A laser-diode-based photoconductive harmonic mixer for microwave waveform and spectrum measurements

Microwave waveform and spectrum measurement via a low frequency replica using a laser-diode-based photoconductive harmonic mixer is demonstrated. Waveforms of optoelectronically phase-locked 12.01-GHz microwave signals as well as waveform and spectrum of picosecond electrical pulses generated by a step recovery diode measured by this technique are presented. In comparison with previous experiments using main-frame lasers, the principal advantages of the present system are compactness, a large number of sampling points, and the ability to display the waveform and spectrum on any convenient time scale or frequency range.<
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