A high-efficiency inverse class-E power amplifier using double CRLH-TL for 3.5 GHz WiMAX applications

This paper reports a high-efficiency inverse class-E power amplifier (PA) using a double composite right/left handed transmission line (CRLH-TL). To achieve high power and high efficiency, the compensation for internal parasitic components of the PA is used and the harmonic control network using a double CRLH-TL is employed. For verifications, the proposed inverse class-E PA is implemented with a 35-W GaN HEMT and tested using a continuous wave (CW) and worldwide interoperability for microwave access (WiMAX) signals of 3.5 GHz. For a CW signal, the peak drain efficiency (DE) of 79.0% with a power gain of 9.8 dB is achieved at a saturation output power of 45.6 dBm. All harmonic power levels are significantly suppressed below -46.3 dBc at over whole output power range. Also, the high efficiency of over 50.1% and high output power level of over 42.2 dBm are maintained at an input power level of 34 dBm in the wide bandwidth of 200 MHz. For WiMAX signals, the DE of 24.7% with a gain of 12.7 dB is achieved at an output power of 35 dBm, which is an 11-dB back-off power region.