Bandwidth-controllable unequal-fractional upper filtering power divider

Abstract

The application discloses a bandwidth-controllable unequal-fragment on-filter power divider, and relates to the technical field of radio frequency integrated circuits.The bandwidth-controllable unequal-fragment on-filter power divider comprises a first input feed line, a second input feed line, a first output feed line, a second output feed line, an isolation element, a first filter branch and a second filter branch, the first filter branch and the second filter branch each comprise N resonators; the first filter branch and the second filter branch are connected in series with the isolation element, and the first filter branch and the second filter branch are located at two ends of the isolation element; the power of the first filter branch is greater than the power of the second filter branch, the first input feed line is wider than the second input feed line, and the feeding position of the first input feed line on the first resonator in the first filter branch is farther away from the open end of the respective resonator than the feeding position of the second input feed line on the first resonator in the second filter branch.The application has controllable double-channel relative bandwidth and can realize inconsistent power division ratio but controllable bandwidth.

Description

Technical Field

[0001] This invention relates to the field of radio frequency integrated circuit design technology, and in particular to a bandwidth-controllable unequal-slice on-chip filter power divider. Background Technology

[0002] A power divider is a device that splits the energy of one input signal into two or more outputs of equal or unequal energy. It is widely used in communications, radar, and other fields, and is generally a three-port circuit. The main technical specifications of an unequal-channel power divider include: 1) operating bandwidth; 2) insertion loss; 3) return loss; 4) isolation; and 5) power ratio. However, due to design and manufacturing limitations, it is difficult to achieve controllable dual-channel relative bandwidth in an unequal-channel power divider. The following are some publicly available examples of unequal-channel power dividers:

[0003] (1) Chinese Patent Application No. 201711223117.6 discloses a design method for a high-isolation microwave unequal-division power divider, which improves in-band matching characteristics by using a quarter-wavelength impedance converter. This design method can achieve broadband characteristics, but the use of a quarter-wavelength impedance converter is not conducive to the miniaturization of RF circuits. Although the absorption zero between the output ports is achieved by replacing the original single isolation resistor with a resistor and a 360° microstrip line that is easy to bend within the operating frequency band, it is only about 25dB, and the isolation bandwidth is narrow, with the in-band partial isolation not reaching 20dB. Moreover, there is no controllable dual-channel output bandwidth.

[0004] (2) Chinese Patent Application No. 201910666085.X discloses a miniaturized 6:1 Wilkinson unequal power divider based on plasmonic waveguide. It introduces two artificial surface plasmonic waveguide stubs with inductive loading, adopts a traditional quarter-wavelength impedance converter, has a large size area, and does not have a controllable dual-channel output bandwidth.

[0005] (3) Chinese patent application No. 202010810033.8 discloses a coplanar waveguide broadband unequal division one-to-two power divider, which adopts the traditional Wilkinson power divider cascade form to increase bandwidth, but the size area is large. Multiple resistors are cascaded to form in-band isolation with multiple absorption zeros, but the isolation bandwidth is narrow, and there is no controllable dual-channel output bandwidth.

[0006] In summary, the publicly available unequal power divider needs improvement in the following aspects: when implementing unequal power division, it does not consider controlling the relative bandwidth of the two output channels, resulting in the inability of the two channels to output a controllable relative bandwidth. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a bandwidth-controllable unequal-segment on-screen power divider with controllable dual-channel relative bandwidth. The power division ratio is inconsistent but the bandwidth is controllable by setting the feed position, feed width, feed length and coupling spacing between resonators.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] According to the present invention, a bandwidth-controllable unequal-segment on-chip filter power divider includes a first input feed line, a second input feed line, a first output feed line, a second output feed line, an isolation element, a first filter stub, and a second filter stub. The first filter stub and the second filter stub each include N resonators, where the N resonators are the first to the Nth resonators, and N is an integer greater than 0.

