Absolute phase measurement testing device and technique

A structure comprising:

• an intermediate frequency (IF) source;
• an RF frequency source;
• a first mixer at an input of a device under test and which up-converts a signal from the IF frequency source;
• a second mixer at an output of the device under test and which down-converts a signal received from the device under test or the up-converted signal;
• a bypass path which bypasses the device under test and provides connection between the first mixer and the second mixer;
• and
• a splitter which splits a signal from the RF source to the first mixer and the second mixer wherein:
• the first mixer is an up-converter that up converts a low frequency signal from the IF frequency source to a higher frequency signal using the RF frequency source;
• and
• the down-converter down converts the converted RF signal to an IF frequency signal and further comprising:
• switches provided at the input side and the output side of the test fixture, wherein:
• the switch located at the input side switches between providing the up-converted signal to the bypass path or the device under test,
• the switch located at the output side provides a signal from the device under test to the down-converter, and
• when the switch closes a signal path between the up-converter and the device under test, the up-converted signal is fed directly to the device under test and the down-converter down converts a signal received from the device under test.

A method comprising:

• up-converting a source signal using a first signal;
• bypassing a device under test with the up-converted source signal;
• down-converting the source signal using the first signal;
• providing the up-converted source signal to the device under test;
• down-converting a signal received from the device under test;
• and
• determining an absolute phase of the device under test by subtracting the down-converted signal of the device under test from the down-converted signal of the bypassing.