Reports until 19:00, Wednesday 01 June 2016
H1 ISC
haocun.yu@LIGO.ORG - posted 19:00, Wednesday 01 June 2016 (27492)
AS WFS RF signals calculation (90MHz updates)

Sheila, Rich, Keita, Haocun

We calculated the expected value of RF signals from AS WFS in different frequencies, and compared them with our measurements.

Based on DC powers on each sensor calculated in the ASC modelling document (T0900511 Append A.2), we considered the WFS notches and transimpedaces at each frequency (S1300635), the triplexer transfer functions (E1600027). There can be some other losses eg. through the cables that we did not take into account in the calculation.

The theoretical and measured signal values at RF IN are summerized as below, with all values calibrated into the unit of dBm.

Frequency @channel Calculation Measurement Discrepancy
36MHz @36MHz  -27.6 -23 -4.6
45.5MHz @45MHz -3.9 -8 4.1
54MHz @45MHz -37.0 -45 8.0
91MHz @91MHz -60.4 -72 11.6