US Patent 7248866 Frequency selective load pull tuner and method

An automatic, frequency selective microwave tuner, used for load pull transistor testing, is capable of generating independently controllable reflection factors, both in amplitude and phase, at several, harmonic or not, frequencies simultaneously. The tuner employs horizontally and vertically adjustable high Q resonant probes and replaces, when used in harmonic load pull set-ups, otherwise required combinations of wide-band tuners with harmonic rejection tuners or wide-band tuners and frequency discriminators (diplexers or triplexers).