Passive-radio frequency blocking of side-lobe reads

A radio-frequency (RF) identification (RFID) system, comprising:

• a signal generator configured for generating a modulating signal;
• and
• an RF mixer configured for modulating a first RF signal with the modulating signal to provide a modulated signal,
• wherein the first RF signal has an RF carrier frequency according to an RFID protocol,
• wherein the signal generator provides the first RF signal to a main directional antenna in the RFID system to radiate a first signal toward a first main lobe of the main directional antenna for reading one or more RFID tags according to the RFID protocol,
• wherein the first RF signal further causes the main directional antenna to radiate an unintended signal toward a side-lobe of the main directional antenna,
• wherein the RF mixer is further configured to provide the modulated signal to a secondary directional antenna installed back to back with the main directional antenna and having a second main lobe extending in a same direction as the side-lobe of the main directional antenna to radiate a second signal toward the second main lobe of the secondary directional antenna to reduce or prevent a reading of one or more stray RFID tags by the RFID system due to the unintended signal.