A Narrow-Band Delta-Sigma Frequency-to-Digital Converter

This paper describes a novel frequency-to-digital conversion technique based on the D flip-flop frequency deltasigma concept. It is shown that given some frequency constraints, there is no need for using a sampling frequency twice the maximum FM frequency. For narrow-band FM demodulation, it is further shown that by sampling the clock signal width the FM signal, the digital resolution is more effectively increased by raising the constant clock frequency. A narrowband D flip-flop frequency-to-digital converter have been realized in a FPGA confirming the theory.