[IEEE 2010 IEEE International Microwave Workshop Series on "RF Front-ends for Software Defined and Cognitive Radio Solutions" (IMWS) - Aveiro, Portugal (2010.02.22-2010.02.23)] 2010 IEEE International Microwave Workshop Series on RF Front-ends for Software Defined and Cognitive Radio Solutions (IMWS) - A GaN class-F PA with 600 MHz bandwidth and 62.5% of PAE suitable for WiMAX frequencies