[Cydrome Leader]

In sci.electronics.misc wrote:
On Mar 7, 1:51?am, "Tim Williams" wrote:
Hmmm, not a big deal I suspect.

Build a general purpose RF block for, say, 2.45GHz BT or 802.11(etc), or
whatever. ?Give it handles to talk with anything (modulations, bit
streams, etc.), design and build it on a particular fab process, and like
magic, anything incorporating that block will also work. ?Monolithic
inductors can be fabricated with not very good Q at 2.45GHz (I think they
usually peak around Q = 10 or 20 around 5GHz), but enough to do "silicon
oscillators" and stuff. ?Voltage regulation (bandgap, or old school buried
zener) and temperature compensation are no-brainers, as ICs go. ?Want a
DDS? ?Just chuck some more IP at it! ?Then whatever ancillary function
(moisture, temperature sensor, etc.) simply plugs into this mess of
transistors and functions.

I remember working on making bluetooth in a "single chip"
we had a working radio and build an evolution of an existing SOC to
stack
on top of it in a single package

Everything worked great when we tested the first samples, but then
the
software guys started running their code in ROM then the sensitivity
dropped

turned out that the ROM being in a different corner of the SOC coupled
noise
into the radio VCO inductors, but the RAM where the test code was run
didn't



Quite crazy, as all that circuitry is squeezing into a few milimeters of
silicon, when a few decades ago it was, well of course it was migrating to
thick film before monolithic, but before that, it was all machined
cavities, hand-soldered RF transistors, and microstrip everywhere. ?I
suppose Bluetooth would've taken up a whole rack, back in the 70s, and
that's assuming the computing power to provide whatever spread spectrum,
encoding, error detection, etc. functionality is required.

Tim


I worked on one of the very first bluetooth implementations, it was;
a DSP, a flash, an FPGA, an RF chip, a saw filter, a whole bunch of
passives
it was probably 5*5cm PCB fully packed on both sides

In the 1988 to 1990s ish time, there was a story in popular mechanics or
popular science about a digital ghost canceler for television signals that
bounced off buildings. It was huge PCB made using an array of DSPs and
have to have pounds of gold plated ceramic chips on it. It was a pretty
looking board, that must have screamed at like 16MHz or something like
that.

What would that take these days, to basically subtract patterns from a
NTSC signal? A couple chips?