GaN Doherty Amplifier With Compact Harmonic Traps

Abstract

In this contribution, the design of an uneven AB-C Doherty power amplifier (DPA) in GaN technology, implementing a new approach to control the higher device harmonics, is presented. The DPA was designed to operate at 2.14GHz and with the aim to reduce as much as possible the chip size, without losing the Doherty operating principle. The measurement results in CW conditions at 2.14GHz had shown average drain efficiency higher than 55% at 6dB of back-off, with a saturated output power of 37dBm.

High Efficiency Power Amplifiers for Modern Mobile Communications: The Load-Modulation Approach

“…More recently, a high-efficiency switched-mode Class-E/F amplifier is employed in [29] to implement both the Main and the Auxiliary cells, while in [30], the efficiency of the Auxiliary stage is enhanced by using input harmonic loading. In [31,32], two extremely compact output combining networks integrating harmonic load terminations are proposed, based on a lumped-element and a harmonic-trap network, respectively. As a final example, in [33], the odd harmonics generated in the Auxiliary amplifier are exploited to shape the drain voltage waveform of the Main device allowing it to operate at a reduced supply voltage, thereby increasing efficiency.…”