Dual-band Metamaterial Antenna Research Articles

A compact short ended dual band metamaterial antenna loaded with hexagonal ring resonators

A compact short ended coplanar waveguide (CPW) feed dual-band antenna encouraged with metamaterial using composite right/left-handed transmission line (CRLH - TL) technique presented here. The antenna designed to operate at series resonance as the performance of the antenna categorised by the combination of series (Lse, Cse) elements. This proposed antenna embraces two novel hexagonal ring resonators (HRR) connected to patch in order to excite higher-order modes, results in bandwidth expansion from 53.2% (fc = 7.03 GHz) to 84.07% (fc = 8.29 GHz). In addition to this, antenna is compact with an electrical size of 0.149λ0 × 0.22λ0 × 0.01λ0 at f0 = 2.23 GHz. The simulated averaged radiation efficiencies of the proposed antenna throughout the first band and the second band are 85.3% and 93.2% respectively. Also, the measured result indicates that the antenna intended to operate over the frequency bands 2.19–2.33 GHz and 4.83–10.87 GHz with 10 dB fractional bandwidth of 5.73% and 74.54% respectively with a measured peak gain of 1.29 dB at 2.23 GHz and 4.81 dB at 7.7 GHz. It observed that the measured results are worthy promising with the simulated one. Due to these attributes, the proposed antenna is an aspirant for recent wireless communication like Bluetooth, WLAN/Wi-Fi band, HiperLAN1 (5.15–5.3 GHz), HiperLAN2 (5.47–5.72 GHz) and for X – Band Applications.

Reconfigurable dual-band metamaterial antenna based on liquid crystals

In this paper, a novel reconfigurable dual-band metamaterial antenna with a continuous beam that is electrically steered in backward to forward directions is first proposed by employing a liquid crystal (LC)-loaded tunable extended composite right-/left-handed (E-CRLH) transmission line (TL). The frequency-dependent property of the E-CRLH TL is analyzed and a compact unit cell based on the nematic LC is proposed to realize the tunable dual band characteristics. The phase constant of the proposed unit cell can be dynamically continuously tuned from negative to positive values in two operating bands by changing the bias voltage of the loaded LC material. A resulting dual band fixed-frequency beam steering property has been predicted by numerical simulations and experimentally verified. The measured results show that the fabricated reconfigurable antenna features an electrically controlled continuous beam steering from backward −16° to forward +13° at 7.2 GHz and backward −9° to forward +17° at 9.4 GHz, respectively. This electrically controlled beam steering range turns out to be competitive with the previously reported single band reconfigurable antennas. Besides, the measured and simulated results of the proposed reconfigurable dual-band metamaterial antenna are in good agreement.

A high selective filtering small size/dual band antenna using hybrid terminated modified CRLH cell

AbstractThis article presents a new small size dual band metamaterial antenna. The antenna is realized using a single cell of a suggested modified version of composite right left handed transmission line terminated by a hybrid capacitive loading with short circuit termination. The hybrid termination leads to decrease the size of the antenna whereas the modified composite right left handed cell configuration leads to introduce dual band antenna functionality at 2.5 and 2.92 GHz. The antenna size is only 31 × 26 mm2. Compared to, single band, non‐selective, conventional patch antenna, the size of the proposed antenna is only 9 and 11.5% at the two former frequencies, respectively. Despite the small size, the antenna gain is more than 3.5 dBi at the two operating frequencies. Moreover, the antenna has a high roll off beyond the operating frequency band which leads to high selective characteristics. The antenna can suppress 100% of the nearby signal power beyond its bands by 300 MHz at lower band and 200 MHz at upper band. The antenna design is discussed; the full wave simulation and experimental measurements are introduced for validating the results.

Compact Low-Profile Dual Band Metamaterial Antenna for Body Centric Communications

A compact low profile dual band metamaterial antenna is presented for wireless body centric communications. It is composed of a zeroth-order loop loaded periodically with mu-negative transmission line (MNG-TL) for a lower frequency band and a circular patch located in the center of loop for an upper frequency band. The MNG-TL loop based on the fundamental infinite wavelength property allows current along the loop to remain the same magnitude and phase to create omnidirectional radiation pattern in azimuth plane at the lower band for on-body communications. On the other hand, a unidirectional radiation pattern is generated by a circular patch in direction normal to a human body at the upper frequency band for off-body communications simultaneously. In order to feed the MNG-TL conveniently, a transition based on a CPW transmission line is proposed. Finally, the proposed antenna is fabricated and measured. It is demonstrated that the measurement has good agreement with simulation.

Novel stackedμ-negative material-loaded antenna for satellite applications

An engineered novel tunable dual-band metamaterial antenna based on stacked split ring resonator (SRR) array is presented. The μ-negative SRR array present at two sublayers of stacked microstrip patch antenna substrate adds tuning capability to the antenna with marginal trade-off between antenna gain and cross-polarization. If the size of resonator element is considerably smaller than resonance wavelength, ideally lesser than λ/10, the resonator would support the resonating mode of antenna. Compact SRR array embedded in radiator facilitate the antenna tuning to intended allocated spectrum of L5- and S-band frequencies without modifying external dimensions of patch antenna, which in turn helps the satellite payload design. The variations in SRR array dimensions and inter-element spacing are subsequently utilized to maintain the antenna gain and voltage-standing wave ratio. The proposed design of inset fed antenna, matched at 50 Ω, was validated by experimental results and it is suitable for global positioning satellite applications.