An ultra-wideband low insertion loss bandpass filter based on GaAs IPD process

Abstract

The application provides a kind of ultra-wideband low insertion loss band-pass filter based on gallium arsenide IPD process, and the ultra-wideband low insertion loss band-pass filter includes first part Section I, second part Section II and capacitor C 10 Three parts are connected in series in turn, Section I is connected in series by capacitor C1, filter unit and capacitor C6 in turn;The filter unit is divided into two T-shaped structures in parallel, each T-shaped structure is composed of two capacitors and an inductor;Section II is a parallel circuit, divided into upper and lower parts, the upper part is a T-shaped structure composed of two capacitors and an inductor, and the lower part is a series connection of a capacitor and an inductor;In each T-shaped structure, one capacitor and inductor are connected in series, and the other capacitor is grounded.The application scheme can effectively optimize the passband signal transmission loss, and greatly improve the frequency selection ability of the filter.

Description

Technical Field

[0001] This invention relates to the field of radio frequency integrated circuits and integrated passive devices, specifically to an ultra-wideband low insertion loss bandpass filter based on gallium arsenide integrated passive device (IPD) technology, suitable for ultra-wideband, 5G radio frequency front-end communication equipment. Background Technology

[0002] Ultra-wideband (UWB) communication technology, with its advantages of high transmission rate, strong anti-interference capability, low power consumption, and high positioning accuracy, is widely used in core scenarios such as short-range high-speed wireless transmission, indoor precise positioning, 5G RF front-end, IoT terminals, and vehicle communication. Bandpass filters, as core passive components of RF front-end systems, primarily function to filter target frequency band signals and suppress out-of-band clutter and interference signals. Their performance parameters, such as bandwidth, insertion loss, out-of-band rejection, and size integration, directly determine the communication quality and operational stability of the entire RF communication system. Existing processes for fabricating RF filters include low-temperature co-fired ceramic (LTCC), printed circuit board (PCB), acoustics, and integrated circuit device (IPD). Among these, filters fabricated using low-temperature co-fired ceramics and microstrip processes suffer from issues such as large overall size, low integration, and severe high-frequency loss, making them unsuitable for the current miniaturization and chip-level integration demands of terminal devices. While acoustic filters offer low insertion loss, their narrow operating bandwidth fails to meet the wideband signal transmission requirements of ultra-wideband communication. IPD (Integrated Circuit Processing) bandpass filters leverage the significant advantages of IPD technology—high chip-level integration, low high-frequency loss, excellent mass production consistency, controllable parasitic parameters, and low cost—to solve the problems of large size, high high-frequency loss, and limited bandwidth of traditional LTCC and PCB filters, as well as acoustic filters. However, existing IPD ultra-wideband bandpass filters generally suffer from technical shortcomings such as the inability to simultaneously achieve wideband characteristics and low insertion loss, weak out-of-band suppression, significant high-frequency parasitic interference, and poor integration and adaptability, making them unsuitable for the application requirements of next-generation ultra-wideband high-speed communication and miniaturized RF terminals. Summary of the Invention

[0003] To address the aforementioned issues, this invention proposes an ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD, which balances ultra-wideband bandwidth characteristics, ultra-low insertion loss, and high out-of-band rejection performance.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] An ultrawideband low insertion loss bandpass filter based on gallium arsenide IPD technology, the ultrawideband low insertion loss bandpass filter includes a first section I, a second section II, and a capacitor C. 10 The three parts are connected in series. Section I consists of capacitor C1, filter unit, and capacitor C6 connected in series. The filter unit is divided into two T-shaped structures connected in parallel, each consisting of two capacitors and one inductor. Section II is a parallel circuit, divided into upper and lower parts. The upper part is a T-shaped structure consisting of two capacitors and one inductor, and the lower part is a series connection of one capacitor and one inductor. In each T-shaped structure, one capacitor and one inductor are connected in series, and the other capacitor is grounded. This bandpass filter circuit has two transmission zeros in the lower stopband, and the two transmission zeros are generated by the two parts of the circuit, Section I and Section II, respectively. There are no transmission zeros in the upper stopband.

[0006] Furthermore, Section I specifically consists of: one end of capacitor C1 connected to input port Port1, and the other end of capacitor C1 connected to one end of capacitor C2 and one end of inductor L2; the other end of capacitor C2 connected to one end of capacitor C3 and also to one end of inductor L1, and the other end of capacitor C3 grounded; the other end of inductor L2 connected to one end of capacitor C4 and also to one end of capacitor C5, and the other end of capacitor C4 grounded; the other end of inductor L1 connected to the other end of capacitor C5, and then together connected to one end of capacitor C6, and the other end of capacitor C6 connected to Section II.

