A 100-element planar Schottky diode grid mixer

The authors present a Schottky diode grid mixer suitable for mixing or detecting quasi-optical signals. The mixer is a planar bow-tie grid structure periodically loaded with diodes. A simple transmission line model is used to predict the reflection coefficient of the grid to a normally incident plane wave. The grid mixer power handling and dynamic range scales as the number of devices in the grid. A 10-GHz 100-element grid mixer has shown an improvement in dynamic range of 16.3 to 19.8 dB over an equivalent single-diode mixer. The conversion loss and noise figure of the grid are equal to those of a conventional mixer. The quasi-optical coupling of the input signals makes the grid mixer suitable for millimeter-wave and submillimeter-wave applications by eliminating waveguide sidewall losses and machining difficulties. The planar property of the grid potentially allows thousands of devices to be integrated monolithically. >