Design Of29dBm High Efficient And Broadband CMOS RF Power Amplifier With Polar Modulation

High efficiency and linearity CMOS RF power Amplifier with polar modulationarchitecture is an attractive choice for multi-mode realization and SOC solution to reducehigh data rate wireless device’s cost and power consumption. Nevertheless, there are someobstacles to design high performance CMOS RF power amplifier such as breakdown voltageand substrate noise.Linear assist switching amplifier as envelop amplifier and cascade differential Class-ERF power amplifier as phase amplifier are the two main parts of the proposed RF poweramplifier with polar modulation of this paper.LTE Envelop characteristics are analyzed by circuit on PCB both in time and frequencydomain to extract parameters for envelop amplifier. An equation about switching frequencyis summarized including the influences of loop delay and bandwidth of linear amplifier forefficiency optimizing. Constructed by Class AB amplifier with local feedback loop andswitching amplifier with edge control, the envelop amplifier shows high performance:0.3V-3V output swing under3.3V supply,600mA output current,98MHz loop bandwidthand achieved91%of maximum efficiency and maximum20mV peak to peak switchingripple voltage.Phase amplifier design is focused on the reliability of output stage and efficiency ofdriver stage. A power control method is also discussed to improve efficiency under lowoutput power. This amplifier has achieved70.5%of efficiency and-60dBc of harmonicunder output power of1210mW. A cascade Class-E RF power amplifier has been tapped outusing HJ0.18um CMOS process, testing results verify the theory.The signal with16QAM and20Mbps is used for simulation. The polar modulationsystem achieves efficiency of54.9%with output power of29.8dBm with low distortion ofIQ signals. Physical design, such as layout, package and testing are also discussed.