[0007] Furthermore, Section II specifically involves: one end of inductor L3 and capacitor C9 being simultaneously connected to the other end of capacitor C6 in Section I; the other end of inductor L3 being connected to one end of capacitors C7 and C8, with the other end of capacitor C7 grounded; the other end of capacitor C9 being connected to one end of inductor L4; the other end of inductor L4 being connected to the other end of capacitor C8, and then both being connected to capacitor C... 10 One end of the capacitor C 10 The other end is connected to the output port Port2.

[0008] Furthermore, an equivalent model of the parasitic parameters of the grounding via is established, and the parasitic parameters in the IPD process are introduced into the design to extract the equivalent circuit of the grounding metal via.

[0009] Furthermore, the small inductance L in the equivalent circuit of the grounded metal via is... 01 L 02 and L 03 When incorporated into an ultra-wideband low insertion loss bandpass filter, it forms an ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology, with a small inductor L. 01After being connected to capacitor C3 in Section I, it is grounded, and the small inductor L 02 After being connected to capacitor C4 in Section I, it is grounded, and the small inductor L 03 After connecting to capacitor C7 in Section II, it is grounded.

[0010] Furthermore, the [ABCD] matrix of the bandpass filter circuit after adding a small inductor is:

[0011]

[0012] Introducing a small inductor L 01 and L 02 The concatenated matrix [ABCD]′ of the first part SⅠ Represented as:

[0013]

[0014] in,

[0015] ,

[0016] ,

[0017] ,

[0018] ,

[0019]

[0020] ,

[0021] ,

[0022] ,

[0023] ,

[0024] .

[0025] Furthermore, a small inductor L is introduced. 03 The concatenated matrix [ABCD]′ of the second part SⅡ Represented as:

[0026]

[0027] in,

[0028]

[0029]

[0030]

[0031]

[0032] , , ,

[0033] Where j represents the imaginary unit and ω represents the angular frequency.

[0034] Furthermore, according to the transmission coefficient S 21 Relationship with the [ABCD] matrix:

[0035]

[0036] Calculate the transmission zero point, let S 21 =0, the transmission zeros satisfy two equations about ω respectively, the first equation is

[0037]

[0038] in,

[0039]

[0040]

[0041]

[0042]

[0043] The component values ​​are C2=1.26pF, C3=0.61pF, C4=12.27pF, C5=1.24pF, L1=0.79nH, L2=1.80nH, and L... 01 =L 02 Substituting 0.047nH into the first equation above and solving, we obtain the transmission zero as: , , .

[0044] Furthermore, the second equation is:

[0045]

[0046] in,

[0047]

[0048]

[0049]

[0050] The component values ​​are C7=6.68pF, C8=0.36pF, C9=10.86pF, L3=1.64nH, L4=1.07nH, and L... 03 Substituting 0.047nH into the second equation above and solving, we obtain the transmission zero as: , .

[0051] Furthermore, a physical layout of an ultrawideband low insertion loss bandpass filter based on gallium arsenide IPD technology was designed. The capacitor model in the physical layout uses a metal-insulator-metal structure, and the capacitance value is adjusted by changing the area of ​​the upper and lower metal plates. The inductor model in the physical layout uses a circular spiral planar inductor, and the inductance value is adjusted by changing the number of turns, line width, and line spacing.

[0052] The beneficial technical effects of this invention are as follows:

[0053] Compared to existing IPD filter structures, the ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology provided in this invention can effectively optimize the transmission loss of the passband signal, significantly improve the frequency selectivity of the filter, accurately filter out out-of-band interference signals, and suppress high-order harmonics. At the same time, relying on the characteristics of IPD chip-level integration technology, the device can be miniaturized. The bandpass filter provided in this invention has the advantages of ultra-wideband operating frequency band, ultra-low passband insertion loss, excellent high-frequency frequency selectivity, and miniaturization. Its comprehensive performance advantages are outstanding, and it is suitable for the large-scale application of various miniaturized, high-precision ultra-wideband wireless communication terminals. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a schematic diagram of an ultra-wideband low insertion loss bandpass filter provided in an embodiment of the present invention;

[0056] Figure 2 This is a schematic diagram of the structure of the filtering unit provided in an embodiment of the present invention;

