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LLRF for SC Heavy Ion Linear Accelerators Paper study at USPAS17 Qi Chen IMPCAS and LBNL
LLRF for SC Heavy Ion LinearAccelerators
Paper study at USPAS17Qi Chen
IMPCAS and LBNL
Low Level RF block-diagram
Phase / Amplitude Detecting
● I & Q Demodulator
LORF
Some trigonometric equations
Low Level RF block-diagram
Phase / Amplitude Modulation
● I & Q Modulator
LO RF
Some trigonometric equations
How mixer works
● We need new frequency
Ideal Mixer
(Multiplier)
Local
Oscillator
Input
Signal
Output
Signal
How to get 90° phase shift
● When a sinusoidal voltage is applied to either asimple capacitor or inductor, the resultant current thatflows is "in quadrature" with the voltage.
Low Level RF block-diagram
I Value
Q V
alu
e Ampl
itude
Phase
Phase Diagram
I & Q Modulation
● I & Q Modulator
Output
Low Level RF block-diagram
