Should we put 90deg delay line before or after schottky diodes in IQ mixer?

[Terminator3]

For example, we have quadrature transmit mixer:
1) power divider, 2)diodes of I and Q channel, 3)90deg delay at Q channel, 4)power combiner

What if we put 90 deg delay line before diodes, does it makes any difference?:
1) power divider, 3)90deg delay at Q channel (before diodes), 2)diodes of I and Q channel, 4)power combiner

Thanks

 

[biff44]

before or after? Care to use engineering terms, like RF port, IF port, etc.

For a downconverting mixer, the 90 degree phase shift has to go in the RF or LO ports. If you put it at the IF port, it does not do the same thing, the signal is already sampled by then.

 

[Terminator3]

Thank for your reply. Sorry for my terminology. Before is lo port after divider, and after is rf port before combiner. So i assume there is no difference when putting 90deg shift to lo port divider or rf port combiner...