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:
Mar. 02, 1999
Filed:
Oct. 31, 1996
Patrick Knowles, Severn, MD (US);
Timothy Waterman, Eldersburg, MD (US);
Northrop Grumman Corporation, Los Angeles, CA (US);
Abstract
A method and apparatus for accomplishing a 90.degree. relative phase shift employing a high characteristic impedance outer leg of length .lambda./2 and a low characteristic impedance through leg of length .lambda./4. The high characteristic impedance outer leg is directly connected to the input and the output. The low characteristic impedance through leg is connected to the input and output with first and second diode paths. When the first and second diode paths are in the on state, the low characteristic impedance through leg receives a majority of the input power. Because of the impedance disparity between the high characteristic impedance outer leg and low characteristic impedance through leg, only a small amount of power is routed through the high characteristic impedance outer leg when the first and second diode paths are in the on state and the combined signal phase is not substantially effected. When the first and second diode paths are in the off state, the input signal is routed through the high characteristic impedance outer leg. Because the relative lengths of the high characteristic impedance outer leg and the low characteristic impedance through leg differ by .lambda./4, a relative phase shift of 90.degree. is provided at the output.