TY - GEN
T1 - Circuit design to stabilize the reflectometer local oscillator signals
AU - Kung, C. C.
AU - Kramer, G. J.
AU - Johnson, E.
AU - Solomon, W.
AU - Nazikian, R.
PY - 2005
Y1 - 2005
N2 - Reflectometry, which uses the microwave radar technique to probe the magnetically confined fusion plasmas, is a very powerful tool to observe the density fluctuations in the fusion plasmas. Typically, two or more microwave beams of different frequencies are used to study the plasma density fluctuations. The frequency separation between these two beams of the PPPL designed reflectometer system upgrade on the DIIID tokamak can be varied over 18 GHz. Due to the performance of the associated electronics, the local oscillator (LO) power level at the LO port of the I/Q demodulator suffers more than 12 dB of power fluctuations when the frequency separation is varied. Thus, the I/Q demodulator performance is impaired. In order to correct this problem, a power leveling circuit is introduced in the PPPL upgrade. According to the test results, the LO power fluctuation was regulated to be within 1 dB for greater than 16 dB of input power variation over the full dynamic bandwidth of the receiver.
AB - Reflectometry, which uses the microwave radar technique to probe the magnetically confined fusion plasmas, is a very powerful tool to observe the density fluctuations in the fusion plasmas. Typically, two or more microwave beams of different frequencies are used to study the plasma density fluctuations. The frequency separation between these two beams of the PPPL designed reflectometer system upgrade on the DIIID tokamak can be varied over 18 GHz. Due to the performance of the associated electronics, the local oscillator (LO) power level at the LO port of the I/Q demodulator suffers more than 12 dB of power fluctuations when the frequency separation is varied. Thus, the I/Q demodulator performance is impaired. In order to correct this problem, a power leveling circuit is introduced in the PPPL upgrade. According to the test results, the LO power fluctuation was regulated to be within 1 dB for greater than 16 dB of input power variation over the full dynamic bandwidth of the receiver.
UR - https://www.scopus.com/pages/publications/34547770371
UR - https://www.scopus.com/pages/publications/34547770371#tab=citedBy
U2 - 10.1109/FUSION.2005.252974
DO - 10.1109/FUSION.2005.252974
M3 - Conference contribution
AN - SCOPUS:34547770371
SN - 142440150X
SN - 9781424401505
T3 - Proceedings - Symposium on Fusion Engineering
BT - 21st IEEE/NPS Symposium on Fusion Engineering, SOFE'05
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 21st IEEE/NPS Symposium on Fusion Engineering, SOFE'05
Y2 - 26 September 2005 through 29 September 2005
ER -