9308979 York This project will explore a new technology for low noise power amplification in the microwave and millimeter wave regime using a combination of parametric effects and quasi optical techniques. Although parametric amplifiers have long been known to posses superior noise properties to conventional transistor amplifiers, they have not been fully utilized in modern microwave systems due to limited power handling capacity, requirement of a strong high frequency pump signal, and sensitive circuit design. Some of these problems can be circumvented by operating a large planar array of low power parametric devices synchronously, with input and output signals coupled through simple antennas to propagating beams in free space. There is also evidence from analogous parametric laser systems that noise figure can be reduced further by exploiting the inherent phase sensitive amplification of parametric systems (squeezed states). Two types of arrays negative resistance parametric amplifiers, and frequency upconverters will be explored during this project. In the former case, spontaneous parametric oscillation is also possible and could provide a useful technique for sub harmonic and harmonic generation.
