This circuit is from a 1980s Signetics documentation. The circuit separates the modulation signal from a carrier. The used components are not common today.
Taiyo Yudem SAW filters can be ordered from Mouser Electronics for UMST (W-DMA), GSM, CDMA, LTE,...
This “people detector” with pyroelectric sensor was found in the April 1991 issue of Radio...
This circuit is from an American magazine that no longer exists, Modern Electronics, in a February...