CN112019181A - Design method of extremely-high-frequency broadband linearizer - Google Patents

Design method of extremely-high-frequency broadband linearizer Download PDF

Info

Publication number
CN112019181A
CN112019181A CN202010692983.5A CN202010692983A CN112019181A CN 112019181 A CN112019181 A CN 112019181A CN 202010692983 A CN202010692983 A CN 202010692983A CN 112019181 A CN112019181 A CN 112019181A
Authority
CN
China
Prior art keywords
matching network
linearizer
value
different frequencies
nonlinear load
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010692983.5A
Other languages
Chinese (zh)
Other versions
CN112019181B (en
Inventor
周东方
邓海林
卞晨阁
张毅
吕大龙
魏进进
刘起坤
张德伟
李建兵
刘庆
柴梦娟
付宇璠
马壮
潘晨清
王显
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Information Engineering University of PLA Strategic Support Force
Original Assignee
Information Engineering University of PLA Strategic Support Force
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Information Engineering University of PLA Strategic Support Force filed Critical Information Engineering University of PLA Strategic Support Force
Priority to CN202010692983.5A priority Critical patent/CN112019181B/en
Publication of CN112019181A publication Critical patent/CN112019181A/en
Application granted granted Critical
Publication of CN112019181B publication Critical patent/CN112019181B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/38—Impedance-matching networks
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Landscapes

  • Amplifiers (AREA)

Abstract

The invention provides a design method of an extremely high frequency broadband linearizer. The linearizer comprises a 3dB directional coupler, a nonlinear load and a matching network, and the design method comprises the following steps: step 1, setting gain compensation quantity and phase compensation quantity required by a linearizer at different frequencies; step 2, obtaining impedance values of the nonlinear load at different frequencies under different input powers through measurement, and converting the impedance values of the nonlinear load into admittance values of the nonlinear load; step 3, according to the admittance value of the nonlinear load, obtaining a port impedance value required by the matching network under the condition of meeting the gain compensation quantity and the phase compensation quantity given in the step 1 by an optimization method; and 4, designing a matching network according to the port impedance value. The invention provides the design method of the linearizer with gain and phase compensation quantities at given different frequencies for the first time, and overcomes the defect that the prior design method can not compensate each frequency.

