[Premium-Rx] first mixer

[John Miles]

> Hello All
> 
> I would like some ideas, I am thinking about designing a mixer stage for a
> hf receiver for the best 3rd order intercept.
> But there are big variety of mixers passive like the balanced diode mixer
> and active like the type used on some Racal with 4 fets.
> As I am a newbie I am trying to understand the issues involved.
> 
> 73's

If you don't already own Hayward et al.'s "Experimental Methods in RF
Design," it'd be well worth your time to chase down a copy.   Chapter 5 is
what you're after.  It sounds like the G3SBI H-mode topology is the authors'
favorite (also see
http://martein.home.xs4all.nl/pa3ake/hmode/hmode_intro.html for more on
that.)

The big win with diode mixers -- possibly their only advantage besides cost
-- is that they can be very broadband in nature, limited only by their
transformers.  At this point in time, I don't think many designers would
advocate passive mixers for a high-performance HF receiver.

-- john, KE5FX