Meander Leaky Wave Antenna With Open Stop-Band Suppression for Millimetre Wave Direction-Finding

A meander unit cell with a pin-based open stop band (OSB) mitigation technique is presented to design a fast frequency-beam-scanning leaky wave antenna (LWA) at millimeter-wave frequencies. The complex propagation constant of the unit cell is obtained based on an S-parameter simulation approach. The classical open stop-band issue is observed and addressed by inserting a pin inside the unit cell. A LWA is accordingly designed which exhibits impedance matching and no drop in the gain at the OSB frequency. This LWA beam seamlessly steers from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-46^{\circ}$</tex> to 44° over only a 400 MHz bandwidth at 27.25 GHz, thereby exhibiting a scanning rate as high as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$61.3^{\circ} / \%$</tex>.