Balanced common-mode non-reflection non-magnetic band-pass filtering isolator

Abstract

The invention discloses a balanced common-mode non-reflection non-magnetic band-pass filtering isolator. Comprising a balanced differential signal input port A, a balanced differential signal output port B, a reverse signal suppression network, two balanced band-pass filter networks, two common-mode reflected wave suppression networks, four microstrip transmission lines, two low-impedance microstrip transmission lines and two high-impedance microstrip transmission lines. The balanced differential signal input port A comprises an input port A + and an input port A-; the balanced differential signal output port B comprises an output port B + and an output port B-; according to the balanced common-mode non-reflection non-magnetic band-pass filtering isolator, the unidirectional transmission function of balanced differential signals is realized by using a reverse signal suppression network. In addition, band-pass filtering characteristics of balanced differential signals, common-mode non-reflection characteristics of balanced differential signal input and output ports and good common-mode rejection are achieved, and the filter is very suitable for being applied to various radio frequency microwave systems to improve the performance of the radio frequency microwave systems.

Description

Technical Field

[0001] The invention relates to a microwave isolator, in particular to a balanced common-mode non-reflection and non-magnetic bandpass filtering isolator. Background Art

[0002] As modern RF microwave systems are developing towards miniaturization and high integration, the requirements for technical indicators such as the size and performance of RF components are becoming increasingly stringent. In traditional RF microwave systems, ferrite isolators are usually used at the ends of some RF components (such as local oscillators, power amplifiers, etc.) to achieve unidirectional transmission and reverse isolation, which plays a role in protecting RF components. Traditional ferrite devices must use permanent magnets to provide a constant bias field, which acts on the ferrite sheet, causing the ferrite to have anisotropic properties and tensor permeability, thereby realizing the non-reciprocal transmission characteristics of the device. However, this implementation method is bound to increase the volume of RF microwave circuits and systems, thereby reducing space utilization, which is contrary to the current development direction of miniaturization and high integration. At the same time, ferrite non-reciprocal materials are incompatible with the materials of semiconductor integrated circuits, and it is difficult to use ferrite materials to design and manufacture integrated circuits with non-reciprocal characteristics. Therefore, non-magnetic technology can be used to design and implement isolators with non-reciprocal characteristics.

[0003] Traditional RF microwave systems are usually designed with single-ended (unbalanced) signal chains, which have been widely used in many types of systems. However, with the miniaturization of the system, the components inside the system are compactly arranged, and the modules in the single-ended signal chain system will generate electromagnetic interference, thereby deteriorating the system performance. Since the balanced signal chain uses differential signals for transmission, it has a good suppression effect on common-mode electromagnetic interference noise. Therefore, in recent years, balanced signal chains have been applied to various types of RF microwave systems. In addition, as a crucial component in the RF microwave system, the bandpass filter plays the role of selecting the required signal frequency band. However, for balanced filters, the common-mode interference signal is usually reflected back to the input end of the filter to achieve good common-mode suppression characteristics, while the reflected common-mode interference signal will interact with adjacent nonlinear circuits (such as amplifiers, oscillators, mixers, etc.) to produce additional intermodulation products, deteriorating system performance. Therefore, for the application scenarios of balanced signal chains, it is necessary to realize RF devices with common-mode non-reflection and bandpass filtering characteristics based on balanced differential signal transmission.

[0004] At present, most of the magnetic tape-pass filter isolators (magnetic-free non-reciprocal filters) reported at home and abroad are single-ended (unbalanced) device designs, while there are very few reports on balanced magnetic tape-pass filter isolators. The reported balanced magnetic tape-pass filter isolators have the disadvantages of large insertion loss, poor input / output matching performance, and poor common-mode suppression performance. At the same time, the reported balanced magnetic tape-pass filter isolators all reflect the common-mode noise back to the input end, ignoring the impact of the common-mode reflected wave on the RF microwave system, thereby deteriorating the system performance. Therefore, in view of the above problems, it is necessary to propose a balanced common-mode non-reflective magnetic tape-pass filter isolator. Summary of the invention

[0005] Based on this, in order to solve the shortcomings of the prior art, the present invention proposes a balanced common-mode non-reflection band-pass filter isolator, a balanced differential signal input port A, a balanced differential signal output port B, a reverse signal suppression network, two balanced band-pass filter networks, two common-mode reflected wave suppression networks, four sections of microstrip transmission lines, two sections of low-impedance microstrip transmission lines and two sections of high-impedance microstrip transmission lines;

[0006] The balanced differential signal input port A includes an input port A+ and an input port A-;

[0007] The balanced differential signal output port B includes an output port B+ and an output port B-;

[0008] The reverse signal suppression network includes a microstrip connection line I, a first attenuation network, an amplifier circuit, a second attenuation network and a microstrip connection line II; the first attenuation network includes a first attenuation resistor, a second attenuation resistor and a third attenuation resistor; the first attenuation resistor and the third attenuation resistor have the same resistance value; the second attenuation network includes a fourth attenuation resistor, a fifth attenuation resistor and a sixth attenuation resistor; the fourth attenuation resistor and the sixth attenuation resistor have the same resistance value;

