Millimeter-Wave Substrate Integrated Waveguide Using Micromachined Tungsten-Coated Through Glass Silicon Via...

Area of Science:

• Electrical Engineering
• Materials Science
• Microwave Engineering

Background:

• Conventional through glass via (TGV) substrates require complex machining and metal-filling processes.
• Millimeter-wave integrated circuits demand efficient and cost-effective substrate solutions.

Purpose of the Study:

• To demonstrate a new micromachined tungsten-coated through glass silicon via (TGSV) structure.
• To apply TGSVs for fabricating substrate integrated waveguides (SIW) for millimeter-wave applications.

Main Methods:

• Utilizing two-step deep reactive ion etching (DRIE) for silicon vias.
• Employing selective tungsten coating via shadow mask and glass reflow techniques.
• Fabricating a Ka-band substrate integrated waveguide (SIW) as a test vehicle.

Main Results:

• Successfully realized metal-coated TGSV structures on a glass substrate.
• The fabricated SIW demonstrated an average insertion loss of 0.69 ± 0.18 dB.
• Achieved a return loss better than 10 dB across the 20-45 GHz frequency range.

Conclusions:

• The proposed metal-coated TGSV offers a simplified fabrication process compared to conventional TGVs.
• This TGSV technology is suitable for developing high-performance millimeter-wave integrated devices.
• The demonstrated SIW validates the effectiveness of TGSV for Ka-band applications.