Low-Loss Dielectric Materials for 5G/6G — PatSnap Eureka
Low-Loss Dielectric Materials for 5G/6G Millimeter-Wave Applications
A structured 2026 landscape of polymer, ceramic, porous inorganic, and liquid crystal dielectric platforms enabling mmWave and sub-THz communication — with measured benchmarks, active patents, and leading institutional contributors drawn from 20+ sources.
The 2026 Low-Loss Dielectric Materials Landscape
The materials landscape for 5G/6G mmWave divides into four dominant technical families, each with distinct performance profiles, processing routes, and IP activity — surveyed across 20+ patents and literature sources spanning 2000–2023.
Advanced Polyimide & Liquid Crystal Polymer
Polyimide (PI) materials have attracted substantial research attention as flexible, processable dielectric candidates. Conventional PI exhibits Dk of 3.0–4.0 and dielectric loss of approximately 0.02 — insufficient for 5G high-frequency circuits. Toray Industries achieved Df = 0.002 and Dk = 2.7 through molecular motion restriction and polarity reduction. Liquid crystal polymer (LCP) offers stable dielectric constant and loss tangent specifically across the millimeter-wave frequency range.
Target: Dk < 2.5, Df < 0.002LTCC, Silicate Ceramics & Glass-Ceramic Composites
Inorganic materials remain a foundational class for precision mmWave components such as resonators, filters, and LTCC substrates. Indialite/cordierite glass-ceramics yield Dk = 4.7 and Qf exceeding 200 × 10³ GHz. Murata's LTCC composite achieves Dk = 8.8, Q = 1620 at 25 GHz, and temperature coefficient τε of +16 ppm/°C. High quality factors arise from ordered SiO₄ tetrahedral connectivity in silicate ceramics.
Qf > 200,000 GHz · near-zero τεPorous Silica Foams & Ultra-Porous Alumina for 6G
As operating frequencies advance toward 300 GHz and above for next-generation wireless, minimizing substrate permittivity as close to unity (air) as possible becomes the dominant design philosophy. University of Oulu's porous silica foam (98.9% porosity, density 0.025 g/cm³) achieved εr = 1.018 ± 0.003 at 300 GHz. Ultra-porous alumina (99% porosity) achieves εr ≈ 1.2 at 130–165 GHz.
εr = 1.018 at 300 GHz · 6G-readyLiquid Crystal Tunable Dielectrics for Phase Shifters
Liquid crystal (LC) materials offer tunability absent in passive ceramic or polymer substrates. University of Southampton demonstrated LC in the nematic phase at 66 GHz, fabricated into phase shifters delivering 0–π tunability with insertion loss of −4 dB. This validates the LC approach as a low-power continuous alternative to semiconductor-based or MEMS-based phase switching in mmWave beamforming networks. Quasi-optical LC-loaded Fresnel lenses have also been demonstrated using 3D-printed structures.
0–π tunability · −4 dB insertion loss at 66 GHzKey Dielectric Metrics Across Material Families
All data points drawn directly from patents and peer-reviewed literature in the dataset. Loss tangent (tan δ) and dielectric constant (εr) are the two primary figures of merit for mmWave substrate qualification.
Loss Tangent (tan δ) — Key Material Benchmarks
Porous silica foam achieves the lowest tan δ of 3×10⁻⁴ at 300 GHz; conventional PI baseline is ~100× higher at 0.02.
Quality Factor & Key LTCC Metrics
Indialite/cordierite glass-ceramics achieve Qf > 200,000 GHz; Murata LTCC delivers Q = 1620 at 25 GHz with τε = +16 ppm/°C.
Porous Inorganic Substrates: Approaching Free-Space Permittivity
As operating frequencies advance toward 300 GHz and above for 6G, minimizing the dielectric substrate permittivity as close to unity (air) as possible becomes the dominant design philosophy. The University of Oulu's work on lightweight porous silica foams (2021) achieved a relative permittivity of εr = 1.018 ± 0.003 at 300 GHz with tan δ < 3 × 10⁻⁴ at the same frequency, using highly porous (98.9%) lightweight silica foams with density of just 0.025 g/cm³, synthesized by template-assisted sol-gel.
After coating with cellulose nanofibers to improve surface smoothness, silver thin films were sputtered through shadow masks — demonstrating printable electronics compatibility critical toward manufacturable 6G substrate integration. The same group's 2020 work on hollow SiO₂ nanoshells reinforced with cellulose nanofibers yielded a composite mass density of 0.19 g/cm³, leveraging polystyrene nanosphere templating followed by polymer burnout.