[0009] The two balanced bandpass filter networks include a first balanced bandpass filter network and a second balanced bandpass filter network; the first balanced bandpass filter network and the second balanced bandpass filter network have the same structure and size; the first balanced bandpass filter network and the second balanced bandpass filter network are both symmetrically arranged left and right and up and down; the first balanced bandpass filter network includes a first eye-shaped resonator, a second eye-shaped resonator, a third eye-shaped resonator and four coupled feed microstrip lines, the four coupled feed microstrip lines include a first coupled feed microstrip line, a second coupled feed microstrip line, a third coupled feed microstrip line and a fourth coupled feed microstrip line which have the same structure and size The first eye-shaped resonator and the third eye-shaped resonator have the same structure and size; the first eye-shaped resonator is located on the upper side of the second eye-shaped resonator; the third eye-shaped resonator is located on the lower side of the second eye-shaped resonator; the spacing between the first eye-shaped resonator and the second eye-shaped resonator is the same as the spacing between the third eye-shaped resonator and the second eye-shaped resonator; the first coupled feeding microstrip line is located on the lower left side of the first eye-shaped resonator; the second coupled feeding microstrip line is located on the lower right side of the first eye-shaped resonator; the third coupled feeding microstrip line is located on the upper left side of the third eye-shaped resonator; the fourth coupled feeding microstrip line is located on the upper right side of the third eye-shaped resonator;

[0010] The first eye-shaped resonator comprises a first circular microstrip line, a first semicircular microstrip line, a second semicircular microstrip line, a first microstrip connecting line and a second microstrip connecting line; the first semicircular microstrip line and the second semicircular microstrip line have the same structure and size; the first microstrip connecting line and the second microstrip connecting line have the same structure and size; one end of the first semicircular microstrip line is connected to the first microstrip connecting line, and the other end is connected to the second microstrip connecting line; one end of the second semicircular microstrip line is connected to the first microstrip connecting line, and the other end is connected to the second microstrip connecting line; the upper middle part of the first circular microstrip line is connected to the middle part of the second microstrip connecting line, and the lower middle part is connected to the middle part of the first microstrip connecting line;

[0011] The second eye-shaped resonator includes a second circular microstrip line, a third semicircular microstrip line, a fourth semicircular microstrip line, a third microstrip connecting line and a fourth microstrip connecting line; one end of the third semicircular microstrip line is connected to the third microstrip connecting line, and the other end is connected to the fourth microstrip connecting line; one end of the fourth semicircular microstrip line is connected to the third microstrip connecting line, and the other end is connected to the fourth microstrip connecting line; the middle part of the second circular microstrip line is connected to the middle part of the fourth microstrip connecting line, and the lower middle part is connected to the middle part of the third microstrip connecting line;

[0012] The first coupled feeding microstrip line includes a first feeding microstrip connecting line, a second feeding microstrip connecting line and a third feeding microstrip connecting line; one end of the second feeding microstrip connecting line is connected to the first feeding microstrip connecting line, and the other end is connected to the third feeding microstrip connecting line;

[0013] The two common-mode reflection wave suppression networks include a first common-mode reflection wave suppression network and a second common-mode reflection wave suppression network; the first common-mode reflection wave suppression network and the second common-mode reflection wave suppression network have the same structure and size; the first common-mode reflection wave suppression network includes a first open-circuit parallel coupled microstrip line, a second open-circuit parallel coupled microstrip line and a grounding resistor; the first open-circuit parallel coupled microstrip line and the second open-circuit parallel coupled microstrip line have the same structure; one end of the first open-circuit parallel coupled microstrip line is connected to the input port A+, and the other end is connected to the connection between the second open-circuit parallel coupled microstrip line and the grounding resistor; one end of the second open-circuit parallel coupled microstrip line is connected to the input port A-, and the other end is connected to the connection between the first open-circuit parallel coupled microstrip line and the grounding resistor;

[0014] The four sections of microstrip transmission lines include a first microstrip transmission line, a second microstrip transmission line, a third microstrip transmission line and a fourth microstrip transmission line with the same structure and size; one end of the first microstrip transmission line is connected to the connection between the input port A+ and the first common-mode reflection wave suppression network, and the other end is connected to the first balanced band-pass filter network; one end of the second microstrip transmission line is connected to the connection between the input port A- and the first common-mode reflection wave suppression network, and the other end is connected to the first balanced band-pass filter network; one end of the third microstrip transmission line is connected to the connection between the output port B+ and the second common-mode reflection wave suppression network, and the other end is connected to the second balanced band-pass filter network; one end of the fourth microstrip transmission line is connected to the connection between the output port B- and the second common-mode reflection wave suppression network, and the other end is connected to the second balanced band-pass filter network;

[0015] The two sections of low-impedance microstrip transmission lines include a first low-impedance microstrip transmission line and a second low-impedance microstrip transmission line of the same structure and size; one end of the first low-impedance microstrip transmission line is connected to a first balanced band-pass filter network, and the other end is connected to a microstrip connection line II; one end of the second low-impedance microstrip transmission line is connected to a second balanced band-pass filter network, and the other end is connected to a microstrip connection line I;

