At the Northrop Grumman Microelectronics Center, millions of mission-critical microelectronics are designed and delivered annually to support next-generation defense and commercial systems. From design to fabrication, Northrop Grumman’s mission-tailored microelectronics solutions deliver excellent performance for any application, drawing on the company’s open access business model. Diamond development began as a research concept at Northrop Grumman and has grown into a successful multi‑branch technology program, backed by strategic partnerships, extensive prototyping and ongoing company investment.

Diamond, with its 5.5 eV bandgap, is an emerging ultra‑wide bandgap (UWBG) semiconductor that combines extraordinary breakdown‑field strength (≥ 10 MV/cm), low dielectric constant (~5.7), exceptional thermal conductivity (≥ 2000 W m^-1 K^-1) and high carrier mobility (electron mobility ≥ 4500 cm²/V*s and hole mobility ≥ 1800 cm²/V*s).¹ These properties place diamond among the very few semiconductor materials capable of handling RF power and voltage levels far beyond the limits of silicon (Si), gallium arsenide (GaAs), gallium nitride (GaN) or silicon carbide (SiC), while also being very thermally resilient. Historically, large electronic‑grade diamond substrates have been scarce or prohibitively expensive; film growth at scale has been non‑uniform and has required subsequent polishing steps; and doping has been difficult to control, all of which have hindered the ability to produce low‑cost, high performance, repeatable diamond electronics. However, recent advances in chemical vapor deposition (CVD) diamond growth now enable wafer‑scale production of high‑quality diamond substrates (≥ 50 mm diameter) and high‑quality epitaxial layers, moving the material from a laboratory curiosity to a viable commercial technology.^2-4

When engineered as a receiver‑protection (RP) diode, diamond delivers high‑power handling, wide bandwidth operation, rapid recovery times and low insertion loss while maintaining robust thermal management, critical for defense platforms where size, weight and reliability are mission‑critical. State‑of‑the‑art RP diodes have been limited by a combination of low power handling (≤ 100 W), modest bandwidth performance (2 to 4 GHz) and high insertion loss (≥ 1 dB), forcing system designers to accept performance penalties. In contrast, preliminary testing performed at Northrop Grumman Systems Corporation (NGSC) in Baltimore, Md., has validated diamond RP devices fabricated by Advent Diamond (AD) that handle > 100 W of RF power with recovery times < 100 ns across both S‑Band and X‑Band frequencies and show potential for even wider bandwidth with lower insertion loss performance. These early results demonstrate a performance envelope that surpasses conventional semiconductor technologies and can meet the demands of today’s high‑power defense subsystems.

The strategic alliance between NGSC, AD, Arizona State University (ASU) and the ASU Southwest Advanced Prototyping Hub (SWAP Hub) establishes a powerful lab‑to‑fab pipeline for diamond‑based RP systems. NGSC contributes system‑level integration, open‑access test facilities and an “Open‑Access Innovation Model” that invites other prime Defense Industrial Base (DIB) partners, startups and academia to co‑develop advanced solutions. AD is a leader in providing all‑diamond semiconductor components built on its full‑range diamond materials platform. ASU provides world‑class CVD diamond growth and expertise in diamond epitaxial layers. The ASU SWAP Hub delivers top diamond facilities, state‑of‑the‑art diamond equipment and support from diamond experts to power this collaboration. By uniting university research, industry‑scale manufacturing and DIB integration, the partnership compresses time‑to‑market for diamond RP diodes from years to months, turning once‑deemed “impossible” concepts into realistic deployable technologies. The collaboration also establishes a reusable, open‑access framework that can be rapidly adapted to future high‑power, wide bandwidth, low insertion loss and thermally‑resilient applications, ensuring sustained technological superiority.

Diamond RP diodes therefore represent a paradigm‑shifting technology that directly addresses the defense sector’s growing need for high‑power receiver protection against emerging RF threats. Continued investment in this collaborative ecosystem will cement diamond‑based RF electronics as the cornerstone of next‑generation defense systems and provide a scalable platform for future high‑power, wide bandwidth, low insertion loss applications that are thermally resilient across the entire DIB.

