrically arranged about the coupling point between the first coupling unit and the second coupling unit; and the first coupling unit and the second coupling unit are coupled through the signal line.

[0016] Optionally, the first resonant unit includes a first capacitor and a first inductor, the first capacitor and the first inductor are connected in parallel between the signal line and the ground plane, wherein the first capacitor is an interdigital capacitor;

[0017] The second resonant unit includes a second capacitor, a second inductor and a third inductor, the second capacitor is connected in series with the signal line, the second inductor and the second capacitor are connected in parallel, and the third inductor is connected between the signal line and the ground plane; wherein the second capacitor is a finger capacitor.

[0018] Optionally, the first resonance unit includes two first capacitors and two first inductors, and the two first capacitors and the two first inductors are symmetrically arranged about the signal line;

[0019] The second resonance unit includes two second inductors and two third inductors, and the first capacitor, the two second inductors and the two third inductors are all symmetrically arranged about the signal line.

[0020] On the other hand, the present application provides a detector, including an antenna, an orthogonal mode coupler, a plurality of dynamic inductive thermal radiometers and a multiplexer, wherein the antenna is connected to the orthogonal mode coupler, the orthogonal mode coupler is connected to the input port, the plurality of dynamic inductive thermal radiometers are respectively connected to the plurality of output interfaces, and the orthogonal mode coupler, the plurality of dynamic inductive thermal radiometers and the multiplexer share one dielectric substrate.

[0021] The multiplexer provided in the present application includes a dielectric substrate, a connection structure, and a plurality of bandpass filters with different operating frequencies. A conductive film layer is provided on one side plane of the dielectric substrate, the conductive film layer includes a signal line and a grounding plate located on the side of the signal line, and the connection structure is provided on the conductive film layer, and a plurality of bandpass filters with different operating frequencies are connected to the signal line and the grounding plate. The signal line and the grounding plate, the connection structure, and the bandpass filter can be located on the same side plane of the dielectric substrate, so that the field distribution of the multiplexer is concentrated between the signal line and the grounding plate on the same layer, which can reduce metal loss and radiation loss, improve the performance of the multiplexer, and the structure and process are simple, and grounding can be achieved on the same layer without grounding vias, which is conducive to integration with other components of the detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0023] Figure 1 It is a structural schematic diagram of a multiplexer shown in an embodiment of the present application;

[0024] Figure 2 for Figure 1 A schematic structural diagram of the first resonant unit in the multiplexer shown;

[0025] Figure 3 for Figure 2 An equivalent circuit diagram of the first resonance unit shown;

[0026] Figure 4 for Figure 1 A schematic structural diagram of the second resonance unit in the multiplexer shown;

[0027] Figure 5 for Figure 4 An equivalent circuit diagram of the second resonance unit shown;

[0028] Figure 6 for Figure 1A schematic diagram of resonance characteristics of a first resonance unit and a second resonance unit in the multiplexer shown;

[0029] Figure 7 It is a structural schematic diagram of the first bandpass filter in the multiplexer shown in the embodiment of the present application;

[0030] Figure 8 for Figure 7 An equivalent circuit diagram of the first bandpass filter in the multiplexer shown;

[0031] Fig. 9 It is a simulation result diagram of the S parameters of the duplexer shown in the embodiment of the present application.

[0032] Figure numerals: multiplexer 1, dielectric substrate 2, connection structure 3, bandpass filter 4, input interface 101, first output port 102, second output port 103, conductive film layer 5, signal line 51, ground plate 52, main branch 31, branch 32, first branch 321, second branch 322, first bandpass filter 401, second bandpass filter 402, first resonance unit A, second resonance unit B, first capacitor 41, first inductor 42, second capacitor 43, second inductor 44, third inductor 45. DETAILED DESCRIPTION

