Beamwidth Control of an Impulse Radiating Antenna Using a Liquid Metal Reflector

In this letter, a beamwidth controllable impulse-radiating antenna (IRA) was proposed. The typical solid reflector of the IRA was replaced with a wired reflector corresponding to the current flow on the reflector surface. The performance of the wired-reflector IRA (WIRA) was shown to be essentially the same as that of the conventional IRA through simulation and measurement. Then, liquid metal was used to replace the solid wires, and a beamwidth controllable WIRA was implemented. The electrical size of the reflector could be expanded up to approximately 400 mm in the H-plane. The beamwidth control capability was validated through simulation and measurement. It was shown that the beamwidth could be varied in the H-plane up to 44% while other parameters, such as the input impedance and E-plane beamwidth, remained almost constant.