Shaped Microstrip Antenna Research Articles

Dual-Frequency Band Circular Microstrip Antenna for Radar Application

This paper presents a circular shaped microstrip antenna through an inset feed. Simulation results show that the designed antenna can be used as a dual frequency antenna with effective return loss of -33.43 dB and -35.90 dB at 1.609GHz and 2.239GHz respectively. The dual band operation of the proposed antenna is due to two exited modes (TM01 TM11).for the proposed antenna TM11 is the fundamental as well as the dominant mode. The two modes have the similar broadside radiation characteristics and same polarization planes.

Circular Polarization in Defected Hexagonal Shaped Microstrip Antenna

A novel circular polarization (CP) design of a single-feed Hexagonal shaped microstrip antenna for enhanced antenna parameters is presented. The CP design is obtained by placing three isosceles triangular defects at proper locations in the hexagonal radiating patch as well as in the square ground plane. By adjusting one of the side lengths of the triangular defect, slightly longer or shorter than that of the others, two orthogonal near degenerate resonant modes for CP radiation are excited. Moreover, the 3 dB axial ratio bandwidth is surrounded by the 10 dB impedance bandwidth, to ensure that the antenna radiates CP waves in its impedance band. The antenna gain of the proposed antenna has increased by 5.34 dB (7.93 vs. 2.59 dB), as compared to the hexagonal microstrip antenna with triangular truncations in patch but without triangular defects in the ground plane having same substrate material, height and same radiating patch size and shape. Prototype antenna is fabricated for experimental evaluation. Simulated and measured results are in good agreement with each other.

Even Mode Network Model for Multi-band and Compact Modified Rectangular Microstrip Antennas

multi-port network model is a simpler tool to analyze microstrip antennas on thinner substrates. While analyzing modified shaped microstrip antennas, the multi-port network model consists of larger number of segments which increases the complexity of the model. In this paper, first multi-port network models of multi-band and compact modified rectangular microstrip antennas are discussed. Further by using the symmetry of multi-port network models, a simpler even mode network equivalent model is proposed. The even mode network model solves only half of the network and thereby reduces the complexity of the multi-port network model. It gives closer match with multi-port network model result in terms of resonance frequency, input impedance and voltage distribution.

Analysis of Broadband Psi (Ψ)-Shaped Microstrip Antennas

A new Ψ -shaped microstrip antenna is reported, which increased the bandwidth of the E-shaped microstrip antenna by cutting an additional pair of slots on the other radiating edge of the E-shaped patch. The Ψ -shaped patch yielded a bandwidth of nearly 60% at a center frequency of around 5500 MHz. It gave a maximum gain of more than 10 dBi, which reduced to less than 4 dBi towards the higher frequencies of the bandwidth. In this paper, the broadband responses of the E-shaped and the reported Ψ -shaped patches are studied. In the E-shaped patch, the pair of rectangular slots did not introduce any mode, but modified the TM20 mode's resonance frequency of the patch and, along with the fundamental TM01 mode, resulted in the broadband response. Furthermore, when an additional pair of slots were cut to realize the Ψ -shaped patch, they modified the higher-order TM21 mode's resonance frequency of the patch. Along with the modified TM20 and TM01 modes, this yielded a larger bandwidth. Since the TM21 mode was present towards the higher frequencies of the bandwidth, the gain was reduced to less than 4 dBi. Furthermore, a proximity-fed design of a Ψ -shaped microstrip antenna in the same frequency band was proposed. The proposed configuration gave a higher bandwidth compared to the reported Ψ -shaped patch, with better gain characteristics over the bandwidth. A proximity-fed design of the Ψ -shaped patch in the 1000 MHz frequency band was also proposed. It gave a bandwidth of more than 50% with a broadside radiation pattern, and a gain of more than 8 dBi over the complete bandwidth.

Bandwidth Enhancement of Pin Shorted Triangular Patch Antenna with Circular Notch

This paper presents the notch loading effect on the pin shorted equilateral triangular shaped microstrip antenna (ETMSA). The proposed antenna shows the dual band behavior due to pin shorting and also the effect of circular notch for bandwidth enhancement, with dual shorting pin. The proposed antenna providing enhanced impedance bandwidth of 13.42%.Also effect of different dielectric on the bandwidth performance has been studied. All the results have been carried out using MOM based IE3D simulation.

Miniaturization of Bow Shaped Microstrip Antenna using Different Substrate

In recent era, the development in communication system requires development of small size electronic system .Now a days, there is demand of small size & low cost microstrip antenna. Microstrip antenna is widely used in wireless communication Applications. Microstrip antenna has small size, low cost, easy in construction & provides high performance over wide band of frequencies. In this paper, we are proposing a new approach for designing a very small size bow shapedmicrostrip antenna. This antenna is used to transmit & receive radio signal at resonant frequency of 3 GHz. At resonant frequency of 3GHz, the antenna concentrates energy through a direction to give a better radiative performance. This antenna is design on different substrate such as roger 5880, roger 5870, benzocyclobuten, epoxy. The effect of these substrates on microstrip antenna is studied & roger 5880 found to be a good substrate to design bow shaped microstrip antenna. Keywordsantenna, Resonant frequency, Roger 5870, Roger 5880, Benzocyclobuten, Epoxy.