[0033] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0034] Please refer to Figure 1 , Figure 1 Schematic diagram of the structure of the multiplexer 1 shown in the embodiment of the present application. Figure 1 As shown, the multiplexer 1 includes a dielectric substrate 2, a connection structure 3 and a plurality of bandpass filters 4 with different operating frequencies. A conductive film layer 5 is provided on one side plane of the dielectric substrate 2, and there is no metal coating on the bottom of the dielectric substrate 2. The conductive film layer 5 is made of superconducting material, which usually has very low resistance and can conduct current without energy loss below the critical temperature, thereby reducing loss and enhancing low-temperature conductivity. The conductive film layer 5 can be processed using a photolithography process, and the processing accuracy can reach the micron level. The conductive film layer 5 is provided on the dielectric substrate 2, and the dielectric substrate 2 can be used as a substrate, which is convenient for the integration and processing of various functional devices in the system.

[0035] The conductive film layer 5 includes a signal line 51 and a ground plane 52 located on the side of the signal line 51, and there is a gap between the signal line 51 and the ground plane 52. Figure 1 In the illustrated embodiment, grounding plates 52 are provided on both sides of the signal line 51, the signal line 51 is located between the grounding plates 52, and there are gaps between the signal line 51 and the grounding plates 52 on both sides to facilitate connection between the device provided on the medium and the signal line 51 and the grounding plates 52.

[0036] The connection structure 3 is provided on the conductive film layer 5, and includes a main branch 31 and a plurality of branches 32. The main branch 31 is respectively connected to the plurality of branches 32. The main branch 31 serves as the input port 101 of the multiplexer 1 and can receive a plurality of signals with different operating frequencies. The plurality of bandpass filters 4 with different operating frequencies are all connected to the signal line 51 and the ground plate 52.

[0037] Each bandpass filter 4 includes a first port and a second port, the first port is connected to the corresponding branch 32 respectively, and the second port is used as the output port of the multiplexer 1, so that the signal of the corresponding working frequency can enter the corresponding bandpass filter 4 through the branch 32 and the first port, and output through the second port. The multiplexer 1 can distribute signals of different frequencies input through an input port 101 to different output channels for output, and can avoid signal interference between different output channels, and is widely used in the field of signal transmission.

[0038] A conductive film layer 5 is provided on one side plane of the dielectric substrate 2, the conductive film layer 5 includes a signal line 51 and a ground plane 52 located on the side of the signal line 51, and the connection structure 3 is provided on the conductive film layer 5, and a plurality of bandpass filters 4 with different operating frequencies are connected to the signal line 51 and the ground plane 52. The signal line 51 and the ground plane 52, the connection structure 3, and the bandpass filter 4 can be located on the same side plane of the dielectric substrate 2, so that the field distribution of the multiplexer 1 is concentrated between the signal line 51 and the ground plane on the same layer, which can reduce metal loss and radiation loss, improve the performance of the multiplexer 1, and the structure and process are simple, and grounding can be achieved on the same layer without grounding vias, which is conducive to integration with other components of the detector.

[0039] exist Figure 1 In the illustrated embodiment, the multiplexer 1 is a duplexer, and the plurality of branches 32 include a first branch 321 and a second branch 322. The plurality of bandpass filters 4 with different operating frequencies include a first bandpass filter 401 and a second bandpass filter 402, wherein a first port of the first bandpass filter 401 is connected to the first branch 321, and a first port of the second bandpass filter 402 is connected to the second branch 322. The second port of the first bandpass filter 401 serves as a first output port 102 of the duplexer, and the second port of the second bandpass filter 402 serves as a second output port 103 of the duplexer.