[0057] Figure 3 This is a schematic diagram of Section II provided in an embodiment of the present invention;

[0058] Figure 4 This is a simulation result diagram of the overall circuit of the ultra-wideband low insertion loss bandpass filter provided in the embodiment of the present invention;

[0059] Figure 5 The C2 and L2 pairs provided in this embodiment of the invention transmit zero point f TZ1 The simulation results of the effect of capacitor C2 on the transmission zero point f are shown in the figure. TZ1 The effect of inductance L2 on the transmission zero point f, (b) is the effect of inductance L2 on the transmission zero point f. TZ1 The impact;

[0060] Figure 6 The C7 and L3 pairs provided in this embodiment of the invention transmit zero point f TZ2 The simulation results of the effect of capacitor C7 on the transmission zero point f are shown in the figure. TZ2 The effect of inductance L3 on the transmission zero point f, (b) is the effect of inductance L3 on the transmission zero point f. TZ2 The impact;

[0061] Figure 7 This is a schematic diagram of an ultrawideband low insertion loss bandpass filter based on gallium arsenide IPD technology with added small inductor, provided in an embodiment of the present invention.

[0062] Figure 8 This is a comparison curve of the S-parameters of the bandpass filter with added small inductor provided in the embodiment of the present invention;

[0063] Figure 9 This is the filter layout model with a smaller inductor provided in the embodiments of the present invention;

[0064] Figure 10 The simulated S-parameter curves of the filter layout with added small inductor provided in this embodiment of the invention;

[0065] Figure 11 This is a comparison chart of simulation test results of an ultra-wideband bandpass filter chip based on gallium arsenide IPD process provided in an embodiment of the present invention. Detailed Implementation

[0066] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0067] Figure 1 This is an ultra-wideband low insertion loss bandpass filter. The bandpass filter is divided into three parts: Section I, Section II, and capacitor C. 10The three parts are connected in series. Section I consists of capacitor C1, a filter unit, and capacitor C6 connected in series. The structure of the filter unit is as follows: Figure 2 As shown, the filter unit consists of two T-shaped structures connected in parallel, one above the other. Each T-shaped structure comprises two capacitors and one inductor, with one capacitor and the inductor connected in series, and the other capacitor grounded. Section I specifically includes: one end of capacitor C1 is connected to the input port Port1, and the other end of capacitor C1 is connected to one end of capacitor C2 and one end of inductor L2; the other end of capacitor C2 is connected to one end of capacitor C3 and also to one end of inductor L1, and the other end of capacitor C3 is grounded; the other end of inductor L2 is connected to one end of capacitor C4 and also to one end of capacitor C5, and the other end of capacitor C4 is grounded; the other end of inductor L1 is connected to the other end of capacitor C5, and then together they are connected to one end of capacitor C6, and the other end of capacitor C6 is connected to Section II.

[0068] Section II consists of a parallel circuit, divided into the following sections: Figure 3 The diagram shows two parts. The upper part is a T-shaped structure consisting of two capacitors and one inductor. In this T-shaped structure, one capacitor and the inductor are connected in series, and the other capacitor is grounded. The lower part is a series connection of one capacitor and one inductor. Specifically, Section II is as follows: one end of inductor L3 is connected to one end of capacitor C9, and then together they are connected to the other end of capacitor C6 in Section I; the other end of inductor L3 is connected to one end of capacitors C7 and C8, and the other end of capacitor C7 is grounded; the other end of capacitor C9 is connected to one end of inductor L4; the other end of inductor L4 is connected to the other end of capacitor C8, and then together they are connected to capacitor C... 10 One end of the capacitor C 10 The other end is connected to the output port Port2.

[0069] The bandpass filter circuit has two transmission zeros in the lower stopband, and the two transmission zeros are generated by two different parts of the circuit, while there are no transmission zeros in the upper stopband.

[0070] The working principle of the above bandpass filter is as follows:

[0071] The [ABCD] matrices of the upper and lower T-shaped structures of the filter unit are respectively

[0072] (1)

[0073] (2)

[0074] To calculate the expression for the parallel combination of two [ABCD] matrices, the [ABCD] matrices must first be transformed into [Y] matrices. This is based on the transformation relationship between [ABCD] and [Y] matrices:

[0075] (3)

[0076] Substituting equations (1) and (2) into equation (3), we obtain the [Y] matrix expressions for the two T-shaped structures as follows:

[0077] (4)

[0078] (5)

[0079] Since parallel [Y] matrices can be directly added, the [Y] of the filter unit is obtained by connecting two T-shaped structures in parallel. U The matrix is:

