Tsv-based millimeter-wave folded sir dipole dual-bandpass filter

Abstract

The application discloses a TSV-based millimeter wave folded SIR double-interdigital dual-band pass filter, which comprises an interdigital resonant structure A and an interdigital resonant structure B connected together through an RDL shaft, and the interdigital resonant structure A and the interdigital resonant structure B are symmetrically arranged about the RDL shaft, and the bottom of the RDL shaft is connected with a TSV. The application has the integration degree after reducing the filter area, and improves the independence of the filter.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of filter, and relates to a TSV-based millimeter wave folded SIR double-interdigital dual-band pass filter. BACKGROUND

[0002] Filters are widely applied to various microwave millimeter wave systems and play an irreplaceable role in the systems, and the filtering characteristics of the filter depend on its frequency response characteristics, that is, the frequency band range that can be passed. However, the current research on millimeter wave band pass filters is mainly about single frequency band. For the complex situation of multiple pass bands, multiple band pass filters often need to be cascaded, which increases the overall size and is poor in integration, and there is usually crosstalk in use, so it is necessary to design a dual-band pass filter applied to millimeter waves. SUMMARY

[0003] The application aims to provide a TSV-based millimeter wave folded SIR double-interdigital dual-band pass filter, which has integration after reducing the area of the filter and improves the independence of the filter.

[0004] The technical scheme adopted by the application is that the TSV-based millimeter wave folded SIR double-interdigital dual-band pass filter comprises an interdigital resonant structure A and an interdigital resonant structure B connected together through an RDL shaft, and the interdigital resonant structure A and the interdigital resonant structure B are symmetrically arranged about the RDL shaft, and the bottom of the RDL shaft is connected with a TSV.

[0005] The application has the following characteristics:

[0006] The interdigital resonant structure A and the interdigital resonant structure B are completely the same in structure, the interdigital resonant structure A comprises resonators I and IV arranged in opposite directions, the resonators I and IV are provided with a plurality of RDL branches parallel to each other, the number of the RDL branches on the resonators I and IV is equal and arranged in opposite directions, and each RDL branch is connected with a TSV at an open end.

[0007] The part offset from the resonators I and IV on one side is a folded SIR structure I, the folded SIR structure I comprises RDL branches with impedance Z2 and RDL branches with impedance Z1, wherein Z2 represents low impedance and Z1 represents high impedance; and the part offset from the resonators I and IV on the other side is connected with the interdigital resonant structure B.

[0008] The interdigital resonant structure B comprises resonators III and IV arranged in opposite directions, the resonator III is the same as the resonator I, and the resonator III is provided with the folded SIR structure II which is the same as the folded SIR structure I.

[0009] The resonator I is connected with the tap RDL input, and the resonator III is connected with the tap RDL output.

[0010] The resonant frequency of the TSV millimeter wave folded SIR double-interdigital double-band pass filter is f0, the center frequency of the first spurious response is fs1, and the following relationship exists between them:

[0011]

[0012] Wherein:

[0013]

[0014] The present application has the advantages that the present application is made into a double-interdigital double-band wideband band pass filter by the SIR structure characteristics and the wideband characteristics of the interdigital band pass filter, the spurious passband is improved to the second passband of the filter, and the double-frequency filtering function of the filter is realized. By utilizing the excellent electrical characteristics of the TSV, the signal transmission path is shortened, the speed during the radio frequency signal transmission is improved, and the shortcomings that the interdigital band pass filter cannot be applied to the millimeter wave frequency band are greatly improved. In addition, the SIR structure is folded, the filter size is further reduced, the characteristics that the SIR interdigital band pass filter has a far spurious passband, good out-of-band suppression characteristics and upper stopband performance are reserved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a perspective structural schematic view of the TSV millimeter wave folded SIR double-interdigital double-band pass filter according to the present application;

[0016] Figure 2 is a top view of the TSV millimeter wave folded SIR double-interdigital double-band pass filter according to the present application.

[0017] In the figure, 1 is a tap RDL input, 2 is a folded SIR structure I, 3 is a resonator I, 4 is an RDL coupling, 5 is a TSV, 6 is a resonator III, 7 is a folded SIR structure II, 8 is a tap RDL output, 9 is a resonator II, and 10 is a resonator IV. DETAILED DESCRIPTION

[0018] The present application will be described in detail below in combination with the drawings and specific embodiments.

[0019] The application is based on a TSV-based millimeter wave folded SIR (Stepped Impedance Resonators, SIR) double-interdigital dual-bandpass filter, which further reduces the circuit size by folding the SIR, and realizes a millimeter wave dual-frequency filtering characteristic based on the structure of double SIR.

