A Miniaturized Patch Antenna Designed and Manufactured Using Slot's Technique for RFID UHF Mobile Applications

In this research work, a novel compact antenna with rectangular slots is presented for radio frequency identification (RFID) handled applications in the ultrahigh frequency (UHF) band that can be manufactured and integrated into RFID readers without difficult. A prototype demonstrating the aforementioned features was constructed and measured. The proposed antenna is fed by 50-Ω coaxial cable and printed on a 1.6mm thick FR4 substrate which has a small size and occupies a volume of 68×66 ×1.6mm3. The patch, the feed-line and ground plane are made of PEC (Perfect Electric Conductor) with a thickness of 0.035 mm. Measured results indicate that the proposed antenna has a good impedance matching characteristic ranging from 889 to 939MHz, which covers the USA RFID-band (902–928MHz), the Chinese RFID-operating-band (920–924.5MHz), and the Korea and Japan RFID-band (917–923.5MHz). These results were achieved by the insertion of slots in the compact structure of the antenna. The electromagnetic simulators HFSS (High Frequency structure simulator) and CST (Computer Simulation Technology) microwave studio were used for the design, modeling and simulation of the antenna. The focus of the study of our antenna was on the parameters of return loss, bandwidth, Voltage Standing Wave Ratio (VSWR), input impedance and gain

Conception d'antennes spirales rectangulaires pour TAG RFID UHF

La radio-identification, le plus souvent désignée par le sigle RFID (de l’anglais radio frequency identification), est une méthode pour mémoriser et récupérer des données à distance en utilisant des marqueurs appelés « radio-étiquettes » (« RFID tag » ou « RFID transponder » en anglais). Cette technologie d’identification peut être utilisée pour identifier les objets, les personnes et les carnivores domestiques. Dans cet article, nous nous intéressons à la conception d’antennes de tags RFID UHF passifs. Nous présentons d'abord le modèle rigoureux, basé sur la théorie de la diffraction par les fils fin. Modèle qui aboutit à une équation intégro-différentielle. La résolution de cette équation se fait par la méthode des moments. Bien que cette méthode soit en très bon accord avec la mesure, elle reste gourmande en temps de calcul et par conséquent ne permet pas d’estimer les paramètres des antennes des TAGs réelles présentant des géométries complexes. Pour cela, nous proposons une approche analytique, permettant de simplifier le calcul des paramètres des antennes spirales pour étiquette RFID sans avoir recours aux méthodes numériques rigoureuses. La validation expérimentale de ces modèles théoriques est réalisée au moyen d’un analyseur de réseaux. La confrontation théorie-expérience nous permet de tirer quelques conclusions intéressantes quant au nombre de boucles de la spirale et au choix du substrat diélectrique

Microwave Imaging Approach for Breast Cancer Detection Using a Tapered Slot Antenna Loaded with Parasitic Components

In this paper, a wideband antenna is proposed for ultra-wideband microwave imaging applications. The antenna is comprised of a tapered slot ground, a rectangular slotted patch and four star-shaped parasitic components. The added slotted patch is shown to be effective in improving the bandwidth and gain. The proposed antenna system provides a realized gain of 6 dBi, an efficiency of around 80% on the radiation bandwidth, and a wide impedance bandwidth (S11 < −10 dB) of 6.3 GHz (from 3.8 to 10.1 GHz). This supports a true wideband operation. Furthermore, the fidelity factor for face-to-face (FtF) direction is 91.6%, and for side by side (SbS) is 91.2%. This proves the excellent directionality and less signal distortion of the designed antenna. These high figures establish the potential use of the proposed antenna for imaging. A heterogeneous breast phantom with dielectric characteristics identical to actual breast tissue with the presence of tumors was constructed for experimental validation. An antenna array of the proposed antenna element was situated over an artificial breast to collect reflected and transmitted waves for tumor characterization. Finally, an imaging algorithm was used to process the retrieved data to recreate the image in order to detect the undesirable tumor object inside the breast phantom

Microwave Imaging Approach for Breast Cancer Detection Using a Tapered Slot Antenna Loaded with Parasitic Components

In this paper, a wideband antenna is proposed for ultra-wideband microwave imaging applications. The antenna is comprised of a tapered slot ground, a rectangular slotted patch and four star-shaped parasitic components. The added slotted patch is shown to be effective in improving the bandwidth and gain. The proposed antenna system provides a realized gain of 6 dBi, an efficiency of around 80% on the radiation bandwidth, and a wide impedance bandwidth (S11 < −10 dB) of 6.3 GHz (from 3.8 to 10.1 GHz). This supports a true wideband operation. Furthermore, the fidelity factor for face-to-face (FtF) direction is 91.6%, and for side by side (SbS) is 91.2%. This proves the excellent directionality and less signal distortion of the designed antenna. These high figures establish the potential use of the proposed antenna for imaging. A heterogeneous breast phantom with dielectric characteristics identical to actual breast tissue with the presence of tumors was constructed for experimental validation. An antenna array of the proposed antenna element was situated over an artificial breast to collect reflected and transmitted waves for tumor characterization. Finally, an imaging algorithm was used to process the retrieved data to recreate the image in order to detect the undesirable tumor object inside the breast phantom