二方向性掃瞄短洩漏波天線結合孔隙耦合式微帶天線陣列

Abstract

首先，我們提出一個二方向性掃瞄的天線架構。此架構是由一短洩漏波天線結合孔隙耦合式微帶天線陣列組成。因為孔隙耦合式微帶天線陣列提供了路徑，所以此架構可以壓制反射波的能量。在基板上方的洩漏波波瓣是由頻率決定掃瞄角度，而在基板上方的微帶天線陣列波瓣是由移相器決定掃瞄角度。因此我們可以獨立掃瞄上下二波瓣。 第二步，我們提出另一個二方向性掃瞄的天線架構。此架構是由一短洩漏波天線結合另一個孔隙耦合式洩漏波天線組成。此架構同樣提供了路徑來壓制反射波的能量波能量，並且提供多波瓣掃瞄。 比較以上兩種架構，前者可以壓制10 dB，後者可以壓制8 dB。由反射係數可以知道加上孔隙耦合式微帶天線陣列或孔隙耦合式洩漏波天線，可以提升天線輻射的效率，增加天線的頻寬。前者結合洩漏波波瓣和微帶天線陣列波瓣，後者提供多波瓣掃瞄，這樣的功能很適合應用在通訊系統中。

First, we present a two-directional scanning method by using a short leaky-wave antenna (LWA) integrated with aperture coupled patch antenna array on the bottom of the substrate. The aperture coupled patch antenna array is connected to the open end of the leaky-wave antenna. Such design offers another radiation path of the reflected wave and thus suppresses the power of reflected wave. The beam of the patch antenna array on the bottom plane can be steered by tuning individual phase-shifter connected to the patch antenna. The beam of the LWA is dominated by the frequency of input signal. Therefore, the two beams of individual direction can be steered independently. Experimental result shows that the suppression of the reflected wave can be 10 dB at 10.5 GHz with a short LWA length of 6cm (2 wavelengths). The results of return loss reveal that the bandwidth of the short LWA is extended by the proposed structure. Secondly, we propose another two-directional scanning topology that is realized by using a short leaky-wave antenna integrated with aperture coupled LWA on the bottom of the substrate. The topology then can accomplish multi-beam scanning and can also suppress the reflected power. The two-directional scanning of two different radiation patterns on different planes provides more flexibility in beam scanning and has great potential in many applications.