dc.description.abstract | In this thesis, a front-end diode switch and power amplifier analog linearized front-end circuit mixer. The switch is an important circuit in the front end of the RF transceiver, which controls signal reception and transmission, and improves and applies the linearity of the diode switch. The mixer is an analog linearized front terminal circuit of the power amplifier. Due to the rapid development of modern communication, the frequency of the fifth-generation dynamic communication is getting higher and higher. The higher the frequency, the faster the transmission speed and the greater the loss. The linearity of the power amplifier is extremely important, so this method is proposed to improve the linearity of the power amplifier.
The first chapter is the introduction of the thesis. The second chapter first uses diodes manufactured by Broadcom Limited to implement on the printed circuit board. The circuit includes series-shunt SPST switch, serial series-shunt SPST switch, parallel series-shunt SPST switch. According to three different series-shunt SPST switch architectures, the effects of series and parallel diodes on the insertion loss, isolation, and linearity of the switch can be observed. The linearity of the switch will cause the diode to be turned on and the linearity will be reduced due to the high input power. According to the situation, a reverse-connected SPST switch is proposed. The DC bias method is used to effectively suppress the diode conduction. Finally, a SPDT switch is designed to use the 1/4λ transmission line. When the switch is off, the negative bias can be used to effectively suppress the diode conduction and increase the linearity of the switch.
The third chapter continues the second chapter, using the WIN PIN-HEMT process design, the circuit includes reverse SPST switching and the use of 1/4λ transmission line design SPDT switch, the verification results of the second chapter used in chip design, according to the simulation results, it can be observed that the reverse connection type and the negative bias method can effectively improve the linearity.
Chapter 4 is a front-end mixer circuit applied to analog linearization circuits of power amplifiers. Using TSMC 65 nm CMOS process and 0.18 μm CMOS process to design an S-band mixer, which uses current injection and active load to improve conversion, the load required for conversion gain. The mixer needs to input the RF input power and the local oscillation power at the same time, so we added an inverter to the local oscillation input to reduce the local oscillation input power.
Finally, the conclusions and future works are addressed in Chapter 5. | en_US |