AD - A 255 781 Millimeter - Wave Quasi - Optical and Spatial Power

Two t>pes of active antenna elements have been studiedexperimentally One type uses a mkrostrip antenna with an active devicemounted directlv on the antenna. The other uses an active device coupledlo a microstrip patch antenna through an aperture. Microstrip activeantenna elements and two-element arrays have been demonstrated for bothtypes of circuits. Injection locking of the antenna elements has beenachieved through space and mutual coupling. The circuit Q factor wascalculated based on the locking gain and the locking bandwidth. The poweroutput from two elements has been successfully combined in free spacewith a combining efficiency of over 90 percent. For a single active antennawith a Gunn diode mounted directly on the patch, an electronic tuningrange exceeding 9 percent has been achieved by varying the dc bias. Theresults should have many applications in low-cost active arrays, activetransmitters, and spatial power combiners.