[Amps] Pre-Distortion Linearizer

[Paul Christensen]

> Check out US Patent 4588958 by Allen Katz K2UYH.  It's a common way to 
> linearize solid state PAs for the cellular market back in the day.

Great info, Jeff.  Looks like K2UYH has multiple, related linearization 
patents.   Also, thanks for passing on the references.

In looking at his patent citations, work really accelerated around the time 
of the cellular industry explosion.   I imagine AT&T/Bell Labs was faced 
with similar spectral efficiency issues with its Long Lines carrier 
microwave systems, but they had more usable licensed spectrum way up at 6 & 
11 GHz where fixed, point-to-point communication is possible at those 
wavelengths -- but not roving communications.

Often when the subject of pre-distortion comes up, the usual questions is 
"why doesn't manufacturer X have this technology?"  Peering through the 
patent data is one reason why.  It's easy for us to want the technology --  
not so easy for the manufacturers to wade through the intellectual property 
landmines or secure licensing agreements.

Paul, W9AC