Apparatus, system and method of phase shifting

An apparatus comprising:

• a phase shifter comprising:
• an input to receive an input clock signal having an input frequency and an input phase;
• a quadrature phase-shift generator configured to generate a first signal and a second signal based on the input clock signal, wherein a phase of the first signal is based on the input phase, wherein a phase of the second signal is shifted by a quadrature phase-shift relative to the phase of the first signal, wherein the quadrature phase-shift generator comprises:
• an inverter to generate an inverted clock signal based on the input clock signal, wherein a phase of the inverted clock signal is shifted by 180 degrees relative to the input phase;
• a delayer to provide a delayed clock signal by applying a predefined delay to the input clock signal;
• and
• an interpolator to generate the second signal based on an interpolation of the delayed clock signal and the inverted clock signal;
• and
• an output to provide an output based on the first signal and the second signal.

An apparatus comprising:

• phase shifter means comprising:
• an input to receive an input clock signal having an input frequency and an input phase;
• quadrature phase-shift generation means configured to generate a first signal and a second signal based on the input clock signal, the first and second signals having the input frequency, wherein a phase of the first signal is based on the input phase, wherein a phase of the second signal is shifted by a quadrature phase-shift relative to the phase of the first signal, wherein the quadrature phase-shift generation means is operable to generate the quadrature phase-shift in a range of 89-91 degrees for any input frequency in at least a frequency range between 0.95*F and 1.05*F, wherein F denotes a frequency value;
• and
• an output to provide an output based on the first signal and the second signal.