What is the Megtron series of PCB laminates and when would I use them for RF applications?

What is the Megtron series of PCB laminates and when would you use them for RF applications? The Megtron series is a family of high-speed, low-loss PCB laminates manufactured by Panasonic that uses a polyphenylene ether (PPE) resin system combined with various glass reinforcement styles to achieve progressively lower dielectric loss while maintaining compatibility with standard FR-4 PCB fabrication processes. The Megtron family includes: Megtron 4 (R-5775, Dk approximately 3.8, Df approximately 0.005 at 10 GHz; the entry-level low-loss laminate, suitable for high-speed digital applications at 10-25 Gbps and RF applications to approximately 6 GHz), Megtron 6 (R-5775K, Dk approximately 3.4, Df approximately 0.002-0.003 at 10 GHz; the workhorse low-loss laminate for 25-56 Gbps and RF applications to approximately 20-30 GHz; uses spread glass for improved Dk uniformity), and Megtron 7 (R-5785N, Dk approximately 3.1-3.3, Df approximately 0.001-0.002 at 10 GHz; the ultra-low-loss grade, approaching PTFE performance while maintaining FR-4 process compatibility; suitable for 56-112 Gbps and RF applications to approximately 40 GHz). For RF applications: Megtron 6 is the most commonly used for applications from 1-20 GHz where the loss tangent of standard FR-4 is too high but the cost and processing complexity of PTFE laminates are undesirable. Megtron 7 extends the usable range to approximately 40 GHz. The key advantage of the Megtron series over PTFE laminates (such as Rogers RO4000 or RO3000 series) is: Megtron laminates are processed using standard FR-4 manufacturing equipment (same drill, lamination, and plating processes), reducing fabrication cost by 30-50% compared to PTFE, making them ideal for applications where you would use them instead of more expensive alternatives.