INTRODUCTION: WHY DIAMOND/UWBG?

The intrinsic limits of conventional semiconductors such as Si have traditionally constrained the pursuit of even higher RF power and frequency. In the 1990s, SiC and GaN emerged as the first widely adopted wide bandgap (WBG) materials, delivering critical breakdown fields of 3 to 4 MV/cm and thermal conductivities in the 150 to 200 W m^-1 K^-1 range. Parallel advances in CVD diamond growth during the early 2000s introduced diamond as a strong UWBG material: a 5.5 eV bandgap, thermal conductivity exceeding 2000 W m^-1 K^-1, a low dielectric constant (ε_r ≈ 5.7), and electron mobility up to 4500 cm² V^-1 s^-1 in high‑purity single‑crystalline diamond (SCD) material. For the first time, a semiconductor could combine high breakdown fields with passive, high‑efficiency thermal management, opening a new class of high‑power RF electronics and components. Figure 1 illustrates that diamond outperforms traditional (e.g., Si, GaAs), wide bandgap (e.g., GaN, SiC) and other UWBG materials (e.g., β-Ga₂O₃) in several key properties, showcasing the highest thermal conductivity, high breakdown field strength, high mobility, low dielectric constant and competitive bandgap energy, making it an exceptional material for advanced electronic applications.

Millimeter wave RF limiters serve as adaptive protectors that shield receiver front‑ends from damaging high‑power signals. As RF systems push higher frequency operation, robust limiters with high power handling capacity become essential, and their performance must be evaluated in terms of insertion loss, flat leakage, threshold power, isolation and other related RP diode parameters. Protecting sensitive receiver front ends from high‑power RF threats is as much a materials challenge as a circuit-device challenge. Commercial Si and GaAs PIN‑diode limiters fail at high input powers because the absorbed (non‑reflected) power must be dissipated in the diode. The low thermal conductivities of GaAs (0.46 W·cm^-1·K^-1) and Si (1.5 W·cm^-1·K^-1) cause the junction temperature to rise rapidly, leading to failure.⁵ The simultaneous demands of wide frequency operation, high power handling and low insertion loss therefore require a semiconductor with fundamentally different thermal properties without sacrificing RF properties.

Recent advances have removed the historic barriers to diamond production. SCD wafers are now available up to 50 mm in diameter, with 100 mm wafers in development, and doping control and wafer‑scale uniformity have been demonstrated on 18 mm × 18 mm substrates.⁶ Earlier work showed that all‑diamond limiters can meet insertion‑relevant specifications.^7-9 Subsequent studies confirmed high‑power performance (i.e., with very low diode ideality factor) of similar structures.^7,10 

Diamond’s UWBG properties help enable high-power RP diodes that dissipate heat passively and operate at power levels unattainable with Si, GaAs, SiC and GaN RF limiter devices. Hybrid integration of diamonds with WBG materials further expands capability and performance (e.g., bonding GaN HEMTs to a diamond substrate triples heat removal compared with AlN or SiC, raising transistor power density without the need for active micro-coolers). At NGSC, their proprietary Super‑Lattice Castellated Field-Effect Transistor (SLCFET) devices use a polycrystalline‑diamond (PCD) heat‑spreading layer for enhanced heat extraction,^11-13 while UWBG heterostructures such as BN/diamond^14-16 and Ga₂O₃/diamond^17-18 improve thermal transport and conductivity. These approaches create a new class of high‑power, broadband devices that meet the most demanding defense requirements.

