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Parasitic Capacitance Losses

This note stems from work looking into detuning and losses associated with large pads on printed circuit boards.
Using a large device with relatively large PCB lands for a thin substrate PCB can exhibit several tenths of a dB in parasitic shunt capacitance.
The chart below illustrates the forward power losses that can be expected for a 50 Ohm system due to reflections caused by the parasitic C.