[0016] The two sections of high-impedance microstrip transmission lines include a first high-impedance microstrip transmission line and a second high-impedance microstrip transmission line; one end of the first high-impedance microstrip transmission line is connected to the connection between the first low-impedance microstrip transmission line and the microstrip connection line II, and the other end is connected to the connection between the second low-impedance microstrip transmission line and the microstrip connection line I; one end of the second high-impedance microstrip transmission line is connected to the first balanced band-pass filter network, and the other end is connected to the second balanced band-pass filter network;

[0017] One end of the second attenuation resistor is grounded, and the other end is connected to the connection between the first attenuation resistor and the third attenuation resistor; one end of the fifth attenuation resistor is grounded, and the other end is connected to the connection between the fourth attenuation resistor and the sixth attenuation resistor; one end of the amplifier circuit is connected to the third attenuation resistor, and the other end is connected to the fourth attenuation resistor; one end of the microstrip connecting line I is connected to the first attenuation resistor, and the other end is connected to the connection between the second low-impedance microstrip transmission line and the first high-impedance microstrip transmission line; one end of the microstrip connecting line II is connected to the sixth attenuation resistor, and the other end is connected to the connection between the first low-impedance microstrip transmission line and the first high-impedance microstrip transmission line.

[0018] The length of the first microstrip connection line and the second microstrip connection line is L1, and the width is W1; the radius of the first circular microstrip line, the first semicircular microstrip line and the second semicircular microstrip line is R1, and the width is W2; the radius of the second circular microstrip line, the third semicircular microstrip line and the fourth semicircular microstrip line is R2, and the width is W3; the length of the third microstrip connection line and the fourth microstrip connection line is L4, and the width is W4; the length of the first feeding microstrip connection line is L5, and the width is W5; the length of the second feeding microstrip connection line is The length of the third feeding microstrip connecting line is L6 and the width is W6; the length of the third feeding microstrip connecting line is L7 and the width is W7; the spacing between the first coupling feeding microstrip line and the first eye-shaped resonator is S1; the spacing between the first eye-shaped resonator and the second eye-shaped resonator is S2; the center frequency of the balanced bandpass filter network is adjusted by adjusting L1, W1, R1, W2, R2, W3, L4 and W4; the passband bandwidth and in-band matching performance of the balanced bandpass filter network are adjusted by adjusting L5, W5, L6, W6, L7, W7, S1 and S2.

[0019] The characteristic impedance of the first low-impedance microstrip transmission line and the second low-impedance microstrip transmission line is Z1, and the electrical length is θ1; the characteristic impedance of the first high-impedance microstrip transmission line and the second high-impedance microstrip transmission line is Z2, and the electrical length is θ2; the resistance values ​​of the first attenuation resistor and the third attenuation resistor are R a The resistance of the second attenuation resistor is R b The resistance of the fourth attenuation resistor and the sixth attenuation resistor is R c The resistance of the fifth attenuation resistor is Rd The characteristic impedance of the microstrip connecting line I is Z3, and the electrical length is θ3; the characteristic impedance of the microstrip connecting line II is Z4, and the electrical length is θ4; by adjusting Z1, θ1, Z2, θ2, R a , R b , R c , R d , Z3, θ3, Z4 and θ4 to achieve balanced magnetic-free non-reciprocal isolation characteristics.

[0020] The even-mode characteristic impedance of the first open-circuit parallel coupled microstrip line is Z ea , the odd-mode characteristic impedance is Z oa , the electrical length is θ a ; The resistance of the grounding resistor is R e The characteristic impedance of the first microstrip transmission line is Z5, and the electrical length is θ5; by adjusting Z ea , Z oa ,θ a , R e , Z5 and θ5 to achieve common-mode non-reflection characteristics.

[0021] In order to realize the bandpass filtering function of balanced differential signals, the balanced common-mode non-reflection function and the unidirectional transmission function of balanced differential signals, the present invention provides a balanced common-mode non-reflection and non-bandpass filter isolator. The balanced common-mode non-reflection and non-bandpass filter isolator realizes the unidirectional transmission function of balanced differential signals by using a reverse signal suppression network. In addition, the bandpass filtering characteristics of balanced differential signals, the common-mode non-reflection characteristics of balanced differential signal input and output ports and good common-mode suppression are also realized, which is very suitable for application in various radio frequency microwave systems to improve their performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a structural schematic diagram of a balanced common-mode non-reflection and non-magnetic tape pass filter isolator of the present invention;

[0024] Figure 2 It is a structural schematic diagram of a balanced bandpass filter network of a balanced common-mode non-reflection and non-magnetic bandpass filter isolator of the present invention;

[0025] Figure 3It is a hybrid S parameter transmission performance curve diagram of a balanced common mode non-reflection and non-magnetic tape pass filter isolator under differential mode signal excitation of the present invention;

