Measure a Gilbert mixer

I'm working with 5V and 0.5μ (Gilbert topology, see picture). Already calculated geometries and DC bias, and I'd like to know :

- how to calculate conversion gain of mixer ?
- if fabricate chip, how to apply RF signal in differential mode (RF port) ? need a balun or a RF generator can provide differential signal ?
- what other lab instuments I need for measuring ? power supplies for biasing, RF generator, etc ?

Thanks and regards,

The best device for mixer tests is VNA (Vector Network Analyzer).
Another option is to use two signal generators and a Spectrum Analyzer.
To supply signal to a differential input/output you need a balun, that covers the working frequencies. Also can be used a VNA with differential ports (4 ports).
This is an application note from Agilent that explain how to test a mixer:
http://www.educatorscorner.com/media/Exp85.pdf