1 www.cst.comCST UGM 2009UWB Antenne Simulation withCST
MICROWAVE STUDIODesign from: A novel tapered slot CPW-fed antenna
for ultra-wideband applications and its on/off-body performance.
Atiqur Rahman, Yang Hao, Member IEEEDepartment of Electronic
Engineering, Queen Mary, University of London IWAT 2007Dr. Frank
Demming-Janssen2 www.cst.comOutline UWB Basics UWB-Antenna
Characterization CST MWS Feature Overview for UWB Antennas/Online
Demo Question/Discussion3 www.cst.comUWB Basics Pulse
communication: no carrier frequency Pulse spectrum of UWB
transmissions pulse in the range from 3.1 GHz to 10.6 GHz UWB is
aimed at high data rates for personal-area networksMain challenge
for Antenna : UWB characteristic of return loss- simulation
possible with any 3D Field Solver (FD, TD, MoM) Ability to preserve
the pulse shape of the transmitted signal in the Farfield- Natural
Solver Choice: TD Solvers!S-ParameterExcitation Pulse and Farfield
signal4 www.cst.comSpecialty of UWB Antennas Broadband antenna
design is often based on frequency independent antennas These
antennas work well for multi band applications but perform badly
for UWB because of pulse distortionLog Spiral Antenna
S-ParameterInput pulse at port Pulse shape in Farfield5
www.cst.comUWB-Antenna Characterization Characterization of the UWB
Antenna performance by Group delay of the transmitted signal Direct
comparison of excitation and transmitted signal (signal
cross-correlation) Group delay is a measure of the transit time of
a signal through a device versus frequency. The variations in group
delay cause signal distortion. Const. group delay -> perfect
signal transmission= - delaygroup The cross-correlation is a
measure of similarity of two waveforms as a function of a time-lag
applied to one of them. Cross-Correlation of 1 -> perfect signal
transmission( ) ( ) d t g f + = n correlatio - cross6
www.cst.comExtraction of Group Delay and Cross-CorrelationGroup
delay and Cross Correlation are secondary data and can be extracted
using the template based post processing features in CST MWS->
Online Demo (later)7 www.cst.comFeatures Overview for UWB Antennas
Arbitrary time signals- Gauss Derivatives- 1st, 2nd.. order
Rayleigh- User Defined- Tabulated Values- Transient Pulse from
Circuit Simulation Time Domain Monitoring- Broadband Farfield
Monitor - Farfield Probe Response Advanced Signal Processing of
Time and Frequency Response including optimization of processed
signals- Power Spectrum Density- Correlation- Standard Operations
(DFTs, FFTs)8 www.cst.comChoice of excitation signalSignal
LibraryVBA scripting of arbitrary time functionsTabulated values9
www.cst.comTime Domain ResultsPort Signal ResponseExcitation and
Reflected SignalPower Spectrum Density of Excitation Signal10
www.cst.comTime Domain ResultsBroadband Farfield MonitorFarfield
Frequency Domain ResponseFarfield Time Response11 www.cst.comTime
Domain ResultsTime Domain FieldsSurface CurrentsE/H Fields12
www.cst.comTime Domain ResultsFarfield Pulse ResponsePulse Response
at arbitrary farfield position13 www.cst.comAdvance Signal
ProcessingSignal ProcessingList can be extended by user specify
operations14 www.cst.comSelect post processing stepAdvance Signal
ProcessingCross-Correlation FunctionLoad Port and Probe SignalTime
DelayMax. Correlation15 www.cst.comUWB Performance of Log
SpiralCross Correlation- no main peak -Farfield Group Delay- large
runtime difference -16 www.cst.comSurface Currents At low
frequency, the full antenna length is used.17 www.cst.comFarfield18
www.cst.comUWB Antenna Test VehicleOnline DemoDesign from: A novel
tapered slot CPW-fed antenna for ultra-wideband applications and
its on/off-body performance. Atiqur Rahman, Yang Hao, Member
IEEEDepartment of Electronic Engineering, Queen Mary, University of
London IWAT 200719 www.cst.comBroadband S-ParameterComparison FD
Solver TD SolverClose match20 www.cst.comUWB Performance of Tapered
Slot CPW AntennaCross Correlationsingle main peakFarfield Group
Delayalmost flat response21 www.cst.comDesign VariationsConformal
UWB AntennaEasy conformal modeling with special bending feature22
www.cst.comDesign VariationsConformal UWB AntennaS-ParameterCross
Correlation23 www.cst.comDesign VariationsNear and Farfield
Results24 www.cst.comThank you