A high frequency ratio microwave millimeter wave cross-band filter circuit and chip

Abstract

The present invention provides a high frequency ratio microwave millimeter wave cross-band filter circuit and chip. The circuit comprises a high frequency bandpass circuit and a low frequency bandpass circuit. The high frequency bandpass circuit comprises a first coupling line and a second coupling line. A dual frequency signal is input into the first coupling line from an input port. A high frequency signal in the dual frequency signal is coupled to the high frequency bandpass circuit through the first coupling line and then input into the second coupling line. The high frequency signal is coupled through the second coupling line and output to an output port. The low frequency bandpass circuit comprises a first series resonator and a second series resonator connected to each other. The first series resonator is connected to the first coupling line, and the second series resonator is connected to the second coupling line. The low frequency signal in the dual frequency signal is output to the second coupling line through a path formed by two series resonators connected to each other, and then output to the output port by the second coupling line.

Description

Technical Field

[0001] The present invention relates to the field of microwave transmission technology, and in particular to a high frequency ratio microwave millimeter wave cross-band filter circuit and chip. Background Art

[0002] In recent years, with the development of mobile communication systems, more electromagnetic wave frequency bands are used for mobile communications. In order to support 2-4G multi-frequency and multi-mode communication signals, mobile communication terminals must have the ability to work in multiple frequency bands. In recent years, dual-frequency or multi-frequency microwave devices have received widespread attention from microwave engineers.

[0003] In the 4G era, microwave filters all work in the Sub-6GHz frequency band, and the interval between the two working frequencies of dual-frequency devices is only a few hundred MHz to one or two thousand MHz, and the frequency ratio is only about 1-3. However, with the development of technologies such as industrial Internet of Things and cloud computing, mobile communication systems must effectively meet the communication needs of large access volume, high speed, and large capacity. Therefore, 5G mobile communication systems have gradually begun to use millimeter wave bands as communication bands. The millimeter wave band has the characteristics of wide bandwidth and low interference. However, the millimeter wave band has large spatial loss, so it is generally used as a hotspot coverage for mobile communications, and is only used as a communication band in short distances and densely populated users. Under normal working conditions, users still use 4G and 5G N79 and other frequency bands for communication. In order to ensure that communication equipment has the ability to work in both normal working conditions and hotspots, dual-frequency filter devices that support traditional Sub-6GHz and millimeter waves must be used in its front-end system.

[0004] In addition to the RF front-end circuits for communication functions, mobile terminals also have a large number of devices for realizing camera and power supply, so mobile terminals are physically space-constrained devices. In order to minimize the area, the RF front-end circuit mainly uses RF chips to build the transceiver link. So far, although dual-band RF microwave devices have been proposed, filter chips with high frequency ratios and covering both microwave and millimeter wave frequency bands have not yet been proposed. The current mainstream design must construct two signal paths in three-dimensional space, which is larger than planar chips, so it cannot be integrated in large quantities in RF terminals. This is also one of the technical bottlenecks that restrict the widespread application of dual-band filters in the 5G era. Summary of the invention

[0005] In view of this, embodiments of the present invention provide a high frequency ratio microwave-millimeter wave cross-band filter circuit and chip to eliminate or improve one or more defects existing in the prior art.

[0006] One aspect of the present invention provides a high frequency ratio microwave millimeter wave cross-band filter circuit, wherein the high frequency ratio microwave millimeter wave cross-band filter circuit comprises a high frequency band pass circuit and a low frequency band pass circuit.

[0007] The high-frequency bandpass circuit includes a first coupling line and a second coupling line. The dual-frequency signal is input into the first coupling line from the input port. The high-frequency signal in the dual-frequency signal is coupled to the high-frequency bandpass circuit through the first coupling line and then input into the second coupling line. The high-frequency signal is coupled through the second coupling line and output to the output port.

[0008] The low-frequency bandpass circuit includes a first series resonator and a second series resonator connected to each other, each of which is composed of a series inductor and a capacitor, the first series resonator is connected to the first coupling line, and the second series resonator is connected to the second coupling line. The low-frequency signal in the dual-frequency signal is output to the second coupling line through a path formed by two interconnected series resonators, and is output to the output port by the second coupling line.

