A highly stable transmitter for use in an experimental wind shear radar

The authors describe the transmitter architecture for a high-stability C-band transmitter and detail the key regulation techniques implemented to ensure the precise performance required to detect wind shear products and other weather-related events. Special emphasis on modulator regulation and time jitter has been incorporated into the design to achieve a phase instability residue of -55 dBc. This performance has been realized by improving existing state-of-the-art equipment in the areas of PFN (pulse forming network) voltage level control and reductions in applied beam voltage time jitter. The transmitter consists of an all-solid-state line type modulator, a klystron amplifier, and a TWT driver whose output is filtered for spectral emission control. The modulator delivers 1.5 MW of peak power to the klystron, resulting in a peak RF output in excess of 250 kW. The design also includes an extensive control and monitor system suitable for local or unattended remote operation. Performance data and test results are presented