Linearity analysis of class-B/J continuous mode power amplifiers using modulated wideband signals

Linearity, along with efficiency and bandwidth, belongs to the fundamental requirements of power amplifiers for nowadays communications systems. This paper discusses how to bring together these partly contradictory goals in power amplifier design. Continuous class-J PAs provide a constant efficiency over a large bandwidth. However, the linearity is not constant due to the unequal current and voltage waveforms along the design space of the continuum. Nevertheless, it is possible to equalize linearity of such a PA over the desired bandwidth. For the PA presented, -50 dBc ACLR with an average power of 38 dBm and an average efficiency of 21.5 % were achieved at 2.14 GHz using a WCDMA test signal. For CW measurements, 48.5 dBm maximum power and 63 % peak drain-efficiency were reached.