we know that we need to avoid parasitic capacitance (electric field) and parasitic inductance (magnetic field) on the RF/Microwave circuit layout. My question is, how about the DC layout and the low frequency crystal layout? we often ignore the parastic capacitance and parasitic inductance on DC and crystal oscillator layout. is it ok?
A capacitor at the DC power supply is a benefit in either case.
It stabilizes the supply voltage while it has no negative influence on EMI/EMC ...
It rather improves EMI/EMC.
Dear KlausST, refer back to my earlier question, do we need to reduce parasitic capacitance and inductance on the DC supply line of the PA, LNA and Osc ? the DC supply lines are placed closed to RF in this case..
Dear KlausST, refer back to my earlier question, do we need to reduce parasitic capacitance and inductance on the DC supply line of the PA, LNA and Osc ? the DC supply lines are placed closed to RF in this case..
If DC tracks are close to RF-especially High Power Level RF-lines, you have to protect DC supply line from RF perturbation.Otherwise RF signals can disturb the oscillator.
But avoiding the circuit from this perturbation is quite difficult due to limited space for decoupling capacitor/choke inductor. Best way is to move it as much as possible from RF or dirty circuits.