Apparatus and method for detecting characteristic of object based on frequency-modulated signal

A method of detecting an object, the method comprising:

• emitting a frequency-modulated ultrasound signal toward the object;
• receiving an echo signal from the object in response to the frequency-modulated ultrasonic signal being reflected from the object;
• mixing the frequency-modulated signal with the echo signal to output a mixer signal;
• estimating a distance to the object based on the mixer signal;
• and
• detecting a characteristic of the object based on the estimated distance.

An electronic device comprising:

• an ultrasound sensor configured to:
• emit a frequency-modulated ultrasonic signal toward an object;
• receive an echo signal from the object in response to the frequency-modulated ultrasonic signal being reflected from the object;
• mix the frequency-modulated ultrasonic signal with the echo signal to output a mixer signal;
• estimate a distance to the object based on the mixer signal;
• and
• detect a characteristic of the object based on the estimated distance;
• a memory storing one or more instructions;
• a display;
• and
• a processor configured to execute the one or more instructions to operate the ultrasound sensor and to control the display to display the characteristic of the object.