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Modified theta‐shaped monopole antenna with defected ground structure for UWB applications
Author(s) -
Singhal Sarthak,
Singh Amit Kumar
Publication year - 2015
Publication title -
microwave and optical technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 76
eISSN - 1098-2760
pISSN - 0895-2477
DOI - 10.1002/mop.29174
Subject(s) - monopole antenna , ground plane , radiation pattern , reflection coefficient , j pole antenna , coplanar waveguide , optics , magnetic monopole , physics , helical antenna , microstrip antenna , omnidirectional antenna , microwave , antenna (radio) , electrical engineering , engineering , telecommunications , quantum mechanics , periscope antenna
A compact modified theta‐shaped monopole antenna for ultrawideband communication is presented. It consists of a modified theta‐shaped radiator fed with a modified microstrip feedline and rectangular notch‐loaded quarter elliptical coplanar waveguide ground plane. An impedance bandwidth of 4.35–20.75 GHz (131%) below −10 dB reflection coefficient line is achieved. The designed antenna structure has nearly omnidirectional radiation pattern in H‐plane and bidirectional pattern in E‐plane. The cross polarization level is also 20 dB lesser than copolarization level in every direction at lower frequencies. The performance of the designed antenna structure for three substrate materials, that is, FR‐4 epoxy, carbon nanotubes, and Ni 0.2 Co 0.2 Zn 0.6 Fe 2 O 4 , are also studied. The experimental and simulation results are found to be in good agreement. The designed antenna structure has advantage of wider bandwidth along with smaller dimensions as compared to previously reported monopole structures. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1625–1632, 2015