Power Dissipation in Mobile Antenna Tuning Circuits Under Varying Impedance Conditions

It is often forgotten that certain load impedances may increase the power loss in real circuit elements significantly compared to the nominal data-sheet values. The problem is very relevant in the case of tuning circuits for mobile terminal antennas. The intrinsic impedance of the antenna, acting as the load for the tuning circuit, is prone to large variations due to electromagnetic interactions between the antenna and its environment. This letter discusses the identification of challenging impedance environments and the loss sensitivity of individual components in the tuning circuit, tradeoffs between losses and other characteristics, as well as countermeasures against increased power losses in matching and tuning circuits for mobile antennas.