Farooq Sultan

An 8-Element Printed V-Shaped Circular Antenna Array for Power-Based Vehicular Localization

The design of an eight-element array of V-shaped circular printed antennas for vehicular localization is presented. The proposed antenna operates in the 2.5-GHz band with a measured bandwidth (BW) of approximately 240 MHz. The simulation results and the field measurements of a fabricated array show a high degree of correlation. For a thorough understanding of the antenna operation, parametric sweeps are conducted to investigate the effect of the various antenna parameters on its resonance frequency and operating BW. The effect of mounting the antenna array on the rooftops of vehicles is investigated, specifically its effect on the half-power beamwidth (HPBW) and maximum gain. These results are based on measurements conducted at an outdoor antenna range facility.

Beam Scanning Properties of a Ferrite Loaded Microstrip Patch Antenna

Axially magnetized ferrite loaded microstrip patch antenna (MPA) with tunable beam scanning properties is presented. Ferrite cylinders are optimally positioned within the near field region of the patch to introduce phase tapers needed for beam scanning. The interaction between the radiated EM wave and the gyrotropic properties of ferrites is controlled by varying the magnetizing fields. A beam scan of ° is achieved for a DC biasing range of 0–0.19 T. Simulated antenna properties are verified using experimental results. Recent LTCC technology allows the biasing coils to be embedded within the ferrite material to considerably reduce the required external magnetizing field.

Beam scannable microstrip patch antenna

A novel beam scanning technique of a ferrite loaded microstrip patch antenna is presented. Beam scanning is produced from controlled interaction of the radiated fields and the gyromagentic properties of the axially magnetized ferrite rods. By varying the magnetizing fields of the ferrite rods, optimally placed in the near field region of the antenna, necessary phase taper of the radiated E-field distribution is achieved. The designed 10 GHz antenna demonstrated an impedance bandwidth of 700 MHz and ±30° of beam scan for a changing magnetizing field of 170 kA/m. Employing embedded biasing coils through LTCC technology, the required biasing fields needed to achieve beam scan can be considerably reduced.

Superstrate-Based Beam Scanning of a Fabry–Perot Cavity Antenna

Incorporating phased array technique to scan the main beam of a Fabry-Perot cavity (FPC) antenna produces sidelobes proportional to the scan angle. An alternative dielectric-ferrite superstrate-based scan mechanism with controlled sidelobe level is presented in this letter. A beam scan of 24 ° is demonstrated by axially magnetizing the ferrite part of the superstrate with ΔH = 0.25 T. Stepped dielectric part of the superstrate is optimized to reduce the sidelobe level of the FPC antenna by 4.49 dB. The fabricated antenna is tested to verify the simulated radiation patterns and reflection responses. The requirement of magnetic biasing can be considerably reduced using LTCC technology, where biasing coils are embedded within the ferrite superstrate.

A comparative performance analysis of SRR embedded ferrite superstrate patch antennas

A unique single rectangular patch antenna, working at 10 GHz, with a split ring resonator (SRR) embedded ferrite superstrate has been presented in this paper. DC biasing of the ferrite superstrate results in a change in the main beam of the antenna structure. Two different configurations of the SRR design have been simulated and beam scans of ±12° and ±17° have been observed when the ferrite rods had been biased. A comparison with the beam scan characteristics of the no SRR case show a significant decrease (87.5%) in the antenna thickness and similar beam scans at comparatively much lower DC biasing values. The presented antennas show a slightly less directivity because of the signal losses encountered due to the biased ferrite; this can be improved by using modified superstrate layers.

A novel printed circular antenna array based on V-shaped elements

A printed circular antenna array based on a V-shaped antenna element is designed and fabricated. The antenna array consisted of 8 elements, had a radius of 100 mm and was fabricated on a 0.8 mm FR-4 substrate. The array operated in the 2.5 GHz band with an approximate bandwidth of 150 MHz. A parametric sweep on the V-shaped antenna parameters was performed to understand the effect of each on the antenna resonance frequency and operating bandwidth. The array is to be used in direction finding applications. Good Correlation was obtained between simulated and measured results.

A Comparative Performance Analysis of Two Printed Circular Arrays for Power-Based Vehicle Localization Applications

A comparative study of the performance characteristics of a printed 8-element V-shaped circular antenna array and an 8-element Yagi circular array operating at 2.45 GHz for vehicular direction finding applications is presented. Two operating modes are investigated; switched and phased modes. The arrays were fabricated on FR-4 substrates with 0.8 mm thickness. Measured and simulated results were compared. Radiation gain patterns were measured on a 1 m diameter ground plane that resembles the rooftop of a vehicle. The HPBW of the Yagi was found to be about 3° narrower than its V-shaped counterpart when measured above a reflecting ground plane and operated in switched mode. The printed V-shaped antenna array offers 2.5 dB extra gain compared to the printed Yagi array.

Design of a reduced size 7-patch antenna array with FSS based directivity enhancement

Technological development has driven electronic component design into the miniature world resulting in surprisingly small yet shockingly powerful devices. In an attempt to decrease the size of handheld wireless communication devices, it is necessary to design the smallest possible antenna structures that fulfill the communication needs. In this paper we present the design and analysis of a 7-patch antenna array operating at 10 GHz with shorting posts that tend to decrease the size by more than 50% as compared to the original. In addition we have succeeded in getting a directivity boost of 3 dB by using Fabry-Perot (FP) cavity utilizing frequency selective surfaces (FSS). Design and analysis of the antenna array as well as the FSS layer is presented in this work. Simulation results clearly indicate the advantages of this design in terms of smaller size and higher directivity.

Design and energy consumption analysis of a custom built wireless sensor node for environmental monitoring.

Wireless sensor networks (WSN) have become increasingly important in recent times. Sensor nodes are the building blocks for a typical WSN. Due to their limited computational, communication and energy abilities, the sensor nodes serve as the deciding factor for a given network design. As the fabrication technology improves, highly powerful, yet energy efficient, components are available to realize a WSN while keeping the cost at an affordable level. This paper introduces a novel wireless sensor node based on the powerful 8-bit Atmel ATMega128L microcontroller unit (MCU) equipped with the CC2420 transceiver having complete compatibility with the IEEE802.15.4. This paper enlightens the design details of the new node; providing complete details of the components used and the sensor unit design. Towards the end, the power consumption measurement results are given along with the experimental setup details.