[0009] By adopting the above scheme, the present invention makes a special design at the common input port of the high-frequency path and the low-frequency path. The circuit node in the high-frequency path is connected to a bandpass coupling line, and the high-frequency and low-frequency signals of the coupling line are input into the first coupling line from the input port. Figure 2 As shown, the high-frequency output and input are located on both sides of the coupling line. The electrical coupling and magnetic coupling of the coupling line fail at low frequencies, so the low-frequency input signal will not reach the other side of the coupling line through coupling, and thus cannot enter the high-frequency path. The high-frequency input signal can reach the other side of the coupling line through electromagnetic coupling, thus forming a high-frequency passband. The low-frequency output port and the low-frequency output port are located on the same side of the coupling line. For low-frequency signals, there is approximately only one transmission line structure between its input and output. This structure mainly exhibits inductive properties, so the low-frequency signal can pass through, so that the low-frequency input signal can reach the low-frequency path through the coupling line. In this solution, the signal paths of the two frequencies share one input port and one output port, but the transmission routes do not affect each other. Therefore, compared with the existing technology, this solution is smaller in size and is convenient for large-scale integration in RF terminals.

[0010] In some embodiments of the present invention, the low frequency bandpass circuit includes a parallel resonator connected in parallel with the second series resonator.

[0011] In some embodiments of the present invention, the parallel resonator includes an inductor and a capacitor connected in parallel, and a spiral inductor connected in series with the parallel inductor and the capacitor.

[0012] In some embodiments of the present invention, one end of the spiral inductor is grounded.

[0013] In some embodiments of the present invention, the high-frequency bandpass circuit further includes a first transmission branch connected in parallel with the first coupling line and the second coupling line, and the first transmission branch is composed of a first transmission line and a second transmission line connected in series.

[0014] In some embodiments of the present invention, the high-frequency bandpass circuit further includes a second transmission branch connected in parallel with the first series resonator and connected to the first coupling line, and a third transmission branch connected in parallel with the second series resonator and connected to the second coupling line.

[0015] In some embodiments of the present invention, the second transmission branch and the third transmission branch are both open-circuit branches with an electrical length of 90°, ie, a quarter wavelength, and have the same characteristic impedance.

[0016] Another aspect of the present invention provides a high frequency ratio microwave millimeter wave cross-band filter chip, characterized in that the high frequency ratio microwave millimeter wave cross-band filter chip applies the high frequency ratio microwave millimeter wave cross-band filter circuit structure.

[0017] In some embodiments of the present invention, the high frequency ratio microwave-millimeter wave cross-band filter chip is manufactured using a thin film integrated passive component process.

[0018] In some embodiments of the present invention, the high frequency ratio microwave millimeter wave cross-band filter chip is provided with a substrate layer, a first metal layer, a second metal layer and a third metal layer from bottom to top; the first metal layer, the second metal layer and the medium between the first metal layer and the second metal layer constitute a capacitor structure; the first metal layer, the second metal layer and the third metal layer together constitute an inductor; the first metal layer or the second metal layer or the third metal layer is used to construct a coupling line and a transmission branch.

[0019] In some embodiments of the present invention, the substrate layer is made of gallium arsenide.

[0020] Additional advantages, purposes, and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The purposes and other advantages of the present invention can be specifically pointed out and obtained in the specification and the accompanying drawings.

[0021] Those skilled in the art will appreciate that the objectives and advantages that can be achieved with the present invention are not limited to the above specific description, and the above and other objectives that can be achieved by the present invention will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention.

[0023] Figure 1 It is a schematic diagram of the structure of a high frequency ratio microwave millimeter wave cross-band filter circuit of the present invention;

[0024] Figure 2 Schematic diagram of the four forms of high frequency when the coupled line exhibits bandpass characteristics;

[0025] Figure 3 This is an ideal simulation result diagram obtained by simulating the high-frequency bandpass circuit using the parameters of Example 1 alone;

[0026] Figure 4 This is an ideal simulation result diagram obtained by simulating the low-frequency bandpass circuit using the parameters of Example 1 alone;

[0027] Figure 5 The high-frequency bandpass circuit and the low-frequency bandpass circuit are combined into S after the embodiment 1 of the present invention 11 Parameter ideal simulation result diagram and simulation and test result diagram of Example 2;

[0028] Figure 6 The high-frequency bandpass circuit and the low-frequency bandpass circuit are combined into S after the embodiment 1 of the present invention 21 Parameter ideal simulation result diagram and simulation and test result diagram of Example 2;

[0029] Figure 7 This is a schematic diagram of the layout design of Example 2 of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0031] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0032] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0033] It should also be noted that, unless otherwise specified, the term “connection” herein may refer not only to a direct connection but also to an indirect connection involving an intermediate.