Description

Design method of extremely-high-frequency broadband linearizer
Technical Field
The invention relates to the technical field of microwaves, in particular to a design method of an ultrahigh-frequency broadband linearizer.
Background
In recent years, military and government satellite communication demands have continued to increase as the competition for space spectrum resources has accelerated, and the space electromagnetic environment has become increasingly complex. However, the existing Ku-band and Ka-band satellite communication systems cannot meet the requirements of people on communication quality at present. It is a research direction of researchers to select a higher frequency band for communication to obtain a higher capacity and design a better satellite communication system. The search for higher frequency bands mainly involves the extremely high frequency bands outside the Ka band, i.e., the Q/V band (about 40-75GHz) and the W band (75-100 GHz). This results in extremely high device and process requirements due to the significant atmospheric attenuation and free-space path loss in the very high frequency band. The power amplifier, which is a crucial module in a satellite transponder, determines the propagation distance and quality of a signal in free space. For better signal quality, the power amplifier usually needs to back off the output power. However, this reduces the efficiency of the power amplifier, further hindering the miniaturization and weight reduction of the satellite.
The linearization technology can widen the linear working interval of the power amplifier, greatly reduce the output power back-off quantity of the power amplifier, and ensure that the power amplifier still works in a high-efficiency state while ensuring the quality of an output signal. This makes the design of current very high frequency broadband linearizers difficult because the non-linear characteristics of the power amplifier are not only related to the input power but also to the frequency in the very high frequency band. The document only gives the phase compensation capability of the Linearizer at different frequencies, does not relate to the gain compensation capability at different frequencies, and has a complicated design structure of the circuit.
In addition, no design method of the extremely-high frequency broadband linearizer exists at present, so the research on the design method can effectively solve the problems of high-frequency atmospheric attenuation and nonlinear distortion encountered in future satellite development, is beneficial to the miniaturization and light weight of the future satellite, and can provide powerful support for the further development of the satellite in China.
Disclosure of Invention
Aiming at the problems that the existing design method of a linearizer cannot perform gain compensation on each frequency and the design method of an extremely high frequency broadband linearizer is lacked, the invention provides a design method of the extremely high frequency broadband linearizer.
The invention provides a design method of an extremely high frequency broadband linearizer, wherein the linearizer comprises a 3dB directional coupler, a nonlinear load and a matching network, and the design method comprises the following steps:
step 1, setting gain compensation quantity and phase compensation quantity required by a linearizer at different frequencies;
step 2, obtaining impedance values of the nonlinear load at different frequencies under different input powers through measurement, and converting the impedance values of the nonlinear load into admittance values of the nonlinear load;
step 3, according to the admittance value of the nonlinear load, obtaining a port impedance value required by the matching network under the condition of meeting the gain compensation quantity and the phase compensation quantity given in the step 1 by an optimization method;
and 4, designing a matching network according to the port impedance value.
Further, step 1 specifically comprises:
the gain compensation amount and the phase compensation amount of the linearizer at different frequencies are determined from gain and phase curves of the power amplifier measured at different frequencies and powers.
Further, step 3 comprises:
setting the transmission matrix of the matching network as
Figure BDA0002590017300000021
The parameters A, B, C and D of the matching network are solved according to equation (2):
Figure BDA0002590017300000022
wherein a and b are respectively the gain compensation amount and the phase compensation amount given in step 1, IL is the insertion loss of the system, and Z0The port impedance value of the coupling end of the 3dB directional coupler is conjugate operation GsAnd BsAdmittance value, G, for a non-linear loadshAnd BshAdmittance value, G, for a non-linear load at maximum input powerslAnd BslFor the admittance value of the non-linear load at minimum input power,handlthe value of the reflection coefficient at maximum input power and the value at minimum input power, phi, respectivelyhAnd philRespectively representing the phase value of the reflection coefficient at maximum input power and the phase value at minimum input power.
Further, step 3 further comprises:
calculating according to the formula (3) according to the parameters of the matching network to obtain the port impedance value Z of the matching networkopt：
Figure BDA0002590017300000031
Further, step 4 comprises:
when designing a matching network, selecting a specific matching network structure, and adopting a formula (4) as an objective function of the matching network:
Figure BDA0002590017300000032
wherein λ isiIs wave number, Zopt(λi) Port impedance value, Z, of the matching network obtained in step 3 at different frequenciesin(λi) N represents the number of frequencies that need to be matched for a port impedance value at a particular matching network configuration at different frequencies.
The invention has the beneficial effects that:
1. the design method of the linearizer with the gain compensation amount and the phase compensation amount at different given frequencies is given for the first time, the defect that the prior design method can not carry out gain compensation on each frequency is overcome, and the method provides a theoretical basis for the automatic design of the linearizer;
2. the circuit adopted by the invention has simple structure and clear design flow;
3. the circuit adopted by the invention is an analog circuit, and has the advantages of small volume, low cost, wide bandwidth, stable performance and the like;
4. the method is not limited to specific working frequency, and is a universal design method.
Drawings
FIG. 1 is a schematic flow chart of a method for designing an ultra-high frequency broadband linearizer according to an embodiment of the present invention;
FIG. 2 is a circuit block diagram of a linearizer provided in an embodiment of the present invention;
fig. 3 is a circuit structure diagram of a hybrid T-type matching network according to an embodiment of the present invention;
FIG. 4 is a circuit diagram of a linearizer of Q/V band (46-52GHz) designed by the design method of the present invention according to an embodiment of the present invention;
FIG. 5 is a graph illustrating gain compensation measurements for a linearizer in the Q/V band (46-52GHz) according to an embodiment of the present invention;
FIG. 6 is a diagram illustrating phase compensation measurement of a linearizer in the Q/V band (46-52GHz) according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
As shown in fig. 1, an embodiment of the present invention provides a design method of an extremely high frequency broadband linearizer, which includes a 3dB directional coupler, a nonlinear load and a matching network, and includes the following steps:
s101, setting gain compensation quantity and phase compensation quantity required by a linearizer at different frequencies;
s102, obtaining impedance values of the nonlinear load at different frequencies under different input powers through measurement, and converting the impedance values of the nonlinear load into admittance values of the nonlinear load;
s103, according to the admittance value of the nonlinear load, obtaining a port impedance value required by the matching network under the condition of meeting the gain compensation quantity and the phase compensation quantity given in the step 1 by an optimization method;
and S104, designing a matching network according to the port impedance value.
Example 2
On the basis of embodiment 1, the embodiment of the present invention further provides a design method of an extremely high frequency broadband linearizer, wherein the linearizer comprises a 3dB directional coupler, a nonlinear load and a matching network, and the design method comprises the following steps:
s201, determining gain compensation quantity and phase compensation quantity of a linearizer at different frequencies according to gain and phase curves of a power amplifier measured at different frequencies and input power;
specifically, when determining the gain compensation amount and the phase compensation amount, it is generally required to satisfy that the gain compression of the power amplifier after linearization by using the linearizer is less than 1dB and the phase change is less than 10 °.
S202, obtaining impedance values of the nonlinear load at different frequencies under different input powers through measurement, and converting the impedance values of the nonlinear load into admittance values of the nonlinear load;
specifically, the formula for converting the impedance value of the nonlinear load into the admittance value of the nonlinear load is shown in formula (1):
Zs＝1/(Gs+jBs) (1)
wherein Z issIs the impedance value of the non-linear load, Gs、BsIs the admittance value of the nonlinear load.
S203, setting the transmission matrix of the matching network as
Figure BDA0002590017300000051
The parameters A, B, C and D of the matching network are solved according to equation (2):
Figure BDA0002590017300000052
wherein a and b are respectively the gain compensation amount and the phase compensation amount given in step 1, the constraint condition AD-BC is 1, which is obtained when the matching network is a reciprocal network, IL is the insertion loss of the linearizer, and Z is the insertion loss of the linearizer0Being coupled ends of 3dB directional couplersThe port impedance value is a conjugate operation, GsAnd BsAdmittance value, G, for a non-linear loadshAnd BshAdmittance value, G, for a non-linear load at maximum input powerslAnd BslFor the admittance value of the non-linear load at minimum input power,handlthe value of the reflection coefficient at maximum input power and the value at minimum input power, phi, respectivelyhAnd philRespectively representing the phase value of the reflection coefficient at maximum input power and the phase value at minimum input power.
S204, calculating according to the parameters of the matching network and the formula (3) to obtain the port impedance value Z of the matching networkopt：
Figure BDA0002590017300000061
S205, when designing a matching network, selecting a specific matching network structure, and adopting a formula (4) as an objective function of the matching network:
Figure BDA0002590017300000062
wherein λ isiIs wave number, Zopt(λi) Is the port impedance value, Z, of the matching network obtained in step S204 under different frequenciesin(λi) N represents the number of frequencies that need to be matched for a port impedance value at a particular matching network configuration at different frequencies.
A matching network satisfying a given gain and phase compensation amount can be obtained from the objective function shown in equation (4), and thus the design parameters of the whole linearizer can be obtained.
Example 3
In this embodiment, a linearizer is designed in the Q/V band (46-52GHz), and a Rogers5880 substrate with a relative dielectric constant of 2.2 and a thickness of 10mil is used as the circuit substrate. The design method of the very high frequency broadband linearizer provided by the invention is further explained. The circuit structure diagram of the linearizer employed in the embodiment of the present invention is shown in fig. 2.
The design method of the linearizer of the Q/V band (46-52GHz) of the present embodiment includes the following steps:
1) given the amount of gain compensation and phase compensation required by the linearizer at different frequencies:
determining the gain compensation quantity Δ G and the phase compensation quantity Δ Φ of the required linearizer at different frequencies according to the gain and phase curves of the power amplifier measured at different frequencies and powers, as shown in table 1:
TABLE 1 amount of gain and phase compensation required for power amplifier and calculated port impedance values
Figure BDA0002590017300000071
2) Obtaining impedance value Z of nonlinear load at different frequencies under different input powers through measurementsConverting the admittance value into an admittance value required by calculation, and storing the admittance value into a computer;
3) according to the related information obtained in the steps 1) and 2), the port impedance values Z of the matching networks required at different frequencies are obtained through an optimization methodoptThe calculation results are shown in table 1.
4) Designing a matching network according to the port impedance value obtained by calculation:
in this embodiment, a hybrid T-type matching network is selected as a matching network structure, a schematic diagram of which is shown in fig. 3, and a transmission matrix of which can be expressed as formula (5):
Figure BDA0002590017300000072
its port impedance value can then be expressed as equation (6):
Figure BDA0002590017300000081
finally, the parameters of the matching network can be obtained according to the objective function shown in formula (7):
Figure BDA0002590017300000082
the resulting design linearizer circuit diagram for the Q/V band (46-52GHz) is shown in FIG. 4. In fig. 4, parameters before and after "/" are the width and length of the microstrip line, respectively, and for example, "0.84/1.5" indicates that the width of the microstrip line is 0.84mm and the length is 1.5 mm. Through actual measurement, the gain compensation quantity of the linearizer is respectively 3.58, 3.67, 4.03 and 4.19dB at 46 GHz, 48 GHz, 50 GHz and 52GHz, the nonlinear performance is good, and the use requirement is met; the phase compensation quantity of the linearizer is respectively 35 degrees, 36.5 degrees, 42.5 degrees and 55 degrees at 46 GHz, 48 GHz, 50 GHz and 52GHz, the nonlinear performance is good, and the using requirement is met. The linearizer gain phase compensation measurements for the Q/V band (46-52GHz) are attempted as shown in FIGS. 5 and 6, respectively;
finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (5)

