Patent ID: 6492877
Filing Date: 2002-12-10
Classification: H03B

Abstract:
A coupling loop system comprising:first and second couplers, first and second LC-based voltage controlled oscillators (VCOs), and first and second buffers, each comprising two input terminals and two output terminals, where the output terminals of the first and second couplers are connected to the input terminals of the first and second VCOs, respectively, the output terminals of the first and second VCOs are connected to the input terminals of the first and second buffers, respectively, the output terminals of the first buffer are connected to the input terminals of the second coupler, and the output terminals of the second buffer are connected with reversed polarity to the input terminals of the first couplers; and wherein the first coupler, first VCO and first buffer are configured to provide a first signal having a first selected phase shift and the second coupler, second VCO and second buffer are configured to provide a second signal having a second selected phase shift at a selected frequency of oscillation.