RF front end arrangement and method for sharing first and second antennas by different frequency bands
An RF front end arrangement comprises first filtering, second filtering, third filtering, fourth filtering and a switching arrangement. The switching arrangement is configured to selectively connect the filtering to plural antennas such that at a particular time the first and third filtering is connected to a first antenna and the second and fourth filtering is connected to a second antenna. This allows filtering with different frequency response characteristics to be in use simultaneously for the same frequency band. This can reduce the insertion loss associated with a signal path.
1. A radiofrequency (RF) front end system comprising:
a first filter for a first frequency band;
a second filter for the first frequency band, the second filter having a frequency response characteristic that is different from a frequency response characteristic of the first filter where the second filter receives a different signal within the first frequency band than the first filter, the different signals received by the first filter and the second filter being intra-band carrier aggregation (CA) signals within the first frequency band;
a third filter for a second frequency band;
a fourth filter for the second frequency band, the fourth filter having a frequency response characteristic that is different from a frequency response characteristic of the third filtering; and
a switching system configured to