On/Off Keying (OOK) or Amplitude Shift Keying (ASK)

Thread Starter

jan.rover

Joined Jun 18, 2011
19
hello, I was looking for an amplitude shift keying (ASK) modulator circuit. Is OOK and ASK the same??
i was wondering if you guys have a circuit/schematic of an OOK or ASK modulator circuit? I've been working on one using a couple of lm741 and a FET, but I still don't get the right ouput. Please do reply ASAP..
 

WBahn

Joined Mar 31, 2012
25,068
OOK and ASK are not quite the same thing, though in practice OOK is frequently implemented as binary ASK. In ASK, your symbols are different amplitudes of a carrier and you are not required to have zero amplitude be one of your symbols, nor are you limited to just two symbols. In OOK, you have a pulse shape, which does not have to be sinusoidal, that you gate on and off to differentiate between two possible symbols.

In the special case that you have an OOK system that is gating an otherwise unmodulated sinusoid, you have something that is also ASK.
 

Thread Starter

jan.rover

Joined Jun 18, 2011
19
Here's the circuit I've been trying to implement. The FET is supposed to be the one to do the switching. The data in is on it's Gate terminal. THe carrier should be inputted to the first op amp (on the left), and the ASK output on the second one (on the right)...What seems to be the problem with the circuit I'm using?

I was wondering if the circuit of an OOK is the same? I reckon it's easier to implement since the carrier is turned off at logic0,and turned on at logic1. DO you have it?
 

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