Research And Design Of The Novel Power Divider And Multi-port Based Transceiver Systems

The rapid development of the mobile communication poses a great challenge to the radio frequency front-end circuits and systems,making the research and design of the power dividers(PDs)and transceivers,which are the fundamental devices in the wireless communication system,academically and commercially important.Based on the microwave theory and the digital signal processing,this paper mainly focuses on the Gysel PD,three-layer out-of-phase PD,planar coupled-line balun,balanced multi-port PD and multi-port transceiver.Besides,the constraint conditions to satisfy the circuit function for all kinds of PDs are discussed.For the multi-port demodulator,different calibration algorithms are proposed to improve the system performance.Meanwhile,a digital predistortion algorithm based on the modified memory polynomial for the multi-port modulator is proposed to suppress the carrier leakage.The main contributions are listed as follows:1.Two coupled-line circuit structure with different performance are proposed to design the Gysel PDs.The first PD features the complex impedance transformation as well as the harmonic suppression.Differently,the second has the advantages of dual-band performance as well as the real impedance transformation.The traditional even-and odd-mode method is adopted to analyze the circuit,and two experiments are used to verify the closed-form equations.Two pertinent papers have been published in Electromagnetics.2.Based on the double-sided parallel striplines,two dual-band three-layer out-of-phase PDs with impedance transformation are designed,with the second circuit featuring wide frequency ratios.Firstly,the generalized analytical method for this kind of three-layer PD is discussed.Then,the proposed circuit structures are analyzed to obtain the constraint conditions,which can satisfy the desired electrical performance.Research about these two PDs have been published in IEEE Microwave and Wireless Components Letters and Electromagnetics,respectively.3.Four kinds of planar baluns,which can divide one signal into two equal signals with out of phase,are proposed based on the coupled lines with weak coupling factors.The first two baluns have the complex impedance transformation,and the third as well as the fourth can operate at two frequencies simultaneously.Since the proposed baluns can be viewed as the four-port symmetrical circuits with one port open,the even-and odd-mode methods can be adopted to derive the closed-form solutions.Four papers about these baluns have been published in IET Microwaves,Antennas&Propagation,China Communications,Electromagnetics,and Progress in Electromagnetics Research Letters,respectively.4.Based on the matrix transformation between the mixed-mode and single-ended scattering parameters,five kinds of balanced PDs are proposed.The first two coupled-line circuits realize the function of equal division from one balanced signal to two single-ended out-of-phase signals,and the third as well as the fourth PD,which are based on the composite left-and right-handed transmission lines,can divide one balanced signals into two equal or unequal single-ended signals with in phase.Differently,the fifth coupled-line PD possesses the performance of equal power division from one single-ended signal to two balanced signals.The relevant papers have been published in IEEE Transactions on Microwave Theory and Techniques,IEEE Microwave and Wireless Components Letters,and Electromagnetics,respectively.5.Based on the microwave theory and digital signal process,the output power of the diode detectors can be calculated and analyzed to obtain the baseband signal recovery theory for the traditional multi-port demodulator.Then,different calibration algorithms,which contains the memory effect and nonliearity,are proposed to realize the single-band and concurrent dual-band receivers.For the traditional six-port modulator,the digital predistortion technique is used to improve the system performance creatively.According to the specificity of the system,a modified memory polynomial is proposed to suppress the carrier leakage.The research has been published in IEEE Transactions on Microwave Theory and Techniques,IEEE Transactions on Instrumentation and Measurement,IEEE Transactions on Circuits and Systems II:Express Briefs,IEEE Microwave and Wireless Components Letters,and IEEE Access.