Why do you want to bring into plane ? Just put in your check-in luggage.

Also, it is probably illegal to bring into another country. Unless the device is generic
And you may have problem to bring it back into Malaysia.
Why ?

All radio comm device, have specific freq approval (type approval - go check SIRIM and MCMC for local M'sia), power rating, etc.
If customs did not stop to check your luggage, then fine.
Otherwise, if they ask for permit or approval or any certification, etc. Then how ? Without it, means consficate (worse case scenario).