Low Profile UWB Antenna Research Articles

Flexible low profile UWB antenna on polyimide film based on silver nanoparticle direct-write dispenser printing for wireless applications

Flexible low profile UWB antenna on polyimide film based on silver nanoparticle direct-write dispenser printing for wireless applications

An approach to achieve directional low‐profile antenna of quintuple stable pattern band by utilising dipole with compound concave corrugated reflector

An approach to achieve directional low-profile UWB antenna by omnidirectional source with a reflector, is proposed. The general theoretical model about the direction and the phase conditions between the upward and reflected field are developed. A bow-tie dipole source antenna is investigated first. To modify its radiation defect, proper phase equations between the original upward field and the reflected downward field are derived so that the aperture field becomes uniform enough to guarantee directional radiation. The concave-shaped reflector is primarily adopted to satisfy the phase conditions. Then the concave-shaped reflector is decorated with corrugated structure to realize good impedance matching within the wide band. Consequently, the split beams caused by multiple long linear currents with phase difference at high frequency is focussed while the directivity at low frequency is also improved. The prototype antenna was fabricated with a profile of 20.5 mm, about 0.156 λ max (maximum wavelength in the work band), and the measured impedance bandwidth of VSWR ≤ 2.2 is over 2.27–26 GHz. Both simulated and measured results demonstrate the stable directional patterns within the quintuple band (2–10.5 GHz). The realised gain is over 7 dBi within the band (2–10.5 GHz) and peak is over 12 dBi.

Design and Analysis of Modified UWB Mono-Cone Antenna for WBAN Applications

A low-profile UWB antenna is presented in this paper for wireless body area network (WBAN) applications. The proposed antenna consists of a modified mono-cone structure by adding a semi-sphere on top of the mono-cone. A top-plate is added as overhead to the proposed antenna. This plate leads to a height reduction when compared to conventional mono-cone antennas. In this paper, the effect of ground plane dimensions, effect of top-plate dimensions, effect of the supporting legs and effect of the total height of the antenna is studied to get a better insight into the working of the radiating structure. The antenna operates in the frequency range of 4.1 GHz to 10.1GHz with return loss less than -10dB. The bandwidth of the proposed antenna is 6 GHz. The frequency domain results are obtained by simulating the design using Ansoft HFSS. The voltage standing wave ratio is less than 2 within the frequency range of the proposed antenna design. The influence of the human proximity on the antenna was simulated by placing the proposed antenna over a human body model.

Miniature low profile UWB antenna: New techniques for bandwidth enhancement and radiation pattern stability

ABSTRACTA miniature (30 × 10 mm2) efficient planar monopole antenna with stable radiation pattern for UWB applications (3.1–10.6 GHz) is proposed in this paper. These characteristics, wide bandwidth and radiation stability, are achieved by using original design solutions with maintaining a small size and good efficiency of the system. Based on modified ground plane and loop feeding structure, the first design solution consist to propose a simple technique which not requires any discrete additional elements or circuits and does not affect the overall dimensions of the basic structure. This technique enhances the (−6 dB) bandwidth of the planar monopole antenna by approximately 50% compared to the basic structure while maintaining the same dimension (30 × 10 mm2). The optimized proposed antenna presents a large bandwidth, good radiation stability, total efficiency higher than 70% over the entire band and small size (30 × 10 mm2) which will enable to use it in different UWB applications. In the second step, two L slots are added in the printed circuit board of the proposed UWB antenna to reach a good stability of the radiation pattern on the overall desired band. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1808–1813, 2016

A Low Profile UWB Antenna with Triple Band Suppression Characteristics

The proposed triple band notch antenna is a coplanar waveguide fed radiator with incorporated notching resonators etched for achieving the desired band rejection. Sequential design of UWB antenna is presented for different frequency band rejections. Three different notch antennas are proposed having single band rejection for each antenna. The optimized antenna is achieved by accumulating the three stop band resonators in a single design. The mutual coupling effect of the proposed resonators are investigated in details. Proposed antenna operates from 2.4 to 11 GHz. The introduction of C-shape slot at main radiator, CSRR at ground plane and inverted U-shape slot at the center of the patch results in narrow band rejection of WiMax (3.5 GHz), WLAN (5.8 GHz) and satellite service band (8.2 GHz), respectively. The antenna prototype measures $$31 \times 30\,\hbox {mm}^2$$31A—30mm2. Measured and simulated results fulfil the performance criteria for the proposed antenna.

Design and Ranging Performance of a Low-profile UWB Antenna for WBAN Localization Applications

A very compact low-profile (37.6 mm×27 mm×3.1 mm) unidirectional UWB antenna is proposed for wireless body area network (WBAN) localization applications by focusing on its ranging performance and impulse fidelity in time domain in addition to frequency domain characteristics. The antenna is immune to direct skin contact, and also demonstrates very good frequency and time domain properties in free space or at any distance to a body: reflection coefficient and radiation pattern resilience to body influence; flat transfer function amplitude and linear phase over the desired frequency band from 6 GHz to 9 GHz. Superior time domain performance is demonstrated in simulation and measurements with average impulse fidelity of 97% in both free space and when placed at 0 mm or 3 mm over the body. Off-body ranging measurements show accuracies of the order of 5 cm and achievable range higher than 5 m for almost all frontal directions (16 m being the maximum), with transmitting power complying with the international regulation.

A Novel, Low-Profile, Vertically-Polarized UWB Antenna for WBAN

This paper proposes a novel, low-profile UWB antenna for wireless body area network (WBAN) applications. The antenna has a polarization perpendicular to the body-free-space interface, which is interesting in order to minimize the coupling into the body. Its structure comprises a modified mono-cone with a top-cross-plate and is coaxially fed through the ground plane. The higher frequency band <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\vert S _{11} \vert $</tex></formula> performance is due to the mono-cone while the top-cross-plate is responsible for the lower frequency band. This plate also leads to a height reduction when compared to conventional mono-cone antennas. A comprehensive parametric study is done to provide design guidelines. Both frequency- and time-domain results have been measured and presented to validate the design. Results show that the antenna operates from 3.06 to beyond 12 GHz based on <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\vert S _{11} \vert \le -10~{\hbox {dB}}$</tex></formula> , radiates omni-directionally in the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$H$</tex> </formula> -plane, and has a radiation efficiency over 95%. The system-fidelity factor for UWB signals is adequate for pulse transmission. Finally, the influence of the human proximity on the antenna matching was tested. Results show that its impedance is nearly unchanged as compared to free-space.