A 25W X-band GaN PA in SMT package

A single stage X-band (9-10GHz) PA module has been developed using a discrete 0.25um GaN transistor with 4.8mm gate periphery, that incorporates input and output matching via discrete substrates in package. The initial demonstrator module achieves 25W of power under pulsed conditions at 9.5-10GHz with Vds=50V, a peak efficiency of 41% and small signal gain of around 12dB. The PA was assembled in a 6mm overmolded QFN package. The power density and peak drain efficiency are in reasonable agreement with the process pcm performance at this frequency, given output matching losses have to be accounted for. This work demonstrates for the first time the feasibility of prematched GaN transistors and MMIC-like modules in high volume SMT packaging and to a frequency of 10GHz.