The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 29, 1997
Filed:
Oct. 10, 1995
Alcatel NV, Rijswijk, NL;
Abstract
A tunable quadrature phase shifter including two branches each constituted by the cascade connection of a filter, an amplifier and a summing circuit, and two cross-connections constituted by amplifiers interconnecting the filter of one branch to the summing circuit of the opposite branch. An accurate 90 degrees phase shift between the two output signals is obtained by controlling the tail currents of the four amplifiers. The phase shifter used in mobile telecommunication transceivers may be easily and accurately tuned because the signals used in the summing circuits all have a similar amplitude. It is further adapted to operate with only a 3 Volt battery supply as used in wireless phones. The bandwidth of the amplifiers is increased by using double differential pair amplifiers which behave as cascode arrangements.