MAD1108 can they be used in HF mixers?
Also do you expect the diodes inside the same package to be matched?
What other DIP options are there for mixing on HF?
I attach the datasheet
The device is optimized for use in data line protection rather than high frequency. The diodes will not be well matched and they have a high Vf so you would probably need higher signal levels than if normal diodes were used. Their maximum Vf is 1.0V at 10mA, compare that with 0.4V for a Shottky device like the BAT85. The manufacturer doesn't provide a V/I graph as it wouldn't normally be important at low voltages in a protection circuit but I would guess it's performance would be poor. It may also suffer from cross coupling between diodes as it wouldn't normally be expected to conduct at HF. Overall - not a good choice.
If you are looking for DIP packages it might be better to look at active mixers, somethng like the SA602 which has a balanced mixer and oscillator in an 8-pin DIP package.
Brian.