OOK modulation device and wireless transmitting device including the same

An on-off keying (OOK) modulation device comprising:

• an oscillator configured to output a first frequency signal having a frequency varying in response to an input voltage;
• a frequency multiplier switching unit that operates according to an OOK input data and on/off switches a second frequency signal that is obtained by multiplying the first frequency signal;
• and
• a switching amplifying unit configured to amplify and switch the second frequency signal according to the OOK input data to output an OOK modulation signal, wherein the frequency multiplier switching unit comprises:
• a first coupling capacitor that has a first terminal receiving the first frequency signal;
• a second coupling capacitor that has a first terminal receiving an inverted version of the first frequency signal;
• a first transistor that has a gate coupled to a second terminal of the first coupling capacitor and a source coupled to a ground;
• and
• a second transistor that has a gate coupled to a second terminal of the second coupling capacitor and a source coupled to the ground.