Research On Q-band CMOS Millimeter Wave Power Amplifier

Millimeter-wave communication system which meets the rapidly growing data requirement from mobile network,has come to the spot light of researchers for its great potential in achieving data rate more than 1Gbps.Introduced by new standards,new application scenarios raise higher requirements to the design of millimeter wave circuits.CMOS technology shows significant advantage against the traditional Class III-V technology in cost and system integration which could be definite in those scenarios,makes it become the hotpot in academics.And as the key part of transceiver circuit,power amplifer's performance is prominent in whole system.In this paper,a power amplifier which based on a new millimeter wave communication standard called Q-LINKPAN is designed using TSMC 90nm CMOS technology.Main outcomes are listed as follows:1)Both active and passive components are analyzed in TSMC 90nm CMOS technology which has the 9-metal-layer structure.Passive components are designed with that structure.At the same time,the equivalent circuits model of passive elements like capacitor,inductor and transmission line are built by eletro-magnetic simulation.2)The power combine structure based on CMOS technology is designed.Power combiners using transmission line such as Wikinson combiner and zero degree combiner take huge areas on chips and only have single function.However,transformer which is designed in this article can realize power combining,DC feeding and balance-unbalance convertion in small area.What's more,insertion loss will be reduced if transformer is matched.3)The unit circuit of millimeter-wave power amplifier is designed after analysis of structures like common source PA,cascode PA,and stacked PA.An improved cascode structure which shows a prominent improvement of gain and bandwidth over cascode structure in simulation is implemented in that unit.4)A Q-band power amplifer using the structure mentioned above is implemented and tested.Then the result is analyzed.