Cyclo-olefin polymer (COP) RS420-LDS from Zeon achieves a loss tangent of 7.5 × 10⁻⁴ at 40 GHz, enabling high-Q substrate integrated waveguide (SIW) bandpass filters fabricated by molding and laser direct structuring (LDS) metallization — a production-compatible route to mmWave cavity filters in the 30–60 GHz range, as demonstrated by UBO Lab-STICC.
Ultra-porous alumina (UPA) with porosity approaching 99% achieves εr ≈ 1.2 at 130–165 GHz and tan δ ≈ 10⁻³. Hydrophobic surface treatment can further reduce loss. ITU spectrum allocations for 6G sub-THz bands make these ultra-low permittivity substrates increasingly critical for high-capacity backhaul link design.
Leading Contributors by Material Family & Application
Analysis of the dataset reveals clear institutional clustering by material family and application type — spanning academic research groups and industrial IP holders across Japan, China, South Korea, Finland, and Europe.
Track Active Patents from Shin-Etsu, Murata & Fenghua
Monitor competitive IP filings across mmWave dielectric substrate families in real time with PatSnap Eureka.
How the Research Landscape Is Shifting Toward 6G
Research published from 2020 onward increasingly targets 6G-relevant sub-THz frequencies (100–300+ GHz) rather than exclusively 5G mmWave bands (24–40 GHz).
Sub-THz Frequency Targeting
Research published from 2020 onward increasingly targets 6G-relevant sub-THz frequencies (100–300+ GHz) rather than exclusively 5G mmWave bands (24–40 GHz), reflecting the industry's forward-looking R&D investment horizon.
Engineered Porosity as the Primary Strategy
Academic research favors either engineered porosity (approaching air-like permittivity) or molecular-level restriction of polarization in polymers as the primary strategy to minimize both Dk and Df simultaneously — a departure from conventional dense ceramic approaches.
Industrial IP Concentrated in 5G / 25–40 GHz
Industrial patent activity from Shin-Etsu, Fenghua, and Murata concentrates in the 5G/25–40 GHz range with a focus on thermal stability and process compatibility — reflecting near-term commercialisation priorities distinct from academic 6G frontiers.
East Asian Academic Investment in Polymer Dielectrics
Both Pusan National University (South Korea) and Shenyang University of Chemical Technology (China) contributed comprehensive polyimide reviews in 2023, signaling active academic investment in polymer dielectrics for 5G/6G across East Asia — complementing established Japanese industrial positions.
D-Band Penetration Loss Context
Fudan University (2022): D-band (110–170 GHz) waves cannot effectively penetrate thick building materials — driving demand for low-loss transparent dielectric radome designs.
Measurement Methods for Material Qualification
Accurate Dk/Df measurement is a prerequisite. Unimicron (2022) found systematic discrepancies between vendor datasheet values and measured performance — stressing application-specific re-measurement.
Key Active Patents Shaping the mmWave Substrate Landscape
Patent landscape analysis via PatSnap Eureka identifies three active patents with direct commercial relevance to 5G/6G substrate manufacturing. Shin-Etsu Chemical's 2023 US patent describes a composite substrate combining quartz glass cloth (Df of 0.0001–0.0015, Dk of 3.0–3.8 at 10 GHz) with an organic resin matched to within 80–150% of the cloth's loss tangent — designed to eliminate differential propagation time between wiring segments at mmWave speeds.
Guangdong Fenghua Advanced Technology's 2023 patent (active in Japan) describes a Ba₅Si₈O₂₁ composition with tunable (Mg,Ca,Sr,Ba)WO₄ content combined with Ba-B-Si glass. By adjusting the phase ratio, the temperature coefficient of resonant frequency can be brought near zero — enabling stable signal transmission in 5G radio frequency applications and reflecting growing Chinese industrial IP presence in LTCC for 5G hardware.
These active filings, alongside Murata's established LTCC portfolio and Toray's photosensitive PI work, define the commercial IP frontier. PatSnap customers in the RF materials space use Eureka to monitor competitor filings, identify white spaces, and track prosecution status across jurisdictions. According to EPO data, mmWave component-related filings have grown significantly alongside 5G infrastructure rollout, with Asia-Pacific jurisdictions accounting for a growing share of active grants.
For R&D teams working on next-generation PCB laminates, LTCC filters, or polymer redistribution layers, understanding the active IP landscape is essential to both freedom-to-operate analysis and identifying collaboration opportunities with academic institutions such as the University of Oulu or University of Southampton.
Low-Loss Dielectric Materials for 5G/6G — key questions answered
The overarching technical driver is achieving simultaneously low dielectric constant (Dk) — ideally below 2.5 — and low loss tangent (Df/tan δ), ideally in the range of 10⁻³ to 10⁻⁴ or below, in order to minimize signal attenuation at mmWave frequencies ranging from 26 GHz to beyond 300 GHz relevant to D-band B5G/6G systems.
