Lidar, [lasers, for the most part] and RF are both in the electromagnetic spectrum but act like and are really totally different animals. A laser is coherent light, RF is generally not, unless possibly like maybe a maser, [coherent microwaves]. Rv1pop made a very good point about how RF can be very dangerous. Many devices even though not designed to produce X-rays, microwaves, etc, can, when overpowered.
I never got into ham like he suggested but have some friends that are, that might be a good place to start to learn about RF, or study antennas maybe, also electronic theory stuff like ohm's law, radio wave propagation, etc.
Many times it's not about more power, but rather tuning, resonance, different types of coupling, etc.
More information on what you're doing I think would be needed for anyone to help you, you mentioned radar and an oscillator but that's really too vague to give any advice on really.