Theoretical analysis of a varactor-loaded half-width leaky-wave antenna

Maintaining a narrow beamwidth is difficult for a linear phased array antenna comprised of wide beamwidth antenna elements with peak gain direction normal to the axis of the array as the beam is steered close to end-fire. Rather, use of near end-fire antennas, either singly or arrayed, offer the potential for achieving reasonably narrow beamwidth even as the beam is steered near endfire. For applications requiring wide bandwidth as well, half-width leaky-wave antennas offer a potential element. Unfortunately, the beam direction is dispersive. In this paper, a method is presented using varactors to overcome these challenges.