Binary Amplitude Shift Keying (BASK) or On Off Keying (OOK) Practical Circuit using CD 4016

Binary Amplitude Shift Keying (BASK) or On Off Keying (OOK) is one of the digital modulation techniques in which the amplitude of carrier is switched according to the binary data. This digital modulation scheme is used to transmit digital data over optical fiber, point to point military communication applications, etc. Binary 1 is represented by a short pulse of light and binary 0 by the absence of light. Amplitude Shift Keying modulation and demodulation processes are relatively inexpensive and easy to implement. The main disadvantage of ASK is that it is sensitive to atmospheric noise, distortions and propagation conditions. Here is the practical circuit diagram of amplitude shift keying modulator using CD4016 IC. CD4016 is a switching IC with four embedded switches.

Also Read: Binary Phase Shift Keying (BPSK) Modulation 

Circuit Diagram

Components Required

  1. CD4016 IC
  2. NOT gate 7404

Output Waveform

Working of ASK circuit

  • Two switches inside the quad analog switch CD 4016 are used in the circuit. When the enable input of one gate is at high, then the input will appear at the output.
  • When the binary data is 1, sine wave is switched to output because the sine wave is connected to 1st switch and the binary data is applied to enable pin (13th pin) of 1st switch.
  • When binary data is 0, the 1st switch is disabled and 2nd switch is enabled using NOT gate arrangement.
  • The input of 2nd pin is grounded, hence we get 0V for binary 0.
  • The output pins of both first and second switches are shorted and the output is taken from it. The block diagram is self explanatory.

Components Pin out

4 thoughts on “Binary Amplitude Shift Keying (BASK) or On Off Keying (OOK) Practical Circuit using CD 4016

    • Hi Angelica,
      With the help of block diagram in the above circuit you can realize with Multisim. Binary input should be a square wave signal.

  1. Hiii i am happy to see the introduction of this BASK here but sorry i would like to ask you to put more explanation on it like how it differ in observation by changing binary amplitude and frequency

  2. Hi,
    I have a question ,that is when simulate it in proteus,it’s sine wave phase is not matching with rising and falling edge of PWM.Sometime it is start with +ve half sometime start -ve half of the cycle.Is this effect my circuit? I also experiment with this, I found that if I ground a resistor with the output of pin 2 of CD4016, then we don’t need any another switch and the NOT gate(7404). But the output pulse is 4v Peak-Peak.

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