Philippe Le Thuc

Dual-Band WLAN Multiantenna System and Diversity/MIMO Performance Evaluation

In this paper, we present a multiantenna system based on closely spaced planar inverted-F antennas (PIFAs) with high port-to-port isolation in two dual bands [2.4-2.48 GHz] and [5.15-5.725 GHz]. The high isolation, respectively higher than 30 and 20 dB in the entire lower and upper bands, is obtained by inserting two slots on the 100 × 50 mm2 printed circuit board (PCB). The multiantenna system was fabricated and measured. The simulated and measured S-parameters and radiation patterns are presented. The envelope correlation, the diversity system gain (DSG), and the channel capacity are also computed and those results discussed. This technique could be implemented on the terminal side of a wireless link to achieve enhanced diversity antennas.

Experimental validation of a miniature implantable RFID tag antenna for small animals monitoring

This paper addresses the design and measurement of an implantable RFID tag for small animal monitoring applications. In particular, the design of a miniature printed dipole antenna and its integration with a commercial RFID transceiver is discussed. Some preliminary numerical results of the antenna performance when implanted under the mouse skin are presented. The experimental validation of the designed antenna in a realistic scenario will be successively provided.

Exploitation of the UC-PBG structure as ground plane to enhance microstrip antenna bandwidth

The uniplanar compact photonic bandgap (UC-PBG) metamaterial structure has been profitably used for antenna miniaturization and radiation enhancement purposes. This paper presents an additional way to exploit it, when it is employed as ground plane for microstrip antennas. As a matter of fact, if a proper number of UC-PBG unit cells is selected, the antenna bandwidth can be remarkably increased. Such a behavior is here presented in dealing with a classical square patch antenna.

PIFA antenna with tilted circular polarization angle for RFID readers

In this paper, a miniaturized circularly polarized (CP) antenna for RFID readers is presented. This structure, made up of two crossed PIFA has been designed to operate in the European RFID UHF band [0.865-0.868 GHz]. Thanks to two shorts circuits, miniaturization and CP are achieved with only one feed. By optimizing the different parameters of the structure, CP direction can be also tilted in a desired angle. The simulated impedance matching and axial ratio bandwidths are 4% and 16%, respectively. The realized gain is 1.85 dBi at 0.866 GHz. The overall dimensions of the structure are 0.5λ0 × 0.5λ0 × 0.06λ0.

Dualband MICS/WIFI small antenna for portable applications in telemedicine

In this paper, we present the study the design and radiation performance of and the optimization of miniature antennas embedded in small devices of various form factors including wrist-watch or pendant, operating in both MICS (402.0-405.0 MHz) and WIFI (2.4-2.483 GHz) bands. Two structures based on Planar Inverted-F Antennas (PIFAs) are proposed, and prototypes are fabricated and tested. Performance in terms of bandwidth, radiation efficiency and gain of the two structures are compared and discussed. As these antennas are dedicated to be placed in contact with the user, the influence of the human body on the antenna performance is investigated.