Connect PCB Ground to chassis ground

[TomS2000]

There are lots recommendations to use a solid PCB ground and connects it directly to the chassis ground through mounting holes. In this case the return current may not through the power cable since chassis ground may have lower impedance for return current. Will it affect the EMI of the cables? for example the part of the twist pair radiation cancellation based on same magnitude but reverse direction current.

 

[marce]

Look up stuff by Henry Ott.
What return current are you reffering to, what frequency...what set-up.

 

[TomS2000]

Look up stuff by Henry Ott.
What return current are you reffering to, what frequency...what set-up.

I have read his books. He suggested to use a separate chassis ground near the IO connector. In general low frequency may return through chassis and high frequency tends to return through cables. My question is either case you don't have full control of the return current which by design it should return through the power ground cable for power supply input/output and ground wire for signal. I see people have asked this similar questions but didn't find a satisfying answer either in books or the Internet.

 

[DrWhoF]

In many devices you can find a combination of a resistor and capacitor connected in parallel and then connecting chassis with PCB-ground.
Resistor is in the range of 10-1000kohm and capacitor is 1nF-1uF, depending on what is the purpose of this termination.