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Measurements >> RF Measurements >> Measuring RX IMR
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Message started by uncle_ezra on Apr 25^th, 2007, 10:40pm

Title: Measuring RX IMR
Post by uncle_ezra on Apr 25^th, 2007, 10:40pm

How do you measure RX IMR? Do we input two tones and measure the wanted and image signal in the baseband?

Title: Re: Measuring RX IMR
Post by uncle_ezra on Apr 26^th, 2007, 2:19am

I guess you just need to input a single tone and if there is I/Q imbalance in your receiver you will see the image appear at the output. How do you determine the frequency at which the image will appear?

Title: Re: Measuring RX IMR
Post by ACWWong on Apr 26^th, 2007, 2:50am

you need to input just one signal at the image frequency at the RF input, which causes an in-band response in your receiver. The ratio of this image stimulated in-band response versus a wanted input signal response gives you the image rejection.

The input RF image frequency depends on your architecture... for a super-het, it is offset from the LO by the IF (opposite side to the wanted frequency).