A very small 3.5 GHz 1 W MMIC power amplifier with die size reduction technologies

This paper describes a development of reducing die size of a monolithic microwave integrated circuit (MMIC) power amplifier (PA). This is realized as follows: first. new process development, where GaAs substrate and SiN film of MIM capacitors are thinned half, respectively. Secondly, reconsideration of pattern layout rules, where line width and spacing between transmission lines are reduced to process constraints. The die size of a 3.5 GHz 1 W MMIC PA newly developed with these technologies is 1.9/spl times/2.1 mm/sup 2/, which is reduced to about 40% of that of an existing PA. Thermal performance of the new PA is shown to be identical to that of the former PA. This MMIC PA shows good electrical performances of a linear gain of 33 dB, input and output return losses of more than 10 dB. P1dB of 30.5 dBm, P3dB of 32.0 dBm, PAE of 29% at P1dB, and more than 41% at P3dB over a wide frequency range of 3.4 to 3.8 GHz.