[0026] Figure 4 It is a hybrid S parameter matching performance curve diagram of a balanced common mode non-reflection and non-magnetic tape pass filter isolator under differential mode signal excitation of the present invention;

[0027] Figure 5 It is a mixed S parameter curve diagram of a balanced common-mode non-reflection and non-magnetic tapepass filter isolator under common-mode signal excitation of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The invention discloses a balanced common-mode non-reflection band-pass filtering isolator, comprising: a balanced differential signal input port A, a balanced differential signal output port B, a reverse signal suppression network, two balanced band-pass filtering networks, two common-mode reflected wave suppression networks, four sections of microstrip transmission lines, two sections of low-impedance microstrip transmission lines and two sections of high-impedance microstrip transmission lines;

[0030] The balanced differential signal input port A includes an input port A+1 and an input port A-2;

[0031] The balanced differential signal output port B includes an output port B+3 and an output port B-4;

[0032] The reverse signal suppression network 5 includes a microstrip connection line I 51, a first attenuation network 52, an amplifier circuit 53, a second attenuation network 54 and a microstrip connection line II 55; the first attenuation network 52 includes a first attenuation resistor 521, a second attenuation resistor 522 and a third attenuation resistor 523; the first attenuation resistor 521 and the third attenuation resistor 523 have the same resistance value; the second attenuation network 54 includes a fourth attenuation resistor 541, a fifth attenuation resistor 542 and a sixth attenuation resistor 543; the fourth attenuation resistor 541 and the sixth attenuation resistor 543 have the same resistance value;

[0033] The two balanced bandpass filter networks include a first balanced bandpass filter network 6 and a second balanced bandpass filter network 7; the first balanced bandpass filter network 6 and the second balanced bandpass filter network 7 have the same structure and size; the first balanced bandpass filter network 6 and the second balanced bandpass filter network 7 are both symmetrically arranged left and right and up and down; the first balanced bandpass filter network 6 includes a first eye-shaped resonator 61, a second eye-shaped resonator 62, a third eye-shaped resonator 63 and four coupled feed microstrip lines, and the four coupled feed microstrip lines include a first coupled feed microstrip line 64, a second coupled feed microstrip line 65, a third coupled feed microstrip line 66 and a fourth coupled feed microstrip line 67 with the same structure and size; The first eye-shaped resonator 61 and the third eye-shaped resonator 63 have the same structure and size; the first eye-shaped resonator 61 is located on the upper side of the second eye-shaped resonator 62; the third eye-shaped resonator 63 is located on the lower side of the second eye-shaped resonator 62; the spacing between the first eye-shaped resonator 61 and the second eye-shaped resonator 62 is the same as the spacing between the third eye-shaped resonator 63 and the second eye-shaped resonator 62; the first coupling feeding microstrip line 64 is located on the lower left side of the first eye-shaped resonator 61; the second coupling feeding microstrip line 65 is located on the lower right side of the first eye-shaped resonator 61; the third coupling feeding microstrip line 66 is located on the upper left side of the third eye-shaped resonator 63; the fourth coupling feeding microstrip line 67 is located on the upper right side of the third eye-shaped resonator 63;

[0034] The first eye-shaped resonator 61 includes a first circular microstrip line 611, a first semicircular microstrip line 612, a second semicircular microstrip line 613, a first microstrip connecting line 614 and a second microstrip connecting line 615; the first semicircular microstrip line 612 and the second semicircular microstrip line 613 have the same structure and size; the first microstrip connecting line 614 and the second microstrip connecting line 615 have the same structure and size; one end of the first semicircular microstrip line 612 is connected to the first microstrip connecting line 614, and the other end is connected to the second microstrip connecting line 615; one end of the second semicircular microstrip line 613 is connected to the first microstrip connecting line 614, and the other end is connected to the second microstrip connecting line 615; the upper middle part of the first circular microstrip line 611 is connected to the middle part of the second microstrip connecting line 615, and the lower middle part is connected to the middle part of the first microstrip connecting line 614;

[0035] The second eye-shaped resonator 62 includes a second circular microstrip line 621, a third semicircular microstrip line 622, a fourth semicircular microstrip line 623, a third microstrip connecting line 624 and a fourth microstrip connecting line 625; one end of the third semicircular microstrip line 622 is connected to the third microstrip connecting line 624, and the other end is connected to the fourth microstrip connecting line 625; one end of the fourth semicircular microstrip line 623 is connected to the third microstrip connecting line 624, and the other end is connected to the fourth microstrip connecting line 625; the upper middle part of the second circular microstrip line 621 is connected to the middle part of the fourth microstrip connecting line 625, and the lower middle part is connected to the middle part of the third microstrip connecting line 624;

[0036] The first coupled feeding microstrip line 64 includes a first feeding microstrip connecting line 641, a second feeding microstrip connecting line 642 and a third feeding microstrip connecting line 643; one end of the second feeding microstrip connecting line 642 is connected to the first feeding microstrip connecting line 641, and the other end is connected to the third feeding microstrip connecting line 643;

