A 65 % drain efficiency GaN HEMT with 200 W peak power for 20 V to 65 V envelope tracking base station amplifier

A 200 W GaN high electron mobility transistor (HEMT) device was developed for envelope tracking (ET) base station amplifier. The device, which consists of a single die of 0.6 um-gate GaN HEMT of 43 mm gate periphery, has a saturated current of 680 mA/mm together with sufficiently high break down voltage of 300 V. We have estimated the average power efficiency of ET amplifier by using the GaN HEMT device over 20 V to 65 V drain bias range. As a result, the estimated average power efficiency reaches at 65.2%. Excellent results of RF high temperature operating life (RF-HTOL) test were also obtained. To the best of our knowledge, this is the highest drain voltage operation of the GaN HEMT device, allowing significant improvement of efficiency for ET amplifiers.