Conformal Monopole Research Articles

Performance analysis of a flexible wearable antenna with low SAR for biomedical application

Abstract This article presents a conformal monopole antenna for wearable application in ISM band frequency of 2.45 GHz. The antenna has a return loss of 50.18 dB with good radiation performance. The gain of the antenna is 1.09 dBi which is improved to 3.28 dBi using a metasurface consisting of 3 × 3 array elements. The proposed metamaterial integrated antenna is fabricated on 1 mm thick flexible PDMS substrate. The metamaterial improves the gain while reducing the specific absorption rate (SAR) of the antenna. The geometry size of the metamaterial integrated antenna is 50 × 50 × 24 mm3. The loading effect of antenna by body is analyzed with a hand phantom model. Flexibility and conformability of antenna is analyzed by bending the antenna with various radii in x and y direction. Measured results of the fabricated prototype demonstrate the safety of the suggested wearable antenna for biomedical applications.

Conformal Deformation, Monopoles, and Their Application to Control the Measurement, Berry Phase’s Path, and Resonant Frequency of a Spin

The effects of the conformal deformation of physical parameters on the measurement, Berry phase, and resonance of a spin are investigated. We first construct a form-invariant yet measurement-tunable representation of a spinor from the deformed parameter surface. Then, it is shown that the evolution path of the Berry phase is tunable by the conformal index. Third, the source of the path-tunable Berry phase is shown to be the conformal monopole revealed by the recent investigation of the transformation design of quantum states. The dual fields produced by the dual conformal monopole are presented. It is demonstrated that the strengths of the pole and its dual partner are determined by the reciprocally quantized conformal index. Finally, we discuss the influence of the deformation on the resonance of the spin, and show that the resonant frequency follows the quantization rule ω¯R=ωRconformalfactorn/n with ωR as the Rabi frequency without deformation.

Broadband Conformal Monopole Antenna Loaded with Meandered Arms for Wireless Capsule Endoscopy

In this paper, a new conformal monopole antenna is presented. The proposed antenna is suitable for using in wireless capsule endoscopy (WCE) as transmitter antenna because of its special structure. The WCE antenna should have particular features, because it will be radiate in human body environment. The WCE antennas specific requirements are: proper size, location, gain, radiation pattern and bandwidth in standard frequency band. The proposed antenna’s basic design is done according to the monopole antenna. Therefore, the antenna radiation pattern is omnidirectional. In order to achieve proper bandwidth the Babinet’s principle is applied to the monopole antenna. Also, the antenna is placed in the capsule’s dome. Finally, the antenna simulations are done with two High Frequency Electromagnetic Field Simulation and Computer Simulation Technology Microwave Studio software. The design results show that the antenna gain is − 30 dB and 89% bandwidth in Industrial, Scientific and Medical band. Therefore the proposed antenna will be an appropriate candidate for using in WCEs.

Design of a conformal monopole antenna on a paper substrate using the properties of graphene-based conductors

Design of a conformal monopole antenna on a paper substrate using the properties of graphene-based conductors

INTEGRATED FLEXIBLE UWB/NB ANTENNA CONFORMED ON A CYLINDRICAL SURFACE

In this paper, an ultra-wideband (UWB) conformal monopole antenna integrated with a narrow-band (NB) rectangular slot antenna is designed and fabricated. The proposed structure consists of a circular disc monopole antenna printed on a cylindrical surface and fed by a coplanar waveguide line (CPW). A rectangular slot antenna, excited by a microstrip line, is integrated in the front of the UWB antenna. The simulations are performed using the CST Microwave Studio software. To validate the proposed antenna concept, an experimental prototype is fabricated and measured. The measured results show that the monopole antenna covers an ultra wideband from 2GHz to 12GHz with S11 < −10 dB and provides a very good isolation with a transmission coefficient below −20 dB across the operating band. Compared to planar integrated antennas, the proposed conformed structure possesses an important wideband, which can be used in many wearable electronic applications and communication systems.

Novel low-profile foam dielectric over-the-shoulder antenna based on coupled patches technique

The article presents a novel wearable antenna composed of two coupled patches excited by an overlapping folded dipole. In spite of being operated in a relatively low frequency band 380 ÷ 390 MHz, the antenna shows a very low profile and other dimensions are acceptable as well. Besides a very low absorption of the radiated RF power by any nearby human body, it also ensures a very good immunity against influence on antenna parameters. In comparison to commonly used simple conformal monopole antennas, the presented solution provides a double-side radiation pattern and a substantially higher gain. The antenna can be manufactured using very light and twistable foam dielectric and conductive fabric, and can be worn as a strap placed over the shoulder. It is intended to be used together with personal radio communication transceivers operated in the given frequency band. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:593–597, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27389

Liquid crystal-reconfigurable conformal monopole antennas structures for microwave applications

In this article, the design of conformal monopole antennas on a very thin layer of flexible liquid crystals (LCs) is introduced. The flexible LC substrate can be bent and folded over the module case, resulting in a tight integration of the antenna with the frontend module. Firstly, a meander monopole antenna, designed for single band operation, is presented with details of the structure, simulation and measurement results. Secondly, a method to increase the peak gain and decrease the return loss of the antenna is proposed. The simulated results are compared with measured data, and good agreement is obtained. Key words: Liquid crystals, monopole antennas, agile structure, microwave.

A Unidirectional Cylindrical Conformal Monopole Antenna Designed for Impulse Radar System

A compact unidirectional cylindrical conformal monopole antenna with 40 mm diameter and 25 mm height is designed for an impulse radar system. The antenna is employed for radiating Gaussian monocycle with peak-peak width of 300 ps. Impedance loaded is adopted to achieve ultrawideband (UWB) impedance matching and unidirectional radiation. Simulations with CST Microwave Studio (CST MWS) and experiments have been conducted to assist with the characterization of the antenna. Simulation results and experimental data showed to be in good agreement. The impedance bandwidth is 0.67-2.15 GHz for S11 ≤ -10 dB and covers the main range of the pulse spectrum. The front-to-back ratio of the amplitude of the received signal reaches about 3.5:1.