Browse Prior Art Database

Active Termination for Transmission Line

IP.com Disclosure Number: IPCOM000090361D
Original Publication Date: 1969-Apr-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Rossi, FR: AUTHOR [+2]

Abstract

The emitter-to-base junction of transistor 10 can be used as the terminating load for a nondistributed transmission line 12 to reduce the overshoot in the output of line 12 when a step function 14 is applied at its input. A nondistributed transmission line can be simulated by a series of LC ladder sections arranged as shown. When such a transmission line is terminated with a resistor whose resistance equals square root of L/C, its response 16 to a step function 14 contains ringing closely approximating a damped sinusoid. Such a response is characteristic of a second order system having complex zeros. Partial cancellation of these zeros to reduce the overshoot can be obtained by terminating the transmission line with a grounded base transistor 10.

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

Active Termination for Transmission Line

The emitter-to-base junction of transistor 10 can be used as the terminating load for a nondistributed transmission line 12 to reduce the overshoot in the output of line 12 when a step function 14 is applied at its input. A nondistributed transmission line can be simulated by a series of LC ladder sections arranged as shown. When such a transmission line is terminated with a resistor whose resistance equals square root of L/C, its response 16 to a step function 14 contains ringing closely approximating a damped sinusoid.

Such a response is characteristic of a second order system having complex zeros. Partial cancellation of these zeros to reduce the overshoot can be obtained by terminating the transmission line with a grounded base transistor 10. The equivalent circuit 18 of a grounded base transistor is also a second order system with complex poles. Therefore, by selection of the transistor's characteristics, a partial cancellation of the complex zeros of transmission line 12 can be effected.

1

Page 2 of 2

2

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