Triangular Microwave Waveforms Generation Based on an Optoelectronic Oscillator

We demonstrate a novel scheme to generate full-duty-cycle triangular microwave waveforms using an optoelectronic oscillator (OEO). The OEO produces high-quality local oscillator signal. Thus, an external microwave source, which is usually involved in orthodox approaches obviates the need. A polarization modulator is involved in both the OEO loop and a microwave photonic filter (MPF) structure. To generate a triangular waveform, the undesired electrical harmonics are suppressed by the MPF. The proposed method is theoretically analyzed and experimentally verified. Triangular waveforms at fundamental tone of 4.6 GHz and frequency doubling tone of 9.2 GHz are generated, which fit well with the stimulated ones. The root mean square errors between the generated and the simulated triangular waveforms are 6.6e-5 and 1.61e-3 for triangular pulses at 4.6 and 9.2 GHz, respectively.