GaN-on-SiC vs GaN-on-Si RF Power Amplifiers — PatSnap Eureka
GaN-on-SiC vs GaN-on-Si for High-Efficiency RF Power Amplifiers in Base Station Applications
SiC substrates deliver ~490 W/m·K thermal conductivity — three times that of silicon — making them the dominant platform for macro base station PAs. But GaN-on-Si is closing the gap for Massive MIMO deployments where per-PA cost drives system economics. Here is the full technical picture, drawn from 50+ patents and publications.
Two Platforms, One Critical Trade-Off
GaN-on-SiC and GaN-on-Si both deliver HEMT-based RF power amplification for 5G NR base station deployments — but they solve the thermal and cost equation in fundamentally different ways.
GaN-on-SiC: The High-Performance Benchmark
Silicon carbide substrates provide thermal conductivity of approximately 490 W/m·K — roughly three times that of silicon. This enables higher power density operation at elevated drain voltages, essential for macro base station transmitters. Commercial foundry processes such as UMS GH25 (0.25 μm) and WIN Semiconductors 0.25 μm are mature, well-characterised, and supported by established design kits used extensively across the literature. Wolfspeed (formerly Cree) is the foundational foundry and IP holder, with patents targeting PAE exceeding 32% at P1dB across 26.5–30.5 GHz for 5G mmWave base station bands.
~490 W/m·K thermal conductivityGaN-on-Si: Integration and Scale Economics
Silicon wafers are 6–10× cheaper than SiC at equivalent diameter and are compatible with existing CMOS fabrication infrastructure at 150 mm and 200 mm wafer sizes. This cost argument becomes decisive for Massive MIMO base stations where each array may use 64–256 antenna elements, each requiring its own PA cell. GaN-on-Si also offers unique co-integration potential with CMOS digital baseband — a system-level advantage that SiC cannot match. However, the higher loss tangent of silicon and poorer thermal dissipation both degrade RF performance relative to SiC, requiring purpose-built matching network strategies to recover efficiency.
6–10× lower substrate cost vs. SiCEpitaxial Quality and Current Collapse Risk
GaN-on-SiC has a lattice mismatch of only ~3.5% with GaN, allowing thinner, higher-quality epitaxial layers with fewer trapping defects. GaN-on-Si faces a ~17% lattice mismatch, requiring thick AlN/AlGaN graded buffer layers to manage both lattice and thermal expansion mismatch. These buffer layers introduce trapping states that cause current collapse — a reduction in saturated drain current under RF drive — degrading linearity and PAE at high power. This is a critical reliability and linearity disadvantage for base station PAs that must pass 3GPP spectral emission mask requirements.
3.5% vs. 17% lattice mismatchFoundry Readiness for Base Station Duty Cycles
Commercial GaN-on-SiC foundry processes are mature, well-characterised, and supported by established design kits used extensively across the academic and industrial literature reviewed in this dataset. GaN-on-Si processes at 100 nm gate length — as used in the Pazhou Lab and Guangdong University of Technology studies — are still maturing in terms of yield, model accuracy, and thermal reliability qualification for continuous-wave base station duty cycles. The reliability qualification gap is a meaningful barrier to GaN-on-Si adoption in outdoor macro base station deployments.
SiC: mature PDKs · Si: still qualifyingPAE and Output Power Benchmarks from the Literature
All values sourced directly from peer-reviewed publications and patents analysed via PatSnap Eureka. No estimated data.
GaN-on-SiC PAE Benchmarks Across Frequency Bands
Power-added efficiency peaks at 68.37% at 1.5 GHz (class-F) and remains competitive at 48% even at 30 GHz with novel AlScN barriers (Fraunhofer IAF, 2023).
Lattice Mismatch: GaN-on-SiC vs GaN-on-Si
GaN-on-Si's 17% lattice mismatch is nearly 5× greater than GaN-on-SiC's 3.5%, requiring thick buffer layers that introduce trapping states and current collapse risk.
GaN-on-SiC vs GaN-on-Si: Key Performance Dimensions
Direct comparison across the technical dimensions that matter most for continuous-wave base station PA design, drawn from 50+ patents and publications.
