Intermediate frequency (IF) filtering for enhanced crossover attenuation in a repeater
Technology for a repeater is disclosed. The repeater can include a signal path configured to carry a signal having a selected radio frequency (RF) bandwidth on an RF carrier at a selected frequency. The signal path can include an intermediate frequency (IF) filter block operable for down-conversion of the RF carrier to an IF carrier to enable the selected RF bandwidth of the signal to be bandpass filtered at an IF filter bandwidth having an IF passband frequency range and the IF passband frequency range of the IF filter bandwidth is greater than the selected RF bandwidth. The down-conversion to the IF carrier can provide increased crossover attenuation or midband isolation of the RF carrier for the repeater.
1. A bi-directional frequency division duplex (FDD) repeater, comprising:
a first antenna port;
a second antenna port; and
a signal path communicatively coupled between the first antenna port and the second antenna port, the signal path configured to carry a signal having a selected radio frequency (RF) bandwidth on an RF carrier at a selected frequency, wherein the signal path includes:
a low noise amplifier (LNA) communicatively coupled to the first antenna port;
a power amplifier (PA) communicatively coupled to the second antenna port; and
an intermediate frequency (IF) filter block between the LNA and the PA, the IF filter block operable for down-conversion of the RF carrier to an IF carrier to enable the selected RF bandwidth of the signal to be bandpass filtered at an IF filter bandwidth having an IF passband frequency range and the IF passband frequency range of the IF filter bandwidth is greater than the selected RF bandwidth.
2. The bi-directional FDD repeater of claim 1 , wherein the down-conversion to the IF carrier provides increased crossover attenuation or midband isolation of the RF carrier for the bi-directional FDD repeater.
3. The bi-directional FDD repeater of claim 1 , wherein the bi-directional FDD repeater is operable to use IF filtering in an RF system to achieve one or more of sharper RF filtering or a flatter RF bandwidth response while providing crossover or midband selectivity and preserving an entire RF bandwidth.
4. The bi-directional FDD repeater of claim 3 , wherein an amount of crossover or midband selectivity from the IF filtering enables RF filter selectivity at a crossover or midband to be reduced, thereby enhancing a ripple performance of RF filtering at the bi-directional FDD repeater.
5. The bi-directional FDD repeater of claim 1 , wherein the IF filter block is cascaded with an equalizer to correct an IF filter passband response over an entire RF bandwidth to achiever a flatter passband.
6. The bi-directional FDD repeater of claim 5 , wherein IF filter attenuation at the crossover frequency or midband frequency reduces an RF crossover or midband selectivity requirement.
7. The bi-directional FDD repeater of claim 5 , wherein a reduced IF frequency enables the equalizer to achieve enhanced selectivity at a crossover or midband frequency.
8. The bi-directional FDD repeater of claim 1 , wherein the down-conversion to the IF signal reduces a minimum number of required RF passband filters in the signal path of the bi-directional FDD repeater.
9. The bi-directional FDD repeater of claim 1 , wherein the IF filter block is operable for up-conversion of the IF carrier to the RF carrier.
10. The bi-directional FDD repeater of claim 1 , wherein the IF filter block includes:
a first mixer;
a second mixer;
a synthesizer communicatively coupled to the first mixer and the second mixer; and
an IF bandpass filter communicatively coupled to the first mixer and the second mixer.
11. The bi-directional FDD repeater of claim 1 , further comprising:
a first RF bandpass filter communicatively coupled to the LNA; and
a second RF bandpass filter communicatively coupled to the PA.
12. The bi-directional FDD repeater of claim 1 , wherein:
the first antenna port is communicatively coupled to a first antenna; and
the second antenna port is communicatively coupled to a second antenna.
13. The bi-directional FDD repeater of claim 1 , wherein the signal path is an uplink signal path or a downlink signal path.
