Patent ID: 6275120
Filing Date: 2001-08-14
Classification: H01P

Abstract:
A three bit phase shifter comprising:a 45 degree phase shift filter device disposed as a first microstrip structure, said 45 degree phase shift filter device comprising a 90 degree phase shift filter device having a substantially ""U"" shaped first reference transmission line and a substantially ""U"" shaped first phased transmission line having a radial stub for subtracting 45 degrees, wherein said ""U"" shaped phased transmission line has a width less than the width of said first reference transmission line;a 90 degree phase shift filter device disposed as a second microstrip structure and operatively connected to said 45 decree phase shift filter device, wherein said 90 degree phase shift filter device comprises a substantially ""U"" shaped second reference transmission line and a substantially ""U"" shaped second phased transmission line, wherein said ""U"" shaped phased transmission line has a width less than the width of said second reference transmission line;a 180 degree phase shift filter device disposed as a third microstrip structure and operatively connected to said 90 degree phase shift filter device, wherein said 180 degree phase shift filter device comprises a substantially ""U"" shaped third reference transmission line and two substantially ""U"" shaped third phased transmission lines, wherein said ""U"" shaped phased transmission lines have a width less than said width of said third reference transmission line; andmeans for selecting said 45 degree, 90 degree and 180 degree phase shift filter devices to provide a beam in a desired direction.