[0040] exist Figure 1 In the illustrated embodiment, the connection structure 3 is T-shaped, and the duplexer is composed of a T-shaped connection structure 3 and two first bandpass filters 401 and second bandpass filters 402 with different operating frequencies. For example, the center frequency of the first bandpass filter 401 is 280 GHz, and the 3 dB fractional bandwidth is about 17.9%, and the center frequency of the second bandpass filter 402302 is 220 GHz, and the 3 dB fractional bandwidth is about 25.5%. The duplexer has three ports, an input port 101 and two output ports, and the two output ports are respectively a first output port 102 and a second output port 103. The T-shaped connection structure 3 includes a main branch 31, a first branch 321 and a second branch 322, wherein the main branch 31 is perpendicular to the first branch 321 and the second branch 322. The first branch 321 and the second branch 322 are parallel and are respectively located on both sides of the main branch 31.

[0041] The impedance of each branch 32 matches the operating frequency of the corresponding bandpass filter 4, and does not match the operating frequency of the bandpass filter 4 corresponding to other branches 32. In this way, the isolation of the multiplexer 1 can be improved, ensuring that the electromagnetic waves of the multiple branches 32 of the connection structure 3 are less leaked from each other, and achieving better isolation between different channels. Specifically, the isolation between different channels can be achieved by using a quarter-wavelength impedance transformation to find an equivalent open-circuit surface.

[0042] The first resonant unit A and the second resonant unit B are quasi-lumped resonant units. The quasi-lumped resonant unit has a compact and small size and a high quality factor, so that the size of the duplexer is about 300×50 μm2, which is about 70% smaller than the duplexer using a quarter-terminal short-circuited microstrip line. The compact structure is more conducive to large-scale integration.

[0043] exist Figure 1 In the illustrated embodiment, each bandpass filter 4 includes a first resonance unit A and a second resonance unit B. The first resonance unit A and the second resonance unit B both generate zero points and poles. The first resonance unit A and the second resonance unit B are coupled and connected, and the frequency of the pole is between the frequency of the zero point.

[0044] When the first resonance unit A and the second resonance unit B are coupled and connected, the frequency of the pole is located between the frequency of the zero. In this way, the first resonance unit A and the second resonance unit B form a frequency response with flatness in the band and strong out-of-band suppression through appropriate coupling, realizing the millimeter wave bandpass filter 4 of the designed frequency band, so that it has a compact structure and strong out-of-band suppression. The transmission zero point of each channel filter is appropriately allocated to the passband of another channel filter, which can improve the output isolation and out-of-band suppression. There are transmission zero points on both sides of the two passbands, so it has excellent passband frequency selection performance and out-of-band suppression performance.

[0045] like Figure 1 As shown, ground plates 52 are provided on both sides of the signal line 51, the first resonance unit A and the second resonance unit B are connected to the signal line 51 and the ground plates 52 on both sides of the signal line 51, and the first resonance unit A and the second resonance unit B are symmetrically arranged with respect to the signal line 51. By providing ground plates 52 on both sides of the signal line 51, the signal line 51 is located between the ground plates 52, and there are gaps between the signal line 51 and the ground plates 52 on both sides, it is convenient to connect the device arranged on the medium with the signal line 51 and the ground plates 52. By symmetrically arranging the first resonance unit A and the second resonance unit B with respect to the signal line 51, it is ensured that a smaller common mode radiation loss is generated in a higher frequency band.

[0046] The first resonant unit A and the second resonant unit B are quasi-lumped resonant units. The quasi-lumped resonant unit has a compact and small size and a high quality factor. When the bandpass filter 4 is designed, a flat passband and multiple out-of-band transmission zeros can be achieved through the combination of quasi-lumped capacitors and inductors, thereby improving the out-of-band suppression performance, which is beneficial for the duplexer to achieve good passband transmission performance and isolation.

[0047] Please refer to Figure 2 , Figure 2 for Figure 1 The schematic diagram of the structure of the first resonant unit A in the multiplexer 1 is shown. Figure 2 As shown, the first resonant unit A includes a signal line 51, a dielectric substrate 2, a grounding plate 52, a first capacitor 41 and a first inductor 42. The first capacitor 41 and the first inductor 42 are connected in parallel between the signal line 51 and the grounding plate 52, which is equivalent to the first capacitor 41 and the first inductor 42 being connected in parallel to the ground relative to the signal line 51. Among them, the first capacitor 41 is a finger capacitor. The finger capacitor is a capacitor whose electrodes are designed as multiple interlaced finger structures, thereby providing a larger effective capacitance area. Compared with traditional planar capacitors, the finger capacitor has a larger capacitance value and can improve the integration density of the capacitor.

