Browse Prior Art Database

Balanced Electronic Hybrid Circuits

IP.com Disclosure Number: IPCOM000079484D
Original Publication Date: 1973-Jul-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Fisk, DE: AUTHOR [+2]

Abstract

These hybrid circuit arrangements are readily fabricated by current solid-state device techniques.

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 82% of the total text.

Page 1 of 2

Balanced Electronic Hybrid Circuits

These hybrid circuit arrangements are readily fabricated by current solid- state device techniques.

A workable basic hybrid circuit is shown in drawing A. A balanced two-wire transmission line 10 is represented, by two lumped series impedance elements 12 and 14 and a voltage generating element 16. A voltage Vs is presented at line terminals 20, 22 across a line impedance Z. This voltage is essentially amplified by an amplifier 26 of gain Ao and the amplified voltage Vo is delivered at a local terminal 30, connected to a telephone receiver, for example. Any voltage Vi at a local terminal 32, coming from a telephone transmitter, for example, is amplified by an amplifier 34 for delivery to the line terminals 20, 22 when desired. However, it is substantially prevented from reaching the amplifier 26 and the terminal 30 by balancing resistors 36 and 38 and voltage dividing resistors 40-42 and 44-46. The impedance of the output circuit of the amplifier 34 and the resistors, as connected, substantially matches the line impedance Z.

Two different embodiments of the basic hybrid circuit are shown in drawing B, one at each end of the line 10'. Here, active circuits replace the passive rejecting circuits. Amplifiers 50 and 52 are connected for common mode rejection and replace the divider resistors. One amplifying circuit is obviated in the embodiment at the other end of the line, wherein one terminal of the amplifier 26' is connected to t...