Be aware that in most countries it is illegal to transmit radio signals without a licence.
Why? Because if you don't understand what you are doing you will interfere with other radio users - and they really don't like that!
So, be prepared to learn all about filters, harmonics, and terms like IP3, S21, dBm, etc.
Or you could purchase a ready-made RF module that has been correctly designed and tested to be legal and operate correctly.
Or you could avoid the problem and use light instead of radio waves - but whatever you do understand the (very low) power levels that will instantly make you blind if the light gets into your eye.