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Simulators >> RF Simulators >> I/Q mismatch
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Message started by yhq0413 on Jan 16^th, 2008, 1:26am

Title: I/Q mismatch
Post by yhq0413 on Jan 16^th, 2008, 1:26am

hi
I do not know how to compute the I/Q mismatch?
for example
IP IN QP QN
amplitude(mv) 193 193 190 190

phase(°) 0 92 182 270

the amplitude mismathc is 3mv, is 3db?
the phase error is 2°?

Title: Re: I/Q mismatch
Post by ACWWong on Jan 16^th, 2008, 3:24am

Hi yhq0413,

I would say the IQ phase error is 2^o (assuming you have mixed up 92 with 182 in your phase list). I guess the phase numbers you give would also suggest that the is a non 50:50 duty cycle (slight error in mark/space ratio) on the output differential I and Q.

The IQ amplitude mismatch would be 0.136dB. (20*LOG10[193/190]). That is I is 0.136dB larger than Q in your case.

Often I use differential I and differential Q at the component of frequency of interest (available from pss analyses) to get the IQ mismatch rather than transient simulation and markers on waveforms.

cheers
aw

Title: Re: I/Q mismatch
Post by yhq0413 on Jan 16^th, 2008, 10:42pm

thanks :)
I use the PSS to evaluate the I/Q mismatch