Not exactly Motorola transistor related but the subject reminded me of this:
AC2IQ has developed an interesting pre-distortion "linearizer."
http://www.qrz.com/db/AC2IQ
Linearizers have been used in the cell phone industry to more efficiently
pack more digitally-modulated channels into licensed spectrum. Broadcasters
have been using this technology for the last decade. Swiss ADAT was the
first amateur manufacturer to use the technology in their ADT-200A
transceiver. In fact, it works so well that within limits, the ADAT will
sample the output of a non-linear amp, and correct for the amp's
non-linearity back in the transceiver.
Apparently, AC2IQ is using an analog, rather than a digital method to
achieve extreme linearity from his SD2931x16 MOSFET amp. Not sure what
class the amp is biased. Scroll down to the middle of the page and you can
see the result of his work. This isn't just lab performance. Folks have
observed his 75m signal with no IMD "wings" on their SDR receivers.
I'm aware of digital adaptive pre-distortion techniques, but I've not seen
this done using analog components. Anyone familiar with this type of
circuit?
Paul, W9AC
----- Original Message -----
From: "Paul" <w8aef@q.com>
To: "Amps" <amps@contesting.com>
Sent: Tuesday, April 30, 2013 7:12 PM
Subject: [Amps] Motorola transistors
From: Paul
Sent: Tuesday, April 30, 2013 4:11 PM
To: ScQRPions
Subject: Motorola transistors
Advanced Semiconductor continues to make most Motorola, Philips, and SGS
Thompson RF transistors.
http://www.advancedsemiconductor.com/index.html
de Paul, W8AEF
ZF2JI/ZF2TA 8Q7AA FO8DX/FO0PLA XZ0A VU7RG/VU3PYM TX5A A52PP
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