An active frequency-tuned beam-scanning leaky-wave antenna

Abstract

A frequency-tuned beam-scanning antenna is developed, which integrated a microstrip leaky-wave antenna with a varactor-tuned HEMT VCO as the source. The microstrip leaky-wave antenna is operated in the first higher mode. To excite the first higher mode, microstrip leaky-wave antenna is fed asymmetrically. The dominant mode excitation has been successfully suppressed by adding a sequence of covered wire in the center of the microstrip leaky-wave antenna. The HEMT oscillator frequency is controlled by tuning the varactor dc bias, and the beam scanning is demonstrated. The measured scanning angle agrees well with the prediction; it is close to 30 degrees as the VCO frequency is tuned from 8.06 to 9 GHz. (C) 1998 John Wiley & Sons, Inc.