On Mon, Aug 17, 2020 at 09:31 AM, Erik Kaashoek wrote:
Above 1GHz RF is like water. It flows? through every hole
? ?[Our lab called it the Dutch boy effect.? You plug one hole and RF finds another path of least resistance.
Hiding with the spur removal does not work as the spur removal removes spurs that do not actually exist but this 48MHz harmonic leakage is an actual signal.
? [There are innovative DSP solutions but I always view them as treating the symptom instead of the problem. I favor the old fashioned way of actually curing the problem by rounding off sharp clock edges so that the harmonics are severely attenuated.? some engineers favor using spread spectrum clocks that attenuate the emissions by spreading the signal power.
? The tinySA meets my needs and expectations as is.? User's with more advanced applications in mind will most likely try mitigating the MCU related emissions using their own bag of tricks.? The tinySA surface mount components damper my enthusiasm to do so.]
In a next HW revision (not planned) I will pay some extra attention to them.
[Hopefully a fellow hardware type will submit an inexpensive solution to the group in the meantime.? Source suppression seems the best route.]
- Herb
