A full-wave analysis of active uniplanar structures

The coplanar waveguide (CPW) is well suited to feed printed antenna thanks to its interesting properties (less radiation, easy component insertion). The ability to insert an amplifier on a CPW-fed slot antenna to increase the bandwidth has been investigated experimentally in terms of the transfer power gain. A full-wave analysis of active uniplanar structures is proposed by combining the loaded scatterers theory, and the integral equation technique. The developed theory is applied to optimize an amplifier on a CPW and an active CPW-fed slot antenna. The results obtained are compared to an equivalent circuit approach and the observed differences are discussed.