-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
A different look at transmission waves, circulators, isolators, gyrators,
scatterometers, and stuff...
See recent PowerPoint presentation entitled "Waves: The Scatterometer and
Other Interesting Circuits" posted in both MS ppt and Adobe pdf formats on
USENET a.b.s.e a couple of days ago.
Discrete componnets! How quaint...
;-) ;-) ;-)
Posted chip-photo and response of 5th order low-pass filter to a.b.s.e as
follow-up. The filter is the lower half of the chip (the upper half is more
of the same at a higher frequency).
I use explicit current for A/B variables and implement the 1st order LP/HP
functions directly in Gm-C blocks, avoiding lossless integration
everywhere.
The reflections (HP response) zeros are not perfect because of (very!)
finite DC gain of the Gm blocks; the response is taken for the Q-tuning
point where the forward (LP) is flat. The difference in flat levels of the
two responses is - again - a function of the finite DC gain. The Qu is
tuned by varying the Gm values in the 1st order sections (a neat trick,
even if I do say so myself).
I'm still annoyed I never got to build a filter using a circulator to
realise an all-pass which in turn is the response I use to emulate Lattice
sections :-(
Best Regards
JEns
- --
Key ID 0x09723C12,
[email protected]/
[email protected]
Analogue filtering / 5GHz RLAN / Mdk Linux / odds and ends
http://www.imaginet.fr/~jensting/ +44 1223 211 585
"We'll get jobs and pay the rent, we'll get credit cards and be happy"
Hartley
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.2 (GNU/Linux)
iD8DBQE/tTKEimJs3AlyPBIRAtuvAKDOA4887HjTPO86w0wzBC4clTpbIgCfQ4ob
b/MtI8OU6K5E4LXdmo3V/TI=
=qM60
-----END PGP SIGNATURE-----