hybrid for a mixer differential input

Hi, guys,
I need to design a Hybrid to generate a differential RF signal as the inputs of a Mixer. Where could I find useful information for this.
Since my points is so small, so could you give me some links, which can be download freely.
Thank you very much!

For your information; I just saw a nice article in MW journal. They made a RF front end, and part of it was a differential LNA. To convert the single ended input and output to differential signals, they designed a ratrace coupler.

I include the pic of input- and output ratrace couplers. For more info on microstrip hybrids, look for pozar's book (microwave engineering) on the ebook forum.

The full article can be found on
http://www.mwjournal.com/default.asp...onth=10&rsno=2
but you will need to register first

Hope this helps