Ravi Prakash Dwivedi

Antenna miniaturization techniques for wireless applications

In wireless communication, antenna miniaturization is a vital issue these days. This paper presents the simulation analysis of small planar antennas using different antenna miniaturization techniques. They have brought to define miniaturization methods by which we can estimate the use of micro strip antennas. Various govt. and private sector organizations made use of these techniques to solve the problem of antenna fabrication in mobiles, satellites, missiles, radar navigational aids and military applications. These techniques are used to reduce the physical size but to increase the bandwidth and efficiency of antenna. Some approaches for antenna miniaturization are introduction of slots, slits, short meandering and novel geometries like fractals or by using higher dielectrics constant. The effect of miniaturization in various antenna parameters like, radiation efficiency, gain and bandwidth are discussed. Finally the paper reports a brief description of miniaturization of antenna by using suitable and efficient methods that includes use of double layered substrate structure in microstrip patch antenna.

High gain dual band antenna using fractal geometry for mobile communication

In this paper, a dual band antenna is designed using fractal geometry. The paper presents a triangular sierpinski fractal antenna which gives higher bandwidth of 670MHz & 1070MHz at resonant frequencies of 10.89GHz & 15.92GHz respectively. So, the triangular patch is used in this fractal antenna which adds some extensive applications in wireless industry. The multiband and ultra wide band properties of antenna are due to their self similarity of fractal geometry while the space filling properties of antenna leads to the miniaturization of antenna. This antenna miniaturization and self similarity property of triangular fractal structure is used for reducing antenna size and for obtaining dual band resonance with high gain of 7.0954dB at 10.89GHz. The double substrate structure is used for obtaining the efficient radiation characteristics which also influences gain and bandwidth of fractal antenna. The fractal antenna is also miniaturized by introducing various iterative procedures in sierpinski fractal structure that is considered as an attempt which has been made to design an antenna of compact size and good radiation characteristics.

Design and simulation of wideband patch antenna for wireless application

In this paper L-strip Electromagnetically coupled rectangular patch antenna is proposed and simulated results were obtained by HFSS tool. The frequency range covered by this single antenna is 1800 MHZ to 2370 MHZ with -10db return loss with optimal height of the patch from the ground plane 16.8mm. The antenna parameters which influence the gain, bandwidth, return loss was analyzed and graphs are plotted. The design mainly focuses on 3G internet services. It covers the DCS, PCS and UMTS. In addition, significant matching and high gain of 10.8 dB at 2.4GHz is obtained.

A Novel Circular Monopole Fractal Antenna for Bluetooth and UWB Applications with Subsequent Increase in Gain Using Frequency Selective Surfaces

In this paper a novel monopole circular fractal disk is analyzed in details. The antenna is mounted on a FR4 substrate having a dimension of 30 × 35 mm2. A 50 Ω impedance matched microstrip line is used as feeding mechanism for the antenna. The antenna exhibits stable radiation patterns and has a bandwidth of 9.64 GHz. A U-shaped slot having appropriate dimensions is etched from the patch in order to make the antenna compatible for Bluetooth applications. In the later section, different types of Frequency Selective Structures (FSS) are introduced for enhancing the gain of the antenna. A gain of 8.94 dB is observed with the introduction of slot type FSS structures beneath the ground plane. All the analysis of the antenna is done in HFSS 2013.

Compartive study of coplanar waveguide feed and microstrip feed for log periodic antennas

Log periodic antennas are widely used in ultra wideband applications. This paper compares the coplanar waveguide and microstrip feed of log periodic array antennas in terms of gain, bandwidth, design complexity and also the effect of the antenna on different substrates. The design criteria of both types of antennas are discussed in detail. The two different types of feeding techniques for the antenna are simulated using High Frequency Structure Simulator which uses efficient Finite Element Method for rigorous electromagnetic analysis. The results are compared and comparison table gives the clear idea of choosing the feed and also the substrate material.