| Dimension | GaN-on-SiC | GaN-on-Si |
|---|---|---|
| Thermal Conductivity | ~490 W/m·K LEADS | ~150 W/m·K |
| Power Density | 4–10 W/mm gate width LEADS | Lower — thermal accumulation limits sustained operation |
| Lattice Mismatch with GaN | ~3.5% — thin, high-quality epi LEADS | ~17% — thick AlN/AlGaN buffer required |
| Substrate Cost | Higher — SiC wafers premium-priced | 6–10× cheaper than SiC at equivalent diameter LEADS |
| PAE at Sub-6 GHz | 68.37% drain efficiency at 1.5 GHz (class-F) LEADS | Competitive but penalised by substrate loss in matching networks |
| PAE at mmWave | 26–48% at 27–30 GHz (Catania 2023, Fraunhofer IAF 2023) LEADS | Demonstrated at 24–30 GHz but requires low-impedance matching mitigation |
| Current Collapse Risk | Low — fewer trapping defects LEADS | Higher — buffer layer trapping states degrade linearity under RF drive |
| CMOS Co-integration | Not compatible | Compatible with CMOS baseband — unique system-level advantage LEADS |
Run your own GaN substrate comparison in PatSnap Eureka
Search 2B+ data points across patents, literature, and clinical studies — all in one AI-powered platform.
Key Players and Emerging Research Clusters
Wolfspeed (formerly Cree) is a foundational GaN-on-SiC foundry and IP holder, with patents explicitly targeting PAE exceeding 32% at P1dB across 26.5–30.5 GHz for 5G mmWave base station bands. Their 2022 and 2024 patent filings confirm continued investment in HEMT reliability and performance at millimeter-wave frequencies.
TriQuint/Qorvo is cited as the commercial GaN-on-SiC HEMT source (12 W, 5–7 GHz) in multiple studies targeting 5G NR bands n77/n78/n79, indicating dominant commercial supply in the sub-6 GHz base station segment. UMS (United Monolithic Semiconductors) GH25 (0.25 μm) is broadly adopted for professional RF applications including base station and electronic warfare MMICs, as demonstrated by the Indra Sistemas 6–18 GHz EW MMIC achieving 39.2 dBm averaged output power with 24.5% peak PAE.
Guangdong University of Technology and Pazhou Lab (Guangzhou) are emerging as the most active GaN-on-Si RF PA research cluster in the dataset, reflecting China's strategic push toward domestic low-cost GaN-on-Si production for large-volume 5G deployment. Their 24–30 GHz 5G GaN-on-Si MMIC PA (2023) directly targets the Massive MIMO cost-performance niche. Learn more about how R&D teams use PatSnap to track competitive innovation in semiconductor platforms.
Fraunhofer IAF represents the next performance frontier: their AlScN/GaN HEMTs on SiC achieve 8.4 W/mm output power density and 48% PAE at 30 GHz — surpassing conventional AlGaN/GaN limits and pointing toward further PA footprint reduction in 5G mmWave base station radios. Fraunhofer IAF and the IEEE continue to publish foundational results on novel barrier materials for GaN HEMTs.
PA Architecture Strategies for Each Platform
Each substrate demands different circuit-level approaches to maximise efficiency and meet 5G NR spectral mask requirements.
Doherty Architecture for GaN-on-SiC mmWave
The University of Catania's Ka-band Doherty PA at 27 GHz achieves 30 dB small-signal gain, 32 dBm saturated output power, and 26% PAE at peak — with 18% PAE at 6 dB output power back-off. This back-off efficiency directly addresses the high PAPR of 5G NR OFDM waveforms, making Doherty the preferred architecture for GaN-on-SiC mmWave base station PAs.
Class-F and Continuous-Mode for Sub-6 GHz SiC
At 1.5 GHz, class-F GaN HEMT PAs achieve 68.37% drain efficiency at 40.79 dBm output power. The National Central University's continuous class-J mode quasi-MMIC demonstrates 40.3 dBm saturation power and 39.5% peak PAE across the 2.85–4.48 GHz band using WIN Semiconductors' 0.25 μm GaN/SiC, incorporating GaAs IPD passives to reduce cost without sacrificing the thermal floor provided by the SiC substrate.
Low-Impedance Matching for GaN-on-Si
The higher loss tangent of Si requires a fundamental redesign of the impedance matching philosophy. The Agency Defense Development W-band GaN-on-Si PA adopts low-impedance microstrip lines (20–30 Ω) instead of conventional 50 Ω-referenced matching as a direct mitigation of Si substrate loss. Guangdong University of Technology's 24–30 GHz MMIC uses shorted stubs with bypass capacitors to minimise output reactance, combined with analytical and numerical optimisation for the matching networks.
Non-Uniform Distributed Amplifier for Ultra-Wideband SiC
The Chinese Academy of Sciences demonstrates a 0.25 μm GaN-on-SiC distributed amplifier topology delivering 16.6–27% PAE across 2–16 GHz — confirming the platform's versatility over very wide bandwidths. This non-uniform distributed approach, combined with a harmonic suppression network, is particularly suited to base station infrastructure requiring multi-band coverage without retuning.