[0034] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0035] To solve the above problems, Figure 1 As shown, the present invention proposes a high frequency ratio microwave millimeter wave cross-band filter circuit, wherein the high frequency ratio microwave millimeter wave cross-band filter circuit comprises a high frequency band pass circuit and a low frequency band pass circuit.

[0036] The high-frequency bandpass circuit includes a first coupling line and a second coupling line. The dual-frequency signal is input into the first coupling line from the input port. The high-frequency signal in the dual-frequency signal is coupled to the high-frequency bandpass circuit through the first coupling line and then input into the second coupling line. The high-frequency signal is coupled through the second coupling line and output to the output port.

[0037] In a specific implementation process, the electrical lengths of the first coupling line and the second coupling line are both 90°.

[0038] The low-frequency bandpass circuit includes a first series resonator and a second series resonator connected to each other, each of which is composed of a series inductor and a capacitor, the first series resonator is connected to the first coupling line, and the second series resonator is connected to the second coupling line. The low-frequency signal in the dual-frequency signal is output to the second coupling line through a path formed by two interconnected series resonators, and is output to the output port by the second coupling line.

[0039] In the specific implementation process, the circuit of the present invention is composed of a distributed parameter high-frequency bandpass circuit and a lumped parameter low-frequency bandpass circuit. The circuit structure is as follows: Figure 1As shown. The signal paths of the two frequencies share one input port and one output port. The high-frequency path contains two coupling lines and three transmission line branches, and the electrical length of each of them is 90°. Due to the existence of the coupling lines, it has a bandpass filtering function, and the existence of the transmission line branches makes the path have more transmission zeros, thereby enhancing the suppression function of non-passband signals and eliminating the influence of low frequencies on high frequencies. By setting the characteristic impedance of the branches, the position of the transmission zero point can be changed, so as to suppress the intermodulation signal at a specific frequency point. The low-frequency path is composed of two series resonators and one parallel resonator. The series resonator can ensure that the signal passes at its resonant frequency, thereby forming a passband, and the parallel resonator has two resonant frequencies to generate an input impedance pole and an input impedance zero point, thereby forming an open circuit and a short circuit for the signal, thereby generating a transmission pole and a transmission zero point. The frequency selectivity of the low-frequency path can be enhanced by reasonably setting the position of the transmission zero point. For signals that do not fall within the high-frequency and low-frequency passbands, the signal is reflected at the input port, and the signal cannot be transmitted between the input and output ports.

[0040] The present invention makes a special design at the common input port of the high-frequency path and the low-frequency path. The circuit node in the high-frequency path is connected to a bandpass coupling line, and the high- and low-frequency signals of the coupling line are input to the first coupling line from the input port. Figure 2 As shown, the high-frequency output and input are located on both sides of the coupling line. The electrical coupling and magnetic coupling of the coupling line fail at low frequencies, so the low-frequency input signal will not reach the other side of the coupling line through coupling, and thus cannot enter the high-frequency path. The high-frequency input signal can reach the other side of the coupling line through electromagnetic coupling, thus forming a high-frequency passband. The low-frequency output port and the low-frequency output port are located on the same side of the coupling line. For low-frequency signals, there is approximately only one transmission line structure between its input and output. This structure mainly exhibits inductive properties, so the low-frequency signal can pass through, so that the low-frequency input signal can reach the low-frequency path through the coupling line. In this solution, the signal paths of the two frequencies share one input port and one output port. Therefore, compared with the prior art, this solution is smaller in size and is convenient for large-scale integration in RF terminals.

[0041] In the specific implementation process, when the coupled line exhibits a bandpass characteristic, it must have the following characteristics at high frequencies: Figure 2 There are four forms shown. The low-pass input and output ports are located on the same side of the coupling line. The low frequency is a lumped element circuit, so an LC resonator is used. The LC resonator is connected to the low-frequency output of the coupling line. In forms one and four, the low-frequency output point must be in an open-circuit state at high frequencies. At this time, the LC resonator connected here must show high impedance at high frequencies to maintain the open-circuit state of the coupling line at high frequencies. Therefore, the LC resonator at this time must be a series LC resonator that is inductive at high frequencies; in forms two and three, as Figure 2As shown, the low-frequency output point must be in a short-circuit state at high frequencies. At this time, the LC resonator connected here must exhibit an impedance close to 0 at high frequencies in order to maintain the short-circuit state of the coupling line at high frequencies. Therefore, the LC resonator at this time must be a parallel LC resonator that exhibits capacitance at high frequencies.

