Focused jammer for UHF RF signal in unshielded coax

Please dont joke on this.

Is it possible to make focused jammer (like beam of laser) for RF UHF (signal in unshielded coax cable) from distance (several meters,...)?

Something with lasers, magnetic guns,.... EMI source (without using atomic bomb explosion)...

"signal in unshielded coax cable" You will have to explain how this is made to me. You can't block a signal in a cable, you can only block its reception.
Frank

Yes. I meant to make some interference and noise to make harder reception. I did not think to eliminate signal in cable.