GaN-on-SiC Output Power Across Key Base Station Bands
Saturated output power figures from peer-reviewed publications, all on GaN-on-SiC processes. GaN-on-Si comparable results remain below these benchmarks at X-band and above due to thermal and substrate losses.
Saturated Output Power by Frequency Band — GaN-on-SiC MMICs
X-band GaN-on-SiC achieves over 40 W output power with 44.7% PAE. Ka-band Doherty reaches 32 dBm (1.6 W). Values from Zhejiang University (2019), University of Catania (2023), and National Central University (2023).
What the Patent and Literature Data Tells Us
Seven evidence-backed conclusions drawn from 50+ patents and publications analysed via PatSnap's IP analytics platform.
- GaN-on-SiC delivers superior thermal management and power density for continuous-wave macro base station PAs, as evidenced by the persistent use of SiC-substrate platforms in 5–7 GHz and 8–18 GHz PA demonstrations from BUITEMS (2021) and Indra Sistemas (2019), where heat dissipation at high drain voltages is mission-critical.
- GaN-on-Si incurs RF performance penalties from substrate loss, requiring specialised matching network designs such as low-impedance microstrip lines (20–30 Ω) to recover efficiency, as shown in Agency Defense Development's W-band PA (2021).
- GaN-on-SiC dominates mmWave 5G base station PA IP, with Wolfspeed patents covering PAE exceeding 32% at 26.5–30.5 GHz and the University of Catania demonstrating a full Ka-band Doherty PA at 27 GHz with 26% peak PAE.
- GaN-on-Si offers cost and integration advantages for Massive MIMO, with 0.1 μm processes at 24–30 GHz being actively developed by Chinese institutions targeting large-volume 5G deployment scenarios where per-PA cost dominates system economics.
- Novel AlScN/GaN-on-SiC barrier materials represent the next performance tier, with Fraunhofer IAF reporting 8.4 W/mm output power density and 48% PAE at 30 GHz — a pathway to further shrink PA footprint in base station radios.
- GaN-on-SiC maintains the performance-per-watt advantage in X-band and above, with 44.7% PAE at over 40 W output power demonstrated on 0.25 μm GaN-on-SiC MMIC by Zhejiang University (2019) — a benchmark not yet matched by equivalent GaN-on-Si implementations.
- Thermal stability of the 2DEG is a key differentiator: FTMC Lithuania (2020) demonstrates thermally stable AlGaN/GaN-on-SiC 2DEG electron density from 77–300 K, confirming SiC substrate devices are inherently better suited for the constant thermal cycling experienced in outdoor base station enclosures.
GaN-on-SiC vs GaN-on-Si for RF Power Amplifiers — key questions answered
SiC's thermal conductivity (~490 W/m·K) is approximately three times that of Si (~150 W/m·K). In continuous-wave base station operation at 28 V drain bias, this difference is decisive: GaN-on-SiC devices can sustain higher channel temperatures before degradation, enabling operation at higher power densities (typically 4–10 W/mm gate width). GaN-on-Si devices, operating at the same power density, accumulate more heat in the channel, leading to earlier electron trapping, current collapse, and long-term reliability degradation.
Wolfspeed patents cover PAE exceeding 32% at P1dB across 26.5–30.5 GHz for mmWave base station bands. The University of Catania demonstrated a full Ka-band Doherty PA at 27 GHz with 26% peak PAE and 18% PAE at 6 dB output power back-off, directly meeting the back-off efficiency requirements of 5G NR waveforms using OFDM modulation with high peak-to-average power ratios.
The higher loss tangent of Si introduces additional microwave losses in the passive elements of the matching network, reducing PAE for a given output power level. The W-band GaN-on-Si amplifier from Agency Defense Development (2021) required a fundamental redesign of the impedance matching philosophy — using low-impedance microstrip lines (20–30 Ω) instead of conventional 50 Ω-referenced matching — as a direct mitigation of Si substrate loss.
Si wafers are 6–10× cheaper than SiC at equivalent diameter and are compatible with existing CMOS fabrication infrastructure at 150 mm and 200 mm wafer sizes. This is a compelling cost argument for massive MIMO base stations where each 5G base station Massive MIMO array may use 64–256 antenna elements each requiring its own PA. Guangdong University of Technology (2023) targets precisely this cost-performance niche with a compact 0.1 μm GaN-on-Si MMIC for 24–30 GHz.