1. A method of designing a very high frequency broadband linearizer comprising a 3dB directional coupler, a nonlinear load, and a matching network, the method comprising:
step 1, setting gain compensation quantity and phase compensation quantity required by a linearizer at different frequencies;
step 2, obtaining impedance values of the nonlinear load at different frequencies under different input powers through measurement, and converting the impedance values of the nonlinear load into admittance values of the nonlinear load;
step 3, according to the admittance value of the nonlinear load, obtaining a port impedance value required by the matching network under the condition of meeting the gain compensation quantity and the phase compensation quantity given in the step 1 by an optimization method;
and 4, designing a matching network according to the port impedance value.
2. The method according to claim 1, wherein step 1 is specifically:
the amount of gain compensation and the amount of phase compensation of the linearizer at different frequencies are determined from the gain and phase curves of the power amplifier measured at different frequencies and input powers.
3. The method of claim 1, wherein step 3 comprises:
setting the transmission matrix of the matching network as
Figure FDA0002590017290000011
The parameters A, B, C and D of the matching network are solved according to equation (2):
Figure FDA0002590017290000012
wherein a and b are respectively the gain compensation amount and the phase compensation amount given in step 1, IL is the insertion loss of the linearizer, and Z0The port impedance value of the coupling end of the 3dB directional coupler is conjugate operation GsAnd BsAdmittance value, G, for a non-linear loadshAnd BshAdmittance value, G, for a non-linear load at maximum input powerslAnd BslFor the admittance value of the non-linear load at minimum input power,handlrespectively the value of the reflection coefficient at maximum input power and at minimum input power,
Figure FDA0002590017290000021
and
Figure FDA0002590017290000022
respectively representing the phase value of the reflection coefficient at maximum input power and the phase value at minimum input power.
4. The method of claim 3, wherein step 3 further comprises:
calculating according to the formula (3) according to the parameters of the matching network to obtain the port impedance value Z of the matching networkopt：
Figure FDA0002590017290000023
5. The method of claim 4, wherein step 4 comprises:
when designing a matching network, selecting a specific matching network structure, and adopting a formula (4) as an objective function of the matching network:
Figure FDA0002590017290000024
wherein λ isiIs wave number, Zopt(λi) Port impedance value, Z, of the matching network obtained in step 3 at different frequenciesin(λi) N represents the number of frequencies that need to be matched for a port impedance value at a particular matching network configuration at different frequencies.
CN202010692983.5A 2020-07-17 2020-07-17 Design method of extremely-high-frequency broadband linearizer Active CN112019181B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010692983.5A CN112019181B (en) 2020-07-17 2020-07-17 Design method of extremely-high-frequency broadband linearizer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010692983.5A CN112019181B (en) 2020-07-17 2020-07-17 Design method of extremely-high-frequency broadband linearizer

