antenna for specific signal
I would like to trigger an operation on my controller but only after receiving a very specific signal from other end, my question is: is it possible to design an antenna that only receives a specific signal?
I don't want to use the ADC on the controller, so I want it to be analog detection.
tuned antenna> tuned filter>pre-amp> peak detect >logic level,
... preamp> LO mix> IF filter> IF Aamp> RSSI detect>logic level.
Define f, Input/Output Thresholds, Ambient Noise & adjacent channel rejection criteria, hysteresis level from noise and latency for trigger and re-trigger and pulse stretch.
Then you can start...
What is specific about that signal?
You can design an antenna with filter + signal detection that is selective for a certain frequency.
If your signal shares the frequency range with other services (e.g. 2.4GHz range used by WLAN, Bluetooth and all sorts of license-free ISM devices) than it becomes more complicated.
The antenna is only part of a remote control receiver, there are also RF front end, possible IF signal processing, demodulator, a command decoder. Selectivity is mostly achieived by using unique codes, also RF frequency selection. The antenna is contributing to the frequency selection but usually with a lesser extent.