Najiba El Amrani El Idrissi

Cylindrical dielectric resonator antenna for multiband communication systems

This paper presents a Dielectric Resonator Antenna for multiband operations. The cylindrical shape is designed and fed through a microstrip feed line technique. The proposed design allows the antenna to operate at multiple frequencies in the range of 1.8-8 GHz. It is demonstrated through simulation that the Return Loss values occurred at 2.91 GHz, 4.39 GHz, 5.85 GHz and 7.3 GHz, respectively, having VSWR ≤ 2. It is also observed that the gain of proposed design is higher than the conventional patch antenna.

Design and simulation of an optimized slotted patch antenna for RFID reader applications

In this work, new form of patch antenna for RFID reader applications in the microwave band has been proposed. The patch is a perfect electrical conductor, excited by a 50 ohms microstrip line, set on an Epoxy FR-4 substrate. The first results were obtained on a basic structure of a rectangular patch antenna adapted with notches. These results have been improved by introducing slots in the basic structure. The structure design, optimization and simulation results analysis were performed under electromagnetic simulators HFSS and CST, and focused on the return loss, bandwidth, gain and directivity.

Comparative Analysis of Different Excitation Techniques for Cylindrical Dielectric Resonator Antenna

Direct Microstrip line, Microstrip slot-coupled feed and hybrid coupler techniques are investigated for Cylindrical Dielectric Resonator Antenna (CDRA). The Dielectric resonator has a dielectric constant of 30, and etched on Arlan dielectric substrate having a relative permittivity of 3.58 and dimensions of 150 × 150 mm2. The structures are numerically analyzed using the numerical software HFSS. Radiation characteristics including return loss, gain, directivity and VSWR versus frequency characteristic are presented and compared based on the excitation method employed for the studied CDRA. The simulation results proved that the 90° hybrid coupler provides good performances particularly: a wider impedance bandwidth of 1.15 GHz and a maximum coupling of −45 dB.

MPA radiation characteristics evolution through a DGS size reduction study

The use of a partial ground plane in the MPA structure can contribute to improving its frequency behavior, and avoid adaptation problems and the bandwidth narrowing, that is why DGS structures are widely used in wireless communication systems based on micro-strip technology, which requires high performances. In this regards, a parametric study of the impact of the ground plane size-reduction on the radiation characteristics of an elementary MPA adapted with notches, has been made in this work. Simulation results were carried out under the electromagnetic simulator HFSS. To show that the impact of a DGS is independent of the radiating element shape, horizontal and vertical slots were inserted separately in the radiating element of the elementary antenna; the same study was conducted on the two resulting antennas. Then, a comparative study of the radiation characteristics evolution of the three antennas has been conducted.

Bandwidth enhancement of rectangular dielectric resonator antenna for UMTS application

A novel wideband rectangular dielectric resonator antenna (RDRA) is proposed in this paper. An equivalent air-dielectric DRs blocs are introduced inside the resonator to enhance the structures bandwidth. The hybrid structure is excited by a simple Microstrip feed line, adapted with a stub at the end of the line. The resonant modes of the isolated DR and the air-dielectric DRs, are merged together to form a wideband impedance bandwidth. Through this paper, it is demonstrated that the bandwidth of a simple rectangular DR antenna can be greatly enhanced by air-dielectric DRs. A detailed parametric study is carried out to analyze the characteristics of the proposed antenna. Simulation results show that the proposed RDRA has a 10 dB impedance bandwidth of 365 MHz, from 1.78GHz to 2.15GHz and the radiation pattern is quasi-stable over the operating range of frequencies.

Design & Simulation of Rectangular Dielectric Resonator Antenna for UMTS Application

This paper represents a design and simulation of Rectangular Dielectric Resonator Antenna (RDRA) for base stations operating in the UMTS (Universal Mobile Telecommunications System). The Dielectric resonator is planned to be used as a radiating element, fed by a 50 Ω Microstrip transmission line technique at frequency around 2 GHz. The return loss, input impedance, VSWR and radiation patterns are studied. The simulation results were performed using two numerical methods. The conception was realized using finite integration method (CST microwave studio) and verified by finite element method (HFSS: Ansoft high frequency structure simulator).