[0010] The first filter stub and the second filter stub are connected in series with the isolation element, and the first filter stub and the second filter stub are located at both ends of the isolation element. The first to Nth resonators in the first filter stub and the second filter stub are arranged in sequence in a direction perpendicular to the isolation element.

[0011] One end of the first input feed line is connected to one end of the second input feed line. This connection end serves as the input port of the filter power divider on the unequal segment. The other end of the first input feed line is connected to the first resonator in the first filter stub. The other end of the second input feed line is connected to the first resonator in the second filter stub. The first output feed line is connected to the Nth resonator in the first filter stub. The second output feed line is connected to the Nth resonator in the second filter stub.

[0012] The power of the first filter stub is greater than the power of the second filter stub, and the width of the first input feed is wider than that of the second input feed.

[0013] The feeding position of the first input feed line on the first resonator in the first filter stub is denoted as A, and the distance between A and the open end of the first resonator in the first filter stub is denoted as B.

[0014] The feeding position of the second input feed line on the first resonator in the second filter stub is denoted as C, and the distance between C and the open end of the first resonator in the second filter stub is denoted as D. B is greater than D.

[0015] The feeding position of the first output feed line on the Nth resonator in the first filter stub is denoted as E. The distance between E and the open end of the Nth resonator in the first filter stub is F, and B is less than F.

[0016] The feeding position of the second output feed line on the Nth resonator in the second filter stub is denoted as G. The distance between G and the open end of the Nth resonator in the second filter stub is H, and D is less than H.

[0017] As a further optimization scheme for the bandwidth-controllable unequal-segment on-screen power divider described in this invention, the isolation element is a combination of lumped resistor and lumped capacitor, or a combination of lumped resistor and lumped inductor, or a combination of lumped resistor and high-impedance transmission line inductor, or only composed of lumped resistor.

[0018] As a further optimization scheme for the bandwidth-controllable unequal-segment on-screen power divider described in this invention, the isolation element is connected in series with the j-th resonator in the first filter stub and the second filter stub, where 0 < j ≤ N and j is an integer.

[0019] As a further optimization scheme for the bandwidth-controllable unequal-segment on-screen power divider described in this invention, the resonators all include interdigital capacitors and high-impedance transmission lines, and the two ends of the interdigital capacitors are respectively connected to the two ends of the high-impedance transmission lines, wherein the exponent of the interdigital capacitors is a positive integer.

[0020] As a further optimization scheme for the bandwidth-controllable unequal-segment on-screen power divider described in this invention, the spacing between the i-th resonator and the (i+1)-th resonator in the first filter stub is smaller than the spacing between the i-th resonator and the (i+1)-th resonator in the second filter stub, where 0 < i < N and i is an integer.

[0021] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0022] (1) It has a controllable dual-channel relative bandwidth. By setting the feed position of the feed line, the width of the feed line, the length of the feed line and the coupling distance between the resonators, the power division ratio is inconsistent but the bandwidth is controllable.

[0023] (2) The power division ratio and relative bandwidth of the dual channels of the power divider on the unequal segmented filter can be set by the external quality factors of the input and output terminals and the coupling coefficient between the resonators. The external quality factor of the input terminal is the decisive factor for the power division ratio. The external quality factor of the output terminal and the coupling coefficient are mainly used to adjust the return loss and control the relative bandwidth of the dual channels. The external quality factors of the input and output terminals are realized by the feed position of the feed line, the width of the feed line and the length of the feed line. The coupling coefficient between the resonators is realized by the spacing between the resonators. For example, keeping the external quality factor of one input terminal unchanged and increasing the external quality factor of the other input terminal (the closer the feed position of the feed line is to the isolation element and the wider the feed line) can increase the power division ratio; increasing the external quality factor of the output terminal (the closer the feed position of the feed line is to the isolation element and the longer the feed line) and decreasing the coupling coefficient (increasing the spacing between the resonators) can decrease the bandwidth. Attached Figure Description

[0024] Figure 1This is a schematic diagram of the structure of the bandwidth-controllable unequal-segment on-chip filter power divider provided by the present invention.

