Mechanically-controlled phase shifter of left-handed waveguide for beam-scanning slot array antennas

A mechanically-controlled phase shifter of left-handed waveguide is developed for beam-scanning slot array antennas. A delay line using similar periodic structures of right-handed waveguide is also developed for grating lobe suppression of slot array antennas with travelling-wave excitation. The left-handed waveguide is composed of periodic structures as the pair of an inductive iris for shunt inductance and a short stub for series capacitance. The delay line of the right-handed waveguide is composed of a capacitive iris for shunt capacitance and a shorter short stub for series inductance. Dispersion diagram is estimated by Bloch analysis in the design. Left-handed phenomenon with phase variation of mechanically-controlled phase shifter and shortening wavelength due to the delay line are confirmed in the experiments.