[0080] (6)

[0081] Then obtain [Y] U Transform the matrix into [ABCD] U Matrix, based on transformation relationship

[0082] (7)

[0083] This allows us to obtain the [ABCD] of the filter unit. U The matrix is:

[0084] (8)

[0085] Therefore, the [ABCD] of the filter unit is obtained. U The expression for a matrix is:

[0086] (9)

[0087] in,

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] Next, two capacitors, C1 and C6, are connected in series across the filter unit. After series connection, the [ABCD] of Section I of the circuit is obtained. SⅠ The matrix is:

[0095] (10)

[0096] in,

[0097]

[0098]

[0099]

[0100]

[0101] .

[0102] Next, we analyze Section II, due to capacitor C 10 It is a tuning element, therefore it is not involved in circuit analysis. The [ABCD] matrices of the two parallel branches in the second part are respectively

[0103] (11)

[0104] (12)

[0105] Similar to the derivation in the first part, connecting the two in parallel yields the parallel circuit [ABCD]. SⅡ The matrix is:

[0106] (13)

[0107] Substituting equations (11) and (12) into equation (13), we obtain the [ABCD] of the second part of the circuit. SⅡ The matrix is:

[0108] (14)

[0109] in,

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] By cascading the two parts, the final bandpass filter circuit's [ABCD] matrix is ​​obtained as follows:

[0116] (15)

[0117] Due to the transmission coefficient S 21 The relationship with the [ABCD] matrix is ​​as follows:

[0118] (16)

[0119] Therefore, substituting equation (15) into equation (16), and letting S 21 =0, and solving for the two transmission zeros in the lower stopband yields the analytical expressions as follows:

[0120] (17)

[0121] (18)

[0122] The component values ​​in the overall circuit are shown in Table 1. The unit for capacitors is pF, and the unit for inductors is nH.

[0123] Table 1 Initial values ​​of each component in the bandpass filter circuit

[0124]

[0125] Substituting C2=1.26pF, C3=0.61pF, C4=12.27pF, C5=1.24pF, L1=0.79nH and L2=1.80nH into equation (17), the transmission zero point f is calculated. TZ1 =1.40GHz; Substituting C7=6.68pF, C8=0.36pF, C9=10.86pF, L3=1.64nH and L4=1.07nH into equation (18), the transmission zero point f is calculated. TZ2 =1.48GHz. The simulation results of the entire ultra-wideband low insertion loss bandpass filter circuit are as follows: Figure 4 As shown, the positions of the two zeros in the lower stopband are located at f. TZ1 =1.40GHz and f TZ2 =1.48GHz.

[0126] Since the expression for the transmission zero point involves many components, and some components have a significant impact on the position of the transmission zero point, this analysis only focuses on the influence of the most influential components. By changing the component values ​​of C2, L2, and C7, L3, the transmission zero point f can be adjusted accordingly. TZ1 and f TZ2 The location. For example... Figure 5 and 6 As shown, as C2 and L2 increase, f TZ1 Shifting to lower frequencies, and f TZ2 No change; as C7 and L3 decrease, f TZ2 Shift to higher frequencies, and f TZ1 Do not move.

[0127] Then, an equivalent model of the parasitic parameters of the grounding via is established. Since the filter circuit has no transmission zero in the upper stopband, to improve the frequency selectivity of the upper stopband, parasitic parameters from the IPD process are introduced into the design without introducing additional components. The equivalent circuit of the grounding metal via in the process is extracted below. According to the process manual, the equivalent circuit of the grounding metal via includes an inductor, a resistor, and an ideal ground. First, the size of the grounding metal via is changed to the minimum value limited by the process, and its corresponding S-parameter curve is simulated. Second, its equivalent circuit is built, with the inductor and resistor values ​​set as variables. Finally, the inductor and resistor values ​​are optimized in the schematic diagram so that the S-curve of the schematic diagram coincides with the S-parameter curve of the grounding metal via, thus obtaining the equivalent circuit of the grounding metal via. Within the filter's operating frequency band, the S-parameter curves of the grounding metal via and its equivalent circuit coincide, resulting in an inductance value of 0.047nH and a resistance value of 0.012Ω in its equivalent circuit.

