A design for a quasi-optical MESFET power-combining array that utilizes gate feedback is presented. This circuit is different from previous MESFET grids that utilized packaged devices and source feedback to produce an oscillator at 5 GHz. The present configuration allows the drain and source leads to couple directly to the radiated field. Simulations indicate that this configuration can be used to build a high-frequency oscillator. A transmission-line model for the grid is presented and used to design a 25-element grid for operation at 10 GHz. Measurements show that the grid delivers an effective radiated power of 2.4 W at 10.9 GHz.