[0025] Figure 2 This is a top view of the bandwidth-controllable unequal-segment on-screen power divider provided in an embodiment of the present invention.

[0026] Figure 3 This is a 3D structural schematic diagram of a bandwidth-controllable unequal-segment on-chip filter power divider provided in an embodiment of the present invention.

[0027] Figure 4 This is a simulation curve showing the relationship between scattering parameters and frequency in an embodiment of the present invention.

[0028] The reference numerals in the figure are explained as follows: 11 is the first input feed, 12 is the second input feed, 21 is the first output feed, 22 is the second output feed, 31 and 32 are both two filter stubs, 40 is an isolation element, 51, 52 and 53 are all three pads, 311 is the first resonator, 312 is the second resonator, 321 is the third resonator, 322 is the fourth resonator, and 51, 52 and 53 are all pads. Detailed Implementation

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings:

[0030] like Figure 1 As shown, a bandwidth-controllable unequal-segment on-screen power divider includes a first input feed line, a second input feed line, a first output feed line, a second output feed line, an isolation element, a first filter stub, and a second filter stub. The first filter stub and the second filter stub each include N resonators, where the N resonators are the first to the Nth resonators, and N is an integer greater than 0.

[0031] The first filter stub and the second filter stub are connected in series with the isolation element, and the first filter stub and the second filter stub are located at both ends of the isolation element. The first to Nth resonators in the first filter stub and the second filter stub are arranged in sequence in a direction perpendicular to the isolation element.

[0032] One end of the first input feed line is connected to one end of the second input feed line. This connection end serves as the input port of the filter power divider on the unequal segment. The other end of the first input feed line is connected to the first resonator in the first filter stub. The other end of the second input feed line is connected to the first resonator in the second filter stub. The first output feed line is connected to the Nth resonator in the first filter stub. The second output feed line is connected to the Nth resonator in the second filter stub.

[0033] The power of the first filter stub is greater than that of the second filter stub, the width of the first input feed line is wider than that of the second input feed line, and the feed position of the first input feed line on the first resonator in the first filter stub is farther away from the open end of the respective resonator than the feed position of the second input feed line on the first resonator in the second filter stub.

[0034] The first input feed line's feed position on the first resonator in the first filter stub is closer to the open end of its respective resonator than the first output feed line's feed position on the Nth resonator in the first filter stub. Similarly, the second input feed line's feed position on the first resonator in the second filter stub is closer to the open end of its respective resonator than the second output feed line's feed position on the Nth resonator in the second filter stub.

[0035] The isolation element is a combination of lumped resistors and lumped capacitors, or a combination of lumped resistors and lumped inductors, or a combination of lumped resistors and high-impedance transmission line inductors, or it may consist only of lumped resistors.

[0036] The isolation element is connected in series with the j-th resonator in the first filter stub and the second filter stub, where 0 < j ≤ N, and j is an integer.

[0037] Resonators all include interdigital capacitors and high-impedance transmission lines, with the two ends of the interdigital capacitors connected to the two ends of the high-impedance transmission lines respectively. The exponent of the interdigital capacitors is a positive integer.

[0038] When achieving consistent output bandwidth for both channels, the distance between the i-th resonator and the (i+1)-th resonator in the first filter stub is smaller than the distance between the i-th resonator and the (i+1)-th resonator in the second filter stub, where 0 < i < N, and i is an integer.

[0039] In this embodiment, a GaAs (gallium arsenide) dielectric substrate using IPD (Integrated Passive Device) metallization process is employed. The substrate thickness is 100 micrometers, the relative permittivity is 12.9, and the loss tangent is 0.001. A schematic diagram of this embodiment is shown below. Figure 2 As shown, its 3D structural diagram is as follows: Figure 3 As shown.

[0040] The unequal-division filter power divider structure includes a first input feed 11, a second input feed 12, a first output feed 21, a second output feed 22, two filter stubs 31 and 32, an isolation element 40, and three pads 51, 52, and 53. The two filter stubs are a high-power filter stub and a low-power filter stub. The high-power filter stub includes a first resonator 311 and a second resonator 312, while the low-power filter stub includes a third resonator 321 and a fourth resonator 322. The isolation element 40 includes a resistor and two identical high-impedance inductors.

