M. Aznabet

Route for Bulk Millimeter Wave and Terahertz Metamaterial Design

A possible route for the design of 3-D metamaterials in the millimeter and terahertz (THz) frequency range is proposed in this paper. It consists of stacks of spatial filtering screens made of resonant subwavelength metallic elements deposited on polypropylene (PP) film substrates by a contact photolithography technique. A thorough characterization of PP films as a substrate in THz and its extension to millimeter waves is carried out. Then, a description of the fabrication process, followed by a thorough analysis of the yield of this process as well as the material properties, is reported. As a direct application, several filtering screens are studied, including the performance of multilayer configurations. It is shown that the losses do not increase significantly in the multilayer case, enabling both the fabrication and use of PP at these frequency ranges. Additionally, slow wave has been measured in a multilayer prototype. Full-wave electromagnetic simulations have been compared with measurement from several configurations, showing reasonably good agreement. These results open the possibility of implementing low-loss metamaterials in the millimeter and THz spectrum.

Stacked complementary metasurfaces for ultraslow microwave metamaterials

We have experimentally realized at microwaves a dual-band ultraslow regime by constructing a metamaterial based upon the alternative stack of conventional- and complementary-split-ring-resonators-surfaces. The group delay reaches values larger than two orders of magnitude than those obtained when the electromagnetic wave propagates the same thickness in free-space. The ultraslow waves have been initially predicted by a numerical eigenmode analysis and finite-integration frequency domain simulations. Such ultraslow modes can be integrated into free-space technology for spatial delay lines, and traveling wave amplifier as well as sensors due to the enhanced interaction between different beams or radiation and matter.

A COMPACT SPLIT RING RESONATOR ANTENNA FOR WIRELESS COMMUNICATION SYSTEMS

In this paper, we report a new design of a compact antenna based on the use of split ring resonator (SRR). The designed antenna consists of two SRRs, with the same geometrical parameters, printed symmetrically on both sides of the dielectric substrate. Excitation of the SRR element is performed by adequately placing the access microstrip lines with respect to the conflnement plane of the split rings. The resonance frequency of the antenna is essentially deflned by geometrical parameters of the SRR, which makes it suitable for a broad range of applications spanning from mobile terminals to WLAN and WPAN systems. The flnal result is low proflle, and can be easily integrated with other RF front-end circuits in a PCB.

A dual-band compact antenna with SRR for wireless communication systems

In this work, a novel design of compact dual-band antenna based on the use of split ring resonator (SRR) is presented. The first resonant frequency can be attributed to the excitation of the second microstrip line which acts a monopole antenna; however the second frequency resonance is originated from the excitation of the SRR resonator embedded on the top layer. Excitation of the SRR element is performed by adequately position the microstrip line with respect to the confinement plane of the split ring resonator. The simulated results are analyzed and compared with measured data.

A new modified S-shaped compact antenna for RFID-UHF tag applications

In this paper, a new modified S-shaped antenna for RFID -UHF tag application is presented. To provide a good conjugate matching between the S-shaped tag antenna and the ship, the technique of adding asymmetrical triangular stubs on both side of the tag chip was applied. The proposed tag antenna operating in the 915MHz RFID band proposed here has dimensions of only 51×43 mm2 and the operating bandwidth is from 909 to 920 MHz (to cover US Band) under -10dB reflection coefficient condition. Furthermore, the measured read range was found to be 0.56 m at 915 MHz. This small value makes the proposed antenna suitable for many RFID-UHF applications, especially those that may involve short reading distance.

A coplanar waveguide-fed printed antenna with complementary split ring resonator for wireless communication systems

In this paper, we report a new design of a compact coplanar waveguide-fed printed antenna with complementary split ring resonator (CSRR). The designed antenna consists of two CSRRs, with same geometrical parameters, printed symmetrically into the top layer. The overall volume of the proposed antenna is only 30 × 20 × 0.8 mm3 (0.58 λ0 × 0.39 λ0 × 0.015 λ0), where λ0 is the wavelength of the simulated resonance frequency. The resonance frequency of the antenna is essentially defined by geometrical parameters of the CSRR, which makes it suitable for various wireless communication systems. The characteristics of the proposed antenna have been investigated using simulation software CST Microwave Studio and experimental results. The measured and simulated results show good agreement, providing a simple and low-cost design.

TRANSMISSION PROPERTIES OF STACKED SRR METASURFACES IN FREE SPACE

In this paper, transmission properties of stacked split ring resonators metasurfaces in free space and under normal incidence are investigated experimentally and numerically. Emphasis is put on studying the interaction between adjacent SRRs metasurfaces. The thorough analysis of the electromagnetic flelds shows that both magnetic and electric coupling can occur between adjacents metasurfaces for vertical and horizontal polarization. In addition, we found that all propagating bands within our spectral window (up to 20GHz) support right-handed behaviour. Both simulation and experiment results in the microwave regime are in good agreement.

Wave propagation properties in stacked SRR/CSRR metasurfaces at microwave frequencies

In this paper, we study wave propagation in stacked SRR/CSRR metasurfaces at microwave frequencies. Computation of the dispersion diagram of both metasurfaces highlights the possibility to obtain forward and backward waves, respectively. The backward waves can be achieved only at the quasi-static resonance in case of stacked CSRRs metasurfaces and provided the longitudinal lattice is small enough. The experimental results for both structures show a good agreement with the computed ones. The physics underlying the left-handed behavior is found to rely on electroinductive waves, playing the interplate capacitive coupling the major role to explain the phenomenon.

A novel compact CPW OCSRR strucutre for 2.45 GHz rectenna application

In this paper, a new and compact rectenna is proposed for the application of ISM band at 2.45 GHz using open complementary split ring resonator (OCSRR). The simulated rectifying efficiency and DC voltage were, respectively 57% and 0.9 V when the input power to the rectifying circuit was 0dBm (1mW). The highest efficiency, 62%, was achieved at 2.45 GHz for 3dBm input power and for a charge load 1kΩ.

Design of a 5.8 GHZ rectenna by using metamaterial inspired small antenna

In this paper, we present a new inspired metamaterial rectenna which is designed in the microstrip line structure at 5.8 GHz for the wireless transmission of microwave power. The proposed rectenna achieves RF-to-DC conversion efficiency of 52% and a DC voltage of 0.8 V when the received RF power is 1 mW at 5.8 GHz. The feasibility of this concept is presented through full-wave simulations. These simulations results will be updated at the conference with measurement results.