Keysight 8478B, Руководство по эксплуатации и обслуживанию

Страница: 27 / 49

Keysight 8478B Thermistor Mount 27
Operating Principles
General Operation
432 Power Detection
Under normal operation, the total power applied to heat thermistor pair “D”
(see Figure 3-1 ) consists of:
1. RF signal
2. heat from the environment
3. dc bias
The total power supplied to heat thermistor “C” consists of:
1. dc bias
2. heat from the same environment
As “D” and “C” are matched thermally, the total amounts of heat applied to
reduce their series resistance equally must be equal.
Figure 3-1 8478B Connected to a 432A Power Meter