Sensor-activated transponder

A transponder, comprising:

• an antenna structure configured for receiving an incoming signal with radio frequency (RF) power of a first frequency f1 and retransmitting the incoming signal as a transparent output signal with RF power of a second frequency f2, different from the first frequency f1, when hit by the incoming signal;
• an amplifier configured for generating an amplified transparent output signal based on the incoming signal;
• a frequency converter configured for frequency converting the incoming signal into the transparent output signal;
• a first frequency filter connected to the antenna structure and tuned to the first frequency f1 for avoiding amplifying incoming signals with RF power of frequencies other than the first frequency f1;
• a sensor configured for responding to a physical stimulus for generating a control signal as an output response, wherein the sensor includes a gas sensor;
• and
• an activator configured for selectively activating or deactivating retransmission based on the control signal, wherein the activator deactivates retransmission if the gas sensor does not detect a predetermined gas or combination of gasses, and activates retransmission if the gas sensor detects the predetermined gas or combination of gasses.

A transponder, comprising:

• an antenna structure configured for receiving an incoming signal with radio frequency (RF) power of a first frequency f1 and retransmitting the incoming signal as a transparent output signal with RF power of a second frequency f2, different from the first frequency f1, when hit by the incoming signal;
• an amplifier configured for generating an amplified transparent output signal based on the incoming signal;
• a frequency converter configured for frequency converting the incoming signal into the transparent output signal;
• a first frequency filter connected to the antenna structure and tuned to the first frequency f1 for avoiding amplifying incoming signals with RF power of frequencies other than the first frequency f1;
• a sensor configured for responding to a physical stimulus and generating a control signal as output response, wherein the sensor includes a temperature sensor;
• and
• an activator for selectively activating or deactivating retransmission based on the control signal, wherein the activator carries out either one of the following:
• deactivates retransmission if the temperature sensor detects that a temperature is lower than a first threshold value, and activates retransmission if the temperature sensor detects that the temperature is higher than a second threshold value;
• or
• deactivates retransmission if the temperature sensor detects that the temperature is higher than the first threshold value, and activates retransmission if the temperature sensor detects that the temperature is lower than the second threshold value.