Polarization/Frequency Hybrid Reconfigurable Microstrip Antenna Utilizing Graphene-Based Tunable Resistor

In this letter, a frequency and polarization hybrid reconfigurable microstrip antenna utilizing graphene-based tunable resistors is proposed. The antenna consists of a T-shaped power divider, a 90° phase shifter and a circular patch. Two pairs of graphene nanoplates connected with open-circuit lines are loaded on the left and right feeding lines of the power divider. By applying bias voltage from 0 to 4 V, the resistance of the graphene nanoplates can be dynamically tuned from 200 Ω to 20 Ω, thus the current flows through the graphene nanoplate to the open-circuit load, making the port inoperative. By choosing different single- or dual-port operation, the antenna can realize horizontal polarization or vertical polarization in the frequency bands 10.84–11.02 GHz and 11.79–12.1 GHz bands, respectively, and right-handed circular polarization in two bands. In addition, the gain manipulation function is completed by adjusting the resistance of the graphene nanoplates.