Signal boosters with compensation for cable loss
Apparatus and methods for signal booster systems with compensation for cable loss are provided herein. In certain configurations, a signal booster system includes two or more antennas for wirelessly communicating RF signals and a signal booster including booster circuitry for providing amplification to at least a portion of the RF signals. At least one of the antennas is connected to the signal booster via a cable. Additionally, the signal booster includes a cable loss compensation circuit that adjusts a gain of the booster circuitry to compensate for a loss of the cable.
1. A signal booster system comprising:
a plurality of antennas comprising a first antenna and a second antenna;
a first cable; and
a signal booster connected to the first antenna via the first cable and configured to be powered by a DC supply voltage provided over the first cable, wherein the signal booster comprises:
booster circuitry configured to generate a boosted RF signal based on amplifying an RF signal received on the second antenna, and to send the boosted RF signal to the first antenna via the first cable; and
a cable loss compensation circuit configured to adjust a gain of the booster circuitry to compensate for a loss of the first cable based on a DC voltage drop of the DC supply voltage provided over the cable.
2. The signal booster system of claim 1 , wherein the signal booster further comprises a first DC detector configured to generate a first detection signal based on detecting a DC voltage level at one end of the cable, wherein the cable loss compensation circuit detects the DC voltage drop based on the first detection signal.
3. The signal booster system of claim 2 , further comprising a second DC detector configured to generate a second detection signal based on detecting a DC voltage level at an opposite end of the cable, wherein the cable loss compensation circuit determines the DC voltage drop based on a voltage difference indicated by the first detection signal and the second detection signal.
4. The signal booster system of claim 2 , wherein the cable loss compensation circuit determines the DC voltage drop based on a difference between the first detection signal and an assumed voltage level at an opposite end of the cable.
5. The signal booster system of claim 4 , wherein the assumed voltage level corresponds to a regulated voltage level of a regulator circuit.
6. The signal booster system of claim 1 , wherein the cable loss compensation circuit is further configured to compensate for the loss of the first cable based on detecting a current flowing through the first cable.
7. The signal booster system of claim 1 , wherein the cable loss compensation circuit comprises data relating a plurality of detected DC voltages to a plurality of compensation values for providing compensation for cable loss.
8. The signal booster system of claim 1 , wherein the first cable is a shared DC power and RF cable including a common conductor for carrying DC power and RF signals.
9. The signal booster system of claim 8 , wherein the cable loss compensation circuit comprises an isolation and separation circuit including a series capacitor connected between the first cable and the booster circuitry, and an inductor including a first end connected to the first cable and a second end configured to output the DC supply voltage.
10. The signal booster system of claim 9 , wherein the isolation and separation circuit further includes a decoupling capacitor connected between the second end of the inductor and a ground voltage.
11. The signal booster system of claim 1 , wherein the first cable is a complex cable bundling separate conductors for carrying DC power and RF signals.
12. The signal booster system of claim 1 , further comprising a secondary unit connected to one end of the first cable, wherein the signal booster is connected to an opposite end of the first cable.
13. The signal booster system of claim 12 , wherein the first antenna is integrated with the secondary unit.
14. The signal booster system of claim 12 , wherein the secondary unit comprises a power cable and an isolation and combining circuit including a series capacitor connected between the first antenna and the first cable and an inductor including a first end connected to the first cable and a second end connected to the power cable.
15. The signal booster system of claim 1 , further comprising a second cable connected between the booster circuitry and the second antenna.
16. The signal booster system of claim 1 , wherein the first antenna is a base station antenna configured to wirelessly communicate with one or more base stations of a cellular network, and the second antenna is a mobile station antenna configured to wirelessly communicate with one or more mobile stations of the cellular network.
17. The signal booster system of claim 1 , wherein the second antenna is a base station antenna configured to wirelessly communicate with one or more base stations of a cellular network, and the first antenna is a mobile station antenna configured to wirelessly communicate with one or more mobile stations of the cellular network.
18. The signal booster system of claim 1 , wherein the booster circuitry comprises a plurality of amplification paths associated with different frequency bands, wherein the cable loss compensation circuit is configured to provide different amounts of gain adjustment to at least a portion of the plurality of amplification paths.
19. The signal booster system of claim 1 , wherein the cable loss compensation circuit is further configured to increase the gain of the booster circuitry by an amount about equal to the loss of the first cable.
20. The signal booster system of claim 1 , wherein the cable loss compensation circuit is configured to increase a gain of the booster circuitry such that a gain of the signal booster system from the first antenna to the second antenna is about equal to a regulatory limitation with respect to antenna-to-antenna gain.