| 摘要 |
Operation of a solid state power amplifier (SSPA) (30) in a very small aperture terminal is controlled by a digitally controlled preemphasis attenuation operator upstream of the input of the SSPA. The attenuation operator contains a temperature compensation section (42) that produces an output control voltage which is complementary to the gain-versus-temperature characteristic of the SSPA. This control voltage is scaled and applied as one input to a analog-to-digital converter (41), the output of which drives a digitally controlled (PIN) attenuator (34) at an input to the SSPA-containing up-converter circuit. A second input to the attenuator is derived from the earth station's monitors and control processor (61) which monitors the operating frequency and accesses an associated look-up table containing a characteristic representative of the variation in the power output of the SSPA versus change in frequency. |