[0020] Embodiment 1

[0021] The application is based on a TSV-based millimeter wave folded SIR double-interdigital dual-bandpass filter, which further reduces the circuit size by folding the SIR, and realizes a millimeter wave dual-frequency filtering characteristic based on the structure of double SIR. Figure 1 、 2 As shown in the figure, it includes two interdigital resonant structures, a total of four resonators, and the two interdigital resonant structures are connected through an RDL shaft 4. The open end of each resonator is connected through a TSV 5, and each TSV 5 is connected with a rewiring layer (RDL) on the upper layer of the silicon substrate. The two interdigital resonant structures are symmetrical about the RDL shaft 4, and each interdigital resonant structure includes resonators arranged in opposite directions, electromagnetic coupling is generated through the upper and lower resonators, and the coupling strength is determined by the gap width between the upper and lower resonators. The SIR double-interdigital filter designed in the application is provided with a folded SIR structure I2 and a folded SIR structure II7 at the tap RDL input 1 and the head RDL output 8, respectively. The folded SIR structure I2 and the folded SIR structure II7 are the same structure, each including a low-impedance Z2 RDL branch composed of a coupling thin strip and a high-impedance Z1 RDL branch composed of a coupling thin strip, and using a TSV to connect with the bottom RDL (not marked in the figure) at the open end of each strip. The TSV 5 is arranged in the silicon substrate. Each resonator open end is short-circuited to the ground through a TSV 5. The application realizes strong coupling between adjacent resonators by using a folded interdigital coupling line.

[0022] The structure of the TSV 5 is subtracted from two concentric cylinders, the inner cylinder adopts electroplated copper column for signal transmission, and the outer layer adopts silicon dioxide as an insulating layer for insulation between the silicon plate and the filled conductive material.

[0023] Embodiment 2

[0024] Based on embodiment 1, the application is based on a TSV-based millimeter wave folded SIR double-interdigital dual-bandpass filter, which includes a group of interdigital resonant structures composed of resonator I3 and resonator IV10, and another group of interdigital resonant structures composed of resonator II9 and resonator III6; the two groups of interdigital resonant structures are completely the same and are symmetrically arranged relative to the RDL shaft 4, and the two groups of interdigital resonant structures are connected together through the RDL shaft 4.

[0025] A set of interdigital resonant structures consisting of resonators I3 and IV10 is connected to tap RDL input 1, and another set of interdigital resonant structures consisting of resonators II9 and III6 is connected to tap RDL output 8.

[0026] The structures of resonator I3 and resonator III6 are exactly the same, and the structures of resonator IV10 and resonator II9 are exactly the same.

[0027] In the structure of TSV5, the inner copper pillar of TSV has a radius of 4.7μm, the outer insulating layer has a thickness of 0.3μm, and a height of 100μm.

[0028] In this embodiment, resonators I3, II9, III6, and IV10 are all described using five RDL stubs as examples;

[0029] The common transmission line of the five RDL stubs of resonator I3 is 425μm long and 10μm wide. Starting from the tap RDL input 1, the first, third, fourth, and fifth RDL stubs are 273μm long and 10μm wide, the second stub is 273μm long and 55μm wide, the distance between the first and second RDL stubs is 20μm, the distance between the second and third RDL stubs is 100μm, the distance between the third and fourth RDL stubs is 100μm, and the distance between the fourth and fifth RDL stubs is 100μm. The first RDL stub (impedance Z1) and the second RDL stub (impedance Z2) form the folded SIR structure I2.

[0030] The common transmission line of the five RDL stubs of resonator II9 is ​​435 μm long and 10 μm wide. The first, second, third, fourth, and fifth RDL stubs are 230 μm long and 10 μm wide. The distance between the first and second RDL stubs is 100 μm, the distance between the second and third RDL stubs is 100 μm, the distance between the third and fourth RDL stubs is 100 μm, and the distance between the fourth and fifth RDL stubs is 65 μm. The coupling is 100 μm long and 8 μm wide.

[0031] The common transmission line of the five RDL stubs of the resonator IV10 is 435 μm long and 10 μm wide; among them, the first, second, third, fourth and fifth RDL stubs are 230 μm long and 10 μm wide, the distance between the first and second RDL stubs is 65 μm, the distance between the second and third RDL stubs is 100 μm, the distance between the third and fourth RDL stubs is 100 μm, and the distance between the fourth and fifth RDL stubs is 100 μm.

