Microstrip Square Ring Antenna for Dual-Band Operation

Abstract

Abstract-This paper presents a generalized approach to design an electromagnetically coupled microstrip ring antenna for dual-band operation. By widening two opposite sides of a square ring antenna, its fractional bandwidth at the primary resonance mode can be increased significantly so that it may be used for practical applications. By attaching a stub to the inner edge of the side opposite to the feed arm, some of the losses in electrical length caused by widening can be regained. More importantly, this addition also alters the current distribution on the antenna and directs radiations at the second resonant frequency towards boresight. It has also been observed that for the dual frequency configurations studied, the ratio of the resonant frequencies (f r2 /f r1 ) can range between 1.55 and 2.01. This shows flexibility in designing dual frequency antennas with a desired pair of resonant frequencies.

Compact Dual-Band Dual-Ring Printed Monopole Antennas for Wlan Applications

“…where λ o is the wavelength in air, and ε e is the effective relative dielectric constant given by [7,11]:…”

“…The use of slot structures to achieve multi-band characteristics was proposed in [3][4][5]. The use of ring shaped antenna to operate on dual band was proposed by [6,7]. Many other planar monopole antennas and microstrip antennas were proposed to operate on dual or multi band fashion [8][9][10][11].…”

Multi-Band Antenna Design by Controlling Characteristic of Third Order Mode

“…지금까지 이중 대역 WLAN 주파수 대역을 만족 하기 위한 안테나가 많이 연구되었었다 [1]～ [4] . 면 전계가 강한 부분을 알 수 가 있고, 전계가 강한 곳은 그렇지 않은 곳보다 안테나 특성에 영향을 많 이 받는다 [5] .…”

A Novel Approach to the Design of Dual-Band Power Divider With Variable Power Dividing Ratio Based on Coupled-Lines

“…Many efforts have been made to develop more versatile dual-band components such as antennas [1][2][3][4], filters [5][6][7][8], coupler [9,10] and transformers [11,12]. Meanwhile, the power divider as one of the most important passive circuits has been widely used in microwave and communication systems.…”