Microwave generators and manufacture of synthetic diamond material

A microwave generator system for use in a microwave plasma enhanced chemical vapor deposition (MPECVD) system, the microwave generator system comprising:

• a microwave generator configured to produce microwaves at an operating power output suitable for fabricating synthetic diamond material via a chemical vapor deposition process;
• wherein the microwave generator system is further configured to detect a fault in the microwave generator which results in a reduction in the operating power output or a change in frequency, and to detect at least one of a tube arcing fault and a π-1 oscillation mode fault;
• and
• wherein the microwave generator system is further configured to restart the microwave generator in response to a fault being detected and recover the operating power output or frequency in a time period of less than 10 seconds after the fault in the microwave generator which caused the reduction in the operating power output or the change in frequency.