Vector network power meter
View Patent ↗System and method for implementing a Vector Network Power Meter (VNPM) as a new class of electronic test instrument that uses a novel topology based upon a reflectometer to combine the functionality of a Power Meter with that of a Vector Network Analyzer (VNA). The VNPM overcomes application limitations of the two existing classes of test instruments, including parallel and simultaneous measurement capability, in-circuit operation, and improved accuracy and repeatability by eliminating the calibration of interconnecting cabling. Also provided are alternate implementations of a correlator for the reflectometer which reduce the size and complexity of the correlator while extending its frequency range without limit.
1. An apparatus including a radio frequency (RF) vectorial signal measurement system, comprising:
reflectometer circuitry having a plurality of signal ports to receive a source signal, to convey to a load an incident signal related to said source signal and to receive from said load a reflection signal, and to provide a plurality of measurement signals related to said incident signal, said reflection signal, and one or more combinations of said incident and reflection signals together, wherein
said plurality of signal ports includes
a source signal port to receive said source signal,
a load signal port to convey to said load said incident signal and to receive from said load said reflection signal,
a first signal port to provide a first measurement signal related to said incident signal,
a second signal port to provide a second measurement signal related to said reflection signal,
a third signal port to provide a third measurement signal related to a sum of said incident signal and said reflection signal, and
a fourth signal port to provide a fourth measurement signal related to another sum of said incident signal and said reflection signal, and
said reflectometer circuitry further includes
first frequency conversion circuitry responsive to a local RF signal and said incident signal by providing said first measurement signal and a corresponding first orthogonal signal with mutually common lower frequencies than and corresponding to said incident signal, and
second frequency conversion circuitry responsive to said local RF signal and said reflection signal by providing said second measurement signal and a corresponding second orthogonal signal with mutually common lower frequencies than and corresponding to said reflection signal; and
conversion circuitry coupled to said reflectometer circuitry and responsive to at least a portion of said plurality of measurement signals by providing a plurality of conversion signals indicative of respective magnitudes of said plurality of measurement signals, wherein said conversion circuitry is responsive to at least said first, second, third and fourth measurement signals by providing at least first, second, third and fourth conversion signals indicative of first, second, third and fourth magnitudes of said first, second, third and fourth measurement signals, respectively.
2. The apparatus of claim 1 , wherein:
said third measurement signal comprises a sum of said incident signal and said reflection signal; and
said fourth measurement signal comprises a sum of said incident signal and a signal corresponding to and orthogonal to said reflection signal.
3. The apparatus of claim 1 , wherein:
said third measurement signal comprises a sum of said incident signal and said reflection signal; and
said fourth measurement signal comprises a sum of said reflection signal and a signal corresponding to and orthogonal to said incident signal.
4. The apparatus of claim 1 , wherein:
said third measurement signal comprises a sum of said first measurement signal and said second measurement signal; and
said fourth measurement signal comprises a sum of said first measurement signal and a signal corresponding to and orthogonal to said second measurement signal.
5. The apparatus of claim 1 , wherein:
said third measurement signal comprises a sum of said first measurement signal and said second measurement signal; and
said fourth measurement signal comprises a sum of said second measurement signal and a signal corresponding to and orthogonal to said first measurement signal.
6. The apparatus of claim 1 , wherein said reflectometer circuitry further includes:
first frequency conversion circuitry responsive to a local RF signal and said incident signal by providing at least said first measurement signal with a lower frequency than and corresponding to said incident signal; and
second frequency conversion circuitry responsive to said local RF signal and said reflection signal by providing at least said second measurement signal with a lower frequency than and corresponding to said reflection signal.
7. The apparatus of claim 6 , wherein said reflectometer circuitry further includes:
first signal combining circuitry coupled to said first and second frequency conversion circuitries, and responsive to said first and second measurement signals by providing said third measurement signal; and
second signal combining circuitry coupled to said first and second frequency conversion circuitries, and responsive to a portion of said at least said first measurement signal and a portion of said at least said second measurement signal by providing said fourth measurement signal.
