Broad and Dualband Sierpiniski Gasket Double Sided Printed Dipole Antennas

Abstract

A Double Sided Printed Dipole Antenna (DSPDA) consists of two radiating arms printed on opposite sides of a dielectric. However, in place of rectangular shaped arms, triangular shape is used in to increase Return Loss (RL)/impedance bandwidth. Flaring of arms helps in gradual transition of impedance and results in increased RL bandwidth. But maximum RL bandwidth reported so far is not sufficient for high speed data application like streaming video, real time navigation, medical imaging, broadband EMI measurement etc. Maximum 10dB RL bandwidth reported with flared arms is 51% [1] and a fat PDA with higher cross polar component 10dB RL bandwidth reported is 58% [2]. Several techniques such as complicated feed structure, use of BALUN, parasitic element etc. are used to increase the RL bandwidth. But their design and fabrication are more complicated. A novel but simple designs of PDA with fractal shaped arms (Sierpiniski Gasket) are reported with 10dB RL bandwidth as high as 76% with the centre frequency of 4.2GHz. Multiband behavior of PDA has been reported by many workers [3-17]. But the impedance bandwidth obtained in each band is very small. Here we propose a novel dual band DSPDA with significantly higher bandwidth of 20% and 39% around the centre frequencies of 1.5GHz and 3.9 GHz.