double quadrature detection

Dear All,

Does any one know her I can find a description/analysis of the so called double quadrature detector? This is basically two IQ detectors acting on the RF signal and on a 180 shifted version of RF. Then, you make 0-180 and 90-270, to get I and Q.

This is supposed to have better performance than the simple IQ detector, but I don't know why.

Tanks

josé mariano

Detector (radio) - Wikipedia, the free encyclopedia

This is the simple one. I'm looking for the double...

I guess the idea is that in a normal quadrature detector, phase or amplitude errors between the LO signals propagates as images in the IF output. With double quadrature, you get two pairs of IF outputs and when they are summed together the errors will cancel.

Here's the best resource I could fine on the topic:
Circuit design for wireless ... - Google Books

Thanks a lot mtwieg, this is exactly what I was looking for.

Cheers

josé mariano