For critical defense applications, diamond RP diodes support fully passive cooling, dramatically reducing system weight and enabling robust operation in electronic warfare (EW) platforms. Diamond’s radiation hardness^19-20 and thermal stability also suit high‑power radar, space‑borne RF amplifiers and emerging directed‑energy threats, where nanosecond recovery and ultra‑low leakage prevent latch‑up after megawatt‑scale pulses. In quantum‑enabled defense solutions, nitrogen vacancy (NV) centers in diamond provide rugged magnetic‑field sensing and ultra‑low noise microwave detection, adding real‑time situational awareness unavailable from conventional semiconductors.^21-22 

As electronic‑grade diamond wafers scale to larger diameters and the cost per area eventually decreases, diamond RP devices are moving from laboratory prototypes to low‑volume production. Integrating diamond with other material structures and architectures will deliver unprecedented power density, bandwidth and reliability for next‑generation RF front ends. Continued investment in diamond UWBG electronics will secure a decisive, long‑term technological edge for defense systems ranging from EW and high‑power radar to space‑borne platforms and quantum‑based sensor networks.

INTRODUCTION OF DIAMOND RECEIVER-PROTECTION (RP) DIODES

An RP device acts as a miniature, robust safety valve that sits directly in front of an RF receiver (see Figure 2), the portion of a radar, satellite or communications system that “listens” for incoming signals. Its function is straightforward in concept but demanding in practice: it must clamp any over‑voltage transient before the signal reaches the sensitive low noise amplifier, then recover fast enough for the legitimate signal to pass with negligible loss.

Current state‑of‑the‑art RF diode limiters are fabricated using Si and GaAs technologies; these diodes protect sensitive receiver electronics from damage caused by high‑power input signals.^24-27  GaN FETs have also been employed as RF limiters to bridge the performance gap between Si, GaAs and diamond diode devices. However, in shunt configurations, their maximum current is limited, leading to channel saturation and voltage spikes. In contrast, in series configurations, they are constrained by strict breakdown‑voltage limits that can cause catastrophic failure.²⁸ As a result, most RP and limiter circuits remain restricted in both power handling and thermal dissipation.^24-29

In a shunt-connected diode power-limiter circuit, the diode remains off for low input signals, with any diode off-capacitance (C_off) contributing to insertion loss (attenuation of low-power signals) and limiting the frequency bandwidth. When the magnitude of the input signal exceeds a threshold, the shunt-connected diode turns on. In its on state, the diode acts as a short to ground, resulting in reflection of most incoming RF power. However, the on-resistance (R_on) of the diode results in the dissipation of a portion of the incident power through the limiter circuit. As incident power increases, the power absorbed by the power limiter circuit increases as well. Device overheating due to dissipated power is the primary failure mechanism that limits a diode’s maximum power handling. Using a larger diode can increase power handling at the expense of higher C_off, leading to greater insertion loss and/or bandwidth limitations. Because the primary failure mechanism and power handling limitation are associated with the rapid overheating of the RP device, the design of the RP becomes a balancing trade-off among the competing demands of power handling, frequency performance and the insertion loss that the RP adds to the overall system, as shown in Figure 3. Simultaneously achieving a compact (λ/2 on-grid element footprint), wideband (multi-octave), low loss (< 1 dB), high-power (> 200 W) RP has been essentially unattainable with current state-of-the-art practices. Furthermore, there is currently no other solid-state RP solution for emerging threats with incident powers > 200 W, aside from that promised by UWBG-based RF limiter devices such as diamond.

Compared to other state-of-the-art RF diode-limiter devices, diamond offers superior thermal conductivity and temperature resilience, along with high charge-carrier mobility and a low relative dielectric permittivity, making it an ideal material for high-power, low loss RF limiters. Diamond-based RF limiter circuits uniquely enable compact protection against 100 W- to kW-level threats, including emerging threats that require higher power protection. Diamond-based solid-state diodes also eliminate the need for a pre-limiter stage by offering significantly enhanced power handling and reduced spike leakage, further reducing size, weight, power, circuit complexity and heterogeneous integration steps.

