I am curious to know how the RF front end of a Wifi receiver works. From my understanding, most RF receivers have to use networks of various oscillators, mixers, and filters to select a given frequency and remain insensitive to undesired signals at different frequencies, and I suspect that WiFi is no different (although I could be wrong). However, Wifi chips are small and to my knowledge don't contain any elements usually used to implement oscillators and filters (like inductors and capacitors). So my question is, how are Wifi devices able to implement those systems? I guess this question doesn't apply specifically to Wifi, but any device that uses a integrated receiver system.