Conformal and Flexible Leaky-Wave Combline/Rampart Hybrid Antenna Arrays

A novel bent-stub hybrid combline/rampart leaky-wave antenna (LWA) is designed and fabricated on a flexible polyethylene terephthalate (PET) substrate, and experimentally verified on flat and curved surfaces. The open stopband (OSB) of a combline structure is suppressed with asymmetrical stubs. Meandering is then introduced in its feed and increases gain and scan range. The meandering is a discontinuity itself known as a rampart antenna and contributes to the radiation. Finally, the antenna is utilized in an array where the combline LWAs are offset by half of a period and intertwined. Mutual coupling is controlled by bending the UC stubs and optimizing antenna separation and is shown to reduce any discontinuities in the gain around the broadside frequency of the LWA array. The designs are manually fabricated on a PET substrate and tested, demonstrating good agreement with simulations. Antennas were shown to retain good performance at bend radiuses of ±1000 mm.