Detecting phase Alexandra Andersson Jonathan Sladen An update on the work on the phase detector for RF syncronisation of CLIC is presented. First results of beam tests, and some offline tests of the full system are presented. This presentation is supported by the Commission of the European Communities under the 6th Framework Programme “Structuring the European Research Area”, contract number RIDS-011899.
System Specifications Phase accuracy: 0.1º Amplitude range: ~6dB Bandwidth: 50MHz, system investigated up to 250MHz
CTF3 Pulse to pulse beam jitter CTF3 beam jitter greatly exceeds the required system accuracy. Two system are built and compared with each other.
CTF3 installation
CTF3 installation
IF phase detection LO generation CTF test setup Down mixing
Static calibration
Static calibration curves Amplifier after mixer limits useful calibration range to a maximum of 22dBm From these curves the amplitude dependant phase multiplication factor, as well as offset, are computed
Test of static calibration routine, offline pulses.
CTF3 results (1)
CTF results (2) Beam data was recorded above the upper limit of the calibration range Fit is not completely terrible
CTF3 results (3) This is the noise for two systems Noise will increase when amplitude dependent phase offset correction is applied Noise measurements look promising at both 250MHz and 50MHz
Work to be completed: Complete static correction algorithm to correct amplitude dependant phase offset Develop a dynamic correction algorithm to correct step response of the system Characterise temperature drift Improve calibration routine Hardware modifications of down converters Further beam tests