8. The apparatus of claim 7 , wherein said reflectometer circuitry further includes:
a fifth signal port to provide a fifth measurement signal related to still another sum of said incident signal and said reflection signal; and
third signal combining circuitry coupled to said first and second frequency conversion circuitries, and responsive to
said portion of said at least said first measurement signal and another portion of said at least said second measurement signal, or
another portion of said at least said first measurement signal and said portion of said at least said second measurement signal,
by providing said fifth measurement signal.
9. The apparatus of claim 1 , wherein said reflectometer circuitry further includes:
first signal combining circuitry coupled to said first and second frequency conversion circuitries, and responsive to said first and second measurement signals by providing said third measurement signal; and
second signal combining circuitry coupled to said first and second frequency conversion circuitries, and responsive to said first measurement signal and said second measurement signal by providing said fourth measurement signal.
10. The apparatus of claim 9 , wherein said reflectometer circuitry further includes:
a fifth signal port to provide a fifth measurement signal related to still another sum of said incident signal and said reflection signal; and
third signal combining circuitry coupled to said first and second frequency conversion circuitries, and responsive to
said first measurement signal and said second orthogonal signal, or
said first orthogonal signal and said second measurement signal,
by providing said fifth measurement signal.
11. The apparatus of claim 1 , wherein said conversion circuitry comprises RF signal power detection circuitry.
12. The apparatus of claim 1 , further comprising processing circuitry coupled to said conversion circuitry and responsive to said first, second, third and fourth conversion signals by providing one or more data signals indicative of one or more of:
a magnitude of said incident signal;
a phase of said incident signal;
a magnitude of said reflection signal; or
a phase of said reflection signal.
13. The apparatus of claim 12 , wherein said processing circuitry comprises a field programmable gate array.
14. The apparatus of claim 1 , further comprising:
a RF signal source to provide a local RF signal; and
processing circuitry coupled to said conversion circuitry and said RF signal source, and responsive to said first, second, third and fourth conversion signals and said local RF signal by providing one or more data signals indicative of one or more of
a magnitude of said incident signal,
a phase of said incident signal,
a magnitude of said reflection signal, or
a phase of said reflection signal.
15. The apparatus of claim 1 , wherein said reflectometer circuitry further includes a fifth signal port to provide a fifth measurement signal related to still another sum of said incident signal and said reflection signal.
16. The apparatus of claim 15 , wherein:
said third measurement signal comprises a sum of said incident signal and said reflection signal;
said fourth measurement signal comprises a sum of said incident signal and a signal corresponding to and orthogonal to said reflection signal; and
said fifth measurement signal comprises a sum of said reflection signal and a signal corresponding to and orthogonal to said incident signal.
17. The apparatus of claim 15 , wherein:
said third measurement signal comprises a sum of said first measurement signal and said second measurement signal;
said fourth measurement signal comprises a sum of said first measurement signal and a signal corresponding to and orthogonal to said second measurement signal; and
said fifth measurement signal comprises a sum of said second measurement signal and a signal corresponding to and orthogonal to said first measurement signal.
18. A method for performing radio frequency (RF) vectorial signal measurements, comprising:
receiving, via one of a plurality of signal ports of reflectometer circuitry, a source signal;
providing, to a load via another of said plurality of signal ports of said reflectometer circuitry, an incident signal related to said source signal;
receiving, from said load via said another of said plurality of signal ports, a reflection signal;
providing, via further ones of said plurality of signal ports of said reflectometer circuitry, a plurality of measurement signals related to said incident signal, said reflection signal, and one or more combinations of said incident and reflection signals together, including
providing, via a first signal port of said reflectometer circuitry, a first measurement signal related to said incident signal,
providing, via a second signal port of said reflectometer circuitry, a second measurement signal related to said reflection signal,
providing, via a third signal port of said reflectometer circuitry, a third measurement signal related to a sum of said incident signal and said reflection signal,
providing, via a fourth signal port of said reflectometer circuitry, a fourth measurement signal related to another sum of said incident signal and said reflection signal,
responding to a local RF signal and said incident signal by providing said first measurement signal and a corresponding first orthogonal signal with mutually common lower frequencies than and corresponding to said incident signal, and
responding to said local RF signal and said reflection signal by providing said second measurement signal and a corresponding second orthogonal signal with mutually common lower frequencies than and corresponding to said reflection signal; and
converting at least a portion of said plurality of measurement signals to a plurality of conversion signals indicative of respective magnitudes of said plurality of measurement signals, including converting at least said first, second, third and fourth measurement signals to at least first, second, third and fourth conversion signals indicative of first, second, third and fourth magnitudes of said first, second, third and fourth measurement signals, respectively.
