X-band RF power performance of GaAs FET´s

The design and development of high RF power GaAs FET´s is the subject of this paper. A mature planar fabrication process developed for small signal FET´s having: gate lengths ≃ 2μ is described. Very respectable Pf²X values at X-band have been achieved with these 300 μ gate width devices. One approach to higher power devices is simply to extend this established planar device technology to larger gate widths. We have fabricated FET structures with 1000 μ and 2000 μ gate widths and multiple source pads and their RF performance is presented here. A potential scheme for interconnecting the source pads to ground with minimum parasitlcs is discussed along with a novel FET device structure utilizing the fabrication techniques of the GaAs IMPATT technology.