[0037] The two common-mode reflection wave suppression networks include a first common-mode reflection wave suppression network 8 and a second common-mode reflection wave suppression network 9; the first common-mode reflection wave suppression network 8 and the second common-mode reflection wave suppression network 9 have the same structure and size; the first common-mode reflection wave suppression network 8 includes a first open-circuit parallel coupled microstrip line 81, a second open-circuit parallel coupled microstrip line 82 and a grounding resistor 83; the first open-circuit parallel coupled microstrip line 81 and the second open-circuit parallel coupled microstrip line 82 have the same structure; one end of the first open-circuit parallel coupled microstrip line 81 is connected to the input port A+1, and the other end is connected to the connection between the second open-circuit parallel coupled microstrip line 82 and the grounding resistor 83; one end of the second open-circuit parallel coupled microstrip line 82 is connected to the input port A-2, and the other end is connected to the connection between the first open-circuit parallel coupled microstrip line 81 and the grounding resistor 83;

[0038] The four sections of microstrip transmission lines include a first microstrip transmission line 10, a second microstrip transmission line 11, a third microstrip transmission line 12 and a fourth microstrip transmission line 13 with the same structure and size; one end of the first microstrip transmission line 10 is connected to the connection between the input port A+1 and the first common-mode reflection wave suppression network 8, and the other end is connected to the first balanced band-pass filter network 6; one end of the second microstrip transmission line 11 is connected to the connection between the input port A-2 and the first common-mode reflection wave suppression network 8, and the other end is connected to the first balanced band-pass filter network 6; one end of the third microstrip transmission line 12 is connected to the connection between the output port B+3 and the second common-mode reflection wave suppression network 9, and the other end is connected to the second balanced band-pass filter network 7; one end of the fourth microstrip transmission line 13 is connected to the connection between the output port B-4 and the second common-mode reflection wave suppression network 9, and the other end is connected to the second balanced band-pass filter network 7;

[0039] The two sections of low-impedance microstrip transmission lines include a first low-impedance microstrip transmission line 14 and a second low-impedance microstrip transmission line 15 having the same structure and size; one end of the first low-impedance microstrip transmission line 14 is connected to the first balanced bandpass filter network 6, and the other end is connected to the microstrip connection line II55; one end of the second low-impedance microstrip transmission line 15 is connected to the second balanced bandpass filter network 7, and the other end is connected to the microstrip connection line I51;

[0040] The two sections of high-impedance microstrip transmission lines include a first high-impedance microstrip transmission line 16 and a second high-impedance microstrip transmission line 17; one end of the first high-impedance microstrip transmission line 16 is connected to the connection between the first low-impedance microstrip transmission line 14 and the microstrip connection line II55, and the other end is connected to the connection between the second low-impedance microstrip transmission line 15 and the microstrip connection line I51; one end of the second high-impedance microstrip transmission line 17 is connected to the first balanced band-pass filter network 6, and the other end is connected to the second balanced band-pass filter network 7;

[0041] One end of the second attenuation resistor 522 is grounded, and the other end is connected to the connection between the first attenuation resistor 521 and the third attenuation resistor 523; one end of the fifth attenuation resistor 542 is grounded, and the other end is connected to the connection between the fourth attenuation resistor 541 and the sixth attenuation resistor 543; one end of the amplifier circuit 53 is connected to the third attenuation resistor 523, and the other end is connected to the fourth attenuation resistor 541; one end of the microstrip connecting line I51 is connected to the first attenuation resistor 521, and the other end is connected to the connection between the second low-impedance microstrip transmission line 15 and the first high-impedance microstrip transmission line 16; one end of the microstrip connecting line II55 is connected to the sixth attenuation resistor 543, and the other end is connected to the connection between the first low-impedance microstrip transmission line 14 and the first high-impedance microstrip transmission line 16.

[0042] Further, the length of the first microstrip connection line 614 and the second microstrip connection line 615 is L1, and the width is W1; the radius of the first circular microstrip line 611, the first semicircular microstrip line 612, and the second semicircular microstrip line 613 is R1, and the width is W2; the radius of the second circular microstrip line 621, the third semicircular microstrip line 622, and the fourth semicircular microstrip line 623 is R2, and the width is W3; the length of the third microstrip connection line 624 and the fourth microstrip connection line 625 is L4, and the width is W4; the length of the first feeding microstrip connection line 641 is L5, and the width is W5; The length of the second feeding microstrip connecting line 642 is L6 and the width is W6; the length of the third feeding microstrip connecting line 643 is L7 and the width is W7; the distance between the first coupling feeding microstrip line 64 and the first eye-shaped resonator 61 is S1; the distance between the first eye-shaped resonator 61 and the second eye-shaped resonator 62 is S2; the center frequency of the balanced bandpass filter network is adjusted by adjusting L1, W1, R1, W2, R2, W3, L4 and W4; the passband bandwidth and in-band matching performance of the balanced bandpass filter network are adjusted by adjusting L5, W5, L6, W6, L7, W7, S1 and S2.

