Band-notched ultra-wideband antennas using nonperiodic composite right/left-handed resonators

摘要

This article investigates the characteristics of a single/double-cell composite right/left-handed (CRLH) resonator and its application on multiple band-notched ultra-wideband (UWB) antennas while suggesting an accurate design procedure. Periodicity assumption and calculating a dispersion diagram allow band-notched frequencies to adequately predict prior to antenna design. Zeroth-order resonance (ZOR) frequency due to the CRLH characteristics of a mushroom resonator and higher-order resonance frequencies are predictable through the hypothetical dispersion diagram. To demonstrate this method, compact, printed, ultra-wideband circular monopole antennas with four/five-band notched characteristics using a single/double mushroom resonator are presented. The effects of mushroom cell size on ZOR and the other band notched resonant frequencies are also investigated. The numerical simulations show that the asymmetrical unit cell provides the capability to tune both ZOR and band notched frequencies. Comparison between the simulation and measurement results shows reasonable agreement.