Bridged ‘V’-shaped patch antenna for dual-band communication

A bridged ‘V’-shaped patch antenna has been designed and fabricated for dual-band communication. The dual-band operation is obtained by placing a bar connecting the two arms at the top of a ‘V’-shaped microstrip antenna. Comparison of the return loss performance of a single ‘V’-shaped antenna and the bridged ‘V’ antenna is carried out. Free space radiation pattern measurement is carried out for the bridged ‘V’-shaped antenna to ascertain the effect of the bridging on the far field pattern. The measured results of the bridged ‘V’-shaped antenna shows good performance of a dual-band operation with the potential of communicating in two different directions.

Electromagnetic Radiation from Arbitrarily Shaped Microstrip Antenna Using the Equivalent Dipole-Moment Method

The equivalent dipole-moment method (EDM) is extended and applied in the analysis of electromagnetic (EM) radiation by arbitrarily shaped microstrip antenna in this paper. The method of moments (MoM) is used to solve the volume-surface integral equation (VSIE). A strip model is applied in the treatment of the feeding probe of the microstrip antenna, in which the discretized triangular elements of the excitation source are equivalent as dipole models. The proposed approach is sufficiently versatile in handling arbitrarily shaped microstrip antenna and is easily constructed through a simple procedure. Numerical results are given to demonstrate the accuracy and efficiency of this method.

A Volume-Surface Integral Equation Solver for Radiation from Microstrip Antenna on Anisotropic Substrate

A volume-surface integral equation (VSIE) solver is presented for the calculation of electromagnetic radiation from arbitrary shaped microstrip antenna on anisotropic substrate. The method of moments (MoM) is used to convert the integral equation into a matrix equation, where the equivalent volume current and surface current are expanded into a finite series of SWG and RWG basis function, respectively. A simple strip model is incorporated in the VSIE to simplify the analysis of the probe-fed microstrip antenna. The present approach is sufficiently versatile in handling microstrip antenna with arbitrary shaped anisotropic dielectric substrate. Numerical results indicate the reliability and accuracy of the proposed method.

Bandwidth enhancement of microstrip antennas using additional gap-coupled hexagonal shape resonators to the radiating edges

In this paper, the hexagonal shaped microstrip antennas (MSA) with defected ground plane and gap coupled multi-resonators are proposed and studied for different di-electric constant. The hexagonal shape structure occupies less area and is suitable for compact antenna design. The results showed gradual improvement in impedance bandwidth from 460 MHz to 2.21 GHz with frequency variation from 8 GHz to 7.96 GHz in case of substrate with di-electric constant 4.4. A sudden improvement of impedance bandwidth from 2.19 GHz to 3.75 GHz with frequency variation from 14.32 GHz to 10.5 GHz is observed by just lowering e r to 2.62.

Efficient Design of Microstrip Antennas for SDR Applications Using Modified PSO Algorithm

In this paper, several irregularly shaped microstrip antenna structures are designed using a new version of Binary Particle Swarm Optimization (BPSO) algorithm in which the velocity calculation is modified towards a more accelerated and still robust search procedure, particularly aimed for software-defined radio (SDR) applications. The optimization results are compared using both the modified and the conventional BPSO algorithms. Pros and cons are studied in terms of optimization length, convergence speed and final design conformability to desired objectives. It is depicted that the modified BPSO achieves the design criterion considerably faster than the conventional one, at the cost of slightly limiting particle exploration ability.

Analysis and Design of Circular Shape Microstrip Antenna for Wireless Communication System

The circular microstrip antenna element is formed by radiating disk closely spaced above a ground plane. It is modeled as a cylindrical cavity with magnetic walls which can be resonant in the transverse magnetic modes. This circular shape microstrip antenna is analysed using cavity model and fields within the cylindrical cavity, radiation pattern and resonant frequency have been calculated. In this paper the circular microstrip antenna is designed at resonant frequency r f = 2.5 GHz. A suitable substrate of relative permittivity r 􀁈 = 4.2 and of thickness h = 1.6 mm is used to design the antenna. The simulation of this microstrip antenna is done on IE3D software and matlab. At last the simulation result and practical result of return loss are compared.

