An MMIC LNA for Millimeter-Wave Radar and 5G Applications with GaN-on-SiC Technology

Area of Science:

• Microwave Engineering
• Semiconductor Devices
• Wireless Communications

Background:

• Fifth-generation (5G) mobile systems require high-frequency components for millimeter-wave bands.
• Low noise amplifiers (LNAs) are critical for maintaining signal integrity in sensitive receivers.
• Gallium Nitride (GaN)-on-Silicon Carbide (SiC) High Electron Mobility Transistors (HEMTs) offer superior performance for high-frequency applications.

Purpose of the Study:

• To design and characterize a monolithic microwave integrated circuit (MMIC) low noise amplifier (LNA).
• To ensure compatibility with 5G millimeter-wave frequency bands n257 (26.5-29.5 GHz) and n258 (24.25-27.5 GHz).
• To achieve a balance between noise figure (NF) and small signal gain while enhancing stability.

Main Methods:

• Utilized Gallium Nitride (GaN)-on-SiC High Electron Mobility Transistors (HEMTs).
• Employed transmission lines connected to the source, analyzed via nonlinear small-signal equivalent circuits.
• Implemented stability enhancement techniques: source degeneration, RC series network, and RF choke.
• Adopted hybrid-matching networks (MNs) with a co-design strategy for broadband performance.

Main Results:

• Achieved a linear gain of 18.2-20.3 dB across the specified frequency bands.
• Obtained a noise figure (NF) ranging from 2.5-3.1 dB.
• Demonstrated input-output return loss better than 10 dB.
• The three-stage MMIC LNA has a compact size of 2.5 × 1.5 mm².

Conclusions:

• The designed GaN-based MMIC LNA meets the stringent requirements for 5G and millimeter-wave radar applications.
• The hybrid-matching network co-design strategy effectively balances gain, return loss, and noise figure.
• The implemented stability measures ensure reliable operation in the target frequency bands.