Suppression of interference in digital frequency synthesis, more particularly in a time reference of a navigation signal transmitting device

A method of digital frequency synthesis comprising:

• quantizing a phase of a signal;
• determining a phase quantization error;
• noise shaping the phase of the phase quantized signal based on the determined phase quantization error;
• converting phase to amplitude;
• quantizing an amplitude of the noise shaped phase quantized signal;
• determining an amplitude quantization error;
• noise shaping the amplitude of the amplitude quantized signal based on the determined amplitude quantization error.

An arrangement for digital frequency synthesis comprising:

• a phase quantizer operable based on a reference clock and a phase increment value;
• a phase quantization error unit coupled to an input and an output of the phase quantizer to determine phase quantization error;
• an amplitude quantizer operable based on the reference clock and the phase increment value;
• an amplitude quantization error unit coupled to an input and an output of the amplitude quantizer to determine amplitude quantization error;
• a first noise shaper that receives the phase quantization error and noise shapes a phase of a signal output from the phase quantizer to suppress the phase quantization error;
• a second noise shaper that receives the amplitude quantization error and noise shapes a signal output from the amplitude quantizer to suppress the amplitude quantization error;
• and
• a phase to amplitude converter arranged to receive a summation signal of outputs from the phase noise shaper and the phase quantizer.

A navigation signal transmitting device comprising:

• an arrangement for digital frequency synthesis comprising:
• a phase quantizer structured and arranged to operate based on a reference clock and a phase increment value;
• an amplitude quantizer structured and arranged to operate based on the reference clock and the phase increment value;
• a phase noise shaper arranged in a signal path after the phase quantizer;
• an amplitude noise shaper arranged in the signal path after the amplitude quantizer;
• a phase quantization error unit coupled to supply a phase quantization error to the phase noise shaper;
• an amplitude quantization error unit coupled to supply an amplitude error to the amplitude noise shaper;
• and
• a phase to amplitude converter arranged to receive a summation signal of outputs from the phase noise shaper and the phase quantizer;
• an atomic clock ensemble;
• and
• a clock monitoring and control unit that comprises the arrangement,
• wherein the atomic clock ensemble comprises a plurality of passive H-masers and a plurality of rubidium atomic clocks, and
• wherein outputs of the atomic clock ensemble are coupled to the arrangement through a switching matrix.

An arrangement for digital frequency synthesis comprising:

• a phase quantizer structured and arranged to operate based on a reference clock and a phase increment value;
• an amplitude quantizer structured and arranged to operate based on the reference clock and the phase increment value;
• a phase noise shaper arranged in a signal path after the phase quantizer;
• an amplitude noise shaper arranged in the signal path after the amplitude quantizer;
• a phase quantization error unit coupled to supply a phase quantization error to the phase noise shaper;
• an amplitude quantization error unit coupled to supply an amplitude error to the amplitude noise shaper;
• and
• a phase to amplitude converter arranged to receive a summation signal of outputs from the phase noise shaper and the phase quantizer,
• wherein the phase noise shaper is a third-order sigma-delta converter and the amplitude noise shaper is a third-order sigma-delta converter.

An arrangement for digital frequency synthesis comprising:

• a phase quantizer structured and arranged to operate based on a reference clock and a phase increment value;
• an amplitude quantizer structured and arranged to operate based on the reference clock and the phase increment value;
• a phase noise shaper arranged in a signal path after the phase quantizer;
• an amplitude noise shaper arranged in the signal path after the amplitude quantizer;
• a phase quantization error unit coupled to supply a phase quantization error to the phase noise shaper;
• an amplitude quantization error unit coupled to supply an amplitude error to the amplitude noise shaper;
• and
• a phase to amplitude converter arranged to receive a summation signal of outputs from the phase noise shaper and the phase quantizer,
• wherein:
• the arrangement is a frequency synthesizer having a useful bandwidth;
• the amplitude error resulting from the amplitude quantizer arises due to a limited bit resolution of the phase to amplitude converter;
• and
• the phase quantization error resulting from the phase quantizer and the amplitude error resulting from the amplitude quantizer are suppressed and each have an interference energy of interference lines which are displaced to higher frequencies outside the useful bandwidth of the frequency synthesizer.

An arrangement for digital frequency synthesis comprising:

• a phase quantizer structured and arranged to operate based on a reference clock and a phase increment value;
• an amplitude quantizer structured and arranged to operate based on the reference clock and the phase increment value;
• a phase noise shaper arranged in a signal path after the phase quantizer;
• an amplitude noise shaper arranged in the signal path after the amplitude quantizer;
• a phase quantization error unit coupled to supply a phase quantization error to the phase noise shaper;
• an amplitude quantization error unit coupled to supply an amplitude error to the amplitude noise shaper;
• and
• a phase to amplitude converter arranged to receive a summation signal of outputs from the phase noise shaper and the phase quantizer,
• wherein:
• the phase to amplitude converter comprises a lookup table, and a first adder is coupled to the lookup table and the phase quantizer;
• and
• a second adder is coupled to the amplitude quantizer and digital-to-analog converter.