Conventional mechanically machined horn antennas integrated with waveguide cavities have been the work horse at microwave and millimeter-wave frequencies since they were first implemented many decades ago during World War II. Very high antenna gain and essentially perfect antenna efficiency can be achieved using these structures. However, they are expensive, bulky, and incompatible with arrays.
In this project, we develop millimeter-wave focal-plane arrays fabricated using silicon micromachining, which are advantageous compared to conventional waveguide horn antennas. It is much easier to fabricate fine three-dimensional structures by using photolithography. Active elements, such as RF and IF amplifiers, mixers and video detectors, local oscillators, and post-detection signal processors, can be integrated with the antenna structures to form monolithic transmitter/receiver systems. Most importantly, focal-plane arrays can be fabricated easily on a single wafer. Such systems will yield a significantly improved spatial resolution in remote sensing, and a much greater antenna gain when implemented with phased-arrays.