Multipoint voltage and current probe system
A metrology system monitors radio frequency (RF) power at a plurality of locations in a circuit. The system includes a plurality of RF sensors that generate respective analog signals based on electrical properties of the RF power, a multiplexing module that generates an output signal based on the analog signals, and an analysis module that generates messages based on the output signal. The messages contain information regarding the electrical properties that are sensed by the plurality of RF sensors.
1. A metrology system for monitoring radio frequency (RF) power at a plurality of locations in a circuit, comprising:
a plurality of RF sensors that each generates a pair of analog signals based on electrical properties of the RF power at one of the locations in the circuit;
a first multiplexer that receives one of the analog signals from each pair of analog signals and routes one of the received signals to an output of the first multiplexer in accordance with a control signal;
a second multiplexer that receives the other one of the analog signals from each pair of analog signals and routes one of the received signals to an output of the second multiplexer in accordance with the control signal; and
an analysis module that generates messages based on the signals from the output of the first and second multiplexers, wherein the messages contain information regarding the electrical properties that are sensed by the plurality of sense channels.
2. The metrology system of claim 1 wherein the RF sensors are directional couplers.
3. The metrology system of claim 1 wherein the RF sensors are voltage/current (V/I) probes.
4. The metrology system of claim 1 further comprising a plurality of signal conditioning and partitioning modules that connect in series with respective ones of the analog signals from the RF sensors, each signal conditioning module comprising:
a plurality of filters that pass respective frequency components of the associated one of the analog signals;
a plurality of scaling modules that amplify or attenuate at least a portion of the frequency components; and
a combiner that combines the frequency components to generate the signal that is communicated to one of the first and second multiplexers.
5. The metrology system of claim 4 wherein the analysis module further comprises filters that filter respective signals from outputs of the first and second multiplexers.
6. The metrology system of claim 5 further comprising a pair of analog to digital converters that convert respective signals from the first and second multiplexers.
7. The metrology system of claim 6 wherein the analysis module further comprises a plurality of conversion modules that convert the signals from the multiplexers to a baseband frequency that is less than a frequency of the RF power.
8. The metrology system of claim 7 wherein each conversion module includes mixer modules that mix converted signals from the pair of analog to digital converters.
9. The metrology system of claim 8 further comprising decimation modules the decimate output signals from respective ones of the mixer modules.
10. The metrology system of claim 9 further comprising low pass filter modules that filter output signals from respective ones of the decimation modules.
11. A method for monitoring radio frequency (RF) power at a plurality of locations in a circuit, comprising:
generating a pair of analog signals based on electrical properties of the RF power at an associated one of the locations in the circuit;
multiplexing one signal of the pair of analog signals to a first output signal;
multiplexing the other one of the signals of the pair of analog signals to a second output signal; and
generating messages based on the signals from the first and second output signals of the multiplexing steps, wherein the messages contain information regarding the electrical properties that are sensed by the plurality of sense channels.
12. The method of claim 11 wherein the electrical properties include forward power and reflected power.
13. The method of claim 11 wherein the electrical properties include voltage and current.
14. The method of claim 11 further comprising
filtering each of the pair of analog signals into a plurality of respective frequency components;
amplifying at least a portion of the frequency components; and
combining the frequency components to generate respective signals in the pair of signals that is communicated to one of the first and second multiplexers.
15. The method of claim 14 further comprising filtering respective signals from outputs of the first and second multiplexers.
16. The method of claim 15 further comprising digitizing respective signals from the first and second multiplexers.
17. The method of claim 16 converting the signals from the multiplexers to a baseband frequency that is less than a frequency of the RF power.
18. The method of claim 17 further comprising mixing the digitized signal with a digital signal.
19. The method of claim 18 further comprising decimating output signals from respective ones of the mixer modules.
20. The method of claim 19 further comprising filtering the decimated signals.