Multipactor in Low Pressure Gas and in ... - of Richard Udiljak

Noise (dBm)
Power #1 (dBm)
Match #1 (dB)
Power #2 (dBm)
−65
−70
−75
−80
−85
Amplitud Modulation, w2/w1=1.16)
0 1 2 3 4 5 6 7 8 9 10
x 10 4
48
47.5
47
46.5
0 1 2 3 4 5 6 7 8 9 10
x 10 4
40
20
0
0 1 2 3 4 5 6 7 8 9 10
x 10 4
−20
−11
−11.5
−12
0 1 2 3 4 5 6 7 8 9 10
x 10 4
Time (ms)
Figure 2.9: Multipactor experiment with two carriers with E2/E1 = 0.36
and ω2/ω1 = 1.16. Due to a high maximum secondary yield,
multipactor suppression is not possible (the material used in the
experiment was plain aluminium, which can have a σse,max ≈ 3).
When the modulation signal is applied, the magnitude of the
multipactor noise increases significantly.
Signal amplitude [−]
1
0.5
0
−0.5
−1
Square Root Raised Cosine filtered QPSK signal
1 1.5 2 2.5
Time [µ s]
3 3.5
Figure 2.10: Example of a QPSK modulated signal after bandpass filtering.
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