Bow-Tie Microstrip Antenna Design

In this paper, the bow-tie microstrip antennas have been designed with two different angles of 40° and 80°. An investigaton on the effect of the angle to the return loss and radiation patterns had been carried out. The impedance matching network with the niicrostrip transmission line feeding was used in this study. Simulation and measurement results for the return loss and radiation patterns were presented

A slot-loaded reduced-size CPW-fed aperture antenna for UWB applications

The paper presents a co-planar wave guide (CPW)-fed slot loaded low return loss planar printed antenna with a small size designed for wireless communication and UWB applications. First, a conventional UWB antenna is modeled to provide a reference point for the modeling and then the shape is modified by a self inverted configuration to achieve higher bandwidth and size reduction. To improve the gain and efficiency, a combination of corner features and loading slots are introduced. The primary aim throughout the modeling was to achieve the minimum possible value of return loss (S11) below -10 dB over the FCC-defined UWB frequency range. The antenna was designed, simulated and modified using Agilent's Advanced Design System (ADS). It was fabricated on FR4 substrate and measured return loss results are presented

Dual-band Sierpinski fractal monopole antenna

A new top-loaded reduced-sized dual-band (1.9 GHz and 3.5 GHz) monopole antenna for wireless communications is presented. The antenna provides better than -15 dB input return loss and keeps the same radiation pattern over both bands. In addition, a low-profile performance is achieved.Peer ReviewedPostprint (published version

The eleven antenna: a compact low-profile decade bandwidth dual polarized feed for reflector antennas

A novel dual polarized ultrawide-band (UWB) feed with a decade bandwidth is presented for use in both single and dual reflector antennas. The feed has nearly constant beam width and 11 dBi directivity over at least a decade bandwidth. The feed gives an aperture efficiency of the reflector of 66% or better over a decade bandwidth when the subtended angle toward the sub or main reflector is about 53°, and an overall efficiency better than 47% including mismatch. The return loss is better than 5 dB over a decade bandwidth. The calculated results have been verified with measurements on a linearly polarized lab model. The feed has no balun as it is intended to be integrated with an active 180° balun and receiver. The feed is referred to as the Eleven antenna because its basic configuration is two parallel dipoles 0.5 wavelengths apart and because it can be used over more than a decade bandwidth with 11 dBi directivity. We also believe that 11 dB return loss is achievable in the near future

Compact dual-band (2.4/5.2GHz) monopole antenna for WLAN applications

Copyright ©2010 IEEE. Reprinted from Antenna Technology (iWAT), 2010 International Workshop. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected] compact and optimized design of a rectangular printed monopole antenna with slits and truncated ground plane on FR-4 substrate is presented. The proposed antenna is designed for dual-band operation at 2.4 GHz and 5.2 GHz for Wireless Local Area Network (WLAN) applications with S11 < -10 dB. This antenna has good return loss and radiation characteristics in required frequency band. The proposed antenna gives omni-directional radiation pattern in the E Plane and H plane over the frequency range of 2.4 GHz and 5.2 GHz. The calculated and measured results in terms of return loss show good agreement and the results also show good wideband characteristics

Analysis of an air-spaced patch antenna near 1800 MHz

Microstrip antennas are a type of printed antenna which consists of a patch on top of a grounded substrate. A major limitation for the performance of the patch antenna is the dielectric substrate. The idea of using air as dielectric was therefore considered to overcome that limitation because air has the lowest permittivity and no loss. The goal of this work is to build an air-spaced patch antenna, with the minimum resonant frequency at 1800 MHz and with a return loss of at least 10 dB. This work is novel because the air-spaced patch antenna has not been extensively studied. Existing literature on patch antennas with dielectric were used for the design of the antenna (dimensions of the patch, ground plane and height) and to understand the principles of operation of microstrip patch antennas in general. Simulations using the NEC code and experiments in the RF laboratory were used for this air-spaced patch antenna study. The Numerical Electromagnetic Code (NEC) was used as the simulation tool in this work. The air-spaced patch antenna was simulated to find a trend for the variation of the return loss and impedance with the resonant frequency. Simulation also helped determine cases that will not be meaningful to explore in the experiment. The experiment was done in the RF laboratory of Marquette University College of Engineering. Two procedures were used to calculate the patch dimensions using two different sources ([2], [3]). They lead to two patch antennas that were tested. For each antenna, the height of the dielectric substrate and the recess feed distance were varied. Antenna 2 (procedure 2 – [3]) provided the best results with a resonant frequency of 1800 MHz and a return loss of 21 dB. It was found that the error between experimental and simulation resonant frequency is generally 5% or less. This error increases as the dielectric height increases, and as the recess distance increases. Simulation results roughly follow the experimental results trend

Statistical method of modeling and optimization for wireless sensor nodes with different interconnect technologies and substrates

A comparison study was carried out between a wireless sensor node with a bare die flip-chip mounted and its reference board with a BGA packaged transceiver chip. The main focus is the return loss (S parameter S11) at the antenna connector, which was highly depended on the impedance mismatch. Modeling including the different interconnect technologies, substrate properties and passive components, was performed to simulate the system in Ansoft Designer software. Statistical methods, such as the use of standard derivation and regression, were applied to the RF performance analysis, to see the impacts of the different parameters on the return loss. Extreme value search, following on the previous analysis, can provide the parameters' values for the minimum return loss. Measurements fit the analysis and simulation well and showed a great improvement of the return loss from -5dB to -25dB for the target wireless sensor node

Low-Return-Loss Printed Log-Periodic Dipole Antenna

International audienceIn this letter, a low-return-loss printed log-periodic dipole antenna (PLPDA) fed by a coaxial cable is presented. The widths of dipole elements are optimized to increase the bandwidth. A study of coaxial cable position is included in order to improve the antenna behavior. The measured return loss is lower than -15 dB from 2.1 to 4.3 GHz. The measured gain varies between 6 and 7 dBi. The measurements, including input impedance, gain and radiation patterns, and simulations are in agreement