Ka-band Power Amplifier Linearization Technology Research

In modern mobile radio communication system, many of signal modulationtechniques are used for the purpose of ameliorating the spectrum utilization and thosetechnologies generally have non-constant envelope characteristics. Modulated signalswhich with varying envelop will generate the third order and the fifth orderinter-modulation distortion by the RF power amplifier. The inter-modulation distortionin the communication system mentioned above will cause dislocation of the amplitudeand the phase, interference with adjacent channel, generating the bit error rated whilethe signal in transmission process and deterioration of communication quality. In recentdecades, requirements with the power amplifier in RF transmitter become higher andthe technology has been used in all sectors of society, so the linearization technologiesbecome a hot issue in the profession accordingly. With the frequency resourcesbecoming tense increasingly in nowadays, millimeter wave technology spring up andbecome research focus because of its advantages in engineering applications. Therefore,the study with the linearization technology of the millimeter wave power amplifiermentioned in this paper could ameliorate PA non-linearity as well as the development ofmillimeter wave technology.As the beginning of this thesis, the nonlinear characteristic parameters with poweramplifier have been analyzed. After understanding the leading indicator of PA, wefigure out the reasons of the distortion generated by the PA: the memory effect of PA,amplitude distortion and phase distortion. Then discuss the nonlinear characteristics ofPA by establishing different forms of model.Secondly, we determine using the solution of pre-distortion linearizationtechnology by comparing various kinds of linearization technology. Design the RFpre-distortion generator which using a reverse parallel diode as a core. And thispre-distortion generator has been simulated by ADS. Get the ideal third orderinter-modulation by testing and debugging the physical circuit.Simulated some microwave device and conduct existing chip confirmatory test.For instance, the XX1000-QT has increased its stable output power by changing the method of the pin to ground as a doubler in circuits.