Carrier suppression UHF RFID

carrier suppression

Hi

In UHF RFID 3 modulation types are used from reader to tag:

SSB-ASK
DSB-ASK
PR-ASK

For SSB a carrier is added, but what about DSB-ASK. When a continuous wave is ASK modulated, two sidebands are created. Is the carrier suppressed in this way, since only the two sidebands remain.

And what about PR-ASK, is there also a carrier added to the signal?

Thanks

dsb-ask

I understand, that in EPC Class-1 Generation-2 modulation methods no carrier is either added or supressed. Cause the digital baseband signal is non-zero in idle state, an idle carrier is transmitted in each of the 3 methods (which is obviously required for RFID with passive tags).

While DSB-ASK has a continuous carrier by definition, SSB-ASK and PR-ASK are effectively emitting a carrier due to the nature of the baseband signal.

I didn't exactly understand, what's the objective of your question. The significance of transmitting a carrier may be regarded different if it's related either to signal generation, spectral analysis or signal demodulation.

As a reference, I added EPC Class-1 Generation-2 spec. annex H, that gives a brief overview of involved modulation methods.