Wideband Dual Polarized Compact Design of Pi-Shape Microstrip Antenna for Gsm, Ism, and Satellite Applications

Abstract

The design of a compact Pi-shape microstrip antenna for dual-polarized wideband response is proposed. The Pi-shape geometry is realized by modifying a compact C-shape patch. The two stubs placed on the Pi-shape patch edge optimize the spacing in between the higher order TM 20 and TM 30 resonant modes with respect to the fundamental TM 10 mode which yield a bandwidth of more than 430 MHz (> 35%). On an air suspended substrate, the antenna exhibits broadside gain of more than 5 dBi over the impedance bandwidth. The orthogonal surface current variations across the TM 10 , TM 20 , and TM 30 modes realize polarization agility satisfying the requirements of GSM900/navigation satellite applications/ISM900. With respect to the band start frequency, the proposed configuration offers 11% reduction as compared with the equivalent rectangular microstrip antenna. Further, by defining the resonant length at each of the Pi-shape patch modes, the formulation for their resonant frequency is proposed. The Pi-shape antennas redesigned using them at the given fundamental mode frequency yield similar dual polarized wideband responses offering bandwidth of > 35%.

The Development of Broadband Microstrip Patch Antenna for Wireless Applications

“…It has achieved a bandwidth of 80 MHz and a directivity gain of 2.611 dBi [16]. Several methods have been introduced, such as using slits [17], slots [18], DGS (Defected Ground Structure) [19], partial ground plane [20][21], split-ring resonator [22], substrate integrated waveguide (SIW) [23], dielectric rezonator (DRA) [24], using air gap [25], shorting pin [26] and using EBG (Electromagnetic Band Gap) structures [27]. Although there are many studies in the literature to increase the bandwidth, the easiest way to increase the bandwidth is to use slots in the patch plane and make changes in the ground plane [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27].…”