Laboratory demonstrations, such as the discrete diamond diode limiters showcased by the NGSC, Advent Diamond and ASU teams, have already validated these advantages, albeit on small‑area devices (1 mm × 1 mm). Previous device modeling has also shown that a two‑stage RFIC using diamond RP diodes can deliver at least a ten‑fold improvement in power‑density handling over the best Si, GaAs, SiC and GaN solutions, while offering strong thermal resiliency. Future efforts will explore scaling diamond substrates and developing RP devices. In short, diamond RP diodes are the only solid‑state technology currently capable of reliably protecting against emerging threats at incident powers ≥ 200 W, positioning them as the cornerstone of future high‑power, wide bandwidth, low insertion loss defense front‑ends that are thermally resilient. Table 1 compares key material properties relevant to RP diodes, including dielectric constant, carrier mobilities, thermal conductivity and maximum junction temperature. The table also highlights the power handling, recovery time and thermal viability of each material for RP diode applications, showing that diamond exhibits the highest thermal conductivity and thermal viability, making it especially promising for high-power, high-temperature protection devices.

DIAMOND EPITAXIAL GROWTH, DIAMOND RP DIODE FABRICATION AND HIGH-POWER RF TESTING RESULTS

Diamond Growth of the High-Power RP Diode Devices
With support from the Microelectronics Commons ASU SWAP Hub, the ASU diamond growth team has commissioned three new commercial‑grade deposition tools for the growth of diamond epitaxial layers. The diamond reactor systems are load‑locked, eliminating atmospheric exposure between runs, reducing contamination and enabling sample turnaround times under 24 hours. ASU grows intrinsic (undoped) epilayers, boron‑doped (p‑type) and phosphorus‑doped (n‑type) material.^30-32 The MPCVD chamber accepts substrates up to 100 mm (4 in.) in diameter, although work to date has used 25 mm and 50 mm diameter wafers and commercially available 18 mm × 18 mm mosaic tiles. Secondary Ion Mass Spectrometry (SIMS) confirms nitrogen background ≤ 10¹⁶ cm^-3 and doping control of 10¹⁶ to 10²⁰ atoms cm^-3 for boron and 10¹⁶ to 10¹⁹ atoms cm^-3 for phosphorus.

Under prior work, the Schottky n‑i‑p diodes were fabricated on heavily boron‑doped substrates, incorporating a 300 nm intrinsic diamond layer and a 50 nm phosphorus‑doped diamond cap that serves as a process‑monitor device. The Schottky diodes exhibit⁶ on‑state current densities > 110 kA cm^-2 and on‑to‑off ratios > 10¹⁴. Performance is unchanged on 2 mm × 2 mm mosaic tiles even across seams, despite higher dislocation density. RF measurements show near‑ideal Schottky behavior that aligns with lumped‑element SPICE models, while TCAD simulations accurately reproduce the DC I‑V data. Figure 4 illustrates the diamond CVD reactors installed at ASU (Figure 4a and 4b) and, in Figure 4c, shows single‑crystal diamond growth on 20 mm × 20 mm substrates.

Fabrication of the Diamond RP Diode Devices
AD fabricated the RP diode device, which consists of two back‑to‑back‑configured diodes that conduct on opposite RF half‑cycles, providing passive, bias‑free protection against high‑power input signals. The threat signal itself drives the protection response, eliminating the need for a bias supply. Both the chiplet and the core diode are proprietary AD designs, backed by empirical equivalent‑circuit models that guide ongoing optimization. This back‑to‑back configuration guarantees that, in every stage, one diode remains conducting under high‑power excitation, delivering robust power‑limiting performance. Specifications will improve beyond those shown, with future designs targeting S‑, C‑, X‑ and Ku‑Band frequency operation.

AD engineers carry out device fabrication on silicon industry-standard equipment to keep costs aligned with defense-component economics. Starting with an SCD substrate sourced from vendors, AD applies a proprietary surface‑defect reduction process that removes subsurface damage and roughness, which is critical because near‑surface defects propagate into active layers, degrading yield and performance. Doped diamond epilayers are then grown by microwave‑plasma CVD to produce the epitaxial wafer, from which the diode structure is fabricated, resulting in a fully “all‑diamond” device.

