A Dual-Mode 2-D Frequency-Scanning Microstrip Periodic Leaky-Wave Antenna Array

A dual-mode two-dimensional(2-D) frequency scanning microstrip periodic leaky-wave antenna array is presented. The antenna array consists of four rampart lines with one-dimensional (1-D) frequency scanning capability and a matching feeding structure. The antenna array has dual-mode two-dimensional frequency scanning capability. In the low-frequency range, the antenna array is in a four beam scanning mode, and as the frequency increases, the four beams gradually move towards the broadside direction. In the high-frequency range, the antenna array is in a bowl shaped radiation mode, and as the frequency increases, the bowl shaped radiation gradually moves away from the broadside direction. A prototype of antenna array is fabricated and tested. The measurement results verify that the antenna array achieves dual-mode 2-D frequency scanning. In the low-frequency range, the four beam radiation scans from 8° to 49° in the <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">φ</b> = 45° plane. The bowl shaped radiation in the high-frequency range scans from 17° to 38° in the <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">φ</b> = 0° (x-z) plane.