Miniaturization of multiband patch antenna using stack configuration

Abstract

A novel technique for miniaturization of microstrip patch antenna is proposed for Portable and multifunctional Communication systems. Our proposed design consists of double fractal patch, PI-Shaped slot on fractal patch with first iteration and combination of L-Shape and U-Shape slots on the Ground plane‥ In this way we get smaller size antenna which is smaller than the conventional antenna. The most interesting feature of our proposed design is that we are getting multiband response in the frequency range of 1-8GHZ having Directivity in the range of 3.76dBi-6.52dBi, good gain and good impedance bandwidth for desired bands. As we have used the double fractal patch with double substrate in which 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> substrate is FR4 and 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> substrate is AIR. Co-axial cable is used as a feeding method. We have design the PI-shape on both fractal patches. We also employed shorting pin between fractal patch and ground plane. By the combination of all these proposed technique size of antenna is reduced 79.12%s and it produces multiband response while the impedance bandwidth and gain are satisfactory for each band. We can adjust different bands by changing position of shorting pin. This type of smaller size antenna has applications in mobile phone for Wi-Max application, Andrew Antenna, GPS, Low Profile Dome Antenna, PCS, C -band, L-band, S-band and also in Radar application.