1. Design and Fabrication of a Q-BPM Calibration Tone Generator for the ATF2 Ian Bullock August 14, 2008

2. ATF2

3. Q-BPMs Cavity BPMs attached to quadrupole magnets Give 6426 MHz signal downmixed to 20 MHz 20 MHz signal is then digitized and analyzed to determine beam position to better than 100 nm

4. Need for a Calibration Tone Downmix boards have variable gain Downmix boards have variable gain Gain must be calibrated to precisely determine electron bunch displacement Gain must be calibrated to precisely determine electron bunch displacement

5. Calibration Tone Design 714 MHz input from master oscillator TTL logic input to control when output is on 6426 MHz output similar in frequency to signal obtained from a passing electron bunch

6. Calibration Tone Requirements 10 dBm 714 MHz input 10 dBm 714 MHz input 25 dBm 6426 MHz output 25 dBm 6426 MHz output High switch isolation High switch isolation Low noise floor Low noise floor Spectrally pure output Spectrally pure output

7. Calibration Tone Design

8. SMA Connector Design RF Switch FinalBPF Tripler Doubler Splitter Mixer Amp Amp HPF LPF 6426MHzOut 714MHzIn TTL In LPF

9. SMA Design Output

10. SMA Switching Performance Power Measured from Downmix Board at 20 MHz 40 MHz 6426 MHz Switch on: 11 dBm -43 dBm -81 dBm Switch off: -80 dBm -100 dBm

11. PCB Design

12. Conclusions 6426 MHz output acceptable 6426 MHz output acceptable Switch isolation also sufficient Switch isolation also sufficient PCB design still to be tested PCB design still to be tested Final amplifier needed Final amplifier needed Installation in chassis required Installation in chassis required

13. Acknowledgements Doug McCormick Doug McCormick Steve Rock, Susan Schultz, Farah Rahbar Steve Rock, Susan Schultz, Farah Rahbar SLAC, SULI, DOE SLAC, SULI, DOE