Optoelectronic isolator for microwave applications

The analysis, design, and implementation of a hybrid optoelectronic isolator for microwave applications is described. The device is designed to operate over a 300-MHz bandwidth centered at 3 GHz. The prototype achieves isolation greater than 80 dB and a forward power gain of 0.13 dB at its center frequency. Prototype results indicate that use of this device in an operating system can control self-oscillation in high-gain receivers and/or provide useful isolation of sensitive radars. Furthermore, the required size is smaller, especially with monolithic implementation, while providing isolation far in excess of competing technologies. For comparison, a packaged ferrite isolator would be about twice the size of the prototype while providing only 30 dB of isolation