Size Reduction and Characteristics Improvement of Espar Antenna Using Metal Disc with Monopoles

In battlefield, the soldiers are equipped with an array of communication systems. The size and weight of these tools will create problems for user. In this paper, a new technique to reduce size of soldiers worn smart espar antenna is suggested. In addition to reducing the size and weight, the proposed antenna will improve radiation characteristics of soldier’s conventional espar. The new technique is based on the use of a metal disc above monopole in conventional espar antenna. The proposed antenna with maximum dimension of 15 cm and height of 2.03 cm has a gain over 5 dB and a bandwidth of 18% (1.6-1.92 GHz). Moreover the antenna has a directional pattern so that the H plane pattern will cover different direction with different position of switch. Directional pattern increase coverage and reduce power consumption and most importantly will enhance the security of communication nodes in ad hoc network.