A Simultaneous Dual-Channel Micro-Radio-Repeater for Ad-Hoc Wireless Communication

A dual-channel subwavelength low-power radio repeater system is presented in this communication. The repeater system is composed of a low-profile miniaturized receive antenna, an end-fire two-element miniaturized transmit antenna array, and a low-power high-gain amplifier chain. The isolation between the receive antenna and transmit antenna is achieved by a near-field cancellation method. To achieve a dual-channel response antennas are made wideband using parasitic elements and the open-loop transfer function is designed in a manner to present zero-crossing phase at two frequency points within the band. The closed-loop gain of the repeater system has a gain higher than that of the amplifier at the zero-crossing phase frequency points, which gives rise to repeater performance at two distinct channels. A prototype of the repeater system operating in 2.4 ~ 2.5 GHz with dimensions of 39.67 mm ×85.39 mm ×3.18 mm is designed and fabricated. Performance of this repeater is characterized experimentally by measuring its radar cross section (RCS). Using an amplifier chain with gain of 45 dB, it is shown that dual-channel repeater exhibits RCS values of 27.7 dBsm and 26.0 dBsm at 2.42 GHz and 2.44 GHz, respectively.