I haven't seen a mention regarding the transmission line vs wavelenght?

On behalf of Ian Collins:

Lambda / 20 is a rule that I guess permits one to almost ignore transmission line theory. So for instance for a 1 GHz signal, the wavelength is about 30 cm, and the Lambda / 20 is about 15 mm.

The transmission line will work, but in my experience it is better to consider anything higher than 100 MHz as a transmission line.

It is best to keep high frequency lines as short as possible, but not always practical.

On behalf of Ian Collins:

Lambda / 20 is a rule that I guess permits one to almost ignore transmission line theory. So for instance for a 1 GHz signal, the wavelength is about 30 cm, and the Lambda / 20 is about 15 mm.

The transmission line will work, but in my experience it is better to consider anything higher than 100 MHz as a transmission line.

It is best to keep high frequency lines as short as possible, but not always practical.