Beamwidth Reconfigurable Magneto-Electric Dipole Antenna Based on Tunable Strip Grating Reflector

A new magneto-electric (ME) dipole antenna with a dynamic beamwidth control in the H-plane is presented. The design methodology uses tunable strip gratings placed on the sides of an ME dipole along its H-plane. Each strip is equally divided into 16 short parts and connected in series by using 15 PIN diodes; accordingly, by controlling the on/off-state of the PIN diodes, the strips can operate as a grating reflector or be transparent for the radiating wave. Therefore, the size of the reflector can be reconfigured, which leads to the tunable beamwidth. A fully functional prototype with an as wide as 40% impedance bandwidth (for SWR ≤ 1.5) is developed and tested, demonstrating the H-plane beamwidth with a tuning range from 81° to 153°. Radiation efficiencies are better than 90% in all the states of operation.