mixer testing

Hi

I am testing mixer (up converter) with LO 1.15 GHz and IF 80 MHz, i am not getting the desired output (ie the mixed freq. components), at the output only LO is seen without being mixed with the IF, what could be the problem, i am using HSMS-2822 diode for mixing. The design is of Single Balanced Mixer.

There could be many reasons. It's not easy to advice you without seeing any schematic diagram, layout drawing, etc.