Hybrid and monolithic active quasi-optical grids

Citation

De Lisio, Michael Peter (1996) Hybrid and monolithic active quasi-optical grids. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/knb4-j089. https://resolver.caltech.edu/CaltechETD:etd-12132007-090419

Abstract

Quasi-optical grids combine the output powers of many solid-state sources in free space, eliminating the conductor losses associated with traditional waveguide or transmission-line combiners. This approach shows most promise at millimeterwave frequencies, where the outputs of thousands of devices could potentially be combined through wafer-scale integration. This thesis will detail three separate active quasi-optical grids. The first grid is a 16-element hybrid tunnel diode oscillator. This grid achieved a locked output frequency spectrum, with a peak Effective Radiated Power (ERP) of 1.3 mW at 1.9 GHz. This grid is a prototype for monolithic Resonant Tunneling Diode (RTD) grid oscillators, designed to operate from 200 to 500 GHz. The second grid is a 100-element hybrid pseudomorphic High Electron Mobility Transistor (pHEMT) amplifier. Modelling techniques, design procedure, and experimental results will be presented. This grid has a peak gain of 12 dB at 9 GHz, with a 15% 3-dB bandwidth. The output power, 3. W, increases with the number of devices, while the noise figure, 3 dB, is similar to that of a single device. The third grid is a 36-element monolithic pHEMT amplifier. This grid has a peak gain of 6.5 dB at 44 GHz. By changing the positions of external polarizers and slabs, the grid can be tuned to operate up to 60 GHz with 2.5 dB gain. In addition, theoretical discussions of two topics relevant to active grids will be discussed. The first is a technique employing the method of moments and the induced emf technique to determine the electromagnetic properties of periodic grating structures. The second explores some thermal properties of quasi-optical grids.

Thesis Files