Identifying and Isolating Signals Using Radio Frequency Photonics

A single antenna can be used for both transmission and reception. To accomplish this, the transmission must be isolated from the reception. In Figure 1, a radio frequency (RF) circulator is connected right after the antenna. The three-port device separates the transmit path from the receive path. After the circulator, a system can be used to identify the frequency of different signals. Once the frequency has been found, a filter with the right pass-band frequency can be used to isolate signals from each other.

RF photonics can be used for RF circulator, frequency identification, and filters. The photonic filters are tunable and narrow. A photonic-based circulator isolates the transmit path from the receive paths. Multiple photonic methods can be used to identify the frequency of the signal. This article discusses these methods for identifying and isolating signals using RF photonics.