[0043] Furthermore, the characteristic impedance of the first low-impedance microstrip transmission line 14 and the second low-impedance microstrip transmission line 15 is Z1, and the electrical length is θ1; the characteristic impedance of the first high-impedance microstrip transmission line 16 and the second high-impedance microstrip transmission line 17 is Z2, and the electrical length is θ2; the resistance of the first attenuation resistor 521 and the third attenuation resistor 523 is R a The resistance of the second attenuation resistor 522 is R b The resistance of the fourth attenuation resistor 541 and the sixth attenuation resistor 543 is R c The resistance of the fifth attenuation resistor 542 is R d The characteristic impedance of the microstrip connecting line Ⅰ51 is Z3, and the electrical length is θ3; the characteristic impedance of the microstrip connecting line Ⅱ55 is Z4, and the electrical length is θ4; by adjusting Z1, θ1, Z2, θ2, R a , R b , R c , R d , Z3, θ3, Z4 and θ4 to achieve balanced magnetic-free non-reciprocal isolation characteristics.

[0044] Furthermore, the even-mode characteristic impedance of the first open-circuit parallel coupled microstrip line 81 is Z ea , the odd-mode characteristic impedance is Z oa , the electrical length is θ a The resistance of the grounding resistor 83 is R e The characteristic impedance of the first microstrip transmission line 10 is Z5 and the electrical length is θ5; by adjusting Zea , Z oa ,θ a , R e , Z5 and θ5 to achieve common-mode non-reflection characteristics.

[0045] In order to further illustrate the balanced common-mode non-reflection and non-magnetic tape pass filter isolator provided by the present invention, a specific example implemented based on the technical solution of the present invention is described in detail below, but the protection scope of the present invention is not limited to the following embodiments, and the methods used in the following embodiments are all conventional methods unless otherwise specified.

[0046] Specific example: This example lists a balanced common-mode non-reflection and non-magnetic bandpass filter isolator, in which the amplifier circuit is implemented using the SBB5089Z amplifier. Figure 3 As shown, the center frequency of the balanced common-mode non-reflection and non-magnetic tape pass filter isolator described in the present invention is 2.45 GHz, the differential mode insertion loss is 0.17 dB, |S ddBA |>-3dB passband frequency range is 2.342GHz~2.537GHz (relative bandwidth is 7.96%), |S ddAB |In the range of 1.0~4.0GHz, the signal is less than -22.81dB, achieving the bandpass filtering and broadband reverse isolation characteristics of differential signals. Figure 4 As shown, the differential mode return loss of the differential signal input port A of the balanced common mode non-reflection and non-magnetic tape pass filter isolator of the present invention |S ddAA The frequency range of |<-10dB is 2.339GHz~2.528GHz, and the differential mode return loss of the differential signal output port B|S ddBB The frequency range of |<-10dB is 2.342GHz~2.528GHz, achieving the input matching characteristics of differential signals. Figure 5 As shown, the common-mode return loss of a balanced common-mode non-reflection and non-magnetic tape pass filter isolator described in the present invention is |S ccAA |=|S ccBB |<-10dB frequency range is 1.748~3.222GHz, achieving common mode non-reflection characteristics; common mode transmission coefficient |S ccBA |In the range of 1.0~4.0GHz, it is less than -57.43dB, achieving broadband common-mode suppression characteristics.

