Loaded dipole antennas with new CRLH cell configuration

In this paper, two different triple band dipole antennas loaded by new modified composite right left handed cell are presented. The modified cell can introduce large electrical length in small size. Thus, the two antennas are designed with smaller operating frequency or reduced physical length compared to a single frequency reference dipole. The designed antennas can serve different wireless services for GPS (1.27 GHz and 1.55 GHz), UMTS (1.85 GHz), and WiFi (2.4 GHz) in triple band functionalities. The lower operating frequency antenna size is (70 × 70 mm2) whereas the reduced physical length antenna size is (60 × 70 mm2). At mid band frequencies the reduced frequency antenna length is (0.29 λ0, 0.37 λ0, and 0.52 λ0), whereas that of the reduced physical length is (0.28 λ0, 0.41 λ0, and 0.56 λ0), at triple band mid frequency, respectively. Compared to a typical dipole antenna, the designed loaded dipoles can achieve a length reduction that can reach up to 50%. Moreover, the antenna has good gain at the triple bands (−1.2 dB, 1.9 dB and 3.5 dB for reduced operating frequency antenna and −3.1 dB, 1.2 dB and 3.4 dB for the reduced length antenna. The two antennas have good radiation efficiency that can reach up to 84% on a low cost antenna substrate. The mathematical analysis, full wave simulation and experimental measurements of the reported antennas are introduced.