Wideband two-port injection matched antenna

Two-port, electrically small, tunable antennas were recently realized based on injection matching theory, inspired by the Doherty radio frequency amplifier design technique. This paper proposes to use injection matching theory to achieve wide bandwidth operation for intrinsically narrowband antennas. The proposed technique is verified through simulation for a miniaturized, proximity-fed patch antenna of -10 dB bandwidth of approximately 16%, which is simultaneously injection matched at two ports to a 50 Ω source over a 2.4:1 -10 dB bandwidth. In earlier work one-port injection matching was demonstrated for electrically small antennas. Furthermore, this paper demonstrates that using injection matching, simultaneous matching at both ports can be achieved leading to a significant improvement of the overall antenna efficiency.