Isofrequency-reconfigurable 8-bit RF repeater

Abstract

A novel isofrequency-reconfigurable RF repeater operating at 4.5 GHz is presented. The repeater uses a total of eight reconfigurable parasitic dipole elements to enhance and reconfigure the isolation level between the receiving (Rx) and the transmiting (Tx) antennas. The reconfiguration of the parasitic dipoles is achieved using p-i-n diodes as microwave switches to change their electrical length. The parasitic dipoles are dynamically reconfigured into an optimum configuration state (to make them work as either director or reflector elements) to enhance and recover the perturbed isolation level when an obstacle is placed near the repeater, while maintaining good impedance matching and pointing the maximum of the radiation pattern at the Rx port toward a specific base station.