[0048] And in Figure 2 In the illustrated embodiment, the first resonant unit A includes two first capacitors 41 and two first inductors 42, and the two first capacitors 41 and the two first inductors 42 are symmetrically arranged about the signal line 51. By symmetrically arranging the two first capacitors 41 and the two first inductors 42 about the signal line 51, it is ensured that a smaller common-mode radiation loss is generated in a higher frequency band.

[0049] Please refer to Figure 3 , Figure 3 for Figure 2 The equivalent circuit diagram of the first resonance unit A is shown in FIG. Since the conductive film layer 5 is formed of a superconducting film, the resistance of the conductor can be ignored. Figure 2The equivalent circuit of the first resonant unit A is shown as Figure 4 As shown, CA is the equivalent capacitance of the two first capacitors 41, LpA is the parasitic inductance of the two first capacitors 41, LA is the equivalent inductance of the two first inductors 42, and CpA is the substrate parasitic capacitance of the two first capacitors 41 and the two first inductors 42. According to the circuit zero-pole generation mechanism, the first resonant unit A can generate a transmission pole and a transmission zero.

[0050] The zero point is mainly generated by the CA and LpA series loop connected in parallel to the ground. From the main signal path, when the equivalent input impedance of the series ground loop composed of CA and LpA is 0 at a certain frequency, the signal will be short-circuited, that is, a transmission zero point is formed at this frequency. The frequencies of the zero point and the pole can be calculated through the equivalent circuit of the first resonant unit A. The frequencies of the zero point and the pole are represented by the capacitance and inductance values. By controlling the values ​​of the first capacitor 41 and the first inductor 42, the zero point frequency can be made higher than the pole frequency.

[0051] Please refer to Figure 4 , Figure 4 for Figure 1 The structural diagram of the second resonant unit B in the multiplexer 1 is shown in FIG. Figure 4 As shown, the second resonance unit B includes a signal line 51, a dielectric substrate 2, a ground plane 52, a second capacitor 43, a second inductor 44 and a third inductor 45, the second capacitor 43 is connected in series with the signal line 51, the second inductor 44 and the second capacitor 43 are connected in parallel, and the third inductor 45 is connected between the signal line 51 and the ground plane 52. Among them, the second capacitor 43 is a forked-finger capacitor. The second resonance unit B includes two second inductors 44 and two third inductors 45, and the first capacitor 41, the two second inductors 44 and the two third inductors 45 are all symmetrically arranged about the signal line 51. By making the first capacitor 41, the two second inductors 44 and the two third inductors 45 all symmetrically arranged about the signal line 51, it can be ensured that a smaller common-mode radiation loss is generated in a higher frequency band.

[0052] Please refer to Figure 5 , Figure 5 for Figure 4 The equivalent circuit diagram of the second resonant unit B is shown in FIG. The equivalent circuit model of the second capacitor 43, the second inductor 44 and the third inductor 45 is as follows: Figure 4 After the connection, the parallel capacitors with the same node are combined to obtain the equivalent circuit diagram of the second resonant unit B as shown in Figure 5As shown. CB is the equivalent capacitance of the second capacitor 43, LpB is the parasitic inductance of the second capacitor 43, L1B is the equivalent inductance of the two second inductors 44, L2B is the equivalent inductance of the two third inductors 45, and Cp1B and Cp2B are the substrate parasitic capacitances. According to the circuit zero-pole generation mechanism, the second resonant single can generate two transmission poles and one transmission zero, wherein the zero is generated by the loop formed by CB, LpB and L1B, and the two poles are generated by the CB, LpB series circuit and the L2B, Cp1B and Cp2B parallel grounding circuit. By adjusting the values ​​of the second capacitor 43 and the second inductor 44 and the third inductor 45, the zero frequency position can be made lower than the pole.

