Patent · US Expired

Phase shifting circuits

US5157288A · kind A · utility

15Cited by
5References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 15, 1991
Grant dateOct 20, 1992
Priority date
Expiry dateMar 15, 2011

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03H11/18
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A phase shifting circuit includes: a pair of input terminals; a pair of output terminals; a variable gain amplifier and an active alternating current integrator, connected in series between the input terminals and the output terminals; and a control circuit for controlling the gain of the amplifier in dependence on the voltage between the input terminals and the voltage between the output terminals so as to maintain the amplitude of the voltage between the output terminals substantially equal to the amplitude of the voltage between the input terminals. The phase shifting circuit exhibits low variation of phase shift with input signal frequency.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.