Design of High-Gain and Small-Aperture Endfire Antenna Using a Phase-Reversal Technique
Shangkun Ge, Qingfeng Zhang, Amir Khurrum Rashid, Hong Wang, Ross Murch
Abstract
A phase-reversal technique is proposed in this article to overcome the gain-aperture tradeoff of endfire antennas. Such a tradeoff fundamentally forbids simultaneous high gain and small cross-section aperture. The phase-reversal technique breaks this tradeoff and hence allows one to design a high-gain endfire antenna with a small cross-section aperture. To illustrate the proposed phase-reversal technique, a crossover stripline structure is implemented. The antenna radiates into the endfire direction within 9.5-10.5 GHz and it achieves 13 dBi endfire radiation gain with only 0.047λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.022λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> cross-section aperture size. These results successfully validate the proposed phase-reversal technique. Such a high-gain and small-aperture endfire antenna is potentially useful for microwave imaging in lossy medium.