Device contacts are formed with AD’s proprietary interlayer and metallization stack, delivering low‑resistance ohmic contacts to the anode. Reducing contact resistance directly lowers series resistance and insertion loss in the conducting state, driving performance gains over prior generations.¹A Schottky contact is used on the cathode side. Both contacts have demonstrated thermal stability above 300°C, with ongoing validation to 500°C.Figure 5shows the RP component design, comprising two back‑to‑back diodes integrated on the diamond chiplet; the self‑actuating circuit requires no bias supply, providing passive protection.Figure 6shows the RP component photographed next to a penny to illustrate its scalability.

Packaging and High-Power RF Testing of Diamond RP Diode Devices
NGSC packaged, wire‑bonded and tested the diamond RP device on a high‑power RF test stand (the packaged limiter is shown in Figure 7) at its Baltimore, Md., foundry. Coaxial connectors were placed on both ends to enable high‑power RF measurements. For both S‑ and X‑Band tests, a 130 µs pulse width at 10 percent duty cycle was used to minimize self‑heating.

Using the NGSC X‑Band test stand (10 GHz), Advent Diamond’s nine‑finger RP diodes handled > 50 dBm (~100 W) without failure (shown in Figure 8). The input RF power was increased incrementally from 50 to 51 dBm, and the output was captured using a high‑power broadband sensor. The diamond RF‑diode limiter remained fully operational with no loss or burnout, demonstrating that the RP diode can sustain continuous > 100 W at X‑Band frequencies, providing robust protection for high‑power transceivers, airborne radar, EW systems and space‑based communication payloads.

A similar result was observed on NGSC’s S‑Band (3 GHz) test stand, shown in Figure 8. The nine‑finger RP diode survived at > 50 dBm (> 100 W) of RF power and exhibited a recovery time < 100 ns, confirming fast turn‑off after high‑power pulses. As with the X‑Band test, no failures occurred at S‑Band, and further destructive RF testing will determine the diode’s full survivability. These preliminary high‑power RF measurements confirm that the diodes can handle 100 W across the targeted bands; upcoming tests will establish the ultimate limits for power handling, breakdown voltage and long‑term reliability.

Discussion of Applications and Future Outlook
The modern electromagnetic environment is becoming ever more crowded with high‑power RF and mmWave signals as GaN‑based transmitters proliferate and drop in cost.^33-35 Sensitive broadband receivers must now operate amid stronger, more numerous interferers, while next‑generation transceivers demand higher RF power densities and leave little room for limiting and protection circuitry. This hostile, multi‑octave EM landscape combined with densely integrated front‑ends creates a compelling opportunity for diamond‑based RP devices.

Diamond diodes can absorb massive power bursts, remain cool without active fan electronics and withstand harsh radiation, enabling lighter, more reliable high‑power systems for battlefield EW receivers and space‑borne links. With commercial‑grade diamond wafers now approaching ≥ 100 mm in diameter and a focus on reducing cost per area, manufacturers are perfecting the integration of diamond RP diodes onto existing components.

Near‑term milestones for advancing diamond technology will focus on scaling wafer diameters, hybrid integration with GaN HEMTs,^36-38 incorporating diamond heat spreaders with GaN HEMTs^39-44 and system‑level insertion into radar T/R modules, wideband EW receiver chains and high‑power‑microwave‑hardened electronics.^44-47 Successful pilot production runs will transition diamond RP diodes from laboratory demos to low‑volume manufacturing, establishing the diodes as the baseline protection solution for high‑power, broadband RF front‑ends. Continued advances in packaging, cost reduction models and wafer‑scale growth will further expand the technology’s reach into RF, radar and space‑grade electronics.^48-49

