Showing papers by "Jayanta Mukherjee published in 2010"

Effect of superstrate material on a high-gain antenna using array of parasitic patches

Abstract: This article highlights the effect of superstrate material on a high-gain antenna using array of parasitic patches for wireless applications. The antenna structure consists of a microstrip antenna, which feeds an array of square parasitic patches fabricated on a ceramic or FR4 superstrate. The patches on a superstrate are suspended in air at λ0/2. The spacing between parasitic patches and patch dimensions decrease with dielectric constant and, thus, a compact antenna with almost same gain can be designed with high dielectric superstrate. The structures with 5 × 5 array of square parasitic patches provide a gain of 17.5 dB on infinite ground plane in both the cases but the array dimension is 55 × 55 mm2 in ceramic as compared to 115 × 115 mm2 Antenna with ceramic superstrate on finite ground requires 25% less ground plane size as compared to FR4. Structure with FR4 superstrate is designed, fabricated, and tested. The measured VSWR is <2 over 5.725–5.875 GHz frequency band. The antenna with 5 × 5 array of square parasitic patches provides a gain of 18.0 dB with 92% efficiency, SLL of −18.4 dB, and front to back lobe ratio of more than 20 dB. The proposed structure can be packaged inside an application platform. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 82–88, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24850

Effect of substrate material on radiation characteristics of an UWB antenna

Abstract: This article highlights the effect of substrate material on radiation characteristics of an ultra wideband antenna. Printed monopole antennas fabricated on a substrate offer impedance band width which can cover UWB. However radiation pattern varies significantly over the bandwidth. The cross polar component increases with frequency and the pattern degrades from the desired omnidirectional characteristics. Structures are designed using different substrate thickness of different materials and radiation characteristics are compared. Omnidirectional radiation bandwidth can be increased significantly by decreasing the substrate thickness and using substrate material of low dielectric constant. Structure with foam substrate is designed, fabricated and tested. The measured VSWR is < 2 over 3.1–10.6 GHz frequency band. The antenna offers high efficiency and its radiation patterns indicate the suitability of this antenna for UWB applications.

Designing Asymmetric 2.4 GHz RF Oscillator for improving Signal Integrity by Design of Experiments

Abstract: Designing of an Asymmetric RF Oscillator for improved Signal Integrity, using Design of Experiments is presented and Taguchi Orthogonal Array is used for the same. Dependence of various physical parameters on output quality parameters that are Eye Height and Jitter, are shown by curves. Jitter is reduced and Eye Height is increased and as outcome of both, Eye SNR is increased. All in all, Designing of an Asymmetric Oscillator for better Signal Integrity is shown using Design of Experiments.

Designing Asymmetric 2.2 GHz RF Oscillator by design of experiments using Taguchi methods

Abstract: Designing of an Asymmetric RF Oscillator using Design of Experiments is presented and Taguchi Orthogonal Array is used for the same. Dependence of various physical parameters on output Quality Parameter, which is Phase Noise, is shown by curves. The improvement in Phase Noise is around 1.5 dB. All in all, Designing of an Asymmetric Oscillator is shown using Design of Experiments.

Performance analysis of CMOS Mode Locked class E Power Amplifier

Abstract: The design of Class E Amplifiers is more difficult than other type of amplifiers as it is imposed by time domain constraints. This paper presents the performance analysis of Mode Locked class E Power Amplifiers using State Space Analysis Algorithm. A technique is introduced which is used to curb the negative effect of parasitic resistance of DC Feed Choke and the Power Amplifier operates at 2.4GHz and simulated with a 0.18µm CMOS process at a supply voltage of 2V.