rf receiver design saw filter

Im considering using a analog devices mixer (adl5350) in a RX design. I believe its either a single balanced or unbalanaced mixer (not sure). Im certain its not double balanced.

My LO freq range going into the Mixer LO port is: 2260MHz - 2343MHz

My IF freq coming out of the MIxer IF port is: 140 MHz

I am using a 140MHz IF Saw FIlter with BW of 1MHz

If this mixer is unbalanced will any of the harmonics/spurs show up within the passband of the 140MHz IF SAW Filter?

If this mixer is single balanced will any of the harmonics/spurs show up within the passband of the 140MHz IF SAW Filter?

Would it help the design any if I place an attenuator in front of the mixer? (see attachment)

An attenuator placed to the input of the mixer will improve IIP3 of the system, but will decrease Noise Figure.
Use the freeware program AppCad for system analysis:
http://www.hp.woodshot.com/

Thanks! What about a "freeware" program for analyzing mixer spurios products?

http://101science.com/RFSim99.exe

I have a RF input range of 2400MHz - 2483Mhz

I have a LO input range of 2260MHz - 2343Mhz

I have a ouput of 140MHz

WHat do I place into the Variable Frequency section?

What do I place into the Fixed Frequency Section?

What is the significance of the order box?