Santanu Maity

Enhancementof gain, bandwidth and directivity of a patch antenna by increasing dielectric layers of the substrate through micromachining technique for RFID application

Bandwidth is the primary resource of any communication system, as the radio spectrum is fixed. The high gain and directivity is also the major issue for a wireless network. Microstrip antenna has popular attractive features such as low profile, low cost, small size and easily integrated with RF devices; but has narrow bandwidth and low gain. This paper comprises one novel technique in order to increase the bandwidth, gain and directivity of the conventional rectangular patch antenna. In this paper gain, directivity and bandwidth of a conventional patch antenna is enhanced by increasing dielectric layer between the patch and ground through silicon micromachining technique. In Radio Frequency Identification (RFID) technology, these types of antenna provide superior performance and all the simulation has been carried out in high frequency structure simulator (HFSS).

RF MEMS and CSRRs-based tunable filter designed for Ku and K bands application

Abstract This paper presents the design and simulation of a reconfigurable stop-band filter on a silicon substrate based on the combination of RF microelectromechanical system and metamaterial-based technologies. The device is implemented on coplanar waveguide structure by embedding complementary split-ring resonators on the central line and an RF MEMS varactor bridge supporting the neighboring ground planes. The response characteristics of this metamaterial-based filter can be dynamically tuned, thus enhancing its usefulness. The device operates within a frequency range of 16.5–19.5 GHz, giving a tuning range of 15%, and can be tuned from Ku-frequency band to K-frequency band. It works with a comparative low pull-in voltage of 17.42 V and a faster switching time of 0.138 µs. A thorough electromechanical analysis has been done by varying various structural and material parameters. Moreover, a comparative electrical performance of silicon and glass has been shown to overcome the cons of silicon by high-resistivity glass.

Dual band operation using metamaterial structure for Radio Frequency Identification (RFID) system

The important functions of Radio Frequency Identification (RFID) technology are radiation and detection. So efficient antenna design and fabrication is the unique solution which perform a very crucial role for many applications. The reader and tag intense are component of the RFID system. In this paper designed has done on RFID antenna for tag and reader application, which also includes the different types of antenna (UHF application, wideband, multiband antenna) and the general consideration for design, them which are currently used for tag and reader application. In this paper we proposed a rectangular patch antenna and then designed a metamaterial structure on the patch to improve the antenna performance.

Simulation and Fabrication of SAW-Based Gas Sensor with Modified Surface State of Active Layer and Electrode Orientation for Enhanced H2 Gas Sensing

The design, analysis, optimization, and fabrication of layered and nanostructure-based surface acoustic wave (SAW) gas sensors are presented. A lithium niobate and zinc oxide (ZnO) nano multilayer structure is proposed to enhance the sensitivity of the SAW-based gas sensor. Different materials are considered for the intermediate layer in the design for optimization purposes. The sensitivity of the sensor could be improved due to increased active surface area obtained by varying the aspect ratio of the nanorods, the thickness of the intermediate layer, and the gap between the electrodes. The total displacement and frequency shift of the device were significantly improved. Overall, the mechanically engineered surface-based (nanorod) SAW gas sensor offered better sensing response than the layered SAW gas sensor in terms of sensitivity performance.

RF MEMS Based Band-Pass Filter for K-Band Applications

In today’s world RF MEMS based Band-pass Filter is an important field of research and application. In this paper an RF MEMS Band-pass Filter model has been designed and proposed that consists of two metamaterial slots i.e., CSRRs. CSRRs are etched in such a way that effective electrical length is increased leading to increase in inductance and thereby reduction in resonant frequency. The Resonant Frequency has been achieved in K-Band. The main focus has been given on reducing the resonant frequency to less than 20 GHz so that the band-pass filter can be used for K-Band applications.

Metamaterial-based miniaturized CPW band stop filter design on silicon substrate for microwave applications

In this work, novel configurations of complementary split ring resonator (CSRR) are introduced to design the high performance of a sharp stop-band band stop filter (BSF). The band stop filters are implemented in microstrip technology by etching complementary split ring resonators (CSRRs) in the ground plane. The structure called metamaterials exhibit a composite right/left handed (CRLH) behaviour and they are of practical interest in microwave engineering. A band stop response with a sharp rejection frequency band is obtained by properly manipulating the structure of the elements. The objective of this paper is to demonstrate that by using complementary split ring resonators (CSRRs), further levels of minimization in these band stop filters can be achieved. Furthermore, introducing slots near the CS RR will modify the stop-band considerably. The unit cell of the design is then fabricated and measured. This work proves the capability of CS RR/CPW structure for microwave applications such as filter designs.

