Adaptive tuning topologies to overcome losses in matching circuits for small antennas

Mobile devices are used in unpredictable dynamic environments making favorable antenna performance a challenge, thus reconfigurable matching circuits are of interest. Existing tuning topologies seek to minimize |S₁₁| of the matching circuit. While this is suitable for less demanding situations, such a network can potentially maximize circuit losses in aggressively agile systems. This paper, presents an understanding of circuit loss mechanisms and recommends tuning topologies which maximize efficiency for agile tuning systems. It is demonstrated that proper sensing with directional couplers are necessary to maximize the power delivered to the load. Mechanical tuning methods are presented as a way to realize agile tuning with low losses.