Description: The goal of this research is to develop high-frequency Faraday rotation isolators that exhibit significantly reduced loss, higher power handling and improved bandwidth over commercially available products. The bandwidth limitations of high-frequency circulators will be explored. It was demonstrated in the Phase I work that the bandwidth of these components can be substantially increased through impedance matching techniques. At the end of the Phase II program, Micro Harmonics will have developed a full line of isolators operating in bands from WR-12 through WR-3 and circulators working in bands from WR-15 through WR-5. In the phase I work our models were proven to be accurate. The approach is fundamentally sound, but there are significant technical challenges. These components will find immediate use in a broad range of systems used by NASA as well as the commercial sector.

Benefits: The proposed isolators and circulators are broadly useful in a wide range of NASA systems including millimeter-wave and terahertz sources, detectors and receivers. Heterodyne receivers based on room temperature technology are a critical Sensor and Detector Technology for NASA's Submillimeter Missions such as Marvel, VESPER, MACO as well as earth observing satellites such as SIRICE. They find potential application in the frequency multiplier local oscillator (LO) chains in the high-resolution heterodyne array receivers at 1.9 THz that are being developed to support the Stratospheric Observatory for Infrared Astronomy (SOFIA) and the Stratospheric Terahertz Observatory (STO-2). They may also be useful in the development of the 4.7 THz multiplied local oscillator source for the observation of neutral oxygen.

The proposed isolators and circulators are broadly used in scientific instruments for plasma diagnostics (ITER), chemical spectroscopy, biomaterial analysis, and radio astronomy. There are also a broad range of applications in military systems that include compact range radar, imaging systems, covert communications systems, and chemical and bio-agent detection systems. There are potential applications in biomedical systems for the real time analysis of skin diseases, portal security scanners, high frequency data links and industrial process control systems.