[0128] Introducing the small inductance from the equivalent circuit of the grounded metal via into the circuit diagram of the aforementioned ultra-wideband low insertion loss bandpass filter, as shown in the example... Figure 7 As shown, the added small inductance is L. 01 L 02 and L 03 Small inductor L 01 After being connected to capacitor C3 in Section I, it is grounded, and the small inductor L 02 After being connected to capacitor C4 in Section I, it is grounded, and the small inductor L 03 After connecting to capacitor C7 in Section II, it is grounded.

[0129] The S-parameter comparison diagram of the entire bandpass filter circuit before and after adding a small inductor is shown below. Figure 8 As shown, three additional transmission zeros are generated in the upper stopband, located at 17.37 GHz, 31.80 GHz, and 32.74 GHz, respectively.

[0130] Similar to the analysis of the bandpass filter above, the [ABCD] matrix of the bandpass filter circuit after adding a small inductor is:

[0131] (19)

[0132] Introducing a small inductor L 01 and L 02 The concatenated matrix [ABCD]′ of the first part SⅠ Represented as:

[0133] (20)

[0134] in,

[0135] ,

[0136] ,

[0137] ,

[0138] ,

[0139]

[0140] ,

[0141] ,

[0142] ,

[0143] ,

[0144]

[0145] Introducing a small inductor L 03 The concatenated matrix [ABCD]′ of the second part SⅡ Represented as:

[0146] (twenty one)

[0147] in,

[0148]

[0149]

[0150]

[0151]

[0152] , , , .

[0153] According to the transmission coefficient S 21 Relationship with [ABCD] matrix

[0154] (twenty two)

[0155] When calculating the transmission zero point, let S 21=0, the transmission zeros satisfy two equations about ω. The expression for the first equation is:

[0156] (twenty three)

[0157] Where W, X, Y, and Z are the coefficients of the equation, and their expressions are as follows:

[0158]

[0159]

[0160]

[0161]

[0162] The component values ​​are C2=1.26pF, C3=0.61pF, C4=12.27pF, C5=1.24pF, L1=0.79nH, L2=1.80nH, and L... 01 =L 02 Substituting 0.047nH into the above equation, we obtain the transmission zero as:

[0163] , ,

[0164] The expression for the second equation is:

[0165] (twenty four)

[0166] Where T, U, and V are the coefficients of the equation, and their expressions are as follows:

[0167]

[0168]

[0169]

[0170] The component values ​​are C7=6.68pF, C8=0.36pF, C9=10.86pF, L3=1.64nH, L4=1.07nH, and L... 03 Substituting 0.047nH into the above equation, we obtain the transmission zero as:

[0171] ,

[0172] This invention also implements the physical layout of an ultra-wideband, low-insertion-loss bandpass filter, while simultaneously achieving miniaturization and high integration. The capacitor model in the layout uses a metal-insulator-metal (MIM) structure, and the capacitance value is adjusted by changing the area of ​​the upper and lower metal plates. The inductor model in the layout uses a circular spiral planar inductor, leveraging its high Q value; the inductance value is adjusted by changing parameters such as the number of turns, linewidth, and line spacing.

[0173] The final filter layout model is as follows Figure 9 As shown, the layout size is 1400um × 800um, and the simulation frequency range is 0.01GHz to 50GHz. The simulated S-parameter curves for the layout are shown below. Figure 10 As shown in the diagram, the simulation results show that the filter's center frequency is 5.48 GHz, with a 3 dB relative bandwidth of 136.10%; the minimum insertion loss in the passband is 0.70 dB, and the minimum return loss is 18.92 dB; the suppression is greater than 20 dB in the 0.01 GHz to 1.87 GHz and 12.74 GHz to 40.67 GHz frequency bands.

[0174] To verify performance, the designed ultra-wideband low insertion loss bandpass filter chip was fabricated and tested using probes. The test results were compared with schematic simulation and layout simulation. Figure 11 As shown in the figure. By comparing the test curves and the layout simulation curves, it can be observed that the measured performance is in good agreement with the simulation results. The test results show that the filter has a center frequency of 5.56 GHz and a 3 dB relative bandwidth of 140.33%; the minimum insertion loss in the passband is 0.87 dB and the minimum return loss is 17.13 dB; the suppression is greater than 28 dB in the 0.01 GHz~2.00 GHz and 14.98 GHz~39.92 GHz frequency bands. Furthermore, there are 5 transmission zeros in the stopband, which almost correspond to the theoretical analysis values. Ultimately, ultra-wideband and low insertion loss performance are achieved.

