Research And Design Of Silicon-based Millimeter-wave Power Amplifier

With the rapid development of wireless communication technology,the whole world will march into a new era of 5G mobile communication.Therefore,millimeter-wave(mm-Wave)communication systems with a high-speed data rate(Gb/s)have received a significant attention in recent years.As key components in mm-Wave wireless communication systems,the mm-Wave power Amplifiers(PAs)have a great influence on the distance and efficiency.For millimeter-wave high-frequency PAs,the operating frequency band is close to the process characteristic frequency,so it is a great challenge to improve the gain,efficiency and output power on the basis of a certain degree of miniaturization.Therefore,the focus of this thesis is to study and design the mm-Wave PAs.The main research content of this paper has two parts:1.Two kinds of differential quadrature couplers are designed:a lumped element differential quadrature directional coupler is designed by parallelizing two single-ended topologies.The return loss(S11,S22,S33)of the coupler is less than-15 d B in the designed frequency band of 84 to104GHz,and the phase error and amplitude imbalance are 1.5°and 0.3 d B respectively.This technique allows tailoring the circuit to the specific impedance requirement of the terminating elements.Arbitrary impedance terminations allow matching the linear and nonlinear elements to the coupler without the requirement of transformer networks.A differential vertical hybrid quadrature coupler is designed using a vertically stacked multi-turn transformer structure.The coupler relies on the magnetic coupling between two mutually folded transformers.The analog insertion loss S21 and S31 are equal to 3.45 d B at 94 GHz,and the return loss S11,S22 and S33 are better than 20 d B at the 20 GHz bandwidth range from 84 to 104 GHz.Compared with the traditional horizontal transformer coupling structure,the vertical coupling effect is better,thereby achieving the advantages of miniaturized layout,low loss,low phase error and low amplitude error in a relatively wide bandwidth range.2.A balanced PA is designed by using two differential couplers and two identical single-ended amplifiers.The single-ended PA adopt the Cascode structure of differential single-stage amplifiers.In the 88GHz-100GHz,S11 is less than-23db,S22 is less than-15 d B,the input and output match well,the isolation degree S12 is less than-27d B.At94GHz,the small signal gain is 5.6d B,the output power of 1d B compression point is about 10.4 d Bm,the core layout area is0.08mm~2.The PA based on the two differential quadrature couplers above meets the design requirements and application requirements well in the key indexes,which can be applied to mm-Wave communication system and radio imaging.