Power supply via coaxial cable

[Ghost Tweaker]

Hi everyone,

I need to supply a PCB board with 5volts, 100mA via coaxial cable. Also on the coaxial cable, an RF signal is transmitted. Does someone have infos, experience or paper about the subject?

Thanx in advance
Ghoster

 

[Kral]

Connect the DC supply to the inner conductor of the coax through an inductor. The inductive reactance must be considerably higher than the characteristic impedance of the coax at the frequency of interest. The inductor must have low distributed capacitance, so that it looks, as closely as possible, like a "pure" inductance. This technique is used in home satellite TV systems to provide DC power to the dish antenna amplifier.