High Gain and Wide Beam Printed LPDA with Improved Bandwidth Based on Multiple Scaling Factors

In this paper, a modified printed log periodic dipole array (MPLPDA) antenna based on multiple scaling factors for high gain and wide beam-width is presented. To improve the gain and broaden the beam while enhancing the impedance bandwidth, a design based on dividing the LPDA dipole elements into three groups with three scaling factors for each group is proposed. The −10 dB bandwidth of 1.36 GHz to 12.8 GHz is realized in addition to some high frequency sub bands. Furthermore a −7.3 dB bandwidth of 1.29 GHz to 18 GHz is achieved. The designed antenna is realized on F4B substrate with thickness of 1mm and a good agreement is noticed in the measurement of the input reflection coefficient and radiation patterns. The measurements show the UWB end-fire operation of the proposed LPDA with a maximum realized peak gain of 10.59 dBi. Moreover, the fabricated antenna maintains a realized gain values greater than 5 dBi and −3 dB beam-widths at both E and H plane wider than 58°in almost all L, S and C band frequencies. The proposed antenna can be used for ESM / ELINT systems by tilting it at an angle of 45°for high polarization receiving capability.