Phase coherent numerically controlled oscillator

A radio frequency (RF) sampling transceiver, comprising:

• a digital mixer circuit;
• and
• a phase coherent numerically controlled oscillator (NCO) circuit coupled to the digital mixer circuit, and comprising:
• a base frequency NCO comprising:
• a base frequency control input;
• and
• a base phase output;
• a phase seeding circuit coupled to the base frequency NCO, and comprising:
• a base phase input coupled to the base phase output;
• and
• a seed phase output;
• a scaled frequency NCO coupled to the phase seeding circuit, and comprising:
• a seed phase input coupled to the seed phase output;
• and
• an oscillator phase output;
• wherein the phase seeding circuitry is activated only while computing a seed phase value.

A phase coherent numerically controlled oscillator (NCO) circuit, comprising:

• a base frequency NCO configured to generate base phase values based on a base frequency control word;
• a phase seeding circuit coupled to the base frequency NCO, and configured to generate a seed phase value based on the base phase values and a scale factor value;
• a scaled frequency NCO coupled to the phase seeding circuit, and configured to generate oscillator phase values based on the phase seed value and an oscillator frequency control word;
• and
• a sine/cosine generator coupled to the scaled frequency NCO, and configured to generate oscillator output samples based on the oscillator phase values;
• wherein the phase seeding circuitry is activated only while computing the seed phase value.