Publications (2)

Publication Number Publication Date
CN112019181A true CN112019181A (en) 2020-12-01
CN112019181B CN112019181B (en) 2023-03-28

Family

ID=73500051

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010692983.5A Active CN112019181B (en) 2020-07-17 2020-07-17 Design method of extremely-high-frequency broadband linearizer

Country Status (1)

Country Link
CN (1) CN112019181B (en)

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4772855A (en) * 1987-02-26 1988-09-20 Siemens Telecommunicazioni, S.P.A. Linearizer for microwave power amplifiers
US5282072A (en) * 1991-11-19 1994-01-25 Harmonic Lightwaves, Inc. Shunt-expansive predistortion linearizers for optical analog transmitters
US5424680A (en) * 1993-11-30 1995-06-13 Harmonic Lightwaves, Inc. Predistorter for high frequency optical communications devices
US5966049A (en) * 1998-12-01 1999-10-12 Space Systems/Loral, Inc. Broadband linearizer for power amplifiers
US6307436B1 (en) * 1999-06-15 2001-10-23 Nec Corporation Predistortion type linearizer with a resonant circuit and common gate FET
US20100225389A1 (en) * 2008-03-07 2010-09-09 Teetzel Andrew M High efficiency rf system linearizer using controlled complex nonlinear distortion generators
CN102545796A (en) * 2012-02-15 2012-07-04 电子科技大学 Traveling wave tube linearizer
US20120242405A1 (en) * 2011-03-25 2012-09-27 Younkyu Chung Frequency-Desensitizer for Broadband Predistortion Linearizers
CN107276541A (en) * 2017-06-14 2017-10-20 电子科技大学 Variable vector mixes superposing type distortion linearizing method
CN107425814A (en) * 2017-08-07 2017-12-01 杭州电子科技大学 A kind of broadband Doherty power amplifier based on compensation parasitic capacitance

