Phase interpolator based on an injected passive RLC resonator

A phase interpolation circuit comprising:

• a first circuit node for conducting a first reference input signal;
• a first switch configured to conduct at least a portion of the first reference input signal from the first circuit node when in a conducting configuration;
• a first capacitor configured to receive the at least a portion of the first reference input signal when the first switch is in the conducting configuration;
• a second circuit node for conducting a second reference input signal having a 90 degree phase shift from the first reference input signal;
• a second switch configured to conduct at least a portion of the second reference input signal from the second circuit node when in a conducting configuration;
• a second capacitor configured to receive the at least a portion of the second reference input signal when the second switch is in the conducting configuration;
• a third circuit node for conducting a third reference input signal having a 180 degree phase shift from the first reference input signal;
• a third switch configured to conduct at least a portion of the third reference input signal from the third circuit node when in a conducting configuration;
• a third capacitor configured to receive the at least a portion of the third reference input signal when the third switch is in the conducting configuration;
• a fourth circuit node for conducting a fourth reference input signal having a 270 degree phase shift from the first reference input signal;
• a fourth switch configured to conduct at least a portion of the fourth reference input signal from the fourth circuit node when in a conducting configuration;
• a fourth capacitor configured to receive the at least a portion of the fourth reference input signal when the fourth switch is in the conducting configuration;
• a fifth circuit node for conducting an interpolated signal having a phase component based on the configuration of the first switch, the second switch, the third switch and the fourth switch;
• and
• an inductor electrically connected to the first capacitor, the second capacitor, the third capacitor and the fourth capacitor and configured to form a resonant circuit with any of the first capacitor, the second capacitor, the third capacitor or the fourth capacitor.

A method of generating a signal with a controllable phase component, the method comprising the steps of:

• providing a first capacitance switchably connected to a first circuit node;
• providing a second capacitance switchably connected to a second circuit node;
• receiving a first reference signal having a first phase component at the first capacitance when the first capacitance is connected to the first circuit node;
• receiving a second reference signal having a second phase component at the second capacitance when the second capacitance is connected to the second circuit node;
• generating an interpolated signal having a third phase component inclusively between the first phase component and the second phase component, the interpolated signal based on the switchable connection of the first capacitance and the second capacitance;
• and
• raising a voltage level of the interpolated signal via an inductor connected with at least one of the first capacitance or the second capacitance.