Been awhile since I've been
on the forum, and in that time, I had to take a
new job. Instead of designing cutting edge products
for the semi industry, I'm performing cost reduction
Easy at first, but now I'm faced
with the mother of all cost reductions - All the
semis are sucked into an asic, and all that surrounds
it are passives.
Anyway, the boss want's his
pennies, and that's what I'm paid for, so here's
This device uses a 430MHz RF
link with one end in the ASIC and the other in a
bottom loaded antenna that's comprised of a descrete
inductor and PCB trace.
Between, there's a fourth-order,
LC, underdamped low pass / matching network with
the (~4dB) bump centered on the desired frequency.
The filter network is comprised of discretes, and
the PCB lacks space for much in the way of resonant
I'm curious whether it would be a worthwhile
to use PCB inductors (15-90nH) and run-of-the-mill
capacitors - currently, the designer has Johanson
Also, I'm curious whether the entire
scheme can be scrapped for a tuned loop antenna
- like you find in car alarm remotes.