Coaxial cable (which is not a PCB transmission line)

[joniengr081]

I have read  "coaxial cable (which is not a PCB transmission line)". Does this means that the coaxial cable is different then PCB transmission lines. But coaxial cable is not a transmission line at all ? Can someone please explain this a bit further. Thanks in advance.

[T3sl4co1l]

A little more context would be helpful. What else is said around it?  Are you asking purely from a language perspective?

If the latter, I would bracket it as:
"[coaxial cable] which is not [a PCB transmission line]"
[coaxial cable] subset of [transmission line]
[PCB transmission line] subset of [transmission line]

Without context, I have no idea why it's relevant to contrast these, nor why it was said this way, instead of a more compact term that either implies its nature, or specifies it as such: "PCB traces" (implied: consistent width, and height over a GND plane), "microstrip" (defined as same); or a more direct difference ("unshielded traces which can radiate"), etc.

Tim

[joniengr081]

I guess the term transmission line is referring to the transmission line effect for example cross talk, attenuation of high frequency components, increasing the rise time of the signal. We know that PCB traces if they are longer then 1/10th of the wavelength of the highest frequency content, usually approximated as 5th harmonics are turned into transmission line on outer and inner layers.

Referring to "Coaxial cable (which is not a PCB transmission line)" does it means that the transmission line effects will no longer be applicable to the coaxial cable ?

[tggzzz]

I guess the term transmission line is referring to the transmission line effect for example cross talk, attenuation of high frequency components, increasing the rise time of the signal. We know that PCB traces if they are longer then 1/10th of the wavelength of the highest frequency content, usually approximated as 5th harmonics are turned into transmission line on outer and inner layers.

The highest frequency content depends only on the risetime. The period is completely irrelevant.

For a little theory and some practical measurements, see https://entertaininghacks.wordpress.com/2018/05/08/digital-signal-integrity-and-bandwidth-signals-risetime-is-important-period-is-irrelevant/

Alternatively, consult any textbook or application note on transmission lines.

[T3sl4co1l]

I guess the term transmission line is referring to the transmission line effect for example cross talk, attenuation of high frequency components, increasing the rise time of the signal. We know that PCB traces if they are longer then 1/10th of the wavelength of the highest frequency content, usually approximated as 5th harmonics are turned into transmission line on outer and inner layers.

Referring to "Coaxial cable (which is not a PCB transmission line)" does it means that the transmission line effects will no longer be applicable to the coaxial cable ?

I have no idea. Again, you'll have to provide the context around this phrase to better understand its role in the passage.

Tim