Binu Paul

CPW-Fed UWB Compact Antenna for Multiband Applications

A planar UWB antenna with added GSM 1800/WMTS and UMTS bands is presented. A CPW-fed circular patch is used to obtain wideband characteristic covering the UWB range. A novel slot formed by merging the alternate sides of a hexagon with isosceles triangles is inserted in the patch to obtain dual-band operation with the lower band suitable for GSM 1800 operation. By inserting a bent monopole in the space created by the slot, a triple-band antenna is developed with two lower bands suitable for WMTS and UMTS operation. The antenna prototype is fabricated and tested. Simulated and experimental results are in good agreement. The antenna exhibits stable radiation characteristics and nearly constant group delay in the UWB range.

Design of a Compact Multiband Microstrip Antenna

A compact microstrip multiband antenna on a modified ground plane which can operate over the bands starting from 900 MHz to 5.35 GHz which includes the GSM (880-960) GPS (1568-1592 MHz), DCS (1710-1880 MHz), and PCS (1850- 1990 MHz). UMTS (1920-2170 MHz), IEEE 802.11 b/g (2400- 2484) and WLAN IEEE 802.11a band (5.15-5.35) is reported in this paper. The overall dimension of the antenna is 33 x 33 mm 2 including the top patch with a dimension 22 x 22 mm 2 . The experimental results of the antenna are presented in this paper. The results confirm that the antenna exhibits wide band characteristics and covers 7 bands of operation.

Metamaterial Inspired CPW Fed Compact Low-Pass Filter

A metamaterial inspired co-planar waveguide (CPW) fed compact low-pass filter is presented in this paper. The 3 dB cutoff frequency of the filter is 1.4 GHz. The roll-off rate achieved for this filter is 47.4 dB/GHz. Sharp roll-off is obtained by introducing an additional resonance using an inductor in series with the shunt capacitor. The usage of chip inductor also results in a compact filter structure. The overall filter dimensions are 39 mm × 32 mm × 1.6 mm. The filter uses defected ground structure (DGS) for attaining stop band attenuation. The measured insertion loss of the filter in the pass band is less than 0.8 dB and average stop band attenuation is better than 23 dB. The equivalent circuit of the proposed filter is similar to that of a dual-CRLH (D-CRLH) transmission line.

Hand written digit recognition system for South Indian languages using artificial neural networks

In this paper a novel approach for recognition of handwritten digits for South Indian languages using artificial neural networks (ANN) and Histogram of Oriented Gradients (HOG) features is presented. The images of documents containing the hand written digits are optically scanned and are segmented into individual images of isolated digits. HOG features are then extracted from these images and applied to the ANN for recognition. The system recognises the digits with an overall accuracy of 83.4%.

CPW-fed fractal antenna with improved UWB response

This paper presents a CPW-fed dual band antenna for improved UWB response. A slotted circular monopole is used to attain dual band operation suitable for GSM 1800 and UWB applications. A fractal pattern is introduced in the design to improve matching in the UWB range. The antenna has an overall size of 34 × 51mm2 and operates in the 1.5-2 GHz and 3.4-11 GHz frequency bands (S11≤-10dB). The measured characteristics of the prototype antenna are in good agreement with the simulation.

GA optimized SRR calculator

Negative magnetic permeability media (NMPM) can be built up by using small resonant metallic particles like Split ring resonator (SRR) which has very high magnetic polarisability. A group of these particles shows a negative permeability region near and above the resonant frequency. The continuous medium parameters describing the SRR array can be predicted from their individual electromagnetic behavior near the resonances. The paper presents an optimizing software using Genetic Algorithm (GA) to design an edge coupled two ring SRR for a particular frequency.

Design of a compact genetic microstrip antenna with improved performance

In this paper the design issues of compact genetic microstrip antennas for mobile applications has been investigated. The antennas designed using genetic algorithms (GA) have an arbitrary shape and occupies less area (compact) compared to the traditionally designed antenna for the same frequency but with poor performance. An attempt has been made to improve the performance of the genetic microstrip antenna by optimizing the ground plane (GP) to have a fish bone like structure. The genetic antenna with the GP optimized is even better compared to the traditional and the genetic antenna.

Conformal FDTD analysis of an Octagonal Microstrip Patch antenna

The conformal FDTD analysis of the dual band dual polarized octagonal patch antenna is presented. During the study it is observed that selection of feed length feed offset from the geometric centre of the patch causes only slight variations in the characteristics. The antenna exhibits gain comparable to that of standard circular patch and is highly suitable for GSM and Bluetooth applications.

FPGA implementation of one-dimensional reduced mapped real transform-based digital beamformer

ABSTRACT The paper presents the field-programmable gate array implementation of a digital beamformer. This beamformer is based on one-dimensional reduced mapped real transform. The computational complexity and computational time of conventional beamformers is reduced with the application of one-dimensional reduced mapped real transform. The digital beamformer model is created using Xilinx system generator, and its hardware implementation is performed on Spartan 3A FPGA using an Altium NB3000 board.

Time-Domain Characterization of Dual Band Spiral Antenna with WMTS/UWB Application

A coplanar waveguide- (CPW-) fed spiral antenna with dual band application is presented. The antenna is designed to operate over the UWB (3.1–10.6 GHz) band as well as in a lower band suitable for WMTS (1.395–1.4 GHz). Frequency domain characterization shows that the antenna is well matched with appreciable gain in both bands. Time-domain studies are carried out to check the suitability of the antenna in pulsed communication. A prototype of the antenna is fabricated and measured results show low group delay variation in the UWB. FWHM and ringing of antenna impulse response, fidelity factor, and radiated power spectral density are also presented.