Improved RF packaging and thermal management approaches will be essential to exploit the extraordinary heat‑spreading capability of diamond‑based RP diodes fully.50-51 This manuscript notes that the devices were mounted in NGSC‑packaged, wire‑bonded assemblies and tested on a discriminating high‑power RF test stand. Still, it stresses that continued advances in RF packaging, cost reduction and wafer‑scale growth are needed to expand the technology into demanding space‑grade and radar applications. Because diamond provides a UWBG material with a high breakdown field and high thermal conductivity, efficiently extracting the dissipated heat from the diamond limiter requires low loss RF interconnects, robust hermetic enclosures and heat‑spreading structures that can conduct heat away from the active area without adding significant parasitics or sacrificing RF performance. Incorporating such optimized RF packaging and thermal management processes not only preserves the diode’s low insertion loss and fast recovery but also ensures reliable operation at higher power‑handling levels, making the thermal path an integral part of the overall high‑power limiter design.

In short, diamonds are more than a gemstone. They are emerging as the super‑material that will drive tomorrow’s high‑power RF systems, delivering unmatched protection, weight and cost savings and rock‑solid reliability for critical defense applications.

ACKNOWLEDGMENTS

The authors thank Northrop Grumman Systems Corporation, Advent Diamond, Arizona State University and the Arizona State University Southwest Advanced Prototyping (SWAP) Hub for their contributions. All trademarks and registered trademarks referenced herein are the property of their respective owners. 

Arizona State University also thanks its colleagues Terry Alford and Stephen Goodnick, as well as the many students who helped establish the diamond‑growth capabilities, including Evangeline Amonoo, Vishal Jha, Shi‑Chun Hsu, Ankita Kashyap, Mihilat Manahile and Harshad Surdi.

