Dual-Polarized Nonreciprocal Spatial Amplification Active Metasurface

This letter presents a dual-polarized nonreciprocal active metasurface (MTS) for spatial electromagnetic wave amplification. The MTS is designed based on receiving, amplifying, and reradiating scheme. Two square patch antennas printed on the opposite sides of two-layer substrates are used as receiving and reradiating antennas, respectively. A T-shaped microstrip line coupling structure is adopted to achieve impedance matching and dc-block function. Two bipolar transistors, which are place on a pair of orthogonal microstrip feed lines, are used as amplifiers to achieve dual polarization spatial amplification of the electromagnetic wave. A prototype MTS is fabricated and tested to verify the design. The measured effective spatial amplification coefficients higher than 0 dB has a band from 4.88 to 5.19 GHz with the peak value of 10.4 dB. Besides, the proposed MTS is insensitive to polarization. The spatial amplification coefficients variation for different polarization is below 0.6 dB. The proposed MTS could be used in the radio frequency transceiver systems to reduce the pressure of the amplifier on the circuit board.

Automated summary

This letter introduces a dual-polarized nonreciprocal active metasurface for spatial electromagnetic wave amplification, using a receiving, amplifying, and reradiating scheme. The design utilizes square patch antennas, T-shaped microstrip line coupling structure, and bipolar transistors for dual polarization spatial amplification of electromagnetic waves. The prototype MTS verified the design with effective spatial amplification coefficients exceeding 0 dB.