Design of Compact Planar Ultra-Wideband Antenna with Band-Notched Characteristics

Abstract

Since the beginning of the human civilization mankind is trying to communicate with the others. It’s the communication process i.e. the sharing of feelings, emotions and information has made us the greatest creation of God on this green earth. It all started with hand gestures, then sounds produced by vocal chords and gradually me moved to wired communication and now wireless communication. In wireless communication we mainly exploit the Electromagnetic Spectrum. Earlier systems were narrowband long range systems but in order to extend the use of available spectrum we are now using UWB (ultra-wide band) short range systems which require low power and these are built using inexpensive digital components. And Microstrip antenna is used for implementing UWB systems as it shows good broadband characteristics.
We propose a compact triple band notched CPW (Co-planar Waveguide) fed MSA (Microstrip Antenna) for UWB (Ultra-Wide Band) applications. The aforementioned antenna is designed using CST MICROWAVE STUDIOTM SUITE 2010.
This band-notched antenna has rejection characteristics at 3.5 GHz (for Wi-MAX band-3.3 to 3.7 GHz), at 5.5 GHz (for WLAN 2 band-5.15 to 5.825 GHz) and at 8.2 GHz (for ITU band-8.025 GHz to 8.4 GHz).
First a Primitive antenna is taken. This antenna consists of a bevelled rectangular radiating patch and a CPW (co-planar waveguide) type feed structure. The essence of this design strategy is that three notching elements are embedded onto the primitive patch antenna to produce band-stop filtering function at those abovementioned frequencies. Notch elements are meticulously selected and embedded onto the antenna.
By etching two nested C-shaped slots in the radiating patch band rejection is achieved for Wi-MAX and WLAN 2. By etching two CSRRs (Complementary Split Ring Resonators) on the ground plane band rejection is achieved for ITU band.
Proper care has been taken while embedding the notch elements in order to minimize cross-coupling among the three notch elements.
The proposed Antennas were successfully designed, simulated and measured showing broadband features, stable radiation patterns and consistent gain. Measured results and graphs show validity of our suggested design.