Two-Way Backscatter Communication Tag Using a Reflection Amplifier

We propose a two-way backscatter tag that uses a
reflection amplifier. The reflection gain S11 is used to modulate
the backscatter signal while the forward gain S21 is fixed. The
circuit is analyzed and designed to operate at 2.45 GHz with
bandwidth of 120 MHz. Measurements show that we can have
S11 = ?20 dB and -20 dB to implement on/off keying (OOK)
backscatter modulation scheme, while S21 ?= 15 dB.