DESIGN OF ULTRA-WIDEBAND ANTENNA
Paper title: Small Planar Monopole UWB Wearable Antenna with Low
SAR Authors: refer to the paper : )
15/4/2014, 11:30PAM
1OutlineIntroductionOverviewBackground
Antenna designAntenna materialsAntenna geometry
Results and discussionsAntenna performance at free space.
Antenna performance at the presence of the bodySPECIFIC ABSORPTION
RATE (SAR)
Conclusion
2Introduction OverviewUWB technology
3Examples for existing communication standard
GPS (1.571.58 GHz)WCDMA (1.922.17 GHz)Bluetooth (2.4-2.48GHz)
WLAN 802.11b/g (5.15-5.825) WLAN802.11b/g (2.4-2.4835)Wi-max
(3.3-3.6GHz)Commercial UWB (3.110.6 GHz)Vehicle UWB radar
system(22-29GHz)
Body-worn antennas systems embedded into the so-called smart
clothes
Merging between wearable systems, (UWB) technology and textile
technology. FCC 2002
Such flexible antennas can be easily integrated into a piece of
clothing.
Medical Body Area Networks (MBAN)
Applications Towards wearable UWB
DefenseTextile Technologies
Rescue EntertainingHealthcare
Compact [size] Planar [flat] UWB [bandwidth] Antenna for On-body
[wearable] Applications
IssuesSize: efficiency and capability of fabrication.BW:
enhancement techniques and complexity. Wearable: material and
safetyMaterial: conductivity and capability of fabricationSafety:
method (affordability) and better approximation
Work in paperAntenna design Material
Geometry32 34 mm2
r = 1.76loss tangent =0.078Cont..Design optimization
Ground plane optimization
Feeding mechanism optimizationResults
Simulated and measured S11 parameter at free spaceSimulated
S11:2.8 GHz 11.6 GHz, fractional bandwidth (FB)=122%Measured
S11:3.04 GHz 11.3 GHz,FB=109 %Results cont..Simulated radiation
pattern at free space
E-plane (phi = 90)H-plane (phi=0)Performance the presence of
phantoms Body representation (physical & numerical) homogenous
(one dielectric cons)homogenous and layered body model (layered
Rectangles)Inhomogeneous (Voxel)Full or partial?
Examples
Numerical phantom
These figures are based on Intel Xeon E5620 2.4 GHz CPU, 4Tesla
2070 GPUs. license (RM 5K ) Cont..Body Tissue Dielectric Parameters
Tool provided by FCC official website.skin = 2 mm, fat = 3 mm,
muscle = 8 mm and bone = 10 mm. (2 ref journals)
this is because of that the truncation can create a capacitive
load that neutralizes the inductive nature of the patch to produce
nearly-pure resistive input impedance18Results..
Simulated S11
E-plane
H-plane The curve of the measured S11 parameter appears with
slight difference from the simulated one for many reasons. The
antenna was simulated on smooth jeans represented by solid planes,
while the texture of the real material has different composition.
In addition, cutting the copper tape to match the design will
involve errors while tracing the edges and slots of both of the
patch and the ground planes.19SPECIFIC ABSORPTION RATE (SAR)
10-g SAR [W/kg] in the 4-layer body phantomFCC restriction
4W/kg
Calculation time [s]: 18236 ~ 5-6hrs (one result)Conclusion
THANK YOU
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Bending conditions
Further studies Conductive material (better
performance)Conductivity Pattern Stability Reliability Textile
material (better performance)Pattern HomogeneitySAR and methods of
reductionMore accurate resultsOptimize radiation direction to
reduce SAR
Wearable antennas
Specific Absorption Rate (SAR)
UWB Antennas
Proposed work
Planar UWB antennas
Design techniques
Narrowband & wideband antennas
Bandwidth enhancement
Materials of prototypes
Performance
Methods
Tissues properties
Phantoms
Agilent 85070E Dielectric Probe Kit
Probe calibrated in liquid
Calibration
Jeans
Measuring jeans properties
Results
Display
