A new two-terminal feeding active leaky-wave antenna

A new two-terminal feeding active-integrated leaky-wave antenna design is demonstrated. The X-band microstrip two-terminal feeding leaky-wave antenna is integrated with an active high-electron mobility transistor (HEMT) oscillator to produce a two-beam radiation pattern. The antenna is fed asymmetrically at both sides to excite the first higher order mode. This configuration, as compared to a single-terminal feeding leaky-wave antenna, has the advantage of the multidirection and the reduction of the reflected wave caused by the open end of the radiating element. Measured results show that the radiation directions of two beams are approximately at 34/spl deg/ and 140/spl deg/, the effectively isotropic radiated power (EIRP) is close to 17.5 dBm, and the return loss is almost less than -10 dB between 9 and 11.5 GHz.