[0053] Please refer to Figure 6 , Figure 6 for Figure 1 Schematic diagram of the resonance characteristics of the first resonance unit A and the second resonance unit B in the multiplexer 1 shown. In the embodiment of the present application, the frequency of the zero point and the pole generated by the first resonance unit A can be controlled by controlling the component values ​​of the first capacitor 41 and the first inductor 42, so that the zero frequency generated by the first resonance unit A is higher than the pole frequency. The frequency of the zero point and the pole generated by the second resonance unit B can be controlled by controlling the values ​​of the second capacitor 43, the second inductor 44, and the third inductor 45, so that the pole frequency generated by the second resonance unit B is higher than the pole frequency. When the first resonance unit A is coupled with the second resonance unit B, the frequency of the pole can be located between the frequency of the zero point by controlling the values ​​of the first capacitor 41, the first inductor 42, the second capacitor 43, the second inductor 44, and the third inductor 45.

[0054] exist Figure 6 In the figure, the horizontal axis is the frequency and the vertical axis is the transmission coefficient. unitA is the transmission coefficient curve of the first resonance unit A, and unitB is the transmission coefficient curve of the second resonance unit B. Figure 6 It can be seen that the first resonant unit A has a pole and a zero with a frequency higher than it. The second resonant unit B has two poles and a zero with a frequency lower than it.

[0055] The resonance characteristics of the first resonance unit A and the second resonance unit B show that by performing appropriate coupling between the first resonance unit A and the second resonance unit B, the frequency response of the required passband can be constructed, the structure is compact, and transmission zeros can be generated in both the upper and lower stopbands of the passband, which is conducive to achieving high frequency selectivity. In this embodiment, the first resonance unit A and the second resonance unit B are coupled through the signal line 51. Since the capacitive coupling is reflected as a series gap on the signal line 51, radiation loss is easily caused. In the embodiment of the present application, the first resonance unit A and the second resonance unit B are coupled through the signal line 51, which is reflected as inductive coupling, which can reduce radiation loss compared to the capacitive coupling method.

[0056] Please refer to Figure 7 , Figure 7 FIG. 4 is a schematic diagram of the structure of the first bandpass filter 401 in the multiplexer 1 shown in the embodiment of the present application. Figure 7 In the illustrated embodiment, each bandpass filter 4 includes two first resonance units A and two second resonance units B, wherein one first resonance unit A and one second resonance unit B are coupled to form a first coupling unit, and another first resonance unit A and another second resonance unit B are coupled to form a second coupling unit. The first coupling unit and the second coupling unit are coupled to each other through two first resonance units A or two second resonance units B. The first coupling unit and the second coupling unit are coupled through a signal line 51. Coupling through the signal line 51 is embodied as inductive coupling, which can reduce radiation loss compared to capacitive coupling. Through coupling between the two first resonance units A and the two second resonance units B, a six-pole and three-zero passband can be obtained, and sufficient poles and zeros are conducive to achieving good passband flatness and frequency selectivity.

[0057] The first coupling unit and the second coupling unit are symmetrically arranged about the coupling point of the first coupling unit and the second coupling unit. A coupling structure of the first resonance unit A, the second resonance unit B, the second resonance unit B, and the first resonance unit A can be formed, and a coupling structure of the second resonance unit B, the first resonance unit A, the first resonance unit A, and the second resonance unit B can also be formed.

[0058] Similarly, the second bandpass filter 402 has a similar structure and can be operated at a different operating frequency from the first bandpass filter 401 by changing the physical dimensions of the first resonance unit A and the second resonance unit B. Other bandpass filters 4 can be operated at different operating frequencies by changing their physical dimensions.