[0032] The common transmission line length of the five RDL branches of resonator III 6 is 425 μm, and the width is 10 μm; wherein, starting from the position close to the tap RDL output 8, the first, third, fourth and fifth branches have a length of 273 μm and a width of 10 μm, and the second branch has a length of 273 μm and a width of 55 μm; the distance between the first RDL branch and the second RDL branch is 100 μm, the distance between the second RDL branch and the third RDL branch is 100 μm, the distance between the third RDL branch and the fourth RDL branch is 100 μm, and the distance between the fourth RDL branch and the fifth RDL branch is 20 μm. The first RDL branch (impedance Z1) and the second RDL branch (impedance Z2) form a folded SIR structure II 7. The RDL is a redistribution layer (ReDistribution Layer) with a thickness of 3 μm, and copper is usually used as the conductor. In the process, a layer of silicon dioxide insulation layer is wrapped outside the conductor to play an isolation role.

[0033] When resonator I 3 and resonator IV 10 form a set of interdigital resonant structures, the resonator I 3 inserts the remaining three RDL branches except the folded SIR structure I 2 into the adjacent two RDL branches among the four RDL branches of the resonator IV 10, respectively.

[0034] When resonator II 9 and resonator III 6 form a set of interdigital resonant structures, the resonator III 6 inserts the remaining three RDL branches except the folded SIR structure II 7 into the adjacent two RDL branches among the four RDL branches of the resonator II 9, respectively.

[0035] Embodiment 3

[0036] On the basis of embodiment 2, the resonant frequency of the TSV millimeter wave folded SIR double-interdigital dual-band bandpass filter of the application is f0, and the center frequency of the first spurious response is fs1, and the following relationship exists between them:

[0037]

[0038] Wherein:

[0039]

[0040] As can be seen from formula (1), the SIR structure can not only adjust the position of the spurious band according to the impedance ratio and reduce the influence on the passband, but also can set it as the second passband by using the relationship between the impedances, to realize a dual-frequency or even multi-band filter.

[0041] The TSV-based millimeter wave folded SIR double-finger dual-band pass filter has the characteristics that, after being compatible with the TSV technology, the dual-band pass filter can be used as a single component, and can also be used as a three-dimensional integrated adapter plate, so that chips are interconnected through an RDL layer on the substrate, and interlayer signal transmission is performed through TSV vertical interconnection, and further three-dimensional laminated packaging with high integration is realized.

Claims

1. A TSV-based millimeter-wave folded SIR dual-dipole dual-bandpass filter, characterized in that: The interdigital resonant structure A and the interdigital resonant structure B are connected together through the RDL shaft coupling (4), and the interdigital resonant structure A and the interdigital resonant structure B are symmetrically arranged about the RDL shaft coupling (4), and the bottom of the RDL shaft coupling (4) is connected with a TSV (5); The interdigital resonant structure A and the interdigital resonant structure B are completely same in structure, the interdigital resonant structure A comprises resonators I (3) and resonators IV (10) arranged in opposite staggered manner, and a plurality of RDL branches parallel to each other are arranged on the resonators I (3) and the resonators IV (10), the number of the RDL branches on the resonators I (3) and the resonators IV (10) is equal and arranged in opposite staggered manner, and a TSV (5) is connected to the open end of each RDL branch; The part staggered on one side of the resonators I (3) and the resonators IV (10) is a folded SIR structure I (2), the folded SIR structure I (2) comprises an RDL branch with impedance Z2 and an RDL branch with impedance Z1, wherein Z2 represents low impedance and Z1 represents high impedance; the part staggered on the other side of the resonators I (3) and the resonators IV (10) is connected with the interdigital resonant structure B; The interdigital resonant structure B comprises resonators III (6) and resonators IV (10) arranged in opposite staggered manner, the resonators III (6) are same in structure with the resonators I (3), and the resonators III (6) are provided with a folded SIR structure II (7) same in structure with the folded SIR structure I (2); the resonators IV (10) are same in structure with the resonators II (9); The resonators I (3) are connected with a tapped RDL input (1), and the resonators III (6) are connected with a tapped RDL output (8).

2. The design method of TSV-based millimeter-wave folded SIR dual-diplexer dual-bandpass filter of claim 1, wherein: The resonant frequency of the millimeter wave folded SIR double-interdigital dual-band bandpass filter of the TSV is f0, the center frequency of the first spurious response is fs1, and the following relationship exists between them: （1） Wherein: （2） Wherein, Z2 is low impedance, and Z2 is high impedance.

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