Graphene Distributed Amplifiers: Generating Desirable Gain for Graphene Field-Effect Transistors.

Area of Science:

• Materials Science
• Electrical Engineering
• Solid State Physics

Background:

• Graphene exhibits high carrier mobility, making it promising for high-frequency electronics.
• A key limitation of graphene in electronics is its low gain, hindering development.
• Distributed amplification is a known technique to enhance gain-bandwidth product in conventional semiconductors.

Purpose of the Study:

• To apply distributed amplification techniques to graphene field-effect transistors (GFETs) for the first time.
• To overcome the inherent gain limitations of graphene in electronic applications.
• To demonstrate the feasibility of graphene-based distributed amplifiers.

Main Methods:

• Simulations were performed using fabricated GFETs with measured fT (8.5-10.5 GHz) and fmax (12-14 GHz).
• Transmission lines were used to phase-synchronize paralleled GFETs, enabling additive gain combination.
• A proof-of-concept PCB-level graphene distributed amplifier was fabricated.

Main Results:

• A simulated four-stage graphene distributed amplifier achieved up to 4 dB gain.
• The simulated amplifier demonstrated a bandwidth of 3.5 GHz.
• The fabricated PCB-level amplifier served as a practical proof of concept.

Conclusions:

• Distributed amplification is a viable strategy to enhance the performance of graphene-based high-frequency electronics.
• The proposed GFET distributed amplifier design shows potential for future integrated circuit processes.
• This work addresses the gain limitation challenge, accelerating graphene's application in advanced electronics.