Quasi-optical integrated antenna and receiver front end

A quasioptical receiver front end applicable to both microwave and millimeter-wave receiver arrays is presented. Two planar microwave integrated circuit (MIC) quasioptical receiver circuit designs that integrate a coupled slot antenna, a Schottky-diode balanced mixer, and a local oscillator on the same substrate are described. The even-mode/odd-mode characteristics of the coupled slotlines are used to achieve intrinsic RF/LO and RF/IF isolation. To demonstrate circuit feasibility, X-band scaled models of the circuit unit using a Gunn-diode oscillator on an Epsilam-10 substrate, and MESFET local oscillator on a R/T Duroid substrate were built and tested. Results of these tests are included.>