변형된 사각 링과 사각 패치를 갖는 WLAN/WiMAX 시스템에 적용 가능한 삼중대역 안테나 설계 및 제작

Design and Manufacture of Triple-Band Antennas with Modified Rectangular Ring and Rectangular Patch for WLAN/WiMAX system applications

Abstract

본 논문에서는 WLAN(Wireeless Local Area Network)과 WiMAX(World Interoperability for Microwave Access) 표준화 주파수 대역에 적합하도록 모노폴 형태의 삼중대역 안테나를 설계 제작하였다. 마이크로스트립 급전방법을 채택하고 사각 링과 사각 패치의 결합 구조로 설계하였으며 임피던스 특성을 향상시키기 위해 사각 링 패치 상단에 두 개의 스터브 추가하여 향상된 삼중대역 특성을 얻었다. 제안된 안테나는 $29.0mm(W){\times}44.0mm(L){\times}1.0mm(t)$의 유전체 기판 위에 $18.0mm(2W_1+W_2){\times}33.0mm(L_7+L_8+L_9)$의 크기로 설계되었다. 제작 및 측정 결과로부터 2.4/2.5 GHz에서는 660MHz (2.08~2.74GHz), 3.5GHz 대역에서는 488.0MHz (3.40 ~ 3.88GHz), 그리고 5.0GHz 대역에서는 2,180MHz (4.61 ~ 6.79GHz)의 대역폭을 얻었다. 또한 무반사실의 측정결과로부터 제작된 안테나의 이득과 방사패턴 특성을 확인하였다.

In this paper, a monopole type antenna applicable to WLAN and WiMAX standard frequency bands is designed and fabricated. The proposed antenna is designed to have rectangular ring and rectangular patch based on microstrip feeding for triple band characteristics and inserted two stub in the top of the rectangular ring patch to enhance impedance bandwidth characteristics. The proposed antenna has $18.0mm(2W_1+W_2){\times}33.0mm(L_7+L_8+L_9)$ on a dielectric substrate of $27.0mm(W_1){\times}44mm(L_1){\times}1.0mm$ size. From the fabrication and measurement results, impedance bandwidths of 660MHz (2,08 to 2.74GHz) for 2.4/2.5MHz band, 488MHz (3.40 to 3.88GHz) for 3.5MHz band, and 2,180MHz (4.61 to 6.79GHz) for 5,000MHz band were obtained based on the impedance bandwidth. The proposed antenna also obtained the measured gain and radiation pattern in the anechoic chamber.

Fig. 1 The structure of the proposed WLAN/WiMAX antenna

Fig. 2 Return loss characteristic of the effect of the L8.

Fig. 3 Return loss characteristic according to the with and without stub of the rectangular ring structure

Fig. 4 Return loss characteristic according to the with and without slit in the ground.

Fig. 5 Return loss characteristic according to the with and without rectangular patch

Fig. 6 The surface current density of proposed antenna (a) 2.515 GHz, (b) 3.46 GHz, and (c) 5.155 GHz.

Fig. 8 The simulated and measured return loss results

Fig. 9 3D radiation pattern of 2.4 GHz

Fig. 11 3D radiation pattern of 5.35 GHz

Fig. 12 3D radiation pattern of 5.75 GHz

Fig. 13 Measured peak gains of the designed antenna

Fig. 10 3D radiation pattern of 3.6 GHz

Table. 1 Results of simulation : L8

Table. 2 Results of simulation with/without stub

Table. 3 Results of simulation with/without slit

Table. 4 Results of simulation with/without rectangular patch

Table. 5 Parameters of proposed antenna

Fig. 7 Fabricated of propose antenna (a) Front view, (b) Back view.

Table. 7 Results of measured gain