A multi-frequency programmable and remotely controllable variable attenuator and phase shifter (MF-VAPS) network utilizes wideband three port circulators, power combiners, high-low pass filters and a calibrated multi-harmonic tuner to control the amplitude and phase of the transmission factor (A21) at up to three user defined frequencies individually. The harmonic signal components are divided in frequency bands and injected into the circulator’s port 1 and extracted from port 3, whereas the tuner is connected to port 2 and terminated with Zo. When the tuner is initialized (S11=0) the transmission factor of the network is zero; when the tuner is at maximum reflection at any frequency the transmission factor is also maximum. Changing the reflection phase of the tuner controls the transmission phase <A21 by the same amount, up to 360°.
Multi-Frequency Attenuation and Phase Shifters / 13/896,764
Friday, May 17, 2013