Hello,
Can you please take a look at HMC381 and see if it fits your requirements. I think the problem will be at the IF frequency that it is min of 50MHz.
http://www.analog.com/media/en/technical-documentation/data-sheets/hmc381.pdf
You need 90deg between IF1 and IF2 to get the max amplitude at the output.
Thank you,
Assaf