[0042] The second transmission branch and the third transmission branch are both open-circuit branches with an electrical length of 90°, i.e., a quarter wavelength, and have the same characteristic impedance. Since the input impedance of the quarter-wavelength open-circuit branch is zero, a short-circuit point can also be constructed in the high-frequency quarter-wavelength transmission line. Therefore, for the coupled lines of form two and form three, their low-frequency output points can be connected to a high-frequency quarter-wavelength transmission line to construct a short-circuit point. Therefore, at this time, connecting any form of low-frequency lumped circuit to this port can avoid its influence on the high frequency.

[0043] In one embodiment of the present invention, the Figure 2 In the third form, due to the use of the above open-circuit branches, the short-circuit end of the coupling line in the third form still exists. Therefore, the parallel LC resonator in the third form can be replaced with a series LC resonator, thereby achieving Figure 1 structure.

[0044] In some embodiments of the present invention, the low frequency bandpass circuit includes a parallel resonator connected in parallel with the second series resonator.

[0045] In some embodiments of the present invention, the parallel resonator includes an inductor and a capacitor connected in parallel, and a spiral inductor connected in series with the parallel inductor and the capacitor.

[0046] In some embodiments of the present invention, the high-frequency bandpass circuit further includes a first transmission branch connected in parallel with the first coupling line and the second coupling line, and the first transmission branch is composed of a first transmission line and a second transmission line connected in series.

[0047] In some embodiments of the present invention, the high-frequency bandpass circuit further includes a second transmission branch connected in parallel with the first series resonator and connected to the first coupling line, and a third transmission branch connected in parallel with the second series resonator and connected to the second coupling line.

[0048] In some embodiments of the present invention, the second transmission branch and the third transmission branch are both open-circuit branches with an electrical length of 90°, ie, a quarter wavelength, and have the same characteristic impedance.

[0049] like Figure 1 As shown, the first coupling line and the second coupling line are marked with Z e , Z o , θ, the first transmission line is marked with Z1, θ, the second transmission line is marked with Z2, θ, the second transmission branch and the third transmission branch are marked with Z3, θ.

[0050] In some embodiments of the invention, θ is 90°.

[0051] Another aspect of the present invention provides a high frequency ratio microwave millimeter wave cross-band filter chip, characterized in that the high frequency ratio microwave millimeter wave cross-band filter chip applies the high frequency ratio microwave millimeter wave cross-band filter circuit structure.

[0052] In some embodiments of the present invention, the high frequency ratio microwave-millimeter wave cross-band filter chip is manufactured using a thin film integrated passive process.

[0053] In the specific implementation process, the present invention adopts thin film integrated passive (IPD) technology, which can construct capacitors, inductors and metal segments. In the microwave frequency band, chip-level circuits can be implemented with lumped parameters, but cannot be implemented with distributed parameters. The reason is that distributed parameter filters often use quarter-wavelength and half-wavelength transmission lines, and in the microwave frequency band, the working wavelength of electromagnetic waves is centimeter-level, so the transmission line has a larger size to implement and cannot be integrated into the chip. In the millimeter wave frequency band, the working wavelength of electromagnetic waves is millimeter-level, which is more suitable for using the transmission line or coupled line structure of the millimeter wave frequency band in the filter chip. Therefore, the present invention innovatively uses distributed parameter circuits to design high-frequency paths, and lumped parameter circuits to design low-frequency paths, and then uses the same thin film processing technology to simultaneously implement circuits of two different design methods, thereby completing the integration of different types of circuits in the chip.

[0054] In some embodiments of the present invention, the high frequency ratio microwave millimeter wave cross-band filter chip is provided with a substrate layer, a first metal layer, a second metal layer and a third metal layer from bottom to top; the first metal layer, the second metal layer and the medium between the first metal layer and the second metal layer constitute a capacitor structure; the first metal layer, the second metal layer and the third metal layer together constitute an inductor; the first metal layer or the second metal layer or the third metal layer is used to construct a coupling line and a transmission branch.

