Dynamic rejection of multiple co-site interferers through wideband RF photonic notch filter

Antennas in congested RF environments are susceptible to co-site interference. Interfering signals are usually stronger than the signal of interest by several orders of magnitude, and offset in frequency but within the bandwidth of the antenna. We present an optical technique to mitigate interfering signals by generating nulls at specific frequencies using a dual-output Mach-Zehnder modulator, optical delay, and balanced detectors. We demonstrate the nulling of interfering signals by over 40 dB without attenuating the signal of interest.