Band-notched printed log-periodic dipole antennas using loaded slots pair (LSP) resonators

Novel printed log-periodic dipole antennas (PLPDAs) with 3.5/5.5 GHz dual band-notched characteristics are investigated in this paper. The proposed antennas are comprised of a modified ground plane etched with rectangular slots, which are capable of tailoring the input impedance. Loaded slots pair (LSP) resonators are cut in the radiators to achieve band-notch mechanism. By etching several pairs of U-shaped LSPs on the radiation structure of the PLPDA, multiple notched bands are generated for blocking the interference from other narrow band wireless communication systems. Antennas with the notched-band of World Interoperability for Microwave Access/Wireless Local Area Network operating frequencies are designed and fabricated. The measured impedance bandwidth defined by voltage standing wave ratios <2 of 8.0 GHz (3.0–11 GHz), with the dual notched bands of 3.3–3.6 and 5.0–6.0 GHz, is obtained. Measured and simulated reflection coefficient curves are provided along with normalized beam patterns, gain and gr...