Miniaturised wideband bandpass filter with good selectivity based on 3D heterogeneous integrated passive device technology

Citation

Zhou, Y., et al.: Miniaturised wideband bandpass filter with good selectivity based on 3D heterogeneous integrated passive device technology. IET Microw. Antennas Propag. 18(4), 266–271 (2024). https://doi.org/10.1049/mia2.12447

Keywords

• 5G mobile communication
• integrated circuit design
• microwave devices
• wideband bandpass filter
• 3D heterogeneous integrated passive device technology
• frequency selectivity
• wide stopband
• GaAs-based
• Glass-based
• micro-nano-scale processes
• quality factors
• insertion loss
• transmission zeros (TZs)
• heterogeneous integration
• flip chip bonding
• ball grid array (BGA)
• through-glass-via (TGV)

Brief

This article presents a miniaturized wideband bandpass filter with good frequency selectivity and a wide stopband designed using 3D heterogeneous integrated passive device technology.

Summary

The article presents a novel design for a miniaturized wideband bandpass filter (BPF) that exhibits good frequency selectivity and a wide stopband using 3D heterogeneous integrated passive device (IPD) technology. This technology integrates components on both GaAs and Glass substrates for enhanced performance.

Here's a breakdown of the key aspects:

• Problem: Traditional methods for designing wideband BPFs face limitations in achieving compact size, low insertion loss, high frequency selectivity, and a wide stopband. Existing techniques for improving these aspects often lead to increased size and loss.
• Solution: The proposed BPF utilizes a sixth-order highpass-lowpass topology implemented through 3D heterogeneous integration. This involves combining 3D spiral inductors on a Glass substrate with high-density capacitors on a GaAs substrate.
• Advantages:

1. Compact Size: The filter's area is only 0.014 × 0.018 λ0² (1.1 × 1.42 mm²), making it suitable for high-density integration.
2. Good Selectivity: The design incorporates multiple transmission zeros (TZs) near the passband, enhancing selectivity and stopband rejection.
3. Low Loss: 3D spiral inductors on Glass exhibit higher Q-factors compared to traditional planar inductors, resulting in lower insertion loss.

• Fabrication and Results: The BPF was fabricated and tested, demonstrating a center frequency of 3.875 GHz, a 3-dB fractional bandwidth (FBW) of 42%, and 20-dB rejection ranging from 5.22 to 20 GHz (5.15 f0). The measured results closely matched the simulated performance.

In conclusion, this research introduces a promising approach for developing miniaturized, high-performance wideband BPFs for applications in advanced wireless communication systems, such as 5G equipment, where compactness and signal filtering are crucial.

Origin: https://ietresearch.onlinelibrary.wiley.com/doi/full/10.1049/mia2.12447