Estimating the performance of matching circuits for antennas

The performance of impedance matching networks for antenna applications consists of two parts: impedance mismatch and losses in the matching components. Traditionally, impedance matching has been computed using S parameter analysis and component losses calculated from currents and voltages using circuit simulator. This paper shows how the total performance and the component losses can be easily computed using the power wave definition of S parameters. The performance is measured by |S21|². In practical applications, due to component losses, the impedance bandwidth may have to be larger than the operational bandwidth of the system due to increasing component losses near the edges of the system band.