What is a generated by VCO FM signal range?

[svensl]

FM signal range

I was wondering how far a FM signal generated by a VCO will travel without an antenna or anything else connected to it. I am asking since I want to know whether an antenna is needed for very short ranges.

Thanks,

 

[throwaway18]

FM signal range

Might be 20cm, might be 100m. Depends on;

Shielding eg VCO inside a metal box or not.
Power level in the VCO.
Power supply decoupling.
Length and shielding of power supply and output pcb traces.
Receiver sensativity.
radiation pattern from the VCO eg if you have a solid ground plane on the bottom of the pcb it will radiate less downward.
Postion of receiver relative to VCO
Receiver antenna gain, pattern and orientation.
Local noise at the VCO frequency.

 

[svensl]

Re: FM signal range

Thanks throwaway18. Your comments were very helpful.

 

[jcpu]

Re: FM signal range

Sometimes the FM modulation index could play an important role.

 

[lmk]

Re: FM signal range

Which Frequency you are talking about ?? if 900MHz what you need just shot wire or make use of pcb pattern as a antenna.