19. The method of claim 18 , wherein:
said providing a third measurement signal comprises combining said incident signal and said reflection signal; and
said providing a fourth measurement signal comprises combining said incident signal and a signal corresponding to and orthogonal to said reflection signal.
20. The method of claim 18 , wherein:
said providing a third measurement signal comprises combining said incident signal and said reflection signal; and
said providing a fourth measurement signal comprises combining said reflection signal and a signal corresponding to and orthogonal to said incident signal.
21. The method of claim 18 , wherein:
said providing a third measurement signal comprises combining said first measurement signal and said second measurement signal; and
said providing a fourth measurement signal comprises combining said first measurement signal and a signal corresponding to and orthogonal to said second measurement signal.
22. The method of claim 18 , wherein:
said providing a third measurement signal comprises combining said first measurement signal and said second measurement signal; and
said providing a fourth measurement signal comprises combining said second measurement signal and a signal corresponding to and orthogonal to said first measurement signal.
23. An apparatus including a radio frequency (RF) vectorial signal measurement system, comprising:
reflectometer means for
receiving a source signal,
providing to a load an incident signal related to said source signal,
receiving from said load a reflection signal, and
providing a plurality of measurement signals related to said incident signal, said reflection signal, and one or more combinations of said incident and reflection signals together, including
providing a first measurement signal related to said incident signal,
providing a second measurement signal related to said reflection signal,
providing a third measurement signal related to a sum of said incident signal and said reflection signal,
providing a fourth measurement signal related to another sum of said incident signal and said reflection signal,
responding to a local RF signal and said incident signal by providing said first measurement signal and a corresponding first orthogonal signal with mutually common lower frequencies than and corresponding to said incident signal, and
responding to said local RF signal and said reflection signal by providing said second measurement signal and a corresponding second orthogonal signal with mutually common lower frequencies than and corresponding to said reflection signal; and
conversion means for responding to at least a portion of said plurality of measurement signals by providing a plurality of conversion signals indicative of respective magnitudes of said plurality of measurement signals, including responding to at least said first, second, third and fourth measurement signals by providing at least first, second, third and fourth conversion signals indicative of first, second, third and fourth magnitudes of said first, second, third and fourth measurement signals, respectively.
24. The apparatus of claim 23 , wherein:
said providing a third measurement signal comprises combining said incident signal and said reflection signal; and
said providing a fourth measurement signal comprises combining said incident signal and a signal corresponding to and orthogonal to said reflection signal.
25. The apparatus of claim 23 , wherein:
said providing a third measurement signal comprises combining said incident signal and said reflection signal; and
said providing a fourth measurement signal comprises combining said reflection signal and a signal corresponding to and orthogonal to said incident signal.
26. The apparatus of claim 23 , wherein:
said providing a third measurement signal comprises combining said first measurement signal and said second measurement signal; and
said providing a fourth measurement signal comprises combining said first measurement signal and a signal corresponding to and orthogonal to said second measurement signal.
27. The apparatus of claim 23 , wherein:
said providing a third measurement signal comprises combining said first measurement signal and said second measurement signal; and
said providing a fourth measurement signal comprises combining said second measurement signal and a signal corresponding to and orthogonal to said first measurement signal.