Embodiments and methods and means for filtering radio frequencies (RF) via coaxial cables with a computer system are provided. Such embodiments generally include modifying an RF coaxial cables communicatively coupling an antenna to a wireless radio module within a mobile computing device allow an RF signal within certain frequency band(s) to pass with minimal attenuation while other frequencies, the RF signal is either reflected or attenuated. Modifying the RF coaxial cable entails inserting sections of varied impedance into the uniform impedance of the RF coaxial cable by altering the mechanical structure of the RF coaxial cable.