Dear Mr.Joel
Thank you for your prompt support.
And sorry for my poor understanding.
Could I ask some points?
Regarding input level,I could not find the description about the input level in "Less than +/- 1 Degree Deviation from Best Fit Line" in dadtasheet.
So I was misreading that we can get such good deviation feature with any level input.
I think, AD8302 stand-alone has about 10 degree VPHS error with only straight line approximation.
is it suitable?
What should I do to get an accurate phase data with AD8302, like as Datasheet TPC27?
I think
1) Calibration using "the phase difference vs phase out data" that taken by the known signal one by one.
2) Keep same temperature.
3) Adjust, input level to -30dBm
(Fixed frequency)
I think, AD8302 must need calibration, like as 1), if it need a few degree accuracy.
Is the passive phase shifter feature an important factor, when we test AD8302?
Could you advice ?
Regards
moto
>Q: Using the passive phase shifter is possible to measure a few degree error?
>A: If you are measuring in and around 90 degrees, the part will be very accurate, less than 0.5 degrees of error. The error may be dominated by the passive phase shifter.
When the phase shifter using transmission delay, signal level will degrade , but the wave form is not so change, I think.
What make the error increase?
What feature should I need to check ?
Regards
moto