TECHNICAL NOTE – OPERATION OF MT4400 TWTA
08/10/2004
TN4400-3
MCL, INC.
19 of 36
4.5.2.3 Conditions that will Suspend Auto Power (Not available on some Multi-Band HPAs—Please
Consult MCL)
When the HPA is in Auto Power, it will stop all Auto Power attenuator action while the HPA is
in the RF Off state. The HPA will remain in the Auto Power state, but no attenuator action will
be taken while in the RF Off state. The Auto Power attenuator action will resume once the
HPA is placed back into RF On.
4.5.2.4 Conditions that will Turn Off Auto Power (Not available on some Multi-Band HPAs—Please
Consult MCL)
The HPA will terminate the Auto Power function if it is active when any of the following
conditions occur.
•
If the set Auto Power level exceeds the top Forward Power calibration point.
•
If the TWTA drops out of Transmit.
•
If a Disable Auto Power command is received while the TWTA is in the
Computer or Remote mode.
•
If the Forward power sample is 0000W.
•
If the Computer or Remote Interface was to set the Auto Power level to 0000W.
•
If the RF attenuator is manually adjusted.
4.5.3 Hold
Power
(Not available on some Multi-Band HPAs—Please Consult MCL)
The MT4400 remote panel contains a Hold Power control and indicator, which will be used to
control the Auto Power Function. The operator will set the RF output power using the Gain
Adjust. Once he has obtained the desired power level, Hold Power Command is sent. The
Hold Power Flag will be true, and the Auto Power function will regulate the RF output power
to the level currently set. If the operator were to send the Hold Power Command again, the
Auto Power regulation function will turn off.
4.6
Band/Sub-Band Selection (Optional)
The MT4400 is available for single or multiple band application. With the multi-band or sub-
band optimized HPA, there is a necessity for the user to set the HPA to the band of interest.
The MT4400 also has optional sub-band Linearizer tuning available on some models.
Typically a Linearizer is adjusted for the best broadband performance, The MT4400 can be
optimized within a band for possible further improvement. Please contact MCL for details on
sub-band tuning.
