A comparison of tunable ferroelectric Π- and T-matching networks

A comparison of tunable pi - and T-matching networks based on ferroelectric capacitors is presented. Both topologies are promising candidates for automated antenna tuners in mobile communication systems. Assets and drawbacks of both circuits are discussed comparing linear and nonlinear simulations and measurements of two exemplary circuits at 850 MHz. The requirements to achieve sufficient linearity are determined by means of simulations. Both matching networks cover an impedance range of approximately |Gamma_in| les 0.6 with a maximum transducer power loss of 4 dB and 6 dB, respectively.