Arslan Kiyani

A compact microstrip patch antenna with circular snipped slot for GSM, Wi-Fi and WiMAX applications

A rectangular microstrip patch antenna with probe feed is proposed in this paper. The patch of an antenna has a key circular slot which is auxiliary truncated in circular style resulting three narrow bands of the most worthy and in-use wireless technologies of the modern age, that are GSM, Wi-Fi and WiMAX. The resonating bandwidths of the presented antenna ranges from 1.79 to 1.83 GHz for GSM 1800, 2.40 to 2.48 GHz for Wi-Fi and from 3.32 to 3.42 GHz used for WiMAX. The design process has been carried out in HFSS (High Frequency Structure Simulator) and antenna is fabricated manually, to assess and evaluate the real characteristics.

Power optimization of Pseudo Noise based optical transmitter using LVCMOS IO standard

In electronic devices when operating frequency is exceeded from its resonant frequency the power of the device increases drastically. Due to this, device reaches in dead zone and will not function anymore. In this work, power optimization is performed for Pseudo Noise sequence based optical transmitter. The PN generator for optical transmitter is designed using linear shift registered generator method. Furthermore, energy efficient design for the PN generator is also proposed using low voltage complementary metal oxide semiconductor (LVCMOS) IO standard available on FPGA virtex-6 board. The PN generator is operated at different frequencies such as 100 MHz, 1 GHz, 10 GHz and 100 GHz and at different LVCMOS IO standard such as LVCMOS 12, 18, 15 and 25. The power reduction is achieved for frequencies using standards available on FPGA. Finally, power optimization is recorded for target device at 100 MHz 97.7%, for 1 GHz 98%, for 10 GHz 95% and for 100 GHz 95% using LVCMOS 12 in comparison with LVCMOS 25. This energy efficient PN generator can be integrated with other optical components to develop green optical communication system. Experiment is performed via Xilinx ISE14.7 design tool and FPGA vertex-6 board.

Investigation of reflection area on strategic reflectarray resonant elements

Selection of strategic resonant elements plays an effective role in enhancing the reflectivity performance of reflectarrays. This paper presents a systematic analysis of various potential reflectarray resonant elements for operation at X-band (8-12GHz) frequency range. The considerations mainly focus on the exploitation of reflection area for an accurate characterization of reflection loss and reflection phase performance. Furthermore, two patch unit cells have been fabricated for each configuration by mounting on the top of the Rogers RT/Duroid 5870 dielectric substrate. The scattering parameter measurements of the fabricated unit cells have also been carried out using vector network analyzer based on waveguide simulator technique. Measured results demonstrated that reduction in reflection area of resonant elements from 105.74mm2 to 7.33mm2 tends to increase the reflection loss values from 2.63dB to 20.25dB. Moreover the reduction in phase errors offering an increased measured static phase range of 290° is also shown by employing triangular loop element.

A planar feeding technique for wideband, low-profile resonant cavity antennas

A low profile, wideband resonant cavity antenna (RCA) is presented. It uses a simple and planar wideband feed antenna. The use of this planar, printed feed antenna reduces the overall height of the RCA. The RCA has a single-layer superstrate, which has radially non-uniform permittivity in the transverse plane. Excellent wideband matching was obtained for the RCA with a -10dB return loss bandwidth ranging from 20.81 to 25.32 GHz. Numerical results predict a peak boresight gain of 16.97 dBi. This RCA is well-suited for scalable RCA configurations such as sparse arrays or switched-polarization arrays with printed feed networks.

MIMO antenna array for wireless local area networks

A MIMO antenna array has been presented in this paper, which has four rectangular microstrip patches as an antenna element(s). An elliptical slot is etched on every radiating patch. The antenna array is simulated in HFSS yielding resonating frequencies of 2.42, 3.49 and 4.98 GHz at S11 <; -10 dB making it applicable for WLANs. RT Duroid 5880 has been used as substrate. The gain ranges from 7 to 11 dB at all resonant frequencies with narrow bandwidth, improving interference rejection characteristics of the proposed antenna. Complete design procedure, comprehensive analysis of mutual coupling among the patches and radiation patterns are also discussed.

Numerical model for phase distribution characterization of reflectarray elements

A mathematical model to obtain a linear progressive phase distribution of six different high performance reflectarray resonant elements in order to realize a planar wave in front of the periodic aperture is formulated in this paper. All the resonant elements under characterization are tuned to operate at X-band frequency range using commercially available CST computer model. The reflection phase curves for each resonant element are then calculated by using analytical equations based on a periodic Method of Moments (MoM). A Figure of Merit (FoM) has been defined for the comparison of reflection phase curves obtained by both simulation and formulation in terms of bandwidth and static phase range performance. It has been demonstrated that among the entire resonant elements triangular loop acquire steepest phase characteristics gradient offering higher static phase range of 190° with minimum bandwidth, whereas rectangular patch element is shown to exhibit smoother phase characteristics gradient giving lower static phase range of 120° with broader bandwidth performance. Furthermore it has been observed that triangular loop depicts the maximum reflection loss of 3.90dB, whereas rectangular patch shows the minimum reflection loss of 0.23dB.

Dense, planar arrays of compact Resonant Cavity Antennas

Compact, wideband, high-gain Resonant Cavity Antennas Arrays (RCAAs) are investigated. The aim is to evaluate their potential meeting ETSI Class-2 antenna specifications for the fixed Point-to-Point communication links. Array performance is characterized in terms of peak directivity and 3dB directivity bandwidth. A radial array (having 91 elements) is shown to achieve the peak directivity of 37 dBi with a 3dB directivity bandwidth greater than 20%. When compared with conventional microstrip patch arrays, this demonstrates a significant reduction in the number of elements required in the array, largely reducing the complexity of the feed network. The feed simplicity and planar configuration of RCA arrays makes them attractive for wireless backhauls and other fixed point-to-point wireless communication systems.