[0047] In summary, the balanced common-mode non-reflection and non-bandpass filter isolator provided by the present invention simultaneously realizes the bandpass filtering characteristics of differential mode signals, the unidirectional transmission characteristics of differential mode signals, the common-mode non-reflection characteristics, and the broadband common-mode suppression characteristics, and is very suitable for application in various balanced RF microwave systems to improve their overall performance.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A balanced common mode non-reflection and non-magnetic bandpass filter isolator, characterized in that: include: Balanced differential signal input port A, balanced differential signal output port B, reverse signal suppression network, two balanced bandpass filter networks, two common mode reflection wave suppression networks, four sections of microstrip transmission lines, two sections of low impedance microstrip transmission lines and two sections of high impedance microstrip transmission lines; The balanced differential signal input port A includes an input port A+(1) and an input port A-(2); The balanced differential signal output port B includes an output port B+(3) and an output port B-(4); The reverse signal suppression network (5) comprises a microstrip connection line I (51), a first attenuation network (52), an amplifier circuit (53), a second attenuation network (54) and a microstrip connection line II (55); the first attenuation network (52) comprises a first attenuation resistor (521), a second attenuation resistor (522) and a third attenuation resistor (523); the second attenuation network (54) comprises a fourth attenuation resistor (541), a fifth attenuation resistor (542) and a sixth attenuation resistor (543); the two balanced bandpass filter networks comprise a first balanced bandpass filter network (6) and a second balanced bandpass filter network (7); the first balanced bandpass filter network (6) and the second balanced bandpass filter network (7) are both symmetrically arranged left-right and top-bottom; the first balanced bandpass filter network (6) comprises a first eye-shaped resonator (61), a second eye-shaped resonator ( 62), a third eye-shaped resonator (63) and four coupled feeding microstrip lines, the four coupled feeding microstrip lines comprising a first coupled feeding microstrip line (64), a second coupled feeding microstrip line (65), a third coupled feeding microstrip line (66) and a fourth coupled feeding microstrip line (67) having the same structure and size; the first eye-shaped resonator (61) is located on the upper side of the second eye-shaped resonator (62); the third eye-shaped resonator (63) is located on the lower side of the second eye-shaped resonator (62); the first coupled feeding microstrip line (64) is located on the lower left side of the first eye-shaped resonator (61); the second coupled feeding microstrip line (65) is located on the lower right side of the first eye-shaped resonator (61); the third coupled feeding microstrip line (66) is located on the upper left side of the third eye-shaped resonator (63); and the fourth coupled feeding microstrip line (67) is located on the upper right side of the third eye-shaped resonator (63); The first eye-shaped resonator (61) comprises a first circular microstrip line (611), a first semicircular microstrip line (612), a second semicircular microstrip line (613), a first microstrip connecting line (614) and a second microstrip connecting line (615); one end of the first semicircular microstrip line (612) is connected to the first microstrip connecting line (614), and the other end is connected to the second microstrip connecting line (615); one end of the second semicircular microstrip line (613) is connected to the first microstrip connecting line (614), and the other end is connected to the second microstrip connecting line (615); the upper middle part of the first circular microstrip line (611) is connected to the middle part of the second microstrip connecting line (615), and the lower middle part is connected to the middle part of the first microstrip connecting line (614); The second eye-shaped resonator (62) comprises a second circular microstrip line (621), a third semicircular microstrip line (622), a fourth semicircular microstrip line (623), a third microstrip connecting line (624) and a fourth microstrip connecting line (625); one end of the third semicircular microstrip line (622) is connected to the third microstrip connecting line (624), and the other end is connected to the fourth microstrip connecting line (625); one end of the fourth semicircular microstrip line (623) is connected to the third microstrip connecting line (624), and the other end is connected to the fourth microstrip connecting line (625); the upper middle part of the second circular microstrip line (621) is connected to the middle part of the fourth microstrip connecting line (625), and the lower middle part is connected to the middle part of the third microstrip connecting line (624); The first coupled feeding microstrip line (64) comprises a first feeding microstrip connecting line (641), a second feeding microstrip connecting line (642) and a third feeding microstrip connecting line (643); one end of the second feeding microstrip connecting line (642) is connected to the first feeding microstrip connecting line (641), and the other end is connected to the third feeding microstrip connecting line (643); The two common-mode reflection wave suppression networks include a first common-mode reflection wave suppression network (8) and a second common-mode reflection wave suppression network (9); the first common-mode reflection wave suppression network (8) includes a first open-circuit parallel coupled microstrip line (81), a second open-circuit parallel coupled microstrip line (82) and a grounding resistor (83); one end of the first open-circuit parallel coupled microstrip line (81) is connected to an input port A+(1), and the other end is connected to a connection point between the second open-circuit parallel coupled microstrip line (82) and a grounding resistor (83); one end of the second open-circuit parallel coupled microstrip line (82) is connected to an input port A-(2), and the other end is connected to a connection point between the first open-circuit parallel coupled microstrip line (81) and a grounding resistor (83); The four sections of microstrip transmission lines include a first microstrip transmission line (10), a second microstrip transmission line (11), a third microstrip transmission line (12) and a fourth microstrip transmission line (13) having the same structure and size; one end of the first microstrip transmission line (10) is connected to the connection between the input port A+ (1) and the first common-mode reflection wave suppression network (8), and the other end is connected to the first balanced bandpass filter network (6); one end of the second microstrip transmission line (11) is connected to the input port A- (2) and the first common-mode reflection wave suppression network (8) The first microstrip transmission line (12) is connected to the connection point of the output port B+ (3) and the second common-mode reflection suppression network (8), and the other end is connected to the first balanced band-pass filter network (6); one end of the third microstrip transmission line (12) is connected to the connection point of the output port B+ (3) and the second common-mode reflection suppression network (9), and the other end is connected to the second balanced band-pass filter network (7); one end of the fourth microstrip transmission line (13) is connected to the connection point of the output port B- (4) and the second common-mode reflection suppression network (9), and the other end is connected to the second balanced band-pass filter network (7); The two low-impedance microstrip transmission lines include a first low-impedance microstrip transmission line (14) and a second low-impedance microstrip transmission line (15) of identical structure and size; one end of the first low-impedance microstrip transmission line (14) is connected to a first balanced bandpass filter network (6), and the other end is connected to a microstrip connection line II (55); one end of the second low-impedance microstrip transmission line (15) is connected to a second balanced bandpass filter network (7), and the other end is connected to a microstrip connection line I (51); The two sections of high-impedance microstrip transmission lines include a first high-impedance microstrip transmission line (16) and a second high-impedance microstrip transmission line (17); one end of the first high-impedance microstrip transmission line (16) is connected to the connection between the first low-impedance microstrip transmission line (14) and the microstrip connection line II (55), and the other end is connected to the connection between the second low-impedance microstrip transmission line (15) and the microstrip connection line I (51); one end of the second high-impedance microstrip transmission line (17) is connected to the first balanced band-pass filter network (6), and the other end is connected to the second balanced band-pass filter network (7); One end of the second attenuation resistor (522) is grounded, and the other end is connected to the connection between the first attenuation resistor (521) and the third attenuation resistor (523); one end of the fifth attenuation resistor (542) is grounded, and the other end is connected to the connection between the fourth attenuation resistor (541) and the sixth attenuation resistor (543); one end of the amplifier circuit (53) is connected to the third attenuation resistor (523), and the other end is connected to the fourth attenuation resistor (541); one end of the microstrip connection line I (51) is connected to the first attenuation resistor (521), and the other end is connected to the connection between the second low-impedance microstrip transmission line (15) and the first high-impedance microstrip transmission line (16); one end of the microstrip connection line II (55) is connected to the sixth attenuation resistor (543), and the other end is connected to the connection between the first low-impedance microstrip transmission line (14) and the first high-impedance microstrip transmission line (16).

