gonsays
Newbie level 5
Hello guys,
I’m doing a lab regarding Sensors & Actuators, using a ultrasonic 40 kHz piezoelectric emitter-receiver board, in order to do distance measurements, velocity of the sound an thickness measurements.
The modulating signal will be a square-wave with 10 Hz and a duty cycle of 20%.
The carrier will be a 40 kHz sinusoidal signal.
I have some doubts regarding some theoretical questions, if you could help me it would be great:
• Why is it used a 40 kHz signal for the carrier?
• Why is it used a square modulation signal?
• Why is it used a low duty-cycle (20%)?
• Why is it used a DC offset voltage for the modulated signal? [I think it is to prevent overmodulation, right?]
• What is the maximum theoretical distance that can be measured with this signal (carrier 40kHz, modulating signal 10Hz)?
Thank you very much in advance.
Best regards,
G
I’m doing a lab regarding Sensors & Actuators, using a ultrasonic 40 kHz piezoelectric emitter-receiver board, in order to do distance measurements, velocity of the sound an thickness measurements.
The modulating signal will be a square-wave with 10 Hz and a duty cycle of 20%.
The carrier will be a 40 kHz sinusoidal signal.
I have some doubts regarding some theoretical questions, if you could help me it would be great:
• Why is it used a 40 kHz signal for the carrier?
• Why is it used a square modulation signal?
• Why is it used a low duty-cycle (20%)?
• Why is it used a DC offset voltage for the modulated signal? [I think it is to prevent overmodulation, right?]
• What is the maximum theoretical distance that can be measured with this signal (carrier 40kHz, modulating signal 10Hz)?
Thank you very much in advance.
Best regards,
G