Conjugador de fase sobre una antena sintonizable en frecuencia para agrupaciones retrodirectivas full-duplex

Abstract

In this paper a frequency agile phase-conjugating active antenna to be employed in full-duplex and secure retrodirective communication links is presented. Thanks to the proper combination of two Enhancement-mode PHEMT devices, a simultaneous subharmonic and 180-degree singly balanced resistive mixer was designed. Full-duplex communication is achieved downconverting an AM interrogating signal and retransmitting a BPSK response. A varactor-controlled printed patch is tuned to the hopping frequency of the desired interrogation, reducing the possibility of communication interception and thus improving link security.