Linearity Improvement of MMIC Power Amplifiers at Reduced Output Power Backoff

We propose utilizing TriQuint’s developing GaN MMW process to achieve a highly efficient millimeter-wave power amplifier. Our approach is to consider the entire amplifier design flow and to work closely with TriQuint as outlined in their letter of intent towards the optimization of their process. We will start by developing accurate device models using a combination of measurements including S-parameters, DC I-V, and harmonic load pull. Included in the loadpull will not only be power, PAE and linearity, but also the actual OQPSK complex modulation waveform. This will allow us to be as accurate as possible in defining the load required. We will next investigate numerous amplifier topologies against the specifications including a Doherty amplifier with high efficiency at power backoff. Finally, we will perform rigorous thermal analysis to ensure our designs have maximum gain and do not have any long term reliability concerns.