US 7,002,428 B2 · Dielectric loss compensation methods and apparatus

Abstract

Multilayer circuit boards include compensator networks configured in one or more conductor layers. A signal trace is configured in one or more layers to transmit an electrical signal from an input to an output and the compensator network is situated at at least one location on the trace to provide compensation for frequency dependent signal propagation losses or distortions such as those due to dielectric loss. In one example, the compensator includes a high frequency path provided by a series capacitance formed by conductor layers that include interleaved digits. Transmitters that include such compensators provide predistorted signals that can be matched or otherwise associated with anticipated propagation losses and distortions. Methods of evaluating dielectric losses include propagating electrical signals through such compensators and along a trace defined with respect to a dielectric under test and determining an associated compensation.

Claims14

Dependent claims

A method of modifying a digital signal passing along a signal trace from an input to an output of the trace to compensate for dielectric signal losses, the method comprising:

evaluating the dielectric losses expected to be incurred in a digital signal which traverses the signal trace from the input to the output;
and
passively distorting the digital signal at least at one location along the trace in accordance with the evaluated dielectric losses to produce a digital signal at the output of the trace which is an amplitude reduced substantial replica of the digital signal at the input of the trace, wherein the act of passively distorting a signal at the at least one location along the trace comprises the act of electrically interconnecting the first and second sections of the signal trace with a resistive shunt and capacitively coupling a first section of the trace to a second section of the trace at the at least one location.

An apparatus for compensating for dielectric losses in digital signals comprising:

a plural layered electronic circuit comprising at least one digital signal transmission path comprising first and second transmission path sections positioned in at least one layer of the electronic circuit, the digital signal path comprising an input at which digital signals are received and an output from which digital signals which have traveled along the digital signal path are delivered;
a dielectric loss compensator coupled to the digital signal transmission path and incorporated at least partially in a layer of the electronic circuit, the dielectric loss compensator being operable to alter a digital signal traveling along the transmission path to provide a digital signal at the output which is a substantial replica of the digital signal at the input, wherein the dielectric loss compensator comprises at least one capacitor in series with the first and second transmission path sections so as to capacitively couple the first section of the transmission path to the second section of the transmission path;
and
a resistive shunt electrically connecting the first transmission path section to the second transmission path section such that low frequency components of digital signals passing along the transmission path bypass the at least one capacitor.

1 more element

Dependencies are inferred from the claim text.

Dielectric loss compensation methods and apparatus

Life of this patent

Dielectric loss compensation methods and apparatus

Life of this patent

Abstract

Claims14