A 45 μW bias power, 34 dB gain reflection amplifier exploiting the tunneling effect for RFID applications RFID applications have power constraints that limit RF tags to short range communications. This article presents the design procedures, validated by experimental results, to make a low-powered reflection amplifier that exploits the quantum mechanical tunneling effect to dramatically enhance the range of passive or semi-passive tags. A return gain of 34.4 dB with bias power of 45 μW at 5.45 GHz and a return gain of 22.1 dB with a bias power of 47 μW at 5.55 GHz have been observed for impinging RF power levels as low as -70 dBm. These results allow, for certain devices, a factor of 7 range improvement to the RFID link while keeping the bias power 10 times lower than any other available reflection amplifier. This prototype could play a key role in enhancing RFID communication ranges without significantly affecting the low power budget typical for RFID technology; the design can be implemented in currently available semi-passive tags and opens the door for a new generation of long-range, passive/semi-passive transponders.