Reflection Amplifier Based on Graphene

While RF transistor amplifiers-such as the field effect transistor (FET) amplifier which leverages its transconductance for amplification-are the key enablers of signal amplification in today's wireless communication; their ability to provide amplification degrades with increasing frequencies, thereby requiring multiple amplification stages which makes the device noisy, expensive and bigger in size. Owing to their broadband amplification capabilities, reflection-type amplifiers based on negative differential resistance (NDR) devices provide means to overcome these limitations. Herein, we propose a novel reflection amplifier circuit consisting of three graphene FETs (GFETs) which leverages its unique NDR characteristics. We show through rigorous simulation and modeling that broadband amplification exceeding several hundreds of GHz should be possible for the scaled graphene circuit. In addition, both the gain and frequency of operation can be highly modulated by varying the bias in the NDR region. Finally, we provide an experimental evidence of reflection amplification in the proposed circuit.