Communication terminal configured to adjust for interference and methods of use
Communication terminals configured for satellite and terrestrial communications and methods of use are disclosed herein. In an embodiment, a communication terminal includes an antenna, a filter and filter control circuitry. The antenna is configured to receive a radio signal. The filter is configured to filter the radio signal to remove an interference signal. The filter control circuitry is configured to detect the interference signal present in the radio signal received by the antenna and cause an adjustment to the filter to block the interference signal. In another embodiment, the communication terminal includes an amplifier and gain control circuitry. The amplifier is configured to configured to amplify the radio signal. The gain control circuitry is configured to detect an interference signal present in the radio signal received by the antenna and cause an adjustment to the amplifier based on the detected interference signal.
1. A communication terminal configured for satellite and terrestrial communications, the communication terminal comprising:
an antenna configured to receive a radio signal from a satellite system and an interference signal from a terrestrial system;
a first filter located along a signal path extending from the antenna to processing circuitry, the first filter configured to filter the radio signal to remove the interference signal; and
filter control circuitry which branches off of the signal path, the filter control circuitry including a second filter and a power detector, the filter control circuitry configured to detect the interference signal received by the antenna and cause an adjustment to the first filter to block the interference signal based on an output from the power detector.
2. The communication terminal of claim 1 , wherein
the filter control circuitry is configured to cause the adjustment to the first filter based on a difference between the output from the power detector and a reference interference signal or threshold.
3. The communication terminal of claim 1 , comprising
a digital signal processor configured to process the radio signal,
the filter control circuitry configured to cause the adjustment to the first filter based on an output from the digital signal processor.
4. The communication terminal of claim 1 , wherein
the filter control circuitry is configured to cause the first filter to block a frequency of the interference signal.
5. The communication terminal of claim 1 , wherein
the filter control circuitry is configured to cause the adjustment to the first filter by adjusting a voltage applied to the first filter.
6. The communication terminal of claim 1 , wherein
the filter control circuitry is configured to determine when the interference signal is no longer present at the antenna and cease causing the adjustment to the first filter when the interference signal is no longer present.
7. The communication terminal of claim 1 , comprising
an amplifier configured to amplify the radio signal, and
gain control circuitry configured to detect the interference signal received by the antenna and cause an adjustment to the amplifier based on the detected interference signal.
8. The communication terminal of claim 1 , wherein
the filter control circuitry includes a mixer configured to output a downconverted signal based on a phase-locked loop frequency, and
the second filter is configured to filter the downconverted signal output from the mixer.
9. The communication terminal of claim 1 , wherein
the first filter is an MEMS filter, and
the second filter is a narrow band-pass filter.
10. A communication terminal configured for satellite and terrestrial communications, the communication terminal comprising:
an antenna configured to receive a radio signal from a satellite system and an interference signal from a terrestrial system;
a filter located along a primary signal path extending from the antenna to processing circuitry configured to process the radio signal, the filter configured to receive the radio signal from the antenna,
a low-noise amplifier located along the primary signal path extending from the antenna to the processing circuitry, the low-noise amplifier having a dynamic range with a low end and a high end and being configured to amplify the radio signal after the radio signal passes the filter;
gain control circuitry located along a gain control path which branches off of the primary signal path, the gain control circuitry configured to detect the interference signal received by the antenna and raise the high end of the dynamic range of the low-noise amplifier based on the detected interference signal; and
filter control circuitry located along a filter control path which branches off of the primary signal path and is separate from the gain control path, the filter control circuitry configured to cause an adjustment to the filter.
11. The communication terminal of claim 10 , wherein
the gain control circuitry is configured to cause the adjustment to the low-noise amplifier by adjusting a voltage applied to the low-noise amplifier.
12. The communication terminal of claim 10 , wherein
the gain control circuitry includes a power detector, and
the gain control circuitry is configured to raise the high end of the dynamic range of the low-noise amplifier based on an output from the power detector.
13. The communication terminal of claim 12 , wherein
the gain control circuitry is configured to raise the high end of the dynamic range of the low-noise amplifier based on a difference between the output from the power detector and a reference interference signal or threshold.
14. The communication terminal of claim 10 , comprising
a digital signal processor configured to process the radio signal,
the gain control circuitry configured to raise the high end of the dynamic range of the low-noise amplifier based on an output from the digital signal processor.
15. The communication terminal of claim 10 , wherein
the gain control circuitry is configured to determine when the interference signal is no longer present at the antenna and cease raising the high end of the dynamic range of the low-noise amplifier when the interference signal is no longer present.
16. A communication terminal configured for satellite and terrestrial communications, the communication terminal comprising:
an antenna configured to receive a radio signal from a satellite system and an interference signal from a terrestrial system;
a filter located along a signal path extending from the antenna to processing circuitry, the filter configured to filter the radio signal;
an amplifier located along the signal path extending from the antenna to the processing circuitry, the amplifier configured to amplify the radio signal;
at least one power detector configured to detect power related to the radio signal; and
filter control circuitry which branches off of the signal path, the filter control circuitry configured to cause an adjustment to the filter based on a subtracted difference between a reference interference signal or threshold and an output from the at least one power detector.
17. The communication terminal of claim 16 , wherein
the filter control circuitry is configured to cause the adjustment by adjusting a voltage applied to the filter.
18. The communication terminal of claim 16 , wherein
the filter control circuitry includes a mixer, the at least one power detector and a tuning controller,
the mixer is configured to downconvert the radio signal,
the at least one power detector is configured to detect power of the downconverted radio signal after output from the mixer, and
the tuning controller is configured to cause the adjustment to the filter based on the subtracted difference between the reference interference signal or threshold and the output from the at least one power detector.
19. The communication terminal of claim 18 , wherein
the filter is a first filter,
the filter control circuitry includes a second filter configured to filter the downconverted radio signal after output from the mixer, and
the at least one power detector is configured to detect power of the radio signal after output from the second filter.
20. The communication terminal of claim 16 , comprising
gain control circuitry configured to cause an adjustment to the amplifier to bias a high end of a dynamic range of the amplifier when the interference signal is determined to be present and to cease causing the adjustment to the amplifier when the interference signal is no longer present.