A microstrip leaky-wave antenna loaded with digitally controlled interdigital capacitors for fixed-frequency beam scanning

A digitally controlled half-width microstrip leaky-wave antenna (LWA) is presented for fixed-frequency beam scanning. The free edge of a half-width microstrip line is loaded with a number of periodic interdigital capacitors. Each capacitor is connected to the ground plane by a digital switch. By dynamically changing the reactance profile at the free edge of the microstrip the beam direction is changed at a fixed frequency. Full-wave numerical simulations show that the antenna has the ability to scan the main beam from 35° to 56 ° at 5.75 GHz.