Analysis of Pull-in-Voltage and Figure-of-Merit of Capacitive MEMS Switch

Theoretical and graphical analysis of pull-in-voltage and figure of merit for a fixed-fixed capacitive Micro Electromechanical Systems (MEMS) switch is presented in this paper. MEMS switch consists of a thin electrode called bridge suspended over a central line and both ends of the bridge are fixed at the ground planes of a coplanar waveguide (CPW) structure. A thin layer of dielectric material is deposited between the bridge and centre conductor to avoid stiction and provide low impedance path between the electrodes. When an actuation voltage is applied between the electrodes, the metal bridge acquires pull in effect as it crosses one third of distance between them. In this study, we describe behavior of pull-in voltage and figure of merit (or capacitance ratio) of capacitive MEMS switch for five different dielectric materials. The effects of dielectric thicknesses are also considered to calculate the values of pull-in-voltage and capacitance ratio. This work shows that a reduced pull-in-voltage with increase in capacitance ratio can be achieved by using dielectric material of high dielectric constant above the central line of CPW.

A Novel MEMS-Based Frequency Tunable Rectangular Patch Antenna

This paper comprises of a frequency tunable patch antenna on which a U-shaped metamaterial structure is designed. The antenna is loaded with coplanar waveguide (CPW) stub on which two MEMS shunt switch with capacitive gap of 1.5 \( \upmu{\text{m}} \) were placed at 0.2 mm distant from each other. The tunability in frequency is achieved by changing the gap between the bridge and the insulating layer, at up state of the switches. The antenna resonant frequency shifted from 10.54 GHz down to 10.52 GHz by changing the capacitive height from 1.5 to 1 \( \upmu{\text{m}} \). The simulation of designed model has been carried out in Ansoft HFSS and different antenna parameters like gain, radiation pattern, efficiency, and scattering parameter have been adopted in this paper.

Miniaturization of MEMs-Based Smart Patch Antennas for Biomedical Applications

In this paper, MEMs-based smart patch antennas which can be used for biomedical applications were investigated. An attention over the main constraints in designing efficient antennas for biomedical devices was made and the analysis is presented, in addition with some of the main issues in their categorization. The foremost constraint which was encountered during simulation was the miniaturization problem. As the size of the antenna is reduced different parameters of the antenna such as directivity, gain, antenna efficiency show degradation in values. The patch antenna is a trendy antenna which can be used in various sophisticated applications due to its small size, robust nature, and low power handling capacity which is the prerequisite in our study. The antenna which has been developed basically consists of a patch antenna along with a meta-material-based rectangular slot over the patch. Bulk micromachining technique is used to etch out certain portions of the silicon substrate and Rogers RT-duroid substrate is intentionally been added within the micro-machined portion. MEMs-based switches have been added in our design in order to make the antenna reconfigurable in nature. The results obtained after simulation is astonishing with considerable increase in bandwidth, directivity, and gain which make the antenna viable for the required purpose despite of considerable reduction in size of the antenna.

Metamaterial based patch antenna with omega shaped slot for RFID system

Radio Frequency Identification (RFID) is one of the implementations under auto identification (AUID) technique. It is basically used in identification of items, animals, books etc. The patch antenna is a trendy resonant antenna for narrow-band microwave wireless link applications such as RFID systems. In this paper a rectangular micro-strip patch antenna is designed and thoroughly analysed. Taking into consideration different antenna parameters like directivity, bandwidth, and gain etc., an improved version from the simple rectangular patch has been developed by introducing a bi-anisotropic omega shaped metamaterial within the patch, also known as reciprocal metamaterial. The results obtained after simulation in High Frequency Structure Simulator (HFSS) were so much effective with the considerable enhancement in the values of directivity, bandwidth. Modelling of this omega shaped patch antenna has revealed results that are suitable for RFID antenna design.