2. A balanced common-mode non-reflection and non-magnetic bandpass filter isolator according to claim 1, characterized in that: The first attenuation resistor (521) and the third attenuation resistor (523) have the same resistance value; the fourth attenuation resistor (541) and the sixth attenuation resistor (543) have the same resistance value; the first balanced bandpass filter network (6) and the second balanced bandpass filter network (7) have the same structure and size; the first eye-shaped resonator (61) and the third eye-shaped resonator (63) have the same structure and size; the distance between the first eye-shaped resonator (61) and the second eye-shaped resonator (62) and the distance between the third eye-shaped resonator (63) and the first eye-shaped resonator (61) and the second eye-shaped resonator (62) are the same. ) is the same as the spacing between the first common-mode reflection wave suppression network (8) and the second common-mode reflection wave suppression network (9); the structure and size of the first semicircular ring microstrip line (612) and the second semicircular ring microstrip line (613) are the same; the structure and size of the first microstrip connecting line (614) and the second microstrip connecting line (615) are the same; the first open-circuit parallel coupled microstrip line (81) and the second open-circuit parallel coupled microstrip line (82) have the same structure.

3. A balanced common-mode non-reflection and non-magnetic bandpass filter isolator according to claim 1, characterized in that: The first microstrip connection line (614) and the second microstrip connection line (615) have a length of L1 and a width of W1; the first circular microstrip line (611), the first semicircular microstrip line (612) and the second semicircular microstrip line (613) have a radius of R1 and a width of W2; the second circular microstrip line (621), the third semicircular microstrip line (622) and the fourth semicircular microstrip line (623) have a radius of R2 and a width of W3; the third microstrip connection line (624) and the fourth microstrip connection line (625) have a length of L4 and a width of W4; the first feeding microstrip connection line (641) has a length of L5 and a width of W5 ; the length of the second feeding microstrip connecting line (642) is L6 and the width is W6; the length of the third feeding microstrip connecting line (643) is L7 and the width is W7; the distance between the first coupling feeding microstrip line (64) and the first eye-shaped resonator (61) is S1; the distance between the first eye-shaped resonator (61) and the second eye-shaped resonator (62) is S2; the center frequency of the balanced bandpass filter network is adjusted by adjusting L1, W1, R1, W2, R2, W3, L4 and W4; the passband bandwidth and in-band matching performance of the balanced bandpass filter network are adjusted by adjusting L5, W5, L6, W6, L7, W7, S1 and S2.

4. A balanced common-mode non-reflection and non-magnetic bandpass filter isolator according to claim 1, characterized in that: The characteristic impedance of the first low-impedance microstrip transmission line (14) and the second low-impedance microstrip transmission line (15) is Z1, and the electrical length is θ1; the characteristic impedance of the first high-impedance microstrip transmission line (16) and the second high-impedance microstrip transmission line (17) is Z2, and the electrical length is θ2; the resistance values ​​of the first attenuation resistor (521) and the third attenuation resistor (523) are R a The resistance of the second attenuation resistor (522) is R b The resistance values ​​of the fourth attenuation resistor (541) and the sixth attenuation resistor (543) are R c The resistance of the fifth attenuation resistor (542) is R d The characteristic impedance of the microstrip connecting line I (51) is Z3 and the electrical length is θ3; the characteristic impedance of the microstrip connecting line II (55) is Z4 and the electrical length is θ4; by adjusting Z1, θ1, Z2, θ2, R a , R b , R c , R d , Z3, θ3, Z4 and θ4 to achieve balanced magnetic-free non-reciprocal isolation characteristics.

5. A balanced common-mode non-reflection and non-magnetic bandpass filter isolator according to claim 1, characterized in that: The even-mode characteristic impedance of the first open-circuit parallel coupled microstrip line (81) is Z ea , the odd-mode characteristic impedance is Z oa , the electrical length is θ a The resistance of the grounding resistor (83) is R e The characteristic impedance of the first microstrip transmission line (10) is Z5 and the electrical length is θ5; by adjusting Z ea , Z oa ,θ a , R e , Z5 and θ5 to achieve common-mode non-reflection characteristics.

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