Subwavelength Radio Repeater System Utilizing Miniaturized Antennas and Metamaterial Channel Isolator

Implementation of a novel high gain miniaturized radio repeater for improving wireless network connectivity in complex environment is presented in this paper. Unlike existing repeater systems, this system utilizes two closely spaced low profile miniaturized planar antennas capable of producing omnidirectional and vertical radiation pattern as well as a channel isolator layer that serves to decouple the adjacent antennas. The metamaterial based channel isolator serves as an electromagnetic shield, thus enabling it to be built in a sub-wavelength size of 0.07λ₀² × 0.014λ₀, the smallest repeater ever built. A prototype of the small radio repeater is fabricated to verify the design performance through a standard free-space measurement setup. The feasibility of amplifying and re-transmitting the received signal is demonstrated through measurement which compares well with the numerical simulation results.