System and method for using dual power meters for satellite terminal calibration

1. A satellite terminal, comprising:

a modem; and

a radio frequency unit (RFU) configured to amplify and frequency upconvert a transmit signal for transmission over an inroute channel of a satellite communications network, the RFU comprising:

an input power meter configured to measure a first power level of an intermediate frequency (IF) signal transmitted from the modem to an input of the RFU;

an upconverter configured to frequency upconvert the IF signal to obtain a radio frequency (RF) signal; and

an output power meter configured to measure a second power level of the RF signal.

2. The satellite terminal of claim 1 , further comprising: a communication link between the modem and the RFU, wherein the modem is configured to receive the measured first power level and the measured second power level over the communication link.

3. The satellite terminal of claim 2 , wherein the modem is configured to calculate a gain value of the upconverter using the received measured first power level and measured second power level.

4. The satellite terminal of claim 3 , wherein the modem is configured to calculate the gain value by performing a gain calibration process, the gain calibration process comprising:

generating a plurality of continuous wave (CW) carrier signals, each of the plurality of CW carrier signals generated at a respective frequency within a frequency range;

transmitting each of the plurality of CW carrier signals to the input of the RFU;

for each of the plurality of transmitted CW carrier signals, receiving from the RFU a first power level measurement made by the input power meter and a second power level measurement made by the output power meter;

determining an RFU gain value for each of the frequencies based on the received first power level measurement and the second power level measurement; and

using the determined RFU gain values to create a gain table.

5. The satellite terminal of claim 4 , wherein the modem is configured to periodically perform the gain calibration process.

6. The satellite terminal of claim 4 , wherein the modem is configured to perform the gain calibration process in response to a command transmitted by a network management system to the satellite terminal over an outroute communication channel of the satellite communications network.

7. The satellite terminal of claim 4 , wherein the input power meter and the output power meter are non-burst mode power meters.

8. The satellite terminal of claim 4 , wherein the RFU comprises a switch that, when opened, prevents RF signals from entering an antenna of the satellite terminal from the RFU, wherein during initialization of the gain calibration process, the modem is configured to signal the RFU over the communication link to open the switch.

9. The satellite terminal of claim 3 , wherein the modem is configured to calculate the gain value during a calibration process for establishing a limit on a linear region of operation of the RFU, the calibration process comprising:

generating each of a plurality of continuous wave (CW) carrier signals at a respective power level of a plurality of power levels;

transmitting each of the plurality of CW carrier signals to the input of the RFU;

for each of the plurality of transmitted CW carrier signals, determining an RFU gain value for each of the plurality of power levels based on power level measurements made by the input power meter and the output power meter; and

using the plurality of determined RFU gain values to determine a maximum power level of the plurality of power levels at which RFU gain stops increasingly linearly with an increasing power level.

10. The satellite terminal of claim 1 , further comprising:

an IF cable connecting the modem to the RFU, wherein the modem is configured to transmit the IF signal over the IF cable; and

a communication link between the modem and the RFU, wherein the modem is configured to receive the measured first power level over the communication link.

11. The satellite terminal of claim 10 , wherein the modem is configured to calculate a cable loss value over the IF cable using the received measured first power level and a power level at which the modem transmitted the IF signal.

12. The satellite terminal of claim 11 , wherein the modem is configured to calculate the cable loss value by performing a cable loss calibration process, the cable loss calibration process comprising:

generating a plurality of continuous wave (CW) carrier signals, each of the plurality of CW carrier signals generated at a respective frequency within a frequency range;

transmitting each of the plurality of CW carrier signals to the input of the RFU;

for each of the plurality of transmitted CW carrier signals, receiving from the RFU a first power level measurement made by the input power meter; and

determining a cable loss value for each of the frequencies based on the received first power level measurement and a power level at which the modem generated the CW carrier signal for the frequency.

13. The satellite terminal of claim 12 , wherein the modem is configured to perform the cable loss calibration process in response to a command transmitted by a network management system to the satellite terminal over an outroute communication channel of the satellite communications network.

14. A method, comprising:

generating, via a modem of a satellite terminal, a plurality of continuous wave (CW) carrier signals, each of the plurality of CW carrier signals generated at a respective frequency within a frequency range or a respective power level within a power level range;

receiving each of the plurality of CW carrier signals from the modem at an input of a radio frequency unit (RFU) of the satellite terminal, the RFU comprising an input power meter, an upconverter, and an output power meter;

for each of the plurality of received CW carrier signals:

measuring, via the input power meter, an input power level of the CW carrier signal;

upconverting, via the upconverter, the CW carrier signal; and

measuring, via the output power meter, an output power level of the upconverted CW carrier signal; and

determining an RFU gain value for each of the frequencies or power levels based on the input power level measurement and the output power level measurement.

15. The method of claim 14 , further comprising: receiving at the modem, from the RFU, the input power level measurement and the output power level measurement made for each of the plurality of received CW carrier signals, wherein the modem is configured to determine the RFU gain value for each of the frequencies or power levels based on the input power level measurement and the output power level measurement.

16. The method of claim 15 , wherein the modem is configured to perform the operations of generating, receiving from the RFU, and determining in response to a command transmitted by a network management system to the satellite terminal over an outroute communication channel of the satellite communications network.

17. The method of claim 15 , wherein the modem is configured to periodically perform the operations of generating, receiving from the RFU, and determining.

18. The method of claim 14 , wherein the input power meter and the output power meter are non-burst mode power meters.

19. The method of claim 14 , further comprising: using the determined RFU gain values to create a gain table.

20. A non-transitory computer-readable medium having instructions stored thereon that, when executed by a processor, cause a modem to perform operations comprising:

generating, via the modem, a plurality of continuous wave (CW) carrier signals, each of the plurality of CW carrier signals generated at a respective frequency within a frequency range or a respective power level within a power level range;

transmitting each of the plurality of CW carrier signals from the modem to an input of a radio frequency unit (RFU), the RFU comprising an input power meter, an upconverter, and an output power meter;

for each of the plurality of transmitted CW carrier signals:

receiving an input power level measurement of the CW carrier signal made via the input power meter; and

receiving an output power level measurement of the CW carrier signal, after upconversion by the upconverter, made via the output power meter; and

determining an RFU gain value for each of the frequencies or power levels based on the input power level measurement and the output power level measurement.