Low-profile Patch Antenna Research Articles

Low-Profile Patch Antenna for RF Identification Applications

A novel low-profile bow-tie patch antenna, which can be mounted on metallic objects for RF identification (RFID) applications is presented. This antenna is fabricated using a single layer printed circuit board with thickness of 1.5 mm without any via-hole or shorting plate. The RFID chip is connected to a small loop, which is magnetically coupled to the radiating body. The loop, as well as the radiating body, can be fabricated as a separate inlay, simplifying the manufacturing process and reducing its cost. A prototype has been fabricated and measured.

TLM modeling and system identification of optimized antenna structures

Abstract. The transmission line matrix (TLM) method in conjunction with the genetic algorithm (GA) is presented for the bandwidth optimization of a low profile patch antenna. The optimization routine is supplemented by a system identification (SI) procedure. By the SI the model parameters of the structure are estimated which is used for a reduction of the total TLM simulation time. The SI utilizes a new stability criterion of the physical poles for the parameter extraction.

Modified Particle Swarm Optimization for Patch Antenna Design Based on IE3D

An evolutionary optimization method for patch antenna designs is presented in this paper. The modified particle swarm optimization (MPSO) based on fitness distance ratio (FDR) is combined with standard software IE3D to achieve the optimum antenna satisfying a certain design criterion. The antenna geometric parameters are extracted and optimized by a MPSO program, and simulated by IE3D. The fitness function of the optimization is calculated by the MPSO program according to the simulation results extracted from IE3D to represent the performance of each candidate design. A microstrip line fed low-profile E-shaped patch antenna is designed and optimized using the MPSO/IE3D method. The designed patch antenna is simulated, fabricated, and measured to validate the effectiveness of the MPSO/IE3D method.

S-band dual-path dual-polarized antenna system for satellite digital audio radio service (SDARS) application

This paper presents a novel compact dual-polarized antenna system for S-band satellite digital broadcasting receivers. The demonstrated antenna system consists of a low form factor dual-polarized antenna pair and two-stage low-noise amplifiers (LNAs) integrated with each antenna. One antenna is a low-profile annular ring patch antenna having a 90/spl deg/ phase-delay element for circular polarization (CP) and the other antenna is a reactively-loaded monopole antenna for linear polarization (LP). Both antennas operate in the same frequency range, from 2.320 to 2.345 GHz, while providing different polarizations to take advantage of the polarization diversity. Switches are used to select the mode (polarization) of operation. This ensures that appropriate dc bias is supplied to the operating LNA to process the received signal while no power is consumed by the idle LNA. The measured gains of the antenna system are 31.3 and 21.9 dBi for the CP and LP modes, respectively.

Implanted Antennas Inside a Human Body: Simulations, Designs, and Characterizations

Antennas implanted in a human body are largely applicable to hyperthermia and biotelemetry. To make practical use of antennas inside a human body, resonance characteristics of the implanted antennas and their radiation signature outside the body must be evaluated through numerical analysis and measurement setup. Most importantly, the antenna must be designed with an in-depth consideration given to its surrounding environment. In this paper, the spherical dyadic Green's function (DGF) expansions and finite-difference time-domain (FDTD) code are applied to analyze the electromagnetic characteristics of dipole antennas and low-profile patch antennas implanted in the human head and body. All studies to characterize and design the implanted antennas are performed at the biomedical frequency band of 402-405 MHz. By comparing the results from two numerical methodologies, the accuracy of the spherical DGF application for a dipole antenna at the center of the head is evaluated. We also consider how much impact a shoulder has on the performance of the dipole inside the head using FDTD. For the ease of the design of implanted low-profile antennas, simplified planar geometries based on a real human body are proposed. Two types of low-profile antennas, i.e., a spiral microstrip antenna and a planar inverted-F antenna, with superstrate dielectric layers are initially designed for medical devices implanted in the chest of the human body using FDTD simulations. The radiation performances of the designed low-profile antennas are estimated in terms of radiation patterns, radiation efficiency, and specific absorption rate. Maximum available power calculated to characterize the performance of a communication link between the designed antennas and an exterior antenna show how sensitive receivers are required to build a reliable telemetry link.

A wideband rectangular patch antenna with shorting pins

AbstractThis paper presents a novel bandwidth enhancement technique by using shorting pins. A low‐profile rectangular‐shaped patch antenna with three shorting pins is presented. The impedance bandwidth of the proposed antenna achieves 33% (SWR < 2) while the overall thickness of the antenna is only 0.06λ0. The antenna has two close resonant bands. The lower resonant band has a conical radiation pattern with 4‐dBi maximum gain and the higher resonant band has a broadside radiation pattern with 8‐dBi maximum gain. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 165–167, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10856

Stacking resonators to increase the bandwidth of low-profile antennas

A method of increasing the bandwidth of low-profile cavity-hacked slot and microstrip patch antennas without appreciably adding to the antenna dimensions is presented. This idea incorporates the stacking of structures which have close resonant frequencies. Energy is coupled between cavities via carefully placed slots in the common wall. An approximate two-and-a-half fold increase in input impedance bandwidth has been observed for a certain cavity-backed slot antenna.