GaN grown on Si substrates requires thick transition layers (AlN/AlGaN graded buffers) to manage the large lattice mismatch (~17%) and thermal expansion mismatch between GaN and Si. These buffer layers introduce trapping states that cause current collapse (a reduction in saturated drain current under RF drive), degrading linearity and PAE at high power. GaN-on-SiC has a much smaller lattice mismatch (~3.5%) with GaN, allowing thinner, higher-quality epitaxial layers with fewer trapping defects — a critical reliability and linearity advantage for base station PAs that must pass 3GPP spectral emission mask requirements.
Novel AlScN/GaN-on-SiC barrier materials represent the next performance tier, with Fraunhofer IAF reporting 8.4 W/mm output power density and 48% PAE at 30 GHz, offering a pathway to further shrink PA footprint in base station radios. This work demonstrates that novel AlScN barriers on GaN-on-SiC can push power density and PAE beyond conventional AlGaN/GaN limits, pointing toward the next performance frontier for 5G mmWave base stations.
Still have questions about GaN substrate selection for your base station PA design?
Ask PatSnap Eureka AI InstantlyMake faster GaN substrate decisions with AI-powered patent intelligence
Join 18,000+ innovators already using PatSnap Eureka to accelerate their R&D. Search 2B+ data points across GaN-on-SiC and GaN-on-Si patents, publications, and competitive filings in one platform.
References
- GaN Monolithic Power Amplifiers for Microwave Backhaul Applications — DET, Politecnico di Torino, 2016
- Design of W-Band GaN-on-Silicon Power Amplifier Using Low Impedance Lines — Agency Defense Development, Korea, 2021
- GaN Based HEMT Power Amplifier Design with 44.5dBm Output Power Operating at 5-7GHz — Balochistan University of Information Technology, 2021
- Power Efficient GaN HEMT High Power Amplifier Design Operating at 5-7GHz Bandwidth — BUITEMS, 2020
- Design and characterization of a 6–18 GHz GaN on SiC high-power amplifier MMIC for electronic warfare — Indra Sistemas S.A., 2019
- A Ka-Band Doherty Power Amplifier in a 150 nm GaN-on-SiC Technology for 5G Applications — University of Catania, 2023
- High-Efficiency and Cost-Effective 10 W Broadband Continuous Class-J Mode Quasi-MMIC Power Amplifier Design Utilizing 0.25 μm GaN/SiC and GaAs IPD Technology for 5G NR n77 and n78 Bands — National Central University, Taiwan, 2023
- High electron mobility transistor with improved performance and reliability and power amplifier including the same — Wolfspeed Inc., 2022
- High electron mobility transistor with improved performance and reliability and power amplifier including the same — Wolfspeed Inc., 2024
- Design of 2–16 GHz Non-Uniform Distributed GaN HEMT MMIC Power Amplifier with Harmonic Suppression Network — Institute of Microelectronics, Chinese Academy of Sciences, 2022
- Efficient GaN-on-Si Power Amplifier Design Using Analytical and Numerical Optimization Methods for 24–30 GHz 5G Applications — Guangdong University of Technology, 2023
- Design of Ka-band broadband low-noise amplifier using 100nm gate-length GaN on silicon technology — Pazhou Lab, Guangzhou, 2021
- Design and Parametric Analysis of GaN on Silicon High Electron Mobility Transistor for RF Performance Enhancement — ECE, 2021
- AlGaN/GaN on SiC Devices without a GaN Buffer Layer: Electrical and Noise Characteristics — Center for Physical Sciences and Technology (FTMC), Lithuania, 2020
- An X-Band 40 W Power Amplifier GaN MMIC Design by Using Equivalent Output Impedance Model — Zhejiang University, 2019
- High gain over an octave bandwidth class-F RF power amplifier design using 10W GaN HEMT — Multimedia University, 2020
- AlScN/GaN HEMTs Grown by Metal-Organic Chemical Vapor Deposition With 8.4 W/mm Output Power and 48% Power-Added Efficiency at 30 GHz — Fraunhofer Institute for Applied Solid State Physics IAF, 2023
- GaN-based single-chip frontend for next-generation X-band AESA systems — HENSOLDT, 2018
- Design of broadband high-gain GaN MMIC power amplifier based on reactive/resistive matching and feedback technique — Guangdong University of Technology, 2021
- IEEE — Institute of Electrical and Electronics Engineers (authoritative source for RF and microwave engineering standards)
- Fraunhofer Institute for Applied Solid State Physics IAF — leading European GaN HEMT research institution
- 3GPP — 3rd Generation Partnership Project (5G NR spectral emission mask standards)
All data and statistics on this page are sourced from the references above and from PatSnap's proprietary innovation intelligence platform. Patent and literature analysis conducted via PatSnap Eureka. For enterprise IP analytics and competitive intelligence, visit PatSnap Analytics.
PatSnap Eureka searches patents and research to answer instantly.