A High-Frequency-Compatible Miniaturized Bandpass Filter with Air-Bridge Structures Using GaAs-Based Integrated...

Area of Science:

• Electrical Engineering
• Materials Science
• Microwave Engineering

Background:

• Integrated passive devices are crucial for miniaturizing electronic components.
• Gallium arsenide (GaAs) technology offers high performance for radio frequency applications.
• Bandpass filters are essential for signal selection in wireless communication systems.

Purpose of the Study:

• To develop a miniaturized bandpass filter using GaAs integrated passive device technology.
• To optimize the filter design for a wide fractional bandwidth and high performance.
• To demonstrate the filter's suitability for L-band applications.

Main Methods:

• Implementation of a bandpass filter using GaAs-based integrated passive device technology.
• Incorporation of an intertwined circle-shaped spiral inductor and a center-located capacitor.
• Utilizing air-bridge structures for space-saving and performance enhancement.
• Selective variation of bridge capacitance to improve return loss.

Main Results:

• Achieved a miniaturized chip area of 1178 μm × 970 μm.
• Obtained a central frequency of 1.71 GHz with a return loss of 32.1 dB.
• Demonstrated a wide fractional bandwidth (FBW) of 66.63% with an insertion loss of 0.50 dB.
• Achieved a transmission zero of 43.42 dB at 4.48 GHz for out-band suppression.

Conclusions:

• The fabricated GaAs bandpass filter is highly miniaturized with excellent performance characteristics.
• The design's wide FBW, good out-band suppression, and high-quality signal yield make it suitable for L-band applications.
• Potential applications include mobile services, satellite navigation, telecommunications, and aircraft surveillance.