Two-Way Backscatter Communication Tag Using a Reflection Amplifier

We propose a two-way backscatter tag that uses a reflection amplifier. The reflection gain S
₁₁
is used to modulate the backscatter signal while the forward gain S
₂₁
is fixed. The circuit is analyzed and designed to operate at 2.45 GHz with the bandwidth of 120 MHz. Measurements show that we can have S
₁₁
≈ 20 and -20 dB to implement ON/OFF keying (OOK) backscatter modulation scheme, while S
₂₁
≈ 15 dB.