Here is the abstract you requested from the IMAPS_2007b technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Uni-Traveling Carrier Traveling Wave Photo-Detector for Efficient Generation of Microwaves and MM Waves|
|Keywords: Generation of MM wave, THz region, uni-traveling carrier PD|
|The generation of microwave signals at high millimeter wave, sub-MM wave and THz frequencies is difficult. Direct generation and active oscillator (transistors or negative resistance devices) are possible up to frequencies of around 150-200 GHz with relatively poor efficiency. Passive frequency multiplication from lower frequencies is being applied up to the THz range. However, this approach also suffers from low efficiency and low output power. In this presentation, the generation of high frequency signals is outlined by optical means. Specifically, it was examined to generate MM and sub-MMwave signals by heterodyning two optical signals in a photo-detector (PD). Previous work in this field has shown that this approach is feasible. However, the work demonstrated to date exhibits very low power efficiency (<1%) and low output power level (<1 mw) for frequencies in the MM wave range. In this research, a simple model and design considerations for an efficient traveling wave uni-traveling carrier PD are presented. Expressions are presented to estimate bandwidth, microwave output power and power efficiency of this type of PD. The effect of the physical design parameters on performance is discussed and the design approach for high efficiency is presented. This research is being conducted in cooperation with the University of California, San Diego, and the new device will be fabricated there. The model has been used to predict performance of a sub-MM wave device. The results are very encouraging, and the next phase of the work involves full design, manufacturing and testing the new device. This project is supported by DARPA.|
|Navya Koka, Student