[Amps] worthwhile patents on RF amplifiers?

[Roger (K8RI)]

I'm no expert on patents although I learned more than I wanted with the 
company I worked for.  Most of their products were based on a 
propitiatory process and not patented.   The rational was that without 
the patent information present, the gamble was no one would figure out 
the rather simple process.  It worked and no knockoffs turned up in over 
50 years. Far longer than the patent  system of the day would have 
offered protection.

Somewhere around 50 years, another company finally figured it out, won a 
patent, got greedy, and sued us for 50 years of patent infringement. It 
came out that we had been doing this for 50 years and they lost the case 
and patent.  Now anyone who figures it out can make the stuff as it went 
from an expensive product to a relative inexpensive commodity.  That was 
under the old system, now it's first to patent something, but if it can 
be shown they are holding a patent on a process, algorithm, or product 
that has been commonly used , configured, or produced, then they will 
lose the patent.
Under the new system, we would likely have lost the case and the 
settlement would likely been in the Billions..

The following is what I believe and may be right or wrong.
I don't know if you even need to prove it works, or produce a working 
model.under the new system
It has paved the way for companies that purchase patents and vigorously 
pursue, or defend those patents. I've forgotten the name for such 
slime.  They have no facilities, no devices, generally nothing but the 
patents.  It started a whole new industry.

These hold until someone with enough money to see it through the courts 
for at least several levels, or prove to the USPO their claim is bogus.. 
These places have relatively little invested and hold a LOT of cash, so 
they can hang in there unless the patent is invalidated on the first 
challenge.

In this case, perhaps a Handbook, or few old magazines that predate 
their application would be enough.

73

Roger (K8RI)


On 2/12/2016 Friday 7:13 PM, jtml at losalamos.com wrote:
> I was looking through some recent solid state RF amplifier patents, 
> and 2 stood out for comment here. You may be able to view these or at 
> least the cover sheet and abstracts with online free patent viewers 
> now that you have these numbers:
>
> US0285168 was awarded by the USPO around Dec. of 2007, invented by 
> Steven Dishop of Bellefontaine, OH. The address is given Pearce and 
> Gordon LLP in Cleveland. In it claims are made for a solid state 
> module that has push pull MOSFETs operating at least 200 watts and 50 
> volts. An input and output transformer or balun is used to convert 
> single ended to balanced for the transistors and match (1:4 on 
> output). Then there is a claim for a four FET similar amplifier where 
> a pair of FETs are operated in push pull, with drains tied together, 
> and these are then operated push pull with another similar par, driven 
> out of phase with the first. This one is 400 watts. I don't understand 
> what is unique about any of this, and have seen similar amplifier 
> constructions for decades. How can this patent hold valid?
>
> The second one, US5187580, assigned to Advanced Energy Industries in 
> Ft Collins (a real RF company, BTW) was awarded in Feb. of 1993. In 
> this one the inventors suggest making a single ended MOSFET class E 
> amplifier that works better without a shunt capacitor across D to S of 
> the output device. They claim that the varactor capacitance of the Cds 
> alone is sufficient, even better, and that the larger devices can be 
> made to work at higher power and frequencies this way. Multi-kilowatts 
> and 65 MHz. Normally in class E the voltage at the device is forced to 
> zero before it switches, in this one it switches with substantial 
> voltage across it, even suggests this is better. I don't see mention 
> of improved efficiency with this technique, just very high power 
> availability. Something bothersome is the claim that it must operate 
> in a different class than A, B, AB, C, D, E, F...but no real math or 
> proof of anything other than a suboptimal class E. Its the first RF 
> amplifier patent I have seen where the invention is of a strange 
> performance without sufficient explanation. Maybe I am being stupid 
> and should just take these at face value? One has to wonder if their 
> wattmeters were tricked, or harmonics were excessive, or whatever. 
> None of this is described.
>
> Solid state RF amplifier experts, chime in!
>
> 73
> John
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