Frequency-Scanning Leaky-Wave Slot Antenna Array Based on Serpentine Waveguide With Open Stopband Suppression

A periodic leaky-wave antenna with backward-to-forward scanning capability is presented. Two versions of the antenna, one with bidirectional radiation and the other with unidirectional radiation, are introduced. The proposed structure, composed of 30 unit cells, is based on a meandered rectangular waveguide loaded with transverse radiating slots. Effective suppression of the open stopband is achieved allowing for efficient broadside radiation at 5 GHz. Measured and simulated
S
-parameters, radiation pattern, and gain are reported. The experimental results demonstrate a backward-to-forward scanning capability from −35° to 42° for both the unidirectional and bidirectional versions, with a maximum measured gain of 15.5 and 16.5 dB, respectively.