Development of a tunable antenna using RF-MEMS based CRLH-transmission lines

We introduce in this contribution a new antenna array for beam steering based on tunable via-free microstrip composite right/left-handed transmission lines (CRLH-TL). A leaky-wave antenna is composed of several cells, where series capacitances and shunt inductances are added to the typical line parameters. To add tunability RF MEMS elements are implemented in the tunable capacitors and stub inductors, which match the line impedance during tuning. The resulting leaky-wave antenna exhibits three different states with forward, backward and zero propagation. The via-free design employing radial stubs enables easy and low-cost fabrication. Measurements of single cells are presented as well as simulations for the complete array. The realization for two-dimensional beam steering avoids a high number of phase shifters and can be produced on one substrate.