Browse Prior Art Database

Microcircuit Ring Modulator

IP.com Disclosure Number: IPCOM000094683D
Original Publication Date: 1965-Apr-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Poulet, A: AUTHOR

Abstract

In this ring modulator, a digital function, i.e., carrier, is modulated by an analog data function. The output transformers of the usual modulator are replaced by transistors T3 and T4. The drawing shows the device equivalent circuit diagram.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Microcircuit Ring Modulator

In this ring modulator, a digital function, i.e., carrier, is modulated by an analog data function. The output transformers of the usual modulator are replaced by transistors T3 and T4. The drawing shows the device equivalent circuit diagram.

Ec is the carrier input, Ed the data f(t) input and S is the modulated function output. The digital function carrier is 0V or -6V. When Ec = 0, transistor T1 is cut off and T2 is saturated. The circuit acts as a differential amplifier. Base B4 potential is f(t) (input data) and base B3 potential is fixed. T5 being a current generator, the amplifier gain is -R/(r +r')

When Ec = t6, T2 is cut off and T1 is saturated. Base B3 potential equals f(t) and base B4 potential is fixed. The differential amplifier gain is R/(r + r').

The circuit is a modulator. When Ec= 0, VS = E0 - >R/(r + r')| f(t). When Ec = -6V, VS =E0 + >R/(r + r')| f(t).

There are no output transformers. Thus, it is possible to use this technique for microcircuits.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]