Patent ID: 8710929
Filing Date: 2014-04-29
Classification: H03K

Abstract:
1. A system for combined generation of In-phase (I) and Quadrature (Q) signal references according to a periodic input signal and selective phase interpolation of an output signal with reference thereto comprising: a ring oscillator portion generating an oscillator signal, said ring oscillator portion including a plurality of delay stages interconnected in cascade to collectively execute an odd number of signal state inversions within a closed loop, said delay stages being configured to establish at respective nodes defined therebetween corresponding delayed versions of the oscillator signal successively shifted in phase by a predetermined phase difference; and a signal injection portion coupled to said ring oscillator portion selectively applying to at least one said node a current bias according to the periodic input signal, said signal injection portion selectively adjusting each said current bias in amplitude, said signal injection portion thereby locking said oscillator signal in frequency to the periodic input signal and defining said I and Q references thereof with respect to the delayed version of said oscillator signal thereafter established at said current biased node.