Broadband Leaky-Wave Antenna Fed With Composite Right/Left-Handed Transmission Line

The broadband feeder line is investigated to exploit the broadband nature of leaky-wave antenna. The feeding structure is realized by inserting the composite right/left-handed transmission line (CRLH-TL) into the feeder. Microstrip CRLH-TL feeder line is designed for the microstrip leaky-wave antenna. The microstrip leaky-wave antenna system shows a return loss of less than 9.5 dB (VSWR < 2.0) from 6.2 GHz to 9.3 GHz in the measured result, and exhibits the beam-steering nature as frequency is varied.