Efficiency of a Compact Elliptical Planar Ultra-Wideband Antenna Based on Conductive Polymers

Abstract

A planar antenna for ultra-wideband (UWB) applications covering the 3.1–10.6 GHz range has been designed as a test bed for efficiency measurements of antennas manufactured using polymer conductors. Two types of conductive polymers, PEDOT and PPy (polypyrrole), with very different thicknesses and conductivities have been selected as conductors for the radiating elements. A comparison between measured radiation patterns of the conductive polymers and a copper reference antenna allows to estimate the conductor losses of the two types of conductive polymers. For a 158 μm thick PPy polymer, an efficiency of almost 80% can be observed over the whole UWB spectrum. For a 7 μm thick PEDOT layer, an average efficiency of 26.6% demonstrates, considering the room for improvement, the potential of this type of versatile materials as flexible printable alternative to conductive metallic paints. The paper demonstrates that, even though the PEDOT conductivity is an order of magnitude larger than that of PPy, the thicker PPy layer leads to much higher efficiency over the whole UWB frequency range. This result highlights that high efficiency can be achieved not only through high conductivity, but also through a sufficiently thick layer of conductive polymers.

A Compact, Highly Efficient and Flexible Polymer Ultra-Wideband Antenna

“…The dielectric losses are assumed to be the same as well, due to the very thin substrate. The radiated power is averaged over all measured angles (in standard spherical coordinates) and the conduction efficiency can then be estimated as follows [9] …”

“…Thus these are very attractive materials for conformal applications which require antenna characteristics including flexibility, light weight and low cost. Some polymer-based narrow band patch antennas using polyaniline (Pani) [6], polypyrrole (PPy) [7] and poly 3, 4-ethylenedioxthiophene (PEDOT) [8] as well as some Ultra-Wideband (UWB) antennas using the latter two materials [9] have been previously reported, showing limitations in mechanical flexibility and efficiency. However, these reports have indicated the promising potential of conductive polymers as antenna materials.…”

Paired Snap-On Buttons Connections for Balanced Antennas in Wearable Systems

“…Considering the wearing comfort and ergonomic requirements for these devices, wearable antennas are required to be flexible, low-cost, lightweight and even washable. To fulfil these characteristics, metallic foils [4], conductive inks [5], conductive polymers [6], conductive threads [7] and conductive fabrics [8], [9] are the most promising choices as flexible conductor materials. Generally antennas made from the latter two materials are garment-integratable and washable thus they offer convenience and re-usability for wearable applications.…”

Shape engineering of the fillers in stretchable, electrically conductive adhesives: Its effect on percolation and conductivity change during stretching

“…These requirements include the following: 1) The material must have a very high electrical conductivity to achieve high-efficiency RF devices. 0 [9]; 2) The material needs to be highly elastic for tunable resonant frequency [14] and still maintain a similar electrical conductivity. By stretching the antenna, the length is increased, leading to a decrease in resonant frequency.…”

“…The first one utilizes conventional rigid materials (such as silicon), but elegantly designed wavy or arc-shaped structures are capable of accommodating applied strains of 100% or more [1][2][3][4][5][6][7]. The second approach is to maintain the conventional layout, but embed stretchable or flowable conductive materials into a sheath, including conductive polymers [8,9], conductive polymer composites [10-12] and liquid metal alloys [13,14] as stretchable conduction lines.For RF electronics, the second approach is usually preferred because of the simplicity in circuit design and fabrication. However, this approach imposes stringent requirements for the conductive materials.…”