Interesting bit here. Can not wait for Mr. Pass to get his hand on these.
https://arxiv.org/abs/2106.09412
https://arxiv.org/abs/2106.09412
Perhaps you missed the voltages used - a couple at most. State of the art microwave semiconductor amp devices are usually very low voltage and impedance (typically much less than 50 ohm), and have to be coupled to external microstrip via narrow band impedance matching reactances to get usable signal voltages from them. This doesn't work at low frequencies so you'd be constrained by the low breakdown voltage of the device.
Even lowly VHF RF power LDFETs are often rated at 28V absolute maximum, even if rated at 100W (ie 71Vrms at 50 ohms on the output). Some
are 50V rated (but upto 300W output).
Standard RF packages include matching networks built in like this: https://www.microwavejournal.com/ar...-transistor-for-900-mhz-cellular-applications
So if and when this graphene-on-diamond tech happens, it will probably be packaged with 50 ohm matching networks and run at a few volts, or even built into a piece of waveguide (since the frequencies are in the 10's of GHz).
Even lowly VHF RF power LDFETs are often rated at 28V absolute maximum, even if rated at 100W (ie 71Vrms at 50 ohms on the output). Some
are 50V rated (but upto 300W output).
Standard RF packages include matching networks built in like this: https://www.microwavejournal.com/ar...-transistor-for-900-mhz-cellular-applications
So if and when this graphene-on-diamond tech happens, it will probably be packaged with 50 ohm matching networks and run at a few volts, or even built into a piece of waveguide (since the frequencies are in the 10's of GHz).