An Overview of Tuning Techniques for Frequency-Agile Antennas

Frequency-agile antennas can be designed to switch between a set of discrete frequencies, or to be tuned over a continuous range of frequencies. Methods for achieving discrete or continuous frequency tuning can be grouped into three categories: mechanical actuation, tunable materials, and integrated electronic devices. Example tuning techniques in each class are presented, highlighting strengths and weaknesses of each method.