Title :
Application of dual-mode filter techniques to the broadband matching of microstrip patch antennas
Author :
Abunjaileh, A.I. ; Hunter, I.C. ; Kemp, A.H.
Author_Institution :
Sch. of Electron. & Electr. Eng., Univ. of Leeds, Leeds West Yorkshire
fDate :
4/1/2007 12:00:00 AM
Abstract :
Structures such as square or circular microstrip patch antennas may support two orthogonal resonant modes. The paper presents a new method of utilising the dual-mode property to increase the bandwidth of microstrip antennas. The input impedance of such a dual-mode antenna may be represented as a second-order ladder network of coupled resonators, where each resonator is coupled to a load resistor. A theoretical method for evaluating the coupling values in the network is presented, enabling the bandwidth of a dual-mode antenna to be maximised. A theoretical bandwidth improvement of up to 3:1 is achieved when compared to a single-mode antenna. This is confirmed with an experimental dual-mode circular microstrip patch antenna
Keywords :
bandwidth allocation; broadband antennas; electric impedance; electromagnetic coupling; ladder filters; microstrip antennas; microstrip filters; microstrip resonators; multifrequency antennas; bandwidth improvement; broadband matching; circular microstrip patch antenna; coupled resonator; dual-mode filter technique; impedance; load resistor; second-order ladder network;
Journal_Title :
Microwaves, Antennas & Propagation, IET
DOI :
10.1049/iet-map:20060049
