Gh. Z. Rafi

Low-Profile Integrated Microstrip Antenna for GPS-DSRC Application

This letter describes the concept, design, and measurement of a low-profile integrated microstrip antenna for dual-band applications. The antenna operates at both the GPS L1 frequency of 1.575 GHz with circular polarization and 5.88 GHz with a vertical linear polarization for dedicated short-range communication (DSRC) application. The antenna is low profile and meets stringent requirements on pattern/polarization performance in both bands. The design procedure is discussed, and full measured data are presented.

The effects of substrate and ground plane size on the performance of finite rectangular microstrip antennas

The effects of substrate and ground plane size on the performance of finite rectangular microstrip antennas are studied. It is shown that the resonant frequency, input resistance at resonance and directivity of the microstrip antenna change periodically by increasing the length of the ground plane. A comparison of their numerical results is presented.

Broad-band U-slot rectangular patch antenna on a microwave substrate using a novel feeding technique

A broad-band U-slotted rectangular patch antenna printed on a microwave substrate is investigated. The dielectric constant of the substrate is 2.2. The antenna is fed through via-hole connecting between patch antenna and feeding line at a lower microwave substrate with dielectric constant equal to 3. The characteristics of the U-slotted patch antenna are analyzed by the method of moments (MoM). The results show maximum impedance bandwidth of more than 20% of centered frequency around 17.25 GHz, with good pattern characteristics.

An overhead V-shape printed dipole array antenna for toll plaza application

Electronic toll collection, as a major area of application of Intelligent Transportation System (ITS) concepts, requires an intelligent radio network, which, in addition to reliable communication between fast moving vehicles and fixed access points, can identify and locate each vehicle in a multi-lane free-flow busy highway and track it during its fast passage through the interrogation region. Current toll and traffic monitoring systems in North America utilize multiple antennas per lane, installed on a gantry, to cover multiple road lanes. Currently, to meet the coverage requirements and to prevent interference a number of fixed antennas with different types of pattern are used in various configurations.

Broad-band phased antenna array based on U-slot microstrip patch antenna element

The paper introduces the complete design of 1/spl times/2, 1/spl times/4 and 1/spl times/8 phased antenna arrays, including feeding and matching networks, using a U-slotted microstrip patch antenna as an array element with a novel patch feeding technique at the frequency band of 16 GHz to 18 GHz. Gain of about 9 dBi is achieved for the 1/spl times/2 array, about 12 dBi for the 1/spl times/4 array and above 14 dBi for the 1/spl times/8 array, with good impedance matching parameters.

Lane position determination techniques for an Electronic Toll Collection system

In this paper various concepts for determining the probable lane position of a vehicle mount Automatic Vehicle Identification (AVI) transponder are presented and compared for Electronic Toll Collection (ETC). In particular, various configurations of roadside mount antennas and transceivers are presented. As a practical example, the system design methodology for a fixed beamwidth Toll Plaza AVI antenna capable of supporting a range of mounting heights is discussed in detail.

Comparison of PBG and perfect magnetic conductor surface effects on the performance of finite micros

Calculated near and far fields of finite rectangular microstrip antennas with and without photonic band-gap (PBG) and perfect magnetic conductor (PMC) surfaces are presented and compared. It is shown that a PMC surface is a model for an ideal PBG surface. Also, it is shown that a microstrip antenna with PBG surface has a larger directivity and lower side and back lobe levels. Using a PMC surface, additional increase in directivity and decrease in back and side radiation levels are obtained. HFSS is used in the calculations.

Silicon image guide (SIG) coupled resonators antenna for millimeter-wave/THz applications

Recently dielectric antennas have gained a huge interest in millimeter-wave (mmWave) and THz range of frequencies for a wide range of applications such as wireless communication, imaging, and radioastronomy. The most common type of dielectric antenna is the tapered antenna, which is inherently long and radiates in the endfire direction. To realize a down-sized antenna for radiating in a tilted angle, the idea of dielectric resonator in the configuration of dielectric waveguide antennas can be utilized.

Broad-band V-slot patch antenna at Ku-band with a novel feeding technique

A broad-band V-slotted rectangular microstrip patch antenna printed on a microwave substrate with dielectric constant of 2.2 is investigated at the Ku frequency-band from 14GHz to 19GHz. A novel feeding and matching technique to the V-slotted patch antenna using via-hole and λ/4 transformer show broad-band impedance bandwidth of 30% of centered frequency. The dimensions of the V-slotted patch antenna are optimized to have a small area. Method of Moment (MoM) is used during the analysis. The results show good pattern characteristics with gain of about 6dBi and efficiency of 80% at center frequency.

The effects of conductor and dielectric back planes on the performance of finite rectangular microstrip antennas

The effects of flat conductor and dielectric back planes on the performance of a finite rectangular microstrip antenna are studied. It is shown that both back plane types have similar effects on the near and far fields of the microstrip antennas. HFSS software has been utilized for the analysis.The effects of flat conductor and dielectric back planes on the performance of a finite rectangular microstrip antenna are studied. It is shown that both back plane types have similar effects on the near and far fields of the microstrip antenna. Also, it is shown that the resonant frequency, input resistance at resonance and directivity of the microstrip antenna change periodically by increasing the length of the back plane. HFSS and ENSEMBLE have been utilized for the analysis. A comparison of their numerical results is presented.