Patent ID: 8045656

Claim:
An apparatus comprising: an analog front end to receive incoming weather band radio signals, the analog front end including: an analog mixer to mix the incoming weather band radio signals with a controllable oscillator frequency to generate a complex downmixed signal, wherein the controllable oscillator frequency is stepwise adjusted; and an analog-to-digital converter (ADC) to convert the complex downmixed signal to a digital signal; a direct digital frequency synthesizer (DDFS) and a decimator coupled to the analog front end to generate from the digital signal a digital input to provide to a digital signal processor (DSP) at a first sampling rate; the DSP coupled to the decimator, wherein the DSP includes: a digital mixer to mix the digital input with a fine tune control signal; a channel filter coupled to receive an output of the digital mixer; a frequency modulation (FM) demodulator to demodulate the channel filter output to generate a FM demodulated signal; a feedback loop coupled between the FM demodulator and the digital mixer, the feedback loop including: a loop filter to receive the FM demodulated signal and to generate a filtered output, wherein the loop filter is controllable based on the stepwise adjustment; and a fine tune controller to receive the filtered output and a frequency control signal and to generate the fine tune control signal; and a microcontroller unit (MCU) to generate the frequency control signal for the fine tune controller.