Through Glass Via (TGV) Based Integrated Passive Device Technology for RF Front End Design

This white paper presents a comprehensive study on TGV based integrated passive devices (IPD) in the context of comparing with other IPD technologies such as low-temperature-cofired-ceramics (LTCC), high resistivity silicon (HRSi), and glass substrate. The comparison is not only on the component (inductor) level but also on the system level, where a carrier aggregation diplexer is designed. Further TGV process improvement is also suggested based on the study.


Mobile and IoT device market has experienced tremendous growth in the past. While Moore’s law continues to drive the technology to shrink for the digital portion of the devices, the RF portion does not scale in the same rate. The further reduction in cost and size comes from the passive integration. To meet the ever growing demand reduce size and cost, increase functionality, integrated passive device (IPD) technology has become a viable technology for RF front end designs. It has evolved from low-temperature cofired ceramics (LTCC) to thin-film technologies such as the one using high-resistivity silicon (HRSi) or glass substrate.

Recently, Through Glass Via (TGV) technology has become a promising technology candidate to realize integrated, low cost and high performance passive devices. Three-dimensional solenoid inductors can be constructed with TGVs for better quality-factor compared with 2D planar inductors. Glass’s lower dielectric constant and higher resistivity compared to silicon lead to better high frequency performance. Passive devices such as filters and diplexers built with TGV can have less in-band insertion loss and greater out-of-band rejection yet still compact size.

This white paper will demonstrate the TGV performance by comparing TGV inductor with those built on LTCC, HRSi, and glass substrate. The similar comparison is also carried out on system level. A carrier aggregation (CA) diplexer is designed with TGV, LTCC, HRSi and glass, respectively. Their performance such as IL, isolation, and attenuation is compared. Further improvement on TGV performance is studied from the TGV process perspective.

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