Research Focus on Quasi-Optical Technology

Several key issues on the use of quasi-optical (QO) combining technology for the microwave and millimeter wave bands are discussed. In terms of performance, QO amplifiers offer the advantage of power scalability to very large arrays, largely because power combining efficiency (PCE) in QO combining does not degrade rapidly with the number of elemental amplifiers combined. QO techniques also provide high instantaneous bandwidth since QO architectures are inherently three-dimensional. This configuration makes multi-element QO components much more compact than microwave integrated circuits (MIC) components, thus more practical for applications.