A 100-element MODFET grid amplifier

A 100-element quasi-optical amplifier is presented. The active devices are custom-fabricated modulation-doped field-effect transistors (MODFETs). Common-mode oscillations were suppressed using resistors in the input gate leads. The grid has 9 dB of gain at 10.1 GHz. The 3-dB bandwidth is 1.2 GHz. We present a model for the gain of the grid versus frequency and compare measurement with theory.