Why is there such a strong preference for 45 degree angles in PCB routing?
That's it !
"Comparators are used to differentiate between two different signal levels. For example, a comparator may differentiate between an over temperature and normal temperature condition. Noise or signal variation at the comparison threshold will cause multiple transitions. Hysteresis sets an upper and lower threshold to eliminate the multiple transitions caused by noise."
Source:
Comparator with Hysteresis Reference Design - Texas InstrumentsBGA Switch-A-Pitch Adapters - ARIES Link
Convert 0.4mm and 0.5mm pitch footprints to 1mm or 1.27mm pitch
Here is a link to some good reading for PCB Stackup and Controlled Impedance.
Light, Humidity and Air Quality Sensors on RF Boards
Case Study: Design of an RF Board with Sensors | Sierra Circuits
That's it !