Patent ID: 6242990
Filing Date: 2001-06-05
Classification: H01P,H04L

Abstract:
A phase modulator for discretely varying the phase of an input carrier signal between at least two different phase states so as to provide a phase modulated carrier output signal having substantially constant amplitude over a selected bandwidth for all of said at least two different phase states, said phase modulator comprising:at least first and second transmission line segments, where each of said first and second transmission line segments includes first and second terminating end regions, and where the length of said first and second transmission line segments differs by a first selected difference value determined at a desired operating carrier signal;at least first and second switch means coupled to said first and second transmission line segments, wherein said first switch means includes an input means for receiving an input carrier signal, and said second switch means includes an output means, and wherein each of said first and second switch means is responsive to a control signal for causing said input carrier signal to conduct through a selective one of said first and second transmission line segments from said input means to said output means; andan amplifier means biased into saturation, said amplifier means having input means electrically coupled to said second switch output means, and an amplifier output for providing an amplifier output signal, where said amplifier output signal is a phase modulated output signal having substantially constant selected phase states, relative to said input carrier signal, over a narrow bandwidth.