Tiger wrote on Mar 27th, 2009, 10:22pm:1.for the Gilbert based mixer, the input signals are all differencial, so the mixer measurements need differencial soure generater, isn`t it?
Use 180degree Hybrid.
http://www.krytar.com/html/180deg.htmhttp://www.designers-guide.org/Forum/YaBB.pl?num=1233236788Tiger wrote on Mar 27th, 2009, 10:22pm:2. for the ssb mixer which have I & Q two path, how to generate the signal having 90 degree phase?
moreover, how to measure the ssb mixer NF?
Use 90degree Hybrid.
http://www.krytar.com/html/90deg.htmhttp://innovativepp.com/90couplers.htmlBut I can't understand what you mean by "
ssb mixer" ?
Usually "
ssb mixer" means ssb upconverter, here you need to feed LOin
I, LOin
Q, BBin
I and BBin
Q for I/Q mixer.
Then you get RFout as SSB signal. In this case you need two 90degree Hybrids.
Observing point is RFout.
Or you mean complex signal downconverter by "
ssb mixer", here you can get almost ssb signal if you see output signal as BBout
I+j*BBout
Q ?
In this case, you need to feed RFin(Noise Source), LOin
I and LOin
Q for I/Q mixer. You need one 90degree Hybrid.
Observing point is BBout
I or BBout
Q.
You can also get SSB signal by another scheme.
Here you need to feed RFin
I, RFin
Q, LOin for I/Q mixer. You need one 90degree Hybrid. Then you can get almost ssb signal if you see output signal as BBout
I+j*BBout
Q You need one 90degree Hybrid.
Observing point is BBout
I or BBout
Q.
http://www.designers-guide.org/Forum/YaBB.pl?num=1164118091http://www.designers-guide.org/Forum/YaBB.pl?num=1221172918