Candelabra shaped microstrip antenna for ultra-wideband applications

This article presents the results of a novel and compact microstrip antenna having a candelabra geometry, which exhibits ultra-wideband (UWB) performance when excited using coplanar waveguide feed. The proposed antenna exhibits an impedance bandwidth of 138% from 2.3 to 12.7 GHz, exceeding Federal Communication Commission's ultra-wideband frequency range with a return-loss performance S11 = −10 dB. The antenna radiates omnidirectionally in the H-plane and bidirectionally in E-plane. Details of the antenna's design and simulation results are presented and validated with practical measurements. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:669–672, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25783

A Reconfigurable Radial Line Slot Array (RLSA) Antenna for Beam Shape and Broadside Application

A reconfigurable beam shape and broadside radiation pattern microstrip antenna is introduced in this paper. The antenna's radiating surface is designed using a radial line slot array (RLSA) arrangement, which is fed from an aperture coupled structure. This novel feeding structure for an RLSA antenna incorporates PIN diode switches which are integrated with the feed line structure to enable the various outcomes of the radiation patterns. The circular arrangement of slots at the radiating surface contributes to the reduction in size of the proposed antenna compared to conventional microstrip antenna that can yield the same antenna gain. The proposed antenna design operates at 2.3 GHz frequency band and has a maximum gain of 14.64 dB. It also produces a broadside radiation pattern with a wider beamwidth covering from −85° to 85° compared to the conventional microstrip antenna which could only cover from −50° to 50°. The proposed antenna has an enormous potential for point-to-point and point-to-multipoint communication, WiMAX, and radar application.

Couple-fed Circular Polarization Bow Tie Microstrip Antenna

This paper presents a novel signal couple fed Circular Polarization (CP) Bow Tie shape Microstrip Antenna (Bow-Ti MA) based on the concept of electromagnetic coupled. The feeding technique and radiation performance of the Bow-Ti MA has been analyzed. The objective of the present design is not limited to both the improvement on the impedance and Axial Ratio (AR) bandwidths of the traditional CP antenna but also the radiation characteristics such as CP gain. The gain bandwidth and 3dB beam widths are also examined. Simulations and measurements show a good matching and a well-behaved CP radiation pattern can be achieved.

A fast analysis of scattering and radiation of large microstrip antenna arrays

An accurate and efficient method that combines the precorrected fast Fourier transform (FFT) method and the discrete complex image method (DCIM) is presented to characterize the scattering and radiation properties of arbitrarily shaped microstrip patch antennas. In this method, the mixed potential integral equation (MPIE) is discretized in the spatial domain by means of the discrete complex image method. The resultant system is solved iteratively using the generalized conjugate residual method (GCR) and the precorrected-FFT technique is used to speed up the matrix-vector multiplication. The precorrected-FFT eliminates the need to generate and store the usual square impedance matrix and thus leads to a significant reduction in memory requirement and computational cost. Numerical results are presented for arbitrarily shaped microstrip antenna arrays to demonstrate the accuracy and efficiency of this technique.

A reciprocity approach for calculating radiation patterns of arbitrarily shaped microstrip antennas mounted on circularly cylindrical platforms

The paper presents a convenient and efficient approach, based on the reciprocity theorem, for calculating the radiation patterns of arbitrarily shaped microstrip antennas with dielectric substrate and superstrate layers mounted on circularly cylindrical platforms. A detailed theoretical development followed by examples with numerical and graphical results illustrate the versatility of the technique. The reciprocity approach presented is very flexible and may be used in conjunction with any of the commonly employed computational electromagnetics modeling approaches such as the method of moments, finite-element methods, and finite-difference time-domain techniques.

Analytical method for a circularly polarised rectangular microstrip antenna

The paper proposes a formulation method for the wall admittance of an arbitrarily shaped microstrip antenna using spectral domain analysis. In the paper, the wall admittance of the circularly polarised rectangular microstrip antenna is calculated. The circularly polarised rectangular microstrip antenna is analysed using the cavity model. The electromagnetic fields within the antenna cavity are expanded in terms of the eigenfunctions in the cavity with sides extended by the edge extension length. The edge extension length is determined so that the eigenfunctions satisfy the Helmholtz equation at all frequencies. Their expansion coefficients are determined by the impedance boundary condition at the aperture. The calculated input impedance and axial ratio of the antenna agree fairly well with the measured data.

Parametric study and temperature sensitivity of microstrip antennas using an improved linear transmission line model

An improved linear transmission line (LTL) model has been developed after incorporating several modifications in the reported linear transmission line model for analyzing arbitrarily shaped microstrip antennas (MSAs), which should be symmetrical with respect to the feed axis. Simulations have been carried out for rectangular, circular, and equilateral triangular MSAs and the results are in good agreement with reported results. A parametric study for these MSAs has also been performed. A study of the temperature sensitivity for rectangular MSAs for different types of substrates has been carried out. An MSA utilizing a substrate with a lower dielectric constant and thermal coefficient is less sensitive to temperature variations.

Analysis of tissue and arterial blood temperatures in the resting human forearm. 1948.

Analysis of tissue and arterial blood temperatures in the resting human forearm. 1948.