[0055] In some embodiments of the present invention, the substrate layer is made of gallium arsenide.

[0056] The beneficial effects of the present invention include:

[0057] 1. The present invention uses the same process to realize two types of circuits, which respectively work in the millimeter wave (high frequency) and microwave (low frequency) frequency bands. The structure is simple and the integration is high, and such a large frequency ratio design can be realized under a single process;

[0058] 2. The present invention proposes a circuit design method for avoiding the mutual influence of parallel high and low frequency paths. The method uses the coupling line characteristics and the different output positions of high and low frequencies on the coupling line to distinguish high and low frequency signals. The method is simple and the theoretical explanation is sufficient.

[0059] 3. The present invention not only has dual-frequency working capability and multiple transmission zero points outside the band, but also can effectively suppress the intermodulation signal generated when the dual-frequency signals are transmitted simultaneously.

[0060] Example 1

[0061] The circuit parameters are: Z e =144.00Ω,Z o =58.05Ω, Z1=14.00Ω, Z2=255.35Ω, Z3=96.00Ω, L1=2.00nH, L2=0.954nH, L3=0.51nH, C1=0.753pF, C2=1.58pF.

[0062] Its low frequency center frequency is f1=4.1 GHz, and its high frequency center frequency is f2=28.0 GHz.

[0063] The ideal simulation results obtained by simulating the high-frequency path using the above parameters are as follows Figure 3 As shown, the ideal simulation results of the low-frequency path using the above parameters are as follows Figure 4 The ideal simulation result after merging the two paths into the embodiment 1 of the present invention is shown as Figure 5 , 6 As shown. By comparing the three simulation graphs, it can be seen that after the two paths are merged, only the positions of some transmission zero points have a small frequency shift. The passband is not affected, which shows that the new innovative design method proposed by the present invention of using coupling lines to make the two paths share the input port but not affect each other is very effective.

[0064] Example 2

[0065] Z e =144Ω,Z o =58.054Ω, Z1=13.71Ω, Z2=255.80Ω, Z3=95.86Ω, L1=2.31nH, C1=0.4855pF, L2=0.73785nH, C2=1.76056pF, L3=0.57282nH.

[0066] Its low frequency center frequency is f1=4.1 GHz, and its high frequency center frequency is f2=28.0 GHz.

[0067] like Figure 5 The S parameters of this design are shown below, where S 21 is the transmission coefficient from input to output port, from S21 It can be seen that the ideal circuit simulation of the second embodiment of the present invention has two passbands, and the center frequencies of the two passbands are 4.1 GHz and 28.0 GHz. The corresponding intermodulation signal frequencies are generated at 19.8 GHz, 23.9 GHz and 32.1 GHz. The positions where the first two intermodulations are generated have |S 21 |The transmission zero points are -106.2dB and -90.8dB respectively. There is a transmission zero point near the location where the third intermodulation signal is generated. The frequency of the transmission zero point is 30.03GHz. 21 The value of | is -80.9 dB. This indicates that the embodiment of the present invention has a good suppression effect on intermodulation signals. In addition, there is a transmission zero point generated by a low-frequency passband at 6.73 GHz.

[0068] like Figure 7 The diagram shows the layout design of Example 2 of the present invention. This example adopts a GSG (ground-signal-ground) port format. The port is connected to one end of the coupling line through a metal wire. The coupling line is 760μm long, 5μm wide, and 7μm apart. The other end of the coupling line is connected to an open branch with a length of 825μm and a width of 30μm. There is also an open end on the other side of the coupling line. There are two microstrip lines between the two coupling lines, with dimensions of 965μm long, 458μm wide, and 885μm long, 5μm wide. The connection between the coupling line and the open branch is also connected through a capacitor and a lumped parameter low-frequency path. The size of the capacitor is 35×34μm. 2 The capacitor is connected to a 2.5-turn spiral inductor with an inner diameter of 80μm, a line width of 16μm, and a line spacing of 10μm through a metal wire with a length of 911.86μm and a width of 26.88μm. This metal wire can show inductance, and together with the spiral inductor, it represents the inductor L1 in the schematic diagram. This spiral inductor is connected to a set of parallel capacitors and inductors. The size of this set of capacitors and inductors is: capacitor area 47.7*47.7μm 2 The size of the inductor is 75μm inner diameter, 30μm line width, 10μm line spacing, and 1.5 turns. This group of capacitors and inductors is connected to a spiral inductor with an inner diameter of 65μm, a line width of 30μm and a 0.5 turn. The other side of this spiral inductor is grounded through a via. The layout is completed through the IPD process.

[0069] Use the probe station and GSG probe to test the finished chip on the wafer. The test results are as follows: Figure 5-6 The figure shows that the communication frequencies of the two passbands of the dual-band pass filter chip of this embodiment are 4.80 GHz and 28.29 GHz respectively, and the frequency ratio of the two passbands is 5.89. The minimum insertion loss at the center frequency is 2.11 dB and 2.94 dB. Low frequency passband | S 111| Bandwidth less than -10dB covers 4.15-5.46GHz, with a relative bandwidth of 27.26%; high frequency passband|S 11 |The bandwidth less than -10dB covers 25.44-35.78GHz, and the relative bandwidth is 33.78%. The tested transmission zero points are located at 7.22GHz, 20.01GHz, 21.69GHz and 35.98GHz, respectively, with good stopband suppression better than 14.42dB in the non-working frequency band.

[0070] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with features of other embodiments or replace features of other embodiments.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high frequency ratio microwave millimeter wave cross-band filter circuit, characterized in that: The high frequency ratio microwave and millimeter wave cross-band filter circuit comprises a high frequency band pass circuit and a low frequency band pass circuit. The high-frequency bandpass circuit includes a first coupling line and a second coupling line. The dual-frequency signal is input into the first coupling line from the input port. The high-frequency signal in the dual-frequency signal is coupled to the high-frequency bandpass circuit through the first coupling line and then input into the second coupling line. The high-frequency signal is coupled through the second coupling line and output to the output port. The low-frequency bandpass circuit includes a first series resonator and a second series resonator connected to each other, each of which is composed of a series inductor and a capacitor, the first series resonator is connected to the first coupling line, and the second series resonator is connected to the second coupling line. The low-frequency signal in the dual-frequency signal is output to the second coupling line through a path formed by two interconnected series resonators, and is output to the output port by the second coupling line.

2. The high frequency ratio microwave millimeter wave cross-band filter circuit according to claim 1, characterized in that: The low frequency band pass circuit includes a parallel resonator connected in parallel with a second series resonator.

3. The high frequency ratio microwave millimeter wave cross-band filter circuit according to claim 2, characterized in that: The parallel resonator includes an inductor and a capacitor connected in parallel, and a spiral inductor connected in series with the parallel inductor and the capacitor.

4. The high frequency ratio microwave millimeter wave cross-band filter circuit according to claim 3, characterized in that: One end of the spiral inductor is grounded.

5. The high frequency ratio microwave millimeter wave cross-band filter circuit according to claim 1, characterized in that: The high-frequency bandpass circuit further includes a second transmission branch connected in parallel with the first series resonator and connected to the first coupling line, and a third transmission branch connected in parallel with the second series resonator and connected to the second coupling line.

6. The high frequency ratio microwave-millimeter wave cross-band filter circuit according to claim 5, characterized in that: The second transmission branch and the third transmission branch are both open-circuit branches with an electrical length of 90° and the same characteristic impedance.

7. A high frequency ratio microwave millimeter wave cross-band filter chip, characterized in that: The high frequency ratio microwave millimeter wave cross-band filter chip applies the high frequency ratio microwave millimeter wave cross-band filter circuit structure as described in any one of claims 1-6.

8. The high frequency ratio microwave-millimeter wave cross-band filter chip according to claim 7, characterized in that: The high frequency ratio microwave millimeter wave cross-band filter chip is manufactured by using a thin film integrated passive component process.

9. The high frequency ratio microwave millimeter wave cross-band filter chip according to claim 7, characterized in that: The high frequency ratio microwave millimeter wave cross-band filter chip is provided with a substrate layer, a first metal layer, a second metal layer and a third metal layer from bottom to top; the first metal layer, the second metal layer and the medium between the first metal layer and the second metal layer constitute a capacitor structure; the first metal layer, the second metal layer and the third metal layer together constitute an inductor; the first metal layer or the second metal layer or the third metal layer is used to construct a coupling line and a transmission branch.

10. The high frequency ratio microwave millimeter wave cross-band filter chip according to claim 9, characterized in that: The substrate layer is made of gallium arsenide.

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