[0041] One end of the first input feed line is connected to one end of the second input feed line, and together they are connected to pad 51. One end of the first output feed line is connected to pad 52, and one end of the second output feed line is connected to pad 53.

[0042] The other end of the first input feed line is connected to the first resonator, the other end of the second input feed line is connected to the third resonator, the other end of the first output feed line is connected to the second resonator, the other end of the second output feed line is connected to the fourth resonator, and the two ends of the complex impedance isolation element are connected to the first resonator and the third resonator respectively.

[0043] The first to fourth resonators each include an interdigital capacitor and a high-impedance transmission line, and the two ends of the interdigital capacitor are respectively connected to the two ends of the high-impedance transmission line. The exponent of the interdigital capacitor is 4.

[0044] The first resonator and the second resonator are interconnected by coupling with each other via a high-impedance transmission line, and the third resonator and the fourth resonator are interconnected by coupling with each other via a high-impedance transmission line. The spacing between the high-impedance transmission lines of the first resonator and the second resonator is smaller than that of the second resonator.

[0045] The power of the high-power filter stub is greater than that of the low-power filter stub. To achieve a higher power distribution ratio, the first input feed line is wider than the second input feed line. The first input feed line is positioned closer to the complex impedance isolation element on the interdigital resonator than the second input feed line. The first output feed line is shorter than the second output feed line.

[0046] The resistance value is approximately 46 ohms, achieved through a thin-film resistor with a width of 49 micrometers and a length of 45 micrometers; the inductance value of the two identical high-impedance inductors is approximately 36 picohens, achieved through a microstrip line with a width of 50 micrometers and a length of 150 micrometers.

[0047] The core circuit size of this unequal-segment on-chip filter power divider is 1079 micrometers × 1510 micrometers, which is equivalent to an electrical size of 0.09 waveguide wavelength × 0.126 waveguide wavelength. Compared with existing publicly available unequal-segment filter power dividers, it has a significant miniaturization advantage.

[0048] Figure 4 This is a simulation curve showing the relationship between scattering parameters and frequency according to an embodiment of the present invention. Figure 4 As shown, the center frequency of the power divider disclosed in this embodiment of the invention is 25 GHz, the relative bandwidth of the 3dB dual channels is approximately 22.5%, the minimum insertion losses are 3.6 dB and 5.2 dB respectively, the power division ratio is 1:1.45, and the minimum insertion loss excluding power distribution loss is 1.3 dB. S 11 |This refers to the return loss at the input port of the power divider filter. It has two transmission poles within the passband, and the in-band return loss is better than 20dB.| S 23 To ensure isolation between the output ports of the power divider filter, the output port isolation exceeds 20dB, and there is also an isolation transmission zero within the passband frequency, achieving an output port isolation exceeding 40dB. Compared with existing technologies, the unequal-division power divider filter provided in this embodiment of the invention achieves controllable dual-channel relative bandwidth.

[0049] The power division ratio and relative bandwidth of the unequal-segment on-screen power divider of this invention can be determined by external quality factors at the input and output terminals. Q ein1 , Q ein2 , Q eout1 , Q eout2 ) and the coupling coefficient between resonators ( k 1, k 2) Setting the input external quality factor ( Q ein1 , Q ein2 For power distribution, the output external quality factor and coupling coefficient are more decisive factors than power distribution factors. Q eout1 , Q eout2 , k 1, k2) Primarily used to adjust return loss and control the relative bandwidth of the dual channels. The external quality factor at the input and output ends is determined by the feed position, width, and length of the feed line. The coupling coefficient between resonators is determined by the spacing between them. For example, keeping the external quality factor of one input constant, increasing the external quality factor of the other input (by placing the feed line closer to the isolation element and widening the feed line) can increase the power division ratio. Increasing the external quality factor at the output end (by placing the feed line closer to the isolation element and lengthening the feed line) and decreasing the coupling coefficient (by increasing the spacing between the resonators) can decrease the bandwidth. Therefore, by setting the feed position or width of the feed line and the spacing between the resonators, it is possible to achieve unequal power division ratios but controllable relative bandwidth between the dual channels.

