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## I/Q Demodulation and Analog Processing

Apr 5th 2018, 15:10

#### WN8P

Joined: Apr 4th 1998, 00:00
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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

Super Moderator

Joined: Apr 4th 1998, 00:00
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Is this the math you want?

This page has references to AM Synchronous Demodulator Circuits
Apr 9th 2018, 00:00

#### WN8P

Joined: Apr 4th 1998, 00:00
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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

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Joined: Apr 4th 1998, 00:00
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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