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4772855A (en) * 1987-02-26 1988-09-20 Siemens Telecommunicazioni, S.P.A. Linearizer for microwave power amplifiers
US5282072A (en) * 1991-11-19 1994-01-25 Harmonic Lightwaves, Inc. Shunt-expansive predistortion linearizers for optical analog transmitters
US5424680A (en) * 1993-11-30 1995-06-13 Harmonic Lightwaves, Inc. Predistorter for high frequency optical communications devices
US5966049A (en) * 1998-12-01 1999-10-12 Space Systems/Loral, Inc. Broadband linearizer for power amplifiers
US6307436B1 (en) * 1999-06-15 2001-10-23 Nec Corporation Predistortion type linearizer with a resonant circuit and common gate FET
US20100225389A1 (en) * 2008-03-07 2010-09-09 Teetzel Andrew M High efficiency rf system linearizer using controlled complex nonlinear distortion generators
US20120242405A1 (en) * 2011-03-25 2012-09-27 Younkyu Chung Frequency-Desensitizer for Broadband Predistortion Linearizers
CN102545796A (en) * 2012-02-15 2012-07-04 电子科技大学 Traveling wave tube linearizer
CN107276541A (en) * 2017-06-14 2017-10-20 电子科技大学 Variable vector mixes superposing type distortion linearizing method
CN107425814A (en) * 2017-08-07 2017-12-01 杭州电子科技大学 A kind of broadband Doherty power amplifier based on compensation parasitic capacitance

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
周丽等: "超宽带桥T型模拟线性化器设计", 《电子科技大学学报》 *
邓海林等: "一种补偿量可调的反射式预失真线性化器", 《真空科学与技术学报》 *
黄微波等: "Ku频段空间行波管形状可调线性化器设计", 《空间电子技术》 *

Also Published As

Publication number Publication date
CN112019181B (en) 2023-03-28

Similar Documents

Publication Publication Date Title
EP3053264B1 (en) Wideband doherty amplifier
Rawat et al. Dual-band matching technique based on dual-characteristic impedance transformers for dual-band power amplifiers design
US9537198B2 (en) Wideband impedance transformer
CN109167144B (en) Microstrip circuit implementation method of conjugate matching coupling suppression network
CN109148243B (en) Broadband high-power energy transmission structure suitable for helix traveling wave tube
CN109302151B (en) Method for determining electric length of compensation line and Doherty power amplifier
CN110601667A (en) Broadband harmonic suppression radio frequency power amplifier structure and design method thereof
CN112019181B (en) Design method of extremely-high-frequency broadband linearizer
CN103346373B (en) Coupler is spent in a kind of broadband 180 of lumped parameter
CN109861651B (en) Radio frequency power amplifier applied to 5G millimeter wave mobile communication
Moubadir et al. Compact and performance evaluation of branch-line hybrid coupler microstrip for long term evolution applications
Sanchez-Perez et al. Figures of merit and performance measurements for RF and microwave tunable matching networks
Bai et al. A compact dual-band negative group delay circuit with independently adjustable characteristics
CN208062483U (en) A kind of pump combiner of high coupling efficiency
CN111969972B (en) High-adjustability reconfigurable linearizer based on adjustable matching network and design method thereof
EP3155720B1 (en) Wideband impedance transformer
CN112397860A (en) Ultra-wideband millimeter wave high-power planar thin-film load
CN202009363U (en) Ku-band ultralow-noise amplifier
CN219611733U (en) Ka frequency band amplitude limiting low-noise discharging circuit
Yüceer Emerging technologies for communication satellite payloads
US20230261615A1 (en) Power amplifier using coupler and electronic device including the same
CN114024117B (en) Coaxial cable microstrip line hybrid impedance transformer
CN102882475A (en) Bandwidth expansion method and bandwidth expansion device for radio-frequency power amplifying circuit
Naeimi et al. Ultra‐broadband microstrip directional couplers
Sun et al. A Bonding Structure with Low Return Loss and High Transmission Bandwidth for Microwave Circuit

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant