Experimental investigation of the beam-scanning capabilities of a stub-loaded half-width microstrip leaky-wave antenna

Microstrip leaky wave antennas find applications in such fields as radar and direction finding because of their wide bandwidth and low profile. For this class of antennas, the main beam direction typically changes with frequency. It is sometimes desirable, however, that the beam direction be held constant over a frequency range. It has been found that such beam control can be achieved by reactively loading the edge of microstrip leaky wave antennas; selective control of the beam can thus be obtained with the use of lumped capacitors. A problem that arises with the use of lumped capacitors is the difficulty in obtaining exact capacitance values. As such, a reactive loading method that utilizes etched elements as opposed to lumped capacitors in the form of the stub-loaded microstrip leaky wave antenna has been found to be feasible through simulations.