Article View: sci.electronics
Article #8096Re: A question about a PLL synth loop filter
From: Kenneth J. Hendrickson
Date: Thu, 01 Nov 1990 22:05
Date: Thu, 01 Nov 1990 22:05
33 lines
1683 bytes
1683 bytes
In article <1990Oct31.210242.20619@aplcen.apl.jhu.edu> @aplvax.jhuapl.edu:mjj@stda.jhuapl.edu (Marshall Jose) writes:
%I have been trying to understand a passive loop filter I have twice seen used
%in ham radio construction articles. It looks like this:
%
%
% O---VVVVV----+-------+------O
% R1 | |
% | >
% | > R2
% | >
% --- |
% --- C1 |
% | |
% | ---
% | --- C2
% | |
% O------------+-------+------O
%
%
% C(as + 1)
% H(s) = ---------------------
% 3 2
% s + ps + qs + r
%
Your first clue, is that since you have two energy storage devices, that
you should have two poles. When I solve this, I get:
c1r1 * s + 1
H(s) = ---------------------------------------------
c1c2r1r2 * s^2 + (c2r2 + c1r1 + c2r1) * s + 1
Ken Hendrickson N8DGN/6 kjh@usc.edu ...!uunet!usc!pollux!kjh
Technical Details
Message-ID:
<12890@chaph.usc.edu>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!usc!chaph.usc.edu!aludra.usc.edu!kjhReferences:
<1990Oct31.210242.20619@aplcen.apl.jhu.edu>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!usc!chaph.usc.edu!aludra.usc.edu!kjh From: kjh@aludra.usc.edu (Kenneth J. Hendrickson) Newsgroups: sci.electronics,rec.ham-radio Subject: Re: A question about a PLL synth loop filter Message-ID: <12890@chaph.usc.edu> Date: 1 Nov 90 22:05:53 GMT References: <1990Oct31.210242.20619@aplcen.apl.jhu.edu> Sender: news@chaph.usc.edu Followup-To: sci.electronics Organization: EE-Systems, USC, Los Angeles Lines: 33 Nntp-Posting-Host: aludra.usc.edu