A Rectangular Waveguide Antenna with Filtering and Beam-steering Capabilities

In this contribution, we discuss a convenient technique for designing rectangular waveguide filtering antennas with reconfigurable radiation properties. The basic structure we consider is an open-ended WR-137 rectangular waveguide working in the frequency range 5.85-8.20 GHz, with a stable realized gain around 7 dB. We will show that by placing two electrically small resonators at the end of the waveguide, the bandwidth of the overall structure can be reduced with important advantages in terms of noise/interference rejection. Moreover, by loading each resonator with a varactor diode, the phase shift introduced by the two elements can be controlled and, thus, exploited for steering the radiation pattern of the antenna.