The University of Oulu's lightweight porous silica foam work (2021) achieved a relative permittivity of εr = 1.018 ± 0.003 at 300 GHz with tan δ < 3 × 10⁻⁴ at the same frequency, using highly porous (98.9%) lightweight silica foams (density 0.025 g/cm³) synthesized by template-assisted sol-gel — approaching the theoretical limit of free space.
Toray Industries reported achievement of a loss tangent (Df) of 0.002 and a dielectric constant of 2.7 in a novel PI formulation. This work established that molecular motion restriction at low temperatures is the critical mechanism for reducing dielectric loss at frequencies of 10–100 GHz, and that reducing polar and flexible segments in the PI chain simultaneously lowers Dk.
Research from the University of Oulu's Microelectronics Research Unit demonstrates that indialite/cordierite glass-ceramics crystallized at 1300°C for 20 hours yield a dielectric constant of 4.7 and an exceptionally high quality factor Qf exceeding 200 × 10³ GHz — performance described as essential for 5G/6G mobile communication systems.
D-band penetration loss data from Fudan University (2022) confirms that D-band waves cannot effectively penetrate thick building materials, mandating indoor-outdoor link architectures that rely on low-loss transparent dielectric panels or dedicated mmWave windows.
Liquid crystal (LC) materials occupy a unique niche in the low-loss dielectric landscape as they offer tunability — a property absent in most passive ceramic or polymer substrates. The University of Southampton demonstrated LC in the nematic phase operating at 66 GHz, fabricated into phase shifters delivering 0–π tunability with an insertion loss of −4 dB, validating the LC approach as a low-power continuous alternative to semiconductor-based or MEMS-based phase switching in mmWave beamforming networks.
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References
- Research on Penetration Loss of D-Band Millimeter Wave for Typical Materials — Key Laboratory for Information Science of Electromagnetic Waves, Fudan University, 2022
- Characterization of Low-Loss Dielectric Materials for High-Speed and High-Frequency Applications — Unimicron Technology Corporation, 2022
- Structural Designs of Transparent Polyimide Films with Low Dielectric Properties and Low Water Absorption: A Review — Pusan National University, 2023
- Lightweight porous silica foams with extreme-low dielectric permittivity and loss for future 6G wireless communication technologies — University of Oulu, 2021
- Ultra-low permittivity porous silica-cellulose nanocomposite substrates for 6G telecommunication — University of Oulu, 2020
- Micro/Millimeter-Wave Dielectric Indialite/Cordierite Glass-Ceramics Applied as LTCC and Direct Casting Substrates — Microelectronics Research Unit, University of Oulu, 2019
- Silicate dielectric ceramics for millimetre wave applications — Technische Universitaet Berlin, 2021
- Dielectric parameters of the modern low-loss ceramics in the microwave, millimeter, and submillimeter ranges — Public Corporation "Magneton", St.-Petersburg, 2018
- Synthesis and applications of low dielectric polyimide — Shenyang University of Chemical Technology, 2023
- Low Df Polyimide with Photosensitivity for High Frequency Applications — Toray Industries, Inc., 2020
- Progress of liquid crystal polyester (LCP) for 5G application — University of Electronic Science and Technology of China, 2020
- LDS Realization of High-Q SIW Millimeter Wave Filters with Cyclo-Olefin Polymers — UBO, Lab-STICC UMR 6285 CNRS, 2018
- Low-loss tunable dielectrics for millimeter-wave phase shifter: from material modelling to device prototyping — University of Southampton, 2020
- Potential of Liquid-Crystal Materials for Millimeter-Wave Application — Akita Prefectural University, 2018
- Dielectric properties of new LTCC material applied to high frequencies — Murata Manufacturing Co., Ltd., 2014
- LTCC microwave dielectric material and its manufacturing method — Guangdong Fenghua Advanced Technology, 2023
- Low dielectric substrate for high-speed millimeter-wave communication — Shin-Etsu Chemical Co., Ltd., 2023
- Complex Permittivity Measurement of Low-Loss Anisotropic Dielectric Materials at Hundreds of Megahertz — Northwestern Polytechnical University, 2022
- Ultra-porous alumina for microwave planar antennas — Université Paris Diderot, 2015
- European Patent Office (EPO) — mmWave component patent filing trends and jurisdiction data
- International Telecommunication Union (ITU) — 6G sub-THz spectrum allocation framework
- Université de Bretagne Occidentale (UBO) / Lab-STICC — COP SIW filter fabrication research
All data and statistics on this page are sourced from the references above and from PatSnap's proprietary innovation intelligence platform, PatSnap Analytics, and PatSnap Trust Center.
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