The Comparative Analysis of UWB Antennas with Complementary Characteristics: A Functionality in FS and Applicability for the Usage Close to Tissues

摘要

The present paper considers planar ultra wideband (UWB) antennas with complementary characteristics and their operation close to tissues. The dipole and slot antennas are first examined by forming they appear as complementary structures according to the Babinet's principle (BP). The influence of a substrate on the complementarity is evaluated and the addition of a substrate is noticed to affect radiators to diminish the capability to appear as ideal complements. A dipole-slot pair is re-designed to have corresponding S_(11) bandwidth to cover the lower UWB band of 3.24-4.74 GHz and the complementary operation is acquired according to the pattern duality. The antennas are concluded to have complementary characteristics based on their radiation properties and current distributions, even though the BP is not ideally satisfied. The performance close to tissues is analysed and discrepancies shown in terms of mismatch and body loss. Although free space performance is observed to appear almost equal (excluding a pattern duality), the performance is found to differ close to tissues.