[0175] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultrawideband low insertion loss bandpass filter based on gallium arsenide IPD technology, characterized in that, The ultra-wideband low insertion loss bandpass filter consists of Section I, Section II, and capacitor C. 10 The three parts are connected in series. Section I consists of capacitor C1, filter unit, and capacitor C6 connected in series. The filter unit is divided into two T-shaped structures connected in parallel, each consisting of two capacitors and one inductor. Section II is a parallel circuit, divided into upper and lower parts. The upper part is a T-shaped structure consisting of two capacitors and one inductor, and the lower part is a series connection of one capacitor and one inductor. In each T-shaped structure, one capacitor and one inductor are connected in series, and the other capacitor is grounded. This bandpass filter circuit has two transmission zeros in the lower stopband, and the two transmission zeros are generated by the two parts of the circuit, Section I and Section II, respectively. There are no transmission zeros in the upper stopband.

2. The ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology according to claim 1, characterized in that, Section I is as follows: One end of capacitor C1 is connected to input port Port1, and the other end of capacitor C1 is connected to one end of capacitor C2 and one end of inductor L2; the other end of capacitor C2 is connected to one end of capacitor C3 and also to one end of inductor L1, and the other end of capacitor C3 is grounded; the other end of inductor L2 is connected to one end of capacitor C4 and also to one end of capacitor C5, and the other end of capacitor C4 is grounded; the other end of inductor L1 is connected to the other end of capacitor C5, and then together they are connected to one end of capacitor C6, and the other end of capacitor C6 is connected to Section II.

3. The ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology according to claim 2, characterized in that, Section II specifically involves connecting one end of inductor L3 and capacitor C9 to the other end of capacitor C6 in Section I; connecting the other end of inductor L3 to one end of capacitors C7 and C8, with the other end of capacitor C7 grounded; connecting the other end of capacitor C9 to one end of inductor L4; connecting the other end of inductor L4 to the other end of capacitor C8, and then connecting them together to capacitor C... 10 One end of the capacitor C 10 The other end is connected to the output port Port2.

4. The ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology according to claim 3, characterized in that, An equivalent model of the parasitic parameters of the grounding via is established, and the parasitic parameters in the IPD process are introduced into the design to extract the equivalent circuit of the grounding metal via.

5. The ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology according to claim 4, characterized in that, The small inductance L in the equivalent circuit of the grounded metal through-hole 01 L 02 and L 03 When incorporated into an ultra-wideband low insertion loss bandpass filter, it forms an ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology, with a small inductor L. 01 After being connected to capacitor C3 in Section I, it is grounded, and the small inductor L 02 After being connected to capacitor C4 in Section I, it is grounded, and the small inductor L 03 After connecting to capacitor C7 in Section II, it is grounded.

6. The ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology according to claim 5, characterized in that, The [ABCD] matrix of the bandpass filter circuit after adding a small inductor is: Introducing a small inductor L 01 and L 02 The concatenated matrix [ABCD]′ of the first part SⅠ Represented as in, ， ， ， ， 。 7. The ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology according to claim 6, characterized in that, Introducing a small inductor L 03 The concatenated matrix [ABCD]′ of the second part SⅡ Represented as in, ， ， ， j represents the imaginary unit, and ω represents the angular frequency.

8. The ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology according to claim 7, characterized in that, According to the transmission coefficient S 21 The relationship with the [ABCD] matrix, i.e. Calculate the transmission zero point, let S 21 =0, the transmission zeros satisfy two equations about ω respectively, the first equation is in, The component values ​​are C2=1.26pF, C3=0.61pF, C4=12.27pF, C5=1.24pF, L1=0.79nH, L2=1.80nH, and L... 01 =L 02 Substituting 0.047nH into the first equation above and solving, we obtain the transmission zero as: , , .

9. The ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology according to claim 8, characterized in that, The second equation is in, The component values ​​are C7=6.68pF, C8=0.36pF, C9=10.86pF, L3=1.64nH, L4=1.07nH, and L... 03 Substituting 0.047nH into the second equation above and solving, we obtain the transmission zero as: , .

10. The ultra-wideband low insertion loss bandpass filter based on gallium arsenide IPD technology according to claim 9, characterized in that, The physical layout of an ultrawideband low insertion loss bandpass filter based on gallium arsenide IPD technology is designed. The capacitor model in the physical layout adopts a metal-insulator-metal structure, and the capacitance value is adjusted by changing the area of ​​the upper and lower metal plates. The inductor model in the physical layout adopts a circular spiral planar inductor, and the inductance value is adjusted by changing the number of turns, line width, and line spacing.

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