14. A repeater, comprising:
a signal path configured to carry a signal having a selected radio frequency (RF) bandwidth on an RF carrier at a selected frequency, wherein the signal path includes:
an intermediate frequency (IF) filter block operable for down-conversion of the RF carrier to an IF carrier to enable the selected RF bandwidth of the signal to be bandpass filtered at an IF filter bandwidth having an IF passband frequency range and the IF passband frequency range of the IF filter bandwidth is greater than the selected RF bandwidth.
15. The repeater of claim 14 , wherein the down-conversion to the IF carrier provides increased crossover attenuation or midband isolation of the RF carrier for the repeater.
16. The repeater of claim 14 , further comprising:
a first antenna port; and
a second antenna port,
wherein the signal path is communicatively coupled between the first antenna port and the second antenna port.
17. The repeater of claim 14 , wherein the signal path further comprises:
a low noise amplifier (LNA); and
a power amplifier (PA),
wherein the IF filter block is between the LNA and the PA.
18. The repeater of claim 14 , wherein the repeater is operable to use IF filtering in an RF system to achieve sharper RF filtering and a flatter RF bandwidth response while providing crossover or midband selectivity and preserving an entire RF bandwidth.
19. The repeater of claim 18 , wherein an amount of crossover or midband selectivity from the IF filtering enables RF filter selectivity at a crossover or midband to be reduced, thereby enhancing a ripple performance of RF filtering at the repeater.
20. The repeater of claim 14 , wherein:
the IF filter block is cascaded with an equalizer to correct an IF filter passband response over an entire RF bandwidth to achiever a flatter passband; and
a reduced IF frequency enables the equalizer to achieve enhanced selectivity at a crossover or midband frequency.
21. The repeater of claim 20 , wherein IF filter attenuation at the crossover frequency or midband frequency reduces an RF crossover or midband selectivity requirement.
22. The repeater of claim 14 , wherein:
the down-conversion to the IF signal reduces a minimum number of required RF passband filters in the signal path of the repeater; and
the IF filter block is operable for up-conversion of the IF carrier to the RF carrier.
23. The repeater of claim 14 , wherein the repeater is a bi-directional FDD repeater.
24. A repeater, comprising:
a signal path configured to carry a signal having a selected radio frequency (RF) bandwidth on an RF carrier at a selected frequency, wherein the signal path includes:
a low noise amplifier (LNA) communicatively coupled to the first antenna port;
a power amplifier (PA) communicatively coupled to the second antenna port; and
an intermediate frequency (IF) filter block between the LNA and the PA, the IF filter block comprising:
a first mixer;
a second mixer;
a synthesizer communicatively coupled to the first mixer and the second mixer; and
an IF bandpass filter communicatively coupled to the first mixer and the second mixer,
wherein the IF filter block is operable for down-conversion of the RF carrier to an IF carrier to enable the selected RF bandwidth of the signal to be bandpass filtered at an IF filter bandwidth having an IF passband frequency range and the IF passband frequency range of the IF filter bandwidth is greater than the selected RF bandwidth, wherein the down-conversion to the IF carrier provides increased crossover attenuation or midband isolation of the RF carrier for the repeater.
25. The repeater of claim 24 , wherein the repeater is operable to use IF filtering in an RF system to achieve one or more of sharper RF filtering or a flatter RF bandwidth response while providing crossover or midband selectivity and preserving an entire RF bandwidth.
26. The repeater of claim 25 , wherein an amount of crossover or midband selectivity from the IF filtering enables RF filter selectivity at a crossover or midband to be reduced, thereby enhancing a ripple performance of RF filtering at the repeater.
27. The repeater of claim 24 , wherein the IF filter block is cascaded with an equalizer to correct an IF filter passband response over an entire RF bandwidth to achiever a flatter passband, wherein a reduced IF frequency enables the equalizer to achieve enhanced selectivity at a crossover or midband frequency.
28. The repeater of claim 24 , wherein:
the down-conversion to the IF signal reduces a number of passband filters in the signal path of the repeater; and
the IF filter block is operable for up-conversion of the IF carrier to the RF carrier.