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I/Q Demodulation and Analog Processing

Apr 5th 2018, 15:10

WN8P

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I am looking for information that gives the mathematics of the output for an I/Q demodulator for various signals, such as for AM: C(t) = [i squared (t) + q squared (t)]1/2 power. And how to implement using analog circuitry.
Apr 5th 2018, 17:43

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Is this the math you want?
http://ecee.colorado.edu/~mathys/ecen4652/pdf/lab08.pdf

This page has references to AM Synchronous Demodulator Circuits
http://user.netonecom.net/~swordman/Radio/ShortWaveRadio.htm
Apr 9th 2018, 00:00

WN8P

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Hi Zachary, Thanks for the links. The CU lab write up was what I was looking for and is complementary to EMRFD clause 9.2 Introduction to the Math. What I meant by how to implement using analog circuitry is how to implement a squaring function, a square root function, an arctan function, and a differentiation function using analog circuitry.
Apr 9th 2018, 07:56

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
http://www.analog.com/media/en/technical-documentation/data-sheets/AD538.pdf
Here is a datasheet for a chip that does analog computations.

https://www.electronics-tutorials.ws/opamp/opamp_7.html
Explanation of analog differentiation. Also talks about the compromises needed to get a stable circuit.

JAN 1987 - QST (PG. 18)
Tandem Match--An Accurate Directional Wattmeter, The
Author: Grebenkemper, John, KA3BLO
Analog computation of SWR.
http://www.arrl.org/arrl-periodicals-archive-search

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