[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A bandwidth-controllable unequal-fractional on-chip filtering power divider, characterized in that, The unequal fractional upper filtering power divider comprises a first input feed line, a second input feed line, a first output feed line, a second output feed line, an isolation element, a first filtering branch and a second filtering branch, the first filtering branch and the second filtering branch each comprise N resonators, the N resonators are the first resonator to the Nth resonator, and N is an integer greater than 0. The first filtering branch and the second filtering branch are connected in series with the isolation element, and the first filtering branch and the second filtering branch are located at two ends of the isolation element, and the first resonator to the Nth resonator in the first filtering branch and the second filtering branch are arranged in sequence in a direction perpendicular to the isolation element. One end of the first input feed line and one end of the second input feed line are connected, and the connected end is used as an input port of the unequal fractional upper filtering power divider, the other end of the first input feed line is connected with the first resonator in the first filtering branch, the other end of the second input feed line is connected with the first resonator in the second filtering branch, the first output feed line is connected with the Nth resonator in the first filtering branch, and the second output feed line is connected with the Nth resonator in the second filtering branch. The power of the first filtering branch is greater than the power of the second filtering branch, and the width of the first input feed line is greater than the width of the second input feed line. The power division ratio of the unequal fractional upper filtering power divider and the relative bandwidth of the double channel are set by the external quality factor of the input and output end and the coupling coefficient between the resonators. The external quality factor of the input and output end is realized by the feeding position of the feed line, the width of the feed line and the length of the feed line. The coupling coefficient between the resonators is realized by the spacing between the resonators. Keeping one of the external quality factors of the input end unchanged and increasing the external quality factor of the other input end can increase the power division ratio. Increasing the external quality factor of the output end and reducing the coupling coefficient can reduce the bandwidth. The feeding position of the first input feed line on the first resonator in the first filtering branch is denoted as A, and the distance between A and the open end of the first resonator in the first filtering branch is denoted as B. The feeding position of the second input feed line on the first resonator in the second filtering branch is denoted as C, and the distance between C and the open end of the first resonator in the second filtering branch is denoted as D, and B is greater than D. The feeding position of the first output feed line on the Nth resonator in the first filtering branch is denoted as E, and the distance between E and the open end of the Nth resonator in the first filtering branch is denoted as F, and B is less than F. The feeding position of the second output feed line on the Nth resonator in the second filtering branch is denoted as G, and the distance between G and the open end of the Nth resonator in the second filtering branch is denoted as H, and D is less than H.

2. A bandwidth-controllable unequal-fractional upper-filtered power divider according to claim 1, characterized in that, The isolation element is a combination of a lumped resistor and a lumped capacitor, or a combination of a lumped resistor and a lumped inductor, or a combination of a lumped resistor and a high-impedance transmission line inductor, or only composed of a lumped resistor.

3. A bandwidth-controllable unequal-fractional upper-filtered power divider according to claim 1, characterized in that, The isolation element is connected in series with the jth resonator in the first filtering branch and the second filtering branch, where 0 < j ≤ N and j is an integer.

4. A bandwidth-controllable unequal-fractional upper-filtered power divider according to claim 1, characterized in that, The resonator comprises an interdigital capacitor and a high-impedance transmission line, and the two ends of the interdigital capacitor are connected with the two ends of the high-impedance transmission line, wherein the index of the interdigital capacitor is a positive integer.

5. A bandwidth-controllable unequal-fractional upper-filtered power divider according to claim 1, characterized in that, The spacing between the i-th resonator and the i+1-th resonator in the first filter branch is smaller than the spacing between the i-th resonator and the i+1-th resonator in the second filter branch, where 0

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