Miniaturized High-Gain UWB Monopole Antenna with Dual Band Rejection Using CSRR

Ultra-wideband technology (UWB) is used for transmitting large amount of data over wide frequency range. There is always a trade-off between gain and bandwidth of micro-strip patch antenna for UWB. It is difficult to obtain wideband and high gain in an antenna simultaneously. In the proposed design, a compact, high-gain ultra-wideband tree-shaped radiating patch antenna with band notch characteristics is designed. The radiating patch is printed on FR4 substrate with permittivity 4.4. Tree-shaped radiating patch and defected ground structure (DGS) provides a wideband over 2.8–11.6 GHz frequency range. For providing stop-band notches in the existing wireless technologies, two complementary split-ring resonators (CSRRs) are used. By etching square complementary split-ring resonator (CSRR) in the feed, a stop-band notch at WLAN (5.1–5.9 GHz) frequency range is obtained, and a single CSRR in the patch provides a notch at WiMAX (3.3–3.6 GHz) frequency range. The antenna has varied positive gain over all the frequencies other than notched bands. Maximum gain of 5 dB at 9 GHz and minimum of 0.4 dB at 4 GHz is obtained. Antenna is simulated using high frequency structure simulator (HFSS) software. The designed antenna is validated by comparing simulated results with measured results.

Design and Parameter Extraction of Split Ring Resonator for Surface Crack Detection in Different Materials

In this paper, a simple approach has been proposed to detect crack using the changes in the resonant frequency of the resonator. Extensive simulations have been carried out using finite element analysis tool HFSS. SRR of various geometrical shapes and the corresponding result is also presented in this paper. A theoretical formulation to estimate the resonant frequency of the split ring resonator is also proposed. A step-by-step procedure is devised for analyzing the material parameters to facilitate and simplify the design procedure of metamaterial structures. The entire idea of this paper is based on the interpretation of S-parameters of SRR.

Multiband High-Gain Antenna with CPW Feed for Wi-Fi, WI-MAX and X Band Application

Due to the recent developments in the domain of wireless network, the demand of multi frequency antenna has increased significantly. Wi-Fi has become a very popular choice available to the end users, providing them broadband connectivity and an alternative to cable and digital subscriber line, while X band finds extensive use in RADAR and satellite communication systems, and the proposed design can be put to use where there is a need for integration of both technologies. In this study, the authors have developed a novel U-shaped slot antenna for Wi-Fi and X band applications which gives a significantly higher gain and better performance than the existing antennas aimed for the same application to validate the model the structure was simulated in HFSS and operating frequencies for the proposed antenna were in compliance with the IEEE 802.11 WLAN protocol and the X band range. The structure has a fairly simple design and is having a fairly compact dimension of 40 mm × 40 mm × 1.6 mm. Moreover, the obtained radiation pattern demonstrates that proposed antenna has a significantly unidirectional pattern in both E-plane and H-plane. In addition to the unidirectional radiation pattern, a significant reduction in conduction loss was obtained.

CPW ultra-wideband tunable notched antenna

The research presents a compact antenna consisting of a simple radiating patch and a slotted radiating patch based on a DMS structure. It is required to have a tunable notched behavior in the antenna to avoid interference of Wi-Fi, Wi-MAX, WLAN frequency as it comes under ultra-wideband (UWB) designated band. Also, a coplanar waveguide (CPW)-fed will be used for UWB monopole antenna in the patch. A DGS structure is used for the notch characteristic to fit the entire antenna into a compact area. The measured results for the proposed antenna provide a notch at 2.4 GHz. The designed CPW ultra-wideband antenna sized of 30 × 30 × 0.8 mm3, operates for the frequency band between 1 and 10 GHz.

Comparative analysis of microstrip antenna for high gain using FSS

The microstrip patch antenna has been designed with noncontact feeding method of aperture coupled microstrip patch antenna (ACMPA). In this study a comparative analysis of high gain antenna has been carried out. ACMPA has been designed with the rectangular shape of aperture coupling. Frequency Selective Surface has been incorporated to enhance the gain. Gain comparison has been done between ACMPA with and without FSS. It has been seen that the performance has been enhanced with FSS. All the simulation has been done using Ansoft HFSS. To validate the design performance parameters like return loss, gain and VSWR has been computed. Prototype has been designed for WiMAX application at 5.8 GHz.