Schottky diode receivers for operation in the 100-1000 GHz region

Increased interest in the millimetre and submillimetre wavelength regions during the past decade has stimulated the development of sensitive heterodyne receivers for a wide range of applications. The GaAs Schottky-barrier diode has received the most attention as a mixer in this wavelength range as a result of its sensitivity, reliability, mechanical stability and wide bandwidth and its ability to operate at room temperature. The concepts of receiver design and the particular problems associated with this region of the frequency spectrum are discussed. The optimization of material parameters and the device topology for low-noise operation are considered. The extension of fundamental waveguide mixers into the submillimetre region and the development of various types of quasi-optical receivers are reviewed. The development of integrated monolithic receivers in which antenna, coupling structure, mixer diode and intermediatefrequency filter network are fabricated on the GaAs surface offers the possibility of increased reliability, repeatable and improved performance, and the potential economy associated with integrated circuit technology. In addition, the possibility of monolithic receiver arrays provides the systems designer with a capability that was not previously attainable using discrete diode receivers. This newly emerging technology is reviewed and the potential impact on the 100-1000 GHz region is discussed.