Upload
truongquynh
View
216
Download
1
Embed Size (px)
Citation preview
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 1
Research activities of the IMP utilizing CST MicrowaveStudio
European User Conference 2013
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 2
Outline
Varactor design based on a tunable ceramic Alex Wiens et al.
Tunable polarizer based on Liquid Crystal (LC) Sebastian Strunck
Cavity sensor for Schottky measurements at particle accelerators
Varactor Design based on a tunable ceramic
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 3
Varactors are part of tunablematching networks e.g. π-network
Multi-band/multi-standard requirementsWifi, LTE, UMTS etc.Software defined radio
Aim: Multi-band coveragewith single transistor type
Varactor Design: Barium-Strontium-Titanate
Ceramic materialNonlinear polarization
dependent on electricalfield
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 4
Metal
Alumina
BST
Varactor Design on BST Thick Film
Varactor realized as Inter-Digital-Capacitor integrated DC Bias-NetworkAim: high tunability (ΔC/ΔUBias )
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 5
Varactor Design: Simulation
Varactor Model construction Electrostatic solver on a homogenious
substrate Local field analysis Construct tuned substrate based on a
BST tunability model RF simulation to extract S-Parameter
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 6
Varactor Design: Macro for tuned substrate
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 7
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 8
Outline
Varactor design based on a tunable ceramic Alex Wiens et al.
Tunable polarizer based on Liquid Crystal (LC) Sebastian Strunck
Cavity sensor for Schottky measurements at particle accelerators
Tunabel polarizer based on Liquid Crystal (LC)
Liquid crystalUniaxial crystals anisotropic material nemantic phase
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 9
Tunabel polarizer based on Liquid Crystal (LC)
Elliptical Waveguide, twisted 90°
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 10
Tunabel polarizer based on Liquid Crystal (LC)
Cylindrical waveguide filled with LC Orientation of LCs causes „electrically elliptical“ waveguide Aim: high transmission and low polarization crosstalk Need for a full tensor material
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 11
Tunabel polarizer based on Liquid Crystal (LC)
Expansion of the „Create full tensor material“-macro allows creation of multiple slices with certain thickness and rotation angle
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 12
Tunabel polarizer based on Liquid Crystal (LC)
Simulation at 50 GHz 90° Twist of Polarisation, 20 LC elements providing a per step rotation of
4,5°.
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 13
Tunabel polarizer based on Liquid Crystal (LC)
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 14
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 15
Outline
Varactor design based on a tunable ceramic Alex Wiens et al.
Tunable polarizer based on Liquid Crystal (LC) Sebastian Strunck
Cavity sensor for Schottky measurements at particle accelerators
Cavity sensor for Schottky measurements
Goal: “Design a Schottky Sensor with very high sensitivity to detect smallest beam-currents down to single particles for the Collector Ring at FAIR.”
Schottky Noise: Current fluctuation caused by the discrete charge carriers Gives insight about the energy/frequency distribution of the particles
Cavity is used as a resonant sensor
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 16
Cavity Sensor: Principle
Charged particles couple to E-field Circular waveguide resonator – „pillbox“ First two modes with E-Field in direction of particle movement Excitation of monopole mode around 10^4 times stronger
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 17
Dipolmode - TM110Monopolmode - TM010
Cavity Sensor : Pillbox
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 18
Pillbox cavity
couple slot
Nose
cavity length
radius
length (z) &heigth (radial)
Cavity Sensor: Waveguides
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 19
waveguides/resonators
coupling slots(length & width)
length
width
heigth
Cavity Sensor
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 20
Cavity Sensor: Eigenmodes
Monopole mode not expanded intowaveguides
Dipole mode expandedinto waveguides
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | 21
Cavity Sensor: Optimization
Matlab is used to control MWS Optimization of R/Q-value with the Eigenmode Solver R/Q is a measure for the energy transfer between particle and cavity dependent on geometry only differrent geometry for the nose Monopole mode frequency is kept as 200 MHz by adjusting the cavity radius
Different dimensions of coupling slot detune cavity modes and waveguideresonator eigenmode frequencies Monopole mode at 200 MHz again with adjusting cavity radius Waveguide length optimized to scope with changed dipole mode frequency
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 22
Cavity Sensor: Optimization
Matlab is used to control MWS Optimization of R/Q-value with the Eigenmode Solver R/Q is a measure for the energy transfer between particle and cavity dependent on geometry only differrent geometry for the nose Monopole mode frequency is kept as 200 MHz by adjusting the cavity radius Different dimensions of coupling slot detune cavity modes and waveguide
resonator eigenmode frequencies Monopole mode at 200 MHz again with adjusting cavity radiusWaveguide length optimized to scope with changed dipole mode frequency
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | 23
Cavity Sensor: Measurement vs. Simulation
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 24
Cavity Sensor: Measurement vs. Simulation
29.03.2013 | ETiT | Institute of Microwave Engineering and Photonics | Matthias Hansli | 25