Shuvashis Dey

Design and evaluation of an elliptical patch textile antenna for RFID application and bending consequences

This paper presents a design of an elliptical patch textile antenna having operating frequency at 2.45 GHz for RFID application. The proposed antenna consists of elliptical patch on Dacron fabric (□r=3) as substrate followed by a partial ground at the back of the substrate. The overall size of the proposed antenna is 45×38 mm2. The proposed antenna has a gain of 3.386 dB with VSWR of 1.07. The performance of the proposed antenna is analyzed under four angles of bending. The effect of change in feed length is also focused. The characteristics, low profile and compact size of the antenna depicts as a potential candidate for RFID application. CST Microwave Studio package is used for design and simulation purpose.

Design of novel super wide band antennas close to the small antenna limitation theory

The fundamental bandwidth limitation theory of small antennas and their applications to Super Wide Band (SWB) antenna designs are investigated in this paper. Firstly, a circular patch antenna with a substrate of permittivity (εr = 3) and patch metallization thickness of 0.5 mm is designed. Thereafter, the same antenna is designed with increased patch height (26.5 mm). The antennas are designed to achieve a super wide bandwidth with a bandwidth ratio ranging from 27:1 to as high as 31:1. The operating frequency bands of antenna with 0.5 mm height are from 1.8 to 50 GHz whereas with increased antenna height, the operating frequency ranges from 1.6 to 50 GHz. A reduction in antenna electrical size and improvement in impedance bandwidth is obtained here by using the spherical volume of the antenna efficiently. A further investigation with respect to classical Chu and Mclean theories depicts that the proposed antenna electrical size almost touches the Mclean and gets very close to the Chu fundamental limit curves.

A novel time domain reflectometry based chipless RFID soil moisture sensor

This Study focuses on the design and analysis of a novel low cost time domain reflectometry (TDR) based soil moisture sensor. This type of sensor enables to employ an efficient irrigation system for agricultural sector by obtaining accurate information about soil moisture profiles. The dielectric properties of the proposed sensor vary with volumetric water content of soil which instigates a variation in the sensors TDR amplitude level. A critical analysis on the feasibility of the designed sensor is carried out here along with an experimental validation of a developed prototype.

A brief overview of chipless RFID sensors with EM transduction

This paper provides a short overview on the state of the art in electromagnetic transduction based chipless RFID sensors. These types of sensors can be used for various applications including structural health monitoring, pressure, airflow and displacement detection, temperature, humidity, partial discharge monitoring and so on. A novel concept of high resolution crack sensing using super wideband antenna is also introduced here along with a brief review on airflow and partial discharge sensors.

Design and analysis of a low-profile, elliptical patch Super Wide Band (SWB) MIMO antenna

In this paper, design of a low-profile, coplanar waveguide fed elliptical patch Super Wide Band (SWB) multiple input multiple output (MIMO) antenna for various applications are presented. Two planar elliptical patch antennas with Microstrip-feed are used as the elements of the MIMO antenna. PTFE (Polytetrafluoroethylene) is used as dielectric substrate whose relative permittivity is 3.5. The proposed antenna occupies a fractional bandwidth of more than 172.12% (2.2473-30 GHz) which covers frequency range for all types of UWB applications along with some other common wireless communication systems such as ISM, Wi-Fi, WiMax, part of LTE and so on. Performance analysis of designed antenna is carried out in free space in terms of reflection coefficient, radiation pattern and voltage standing wave ratio (VSWR) and the results show that, this antenna could be a very suitable one for above mentioned applications.