[0059] Figure 8 for Figure 7 FIG. 4 is a schematic diagram of an equivalent circuit of the first bandpass filter 401 in the multiplexer 1. Figure 3 and Figure 5 The equivalent circuit model of the first resonant unit A and the second resonant unit B is constructed to construct the first bandpass filter 401 to achieve a good bandpass frequency response. The second resonant unit B and the first resonant unit A are inductively coupled through the signal line 51, represented by the inductor LM12, the first resonant unit A and the first resonant unit A signal line 51 are inductively coupled, represented by the inductor LM23, and the first resonant unit A and the second resonant unit B are inductively coupled through the signal line 51, represented by the inductor LM34.

[0060] The inductive coupling strength can be adjusted through the signal line 51 to achieve the desired frequency response. The bandpass filter circuit formed has a passband center frequency of 280 GHz, and both the upper and lower sidebands have two transmission zeros, which can achieve a sixth-order bandpass frequency response with a flat passband and good out-of-band suppression characteristics. Similarly, the equivalent circuit diagram of the second bandpass filter 402 is similar, but the values ​​of the capacitor and inductor components are different, so that the working passband center frequency is 220 GHz.

[0061] Please refer to Fig. 9 , Fig. 9 HFSS is used to simulate the frequency response of the duplexer in the above embodiment to verify its performance. Figure 8 As shown. The two passband center frequencies of the duplexer are 220 GHz (the operating frequency of the first bandpass filter 401) and 280 GHz (the operating frequency of the second bandpass filter 402). S11 is the return loss curve of the duplexer input port 101, S21 is the insertion loss curve of the first output port 102 of the duplexer, S31 is the insertion loss curve of the second output port 103 of the duplexer, and S32 is the isolation curve of the first output port 102 and the second output port 103 of the duplexer. It can be seen that in the two frequency bands of 220 GHz and 280 GHz, the return loss of the input port 101 of the duplexer is less than -16 dB, and the insertion losses of the first output port 102 and the second output port 103 are both less than 0.5 dB. Figure 8 It is proved that the signals of the duplexer design frequency band obtained by the method of the present invention can pass well, while attenuating the signals of other unnecessary frequency bands. And the isolation between the first output port 102 and the second output port 103 is greater than 42 dB, which proves that the signals of the two frequency bands in the first bandpass filter 401 and the second bandpass filter 402 of the duplexer basically do not interfere with each other, and the feasibility of the duplexer of the present invention is verified by simulation.

[0062] On the other hand, the present application provides a detector, including an antenna, an orthogonal mode coupler, a plurality of dynamic inductive thermal radiometers and a multiplexer 1, wherein the antenna is connected to the orthogonal mode coupler, the orthogonal mode coupler is connected to the input port 101, the plurality of dynamic inductive thermal radiometers are respectively connected to a plurality of output interfaces, and the orthogonal mode coupler, the plurality of dynamic inductive thermal radiometers and the multiplexer 1 share a dielectric substrate 2. This is conducive to integrated design and large-scale integration of pixels. In addition, the signal line 51 is in the same layer as the ground plane, which simplifies the layer process and facilitates processing. This avoids the problem that in the conventional microstrip line multiplexer with a quarter-wavelength terminal short circuit, the metal conductor and the ground plane are not in the same plane, and a ground plane needs to be set on the other side of the dielectric substrate 2, and grounding is achieved through metal vias, which makes the process complicated and inconvenient to integrate.

[0063] The detector is mainly made of superconducting film. The multiplexer 1 provided in the embodiment of the present application is also made of superconducting film. It is directly interconnected and integrated with the orthogonal mode coupler and the dynamic inductive thermal radiation meter on the silicon substrate. The photolithography process is used to obtain a millimeter wave superconducting detector using a simple single-layer planar structure. The structure is simple, easy to manufacture, small in size, easy to integrate, and has broad application prospects in superconducting detector arrays.

