Webmaster's Note: This page was created by Randy Roberts of RFSS Consulting on 8/5/98.
We have updated the links and have changed the manufacturer's name from "Harris" to
"Intersil". No changes have been made at this time to the contents of the
"Experience" section; one of these days I'll pin Jim down and get an update!
We just completed our third radio design with this great chipset. In two of these designs we used only selected parts from
this growing lineup, in the third however, we used five of the six of the chips in the basic "PRISM" chipset.
All three of these new designs were done for clients and all essential design details are their proprietary property. However, we
learned a few things along the way. We will share some of what we learned on this page.
This page provides links to many of Intersil's PRISM information pages, as well as other pertinent
"PRISM" design information.
NOT ALL of the six Intersil PRISM chips are useful (or even work!) -- stick to the THREE Basic
useful chips: 3524 PLL, 3724 Mod / Demod / LPF & 3824 Baseband!
Find and use a new RF section if you are serious about building a DSSS radio quickly
with these parts!
Start your software / firmware development with the Intersil PRISM software furnished
with the Eval Boards!
Buy the PCMCIA Demo Board Kit -- It makes a great "Show & Tell" demonstration for
management and marketing! You can also use them for live on-the-air tests, protocol development and
RF environment testing.
Use the Intersil PRISM Reference Design schematic ONLY as a starting point!
Seriously consider hiring a consulting company like Pegasus Technologies, one of Intersil's PRISM certified
consultants, or other EXPERT who has real live experience with PRISM -- It'll save plenty of time, money AND headaches!
Passing Thoughts
The full Intersil PRISM chipset is not OPTIMUM for EVERY Application -- select the Intersil PRISM
chip subset you need very carefully!
Getting more than 50 to 80 milliwatts through that RF output bandpass filter, diversity antenna
switch and other RF output matching / protection circuitry (with decent intermods that meet FCC specs)
is not easy (IT'S NEARLY IMPOSSIBLE!)
If you want more radio range than you can get with the Intersil RF PA - T/R Switch, look at discrete
GaAsFET RF power amplifier designs that are capable of 2 to 4 Watts to give you enough linearity and
"headroom" to linearly amplify a DSSS signal!
Processing Gain in Spread Spectrum
Signals
