In this paper, an overview of antenna design for passive radio frequency identification (RFID) tags is presented. We discuss various requirements of such designs, outline a generic design process including range measurement techniques and concentrate on one practical application: RFID tag for box tracking in warehouses. A loaded meander antenna design for this application is described and its various practical aspects such as sensitivity to fabrication process and box content are analyzed. Modeling and simulation results are also presented which are in good agreement with measurement data.

Antenna design for UHF RFID tags: a review and a practical application

Several solutions are presented to reduce the mutual coupling between two planar inverted-F antennas (PIFAs) working in close radiocommunication standards and positioned on a finite-sized ground plane modeling the printed circuit board (PCB) of a typical mobile phone. First, the two PIFAs are designed on separate PCBs to, respectively, operate in the DCS1800 and UMTS bands. In a second step, they are associated on the top edge of the same PCB. Realistic arrangements are then theoretically and experimentally studied. Finally, several solutions are investigated to maximize the isolation. They consist in inserting a suspended line between the PIFAs' feedings and/or shorting points. All along this paper, several prototypes are fabricated and their performances measured to validate the obtained IE3D moment method-based simulation results

Study and Reduction of the Mutual Coupling Between Two Mobile Phone PIFAs Operating in the DCS1800 and UMTS Bands

A wide operating bandwidth for a single-layer coaxially fed rectangular microstrip patch antenna can be obtained by cutting a U-shaped slot on the patch. This antenna structure has recently been found experimentally to provide impedance bandwidths of 10%-40%, even with nonair substrates. However, design rules for this antenna have not yet been presented. This paper develops principle design procedures through examination of the structure's multiple resonant frequencies as well as the radiation and impedance properties of different antenna geometries. The approximate design rules are derived by analysis of former experiments, method of moments (MoM) simulations, and measurement results. Simulations and measurements of several antennas designed using these new rules are presented and directions for further study are discussed.

Analysis and design of broad-band single-layer rectangular U-slot microstrip patch antennas

Basic principles for ultra-wide-band (UWB) radiation are presented and discussed in this paper. The discussion starts with a description of the influence of antennas on UWB transmission. The parameters characterizing antennas in time and in frequency domain are specified. Since the number of possible antenna structures is nearly unlimited, the focus will be on a classification according to different radiation principles. For each of these mechanisms, the typical advan- tages and disadvantages are discussed, and an example antenna and its characteristics are presented. For a wireless engineer, the problem to solve is the proper design of an antenna with the desired radiation characteristics. The final outcome of this paper is that there exist numbers of UWB antennas, but not each of them is suited for any application, especially in view of radar and communication systems requirements.

http://ieeexplore.ieee.org/iel5/5/4802183/04802200.pdf

Basic Properties and Design Principles of UWB Antennas Selection of suitable antennas from the many existing types, based on understanding their characteristics, is essential for effective ultrawide-band system design.

A polarization reconfigurable E-shaped patch antenna with wideband performance is proposed in this communication. The antenna is capable of switching its polarization from right hand circular polarization (RHCP) to left hand circular polarization (LHCP) and vice versa. Its structure is simple and consists of a single-layer single-feed E-shaped patch and two RF switches placed at appropriate locations in the slots. The design targets the WLAN IEEE 802.11 b/g frequency band (2.4-2.5 GHz) being used in various wireless communication systems. Full wave simulation is used for the antenna analysis, and a prototype of the antenna with an integrated DC biasing circuit has been fabricated and tested. Good agreement is obtained between simulated and measured results. The antenna exhibits a 7% effective bandwidth from 2.4 GHz to 2.57 GHz with a 8.7 dBic maximum gain. The antenna radiation symmetry is maintained upon switching between the two circular polarization modes.

Circular Polarization Reconfigurable Wideband E-Shaped Patch Antenna for Wireless Applications

The goal of the paper is to improve the log-periodic dipole antenna (LPDA) design procedure introduced by Carrel (1961). A computer-aided design technique is introduced, providing an easy-to-use design method of LPDAs. Corrections to Carrel's design contours, and new constant input resistance and truncation coefficients diagrams are presented. The influence of the feeder characteristic impedance, and dipole length-to-diameter ratio on LPDA parameters is studied. Design diagrams for LPDA's typical of HF communications are included.<
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Design of log-periodic dipole antennas

Design, fabrication, and test of a novel single-band wearable antenna with dual-mode operation (on-body and off-body) for body area network's applications in the 2.45 GHz industrial scientific and medical band are presented. The on-body mode is achieved with a microstrip ring while the off-body mode is obtained with a compact meandered microstrip patch placed inside the ring. The two antennas are fed separately but share a common ground plane and use only fabric materials facilitating the integration into the user's clothes. The antenna operation is characterized when placed on a phantom mimicking a human torso. Input match, mutual coupling, radiation pattern, radiation efficiency, and path loss measurements are presented and show good agreement with simulations.

A Dual-Mode Single-Band Wearable Microstrip Antenna for Body Area Networks

This paper presents a new procedure for the miniaturization of rectangular microstrip patches based on genetic algorithms. The shape of a typical rectangular patch is modified in order to reduce its resonance frequency keeping the physical volume of the antenna constant. As an example, the resonance frequency of a square microstrip patch is reduced from 3 to 1.8 GHz. The patch is divided in 9/spl times/9 square cells. The genetic algorithm optimization procedure is subsequently used to remove some of the metallic cells. To validate the procedure an antenna prototype has been fabricated and tested. Good agreement is obtained between theoretical and experimental results.

Miniaturization of rectangular microstrip patches using genetic algorithms

A simple right-angle transition between a rectangular waveguide (RWG) and a substrate integrated waveguide (SIW) is proposed. Two slots etched on the broad wall of the SIW are used to couple the waveguides. To obtain a wide bandwidth of operation the slots have different lengths to create a double resonance behaviour. The proposed component has a simple mechanical configuration with the flange of the standard RWG flush-mounted to the substrate of the SIW. A sample transition is designed to work in the lower part of the Ka-band. The experimental results agree well with numerical predictions. The proposed component has 6.6% bandwidth and insertion loss below 0.5 dB.

Broadband Ka-band rectangular waveguide to substrate integrated waveguide transition

In this paper, two THz reflectarray surfaces have been designed and fabricated in order to deflect a plane wave with any polarization and with a specific incident angle to three different specific directions each at distinct three frequencies of 0.7, 1.0 and 1.5 THz. The surface is composed of an array of 100 $\times$ 100 cells, each comprised of gold crosses and parasitic dipoles printed on thin grounded high resistivity silicon. Finite-element method (FEM) simulations are in line with the measurement results obtained using THz time-domain spectroscopy (THz TDS) showing the intended deflections for the two fabricated samples each with an arbitrary frequency-vs-deflection angle relationship. In addition, the use of silicon as the substrate paves the way for the integration of reconfigurable technologies which enhances the reflectarray versatility.

Custodio Peixeiro

Papers

Design of log-periodic dipole antennas

A Dual-Mode Single-Band Wearable Microstrip Antenna for Body Area Networks

Miniaturization of rectangular microstrip patches using genetic algorithms

Broadband Ka-band rectangular waveguide to substrate integrated waveguide transition

Tri-Band, Polarization-Independent Reflectarray at Terahertz Frequencies: Design, Fabrication, and Measurement