[Amps] Cell Phone power amps

[Chris Trask]

On Sunday, December 05, 2004 Dan K9EA wrote:

>
> Does anyone have any info or leads to such for using cell phone
> power amps on 903 MHz.  There doesn't seem to be much around that
> I have found.
>
> I have an Ericsson unit that looks good but don't want to reinvent
> the wheel if it's not necessary.
>

    I designed 900MHz and 1800-1900MHz power amps up to 120W when working
for Xemod (now part of Sirenza Microdelusions).  Damned difficult to make
them reproducible for mass production.  But the problem there was that the
LDMOS transistor parameters were all over the place, even for adjacent die.
That and the internal politics (from former Motorola employees) finally
killed that place.  They lost $50M in just 5 years and never had a real
product.  Now they're down to making 10W CATV amplifiers and cell phone
power amplifier drivers.  They won't be around for much longer, and I'm
actually amazed that they haven't already disappeared.

Chris

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