[0064] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0065] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A multiplexer, characterized in that: include: A dielectric substrate, one side plane of which is provided with a conductive film layer, the conductive film layer includes a signal line and a ground plate located on the side of the signal line, and there is a gap between the signal line and the ground plate; A connection structure, provided in the conductive film layer, comprising a main branch and a plurality of branches, wherein the main branch is respectively connected to the plurality of branches, and the main branch serves as an input port of the multiplexer; and Multiple bandpass filters with different operating frequencies are all connected to the signal line and the ground plate. Each of the bandpass filters includes a first port and a second port. The first port is respectively connected to the corresponding branch, and the second port serves as the output port of the multiplexer.

2. The multiplexer according to claim 1, characterized in that: The multiple branches include a first branch and a second branch, the multiple bandpass filters with different operating frequencies include a first bandpass filter and a second bandpass filter, the first port of the first bandpass filter is connected to the first branch, and the first port of the second bandpass filter is connected to the second branch.

3. The multiplexer according to claim 1, characterized in that: The impedance of each branch matches the operating frequency of the corresponding bandpass filter, and does not match the operating frequencies of the bandpass filters corresponding to other branches.

4. The multiplexer according to claim 1, wherein: Each of the bandpass filters includes a first resonance unit and a second resonance unit, the first resonance unit and the second resonance unit both generate a zero point and a pole, the first resonance unit and the second resonance unit are coupled and connected, and the frequency of the pole is located between the frequencies of the zero point.

5. The multiplexer according to claim 4, characterized in that: The ground plates are provided on both sides of the signal line, the first resonance unit and the second resonance unit are connected to the signal line and the ground plates on both sides of the signal line, and the first resonance unit and the second resonance unit are symmetrically arranged about the signal line.

6. The multiplexer according to claim 4, characterized in that: The first resonance unit and the second resonance unit are coupled and connected via the signal line; and / or The first resonance unit and the second resonance unit are quasi-lumped resonance units.

7. The multiplexer according to claim 4, characterized in that: Each of the bandpass filters comprises two first resonance units and two second resonance units, wherein one of the first resonance units and one of the second resonance units are coupled to form a first coupling unit, another of the first resonance units and another of the second resonance units are coupled to form a second coupling unit, and the first coupling unit and the second coupling unit are coupled to each other through the two first resonance units or the two second resonance units; The first coupling unit and the second coupling unit are symmetrically arranged about a coupling point between the first coupling unit and the second coupling unit; the first coupling unit and the second coupling unit are coupled through the signal line.

8. The multiplexer according to claim 4, characterized in that: The first resonant unit includes a first capacitor and a first inductor, the first capacitor and the first inductor are connected in parallel between the signal line and the ground plane, wherein the first capacitor is an interdigital capacitor; The second resonant unit includes a second capacitor, a second inductor and a third inductor, the second capacitor is connected in series with the signal line, the second inductor and the second capacitor are connected in parallel, and the third inductor is connected between the signal line and the ground plane; wherein the second capacitor is a finger capacitor.

9. The multiplexer according to claim 8, characterized in that: The first resonance unit includes two first capacitors and two first inductors, and the two first capacitors and the two first inductors are symmetrically arranged about the signal line; The second resonance unit includes two second inductors and two third inductors, and the first capacitor, the two second inductors and the two third inductors are all symmetrically arranged about the signal line.

10. A detector, comprising an antenna, an orthogonal mode coupler, a plurality of dynamic inductive thermal radiometers and a multiplexer as described in any one of claims 1 to 9, wherein the antenna is connected to the orthogonal mode coupler, the orthogonal mode coupler is connected to the input port, the plurality of dynamic inductive thermal radiometers are respectively connected to the plurality of output ports, and the orthogonal mode coupler, the plurality of dynamic inductive thermal radiometers and the multiplexer share one dielectric substrate.

Images