ASK or AM transmitter?
Hi,
I don't know RFID, but I just wanna give a bit explanation on ASK and AM.
ASK as far as I know is only good for transmitting digital information via short cable, not wireless channel. This is because ASK has amplitude fluctuation which is not suitable for amplifier at the transmitter or repeter. So usually people use FSK in wireless communication, instead.
AM is somehow good for transmitting analog signal via wireless channel.
So if your application is to transmit the data via wireless channel, then between ASK and AM, you must choose AM. However, there are some other modulation which suit better, e.g. FM or FSK.
best