References

1. J. Y. Tsao, et al., “Ultrawide‐bandgap semiconductors: research opportunities and challenges,” Advanced Electronic Materials 4.1 (2018): 1600501.
2. C. E. Nebel, “CVD diamond: a review on options and reality,” Functional Diamond, 3.1 (2023): 2201592.
3. Y. Ren, et al., “Recent progress in homoepitaxial single-crystal diamond growth via MPCVD,” Journal of Materials Science: Materials in Electronics, 35.7 (2024): 525.
4. J-C. Arnault, S. Saada and V. Ralchenko, “Chemical vapor deposition single‐crystal diamond: a review,” physica status solidi (RRL)–Rapid Research Letters, 16.1 (2022): 2100354.
5. AV Sukhadolau, EV Ivakin, VG Ralchenko, AV Khomich, AV Vlasov, AF Popovich, “Thermal conductivity of CVD diamond at elevated temperatures, Diam Relat Mater, 2005;14(3–7):589–93.
6. M. Manahile, et al., “Diamond Schottky diode arrays on large area 2×2 mosaic tile substrates,” Diamond and Related Materials, 2025, 113039.
7. U. Ohiri, et al., “Development of RF Schottky Diamond Diodes for High-Power Receiver-Protection (RP) Applications,” 2025 IEEE BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium (BCICTS), 2025.
8. H. Surdi, et al., “PiN and Schottky PiN diamond diodes for high power limiters,” Applied Physics Letters, 124.6, 2024.
9. V. Jha, et al. “Diamond Schottky pin diodes for high power RF receiver protectors,” Solid-State Electronics, 186, 2021, 108154.
10. V. Jha, et al., “Diamond Schottky PIN Diodes: DC, Small-Signal and Large-Signal Behavior for RF Applications,” 2022 IEEE/MTT-S International Microwave Symposium, 2022.
11. R. S. Howell, et al., “GaN SLCFET technology for next generation mmW systems, demonstrating P out of 10.87 W/mm with 43% PAE at 94 GHz,” IEEE Microwave and Wireless Technology Letters, 33.6, 2023, pp. 839–842.
12. R. S. Howell, “SLCFET Technology: Current Progress and Future Directions for Monolithically Integrated Low Loss Switches with High Performance Amplifiers.” Compound Semiconductor Week (CSW), 2022, pp. 1–2.
13. J-K. Kim, et al., “Performance Enhancement of GaN Super-Lattice Castellated Field-Effect Transistors (SLCFETs) via Topside Integration of Near-Isotropic Polycrystalline Diamond,” IEEE Electron Device Letters, 2025.
14. J. Chen, et al., “The interface microstructure and band alignment of hexagonal boron nitride/diamond heterojunctions,” Journal of Materials Chemistry, C 11.16, 2023, pp. 5324–5330.
15. J. M. Brown,  et al., “Nucleation of cubic boron nitride on boron-doped diamond via plasma-enhanced chemical vapor deposition,” Journal of Applied Physics, 133.21, 2023.
16. A. Biswas, et al., “Growth of Cubic Boron Nitride Thin Film on Diamond Surface,” Small, 21.40, 2025, e06840.
17. L. Gu, et al., “Investigation of gallium oxide thin film hetero-integrated with bulk diamond via atomic layer deposition,” Applied Surface Science, 641, 2023, 158502.
18. I. Rahaman, et al., “Investigation of diamond/Ga₂O₃ and diamond/GaN hetero-p–n junctions using mechanical grafting,” Semiconductor Science and Technology, 40.8, 2025, 085002.
19. C. Bauer, et al., “Radiation hardness studies of CVD diamond detectors,” Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 367.1-3,1995, pp. 207–211.
20. S. Lagomarsino, et al., “Radiation hardness of three-dimensional polycrystalline diamond detectors,” Applied Physics Letters, 106.19, 2015.
21. N. Savage, “Quantum diamond sensors,” Nature, 591.7851, 2021, S37.
22. J. L. Sánchez Toural, et al., “Hands-on quantum sensing with NV− centers in diamonds,” C 9.1, 2023, 16.
23. R. Rizzato, N. R. von Grafenstein and D. B. Bucher, “Quantum sensors in diamonds for magnetic resonance spectroscopy: Current applications and future prospects,” Applied Physics Letters 123.26, 2023.
24. B. Yang, et al., “An X-band 3000W high-power limiter based on silicon-based PIN diodes,” 2023 International Conference on Microwave and Millimeter Wave Technology (ICMMT), 2023.
25. Y. Zhang, et al., “Design and failure mechanism analysis of a high-power limiter at DC-6 GHz with GaAs PIN technology,” IEEE Transactions on Electromagnetic Compatibility, 67.1, 2024, pp. 227–236.
26. S. Li, et al., “High power 10–18 GHz monolithic limiter based on GaAs pin technology,” IEEE Microwave and Wireless Components Letters, 32.9, 2022, pp. 1107–1110.
27. H-R Zhu, J. Wang and M. Tang, “Compact, high power capacity, and low insertion loss millimeter-wave on-chip limiting filter with GaAs PIN technology,” IEEE Transactions on Circuits and Systems I: Regular Papers, 70.3, pp.1175–1188.
28. X. Hao, et al., “Millimeter-Wave Limiter Based on GaN MMIC Technology.” IEEE Microwave and Wireless Technology Letters, 2026.
29. G. Zhang, et al., “Scalable model, parameter extraction of GaN Schottky barrier diode (SBD) and its application in C-band limiter design,” IEEE Transactions on Electron Devices, 71.12, 2024, pp. 7350–7357.
30. F. Lloret, et al., “High phosphorous incorporation in (100)-oriented MP CVD diamond growth,” Diamond and Related Materials, 133, 2023, 109746.
31. F. AM Koeck and R. J. Nemanich, “Residual Gas Analysis for Controlling the Phosphorus Incorporation in Diamond,” physica status solidi, (a) 222.22, 2025, 2500368.
32. F. AM Koeck and R. J. Nemanich, “Advances toward diamond electronics,” 2025, pp. 1-6.
33. R. Giofrè, et al., “Gallium nitride power amplifiers for Ka-band Satcom applications: Requirements, trends, and the way forward,” IEEE Microwave Magazine, 24.12, 2023, pp. 74–86.
34. M. Faizan, et al., “A Comprehensive Review of Supply Modulators in Gallium Nitride Technologies for Envelope Tracking Power Amplifiers,” Engineered Science, 40, 2026, 2075.
35. J. K. Dusenbury, et al., “Scaling Power and Efficiency of Direct Antenna Modulation Transmitters using Gallium Nitride Transistors,” IEEE International Symposium on Antennas and Propagation and INC/USNC‐URSI Radio Science Meeting (AP-S/INC-USNC-URSI), 2024.
36. T. J. Anderson, et al., “Nanocrystalline      diamond integration with III-nitride HEMTs,” ECS Journal of Solid State Science and Technology, 6.2, 2017, Q3036-Q3039.
37. H. Guo, et al., “Thermal performance improvement of AlGaN/GaN HEMTs using nanocrystalline diamond capping layers,” Micromachines, 13.9, 2022, 1486.
38. M. J. Tadjer,  et al., “Reduced self-heating in AlGaN/GaN HEMTs using nanocrystalline diamond heat-spreading films,” IEEE electron device letters, 33.1, 2011,  pp. 23–25.
39. H. Walwil, et al., “Interfacial Thermal Transport in Top-Side Diamond Integrated AlGaN/GaN High Electron Mobility Transistors,” ACS Applied Materials & Interfaces, 17.43, 2025, pp. 59519-59530.
40. R. Soman, et al., “Integration of top-side low-temperature diamond on AlGaN/GaN RF HEMT for device-level cooling,” Applied Physics Letters, 126.21, 2025.
41. M-C. Lu, “Development of diamond device-level heat spreader for the advancement of GaN HEMT power and RF electronics,” IEEE Transactions on Device and Materials Reliability, 23.4, 2023, pp. 468-485.
42. M. N. A. M. Ridzwan,  et al., “Understanding the role of near-junction diamond heat spreaders in packaged 20-gate GaN HEMT chips via thermal simulation,” Journal of Electronic Materials, 53.9, 2024, pp. 5519–5533.
43. A. Aleksov, et al., “Diamond-based electronics for RF applications,” Diamond and related materials, 13.2, 2004, pp. 233–240.
44.  Y. Xiang, et al., “Recent Advances in Diamond-Capped GaN HEMTs for RF Application,” Nanomaterials, 16.4, 2026, 224.
45. M. M. Hasan, et al., “Diamond for high-power, high-frequency, and terahertz plasma wave electronics,” Nanomaterials, 14.5, 2024, 460.
46. Y. Jeon, et al., “Design of a Receiver Path with Self-Developed Limiter MMIC of X-Band for AESA Radar Systems,” Electronics, 15.6, 2026, 1272.
47. K. J. Gray and P. M. Fabis, “Design-to-implementation case studies of CVD diamond in RF/microwave package and detector applications,” Diamond and Related Materials, 6.2-4, 1997, pp. 191–195.
48. P. M. Fabis, “The processing technology and electronic packaging of CVD diamond: a case study for GaAs/CVD diamond plastic packages,” Microelectronics Reliability, 42.2, 2002, pp. 233–252.
49.  C. Schaffauser, et al., “Optimised thermal and microwave packaging for wide-band gap transistors: diamond & flip chip,” European Gallium Arsenide and Other Semiconductor Application Symposium, IEEE, 2005.
50. P. M. Fabis, D. Shum and H. Windischmann, “Thermal modeling of diamond-based power electronics packaging,” Fifteenth Annual IEEE Semiconductor Thermal Measurement and Management Symposium (Cat. No. 99CH36306), IEEE, 1999.
51. M. Danner, et al., “Low temperature bonding of diamond heat spreaders for advanced thermal management,” Japanese Journal of Applied Physics, 64.4, 2025, 04SP45.