+ PIL/FLLreflection signal --> maybe have phase + frequence modulation with amplitude modulation
--> so use demodulation scheme (eg. quadrature demodulator) --> extract all the components
example
reflection signal carrier frequency --> 100 MHz
modulated by 10kHz sine wave with amplitude mod depth --> 0.1. frequency mod depth --> 1khz
PLL/FLL --> loop bandwidth 1khz to track carrier frequency+phase and generate reference signal that is phase locked/frequency locked))