A 77 GHz Power Amplifier with 19.1 dBm Peak Output Power in 130 nm SiGe Process

Area of Science:

• Electrical Engineering
• Materials Science

Background:

• High-frequency power amplifiers are crucial for advanced communication systems.
• SiGe (Silicon-Germanium) technology offers a viable platform for millimeter-wave applications.

Purpose of the Study:

• To design and characterize a two-stage differential power amplifier operating at 77 GHz.
• To improve amplitude and phase balance in the balun for consistent output power.
• To ensure stable performance under varying ambient temperatures.

Main Methods:

• Utilized a 130 nm SiGe process for amplifier fabrication.
• Incorporated a tunable capacitor in the Marchand balun for improved balance.
• Implemented a 3-bit digital analog converter (DAC)-controlled base bias current source.

Main Results:

• Achieved amplitude imbalance < 0.5 dB and phase imbalance < 1 degree in the balun (70-85 GHz).
• Demonstrated small signal gain fluctuation < 5 dB and saturation output power fluctuation < 2 dB ( -40 °C to 125 °C).
• Exhibited small signal gain > 16 dB, saturation output power > 18 dBm, and peak output power of 19.1 dBm (70-85 GHz).

Conclusions:

• The developed differential power amplifier shows excellent performance at 77 GHz.
• The design ensures stable operation over wide frequency and temperature ranges.
• This amplifier is suitable for high-frequency communication applications requiring consistent power output.