CST天线仿真笔记

Co- / Cross-Polarization
The co-polarized far field component has the same polarization as the excitation (y-oriented in above case). The cross-polarized far field component is orthogonal to the copolarized component and main lobe direction.

For lossless antennas in isotropic environment the correlation and diversity gain can also be calculated from S-Parameters
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Antenna Examples Overview
Category Reflector Examples Parabolic dish Corner reflector Rectangular horn Circular horn Ridged horn Waveguide array Dipole LPDA, Yagi-Uda Helix Printed antennas Discone Typical Applications Communication Radar Radio astronomy Radar Reflector feed Calibration standards Measurement Communication GPS EMC measurement RFID Almost anything else… Radar Communication GPS Imaging Solvers
Construct simple Antenna Examples
Please note: Simulation settings in these macros are optimal for fast simulation runtime.
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TIS far-field monitors are created. TIS is also displayed in far-field plot.
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SAR Results
2D or 3D plot including information about the position of the maximum. Opens logfile containing all results.
Kra, Jeb / v1.0 / 02. July 2012 CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com
Antenna Examples
Ready-to-simulate antennas are available here:
Online Help -> Examples and Tutorials
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Farfield Definitions
Approximation:
EAbs (enabled)
EAbs (disabled)
E1
E1
2
2
E2
E2
2
2
ER
2
Radiation efficiency:
CST MWS Examples -> Transient Analysis Examples -> Antennas -> Overview
CST MWS Examples -> Integral Solver Examples -> Antennas -> Overview
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Co- / Cross-Polarization
1. Select the tab “Axes“. 2. Click “Main lobe alignment“. 3. Choose the “Ludwig 3“ coordinate system. Polarization vector direction (arbitrary user input possible). If “Main lobe ... “ is not selected, the user can enter arbitrary directions for: polarization plane normal (z‘) (= theta axis), cross-polarized component (x‘) (= phi axis).
Diversity / MIMO Antennas
Multiple antennas (antenna diversity) may overcome problem of fading dips.
Antenna 1

TBP -> Farfield Result -> MIMO
Select from:
Specify linear or logarithmic TIS output. Only one (TIS or TRP) can be displayed at the time. TIS can also be applied to CST Design Studio full system or multi-port combined results (similar to TRP).
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Definition of Farfield Probes
Farfield monitors record the radiation in all directions for one frequency. Farfield probes record the radiation in one direction for all frequencies.
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Phase Center Calculation
= y‘z‘ plane = x‘z‘ plane
Finding the best location to place the horn inside a parabolic antenna. The best position is to match the focal point of the dish with the phase center of the horn.
In order to use different polarizations for transmitting/receiving, an antenna design goal might be to maximize the co-polarized and minimize the cross-polarized component.
Visualization of max. SAR cube Macros -> Results -> 2D 3D Results -> Plo来自百度文库 Averaging Volume for maximum SAR value
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Specify power level in Watt or dBm. Choose linear or logarithmic TRP output (in farfield plot).
Results -> Combine Results Template Based Postprocessing (TBP) -> Farfield and Antenna Properties -> Farfield Result -> Evaluation Range: 3D -> Result value: TRP
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How to generate Farfield Results II
Define a farfield monitor at several frequencies (macro is available)
erad radiated power accepted (input) power
Total efficiency:
etotal radiated power stimulated power power radiated per unit solid angle radiated power
Directivity:
Antenna Simulation
Application Note CST STUDIO SUITE™
Antenna Examples Simulation Setup Post Processing Co/Cross Polarization Phase Center Ludwig 3 Antenna Array Tips & Tricks
Aperture
Wire (Slot)
Patch
Rectangular patch Circular patch Patch arrays
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How to generate Farfield Results I
Define boundaries as open (add space) Define a farfield monitor at the frequency of interest Make sure that the antenna radiates at the farfield monitor frequency
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Total Isotropic Sensitivity (TIS)
TIS handling is very similar to TRP .
Specify receiver sensitivity in Watt or dBm.
D( , ) 4
Component definition:
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Total Radiated Power (TRP)
There are three possibilities to calculate the TRP value: Macros -> Results -> Farfield -> Show Total Radiated Power (TRP)
• Diversity Gain • Envelope Correlation Coefficient • Multiplexing Efficiency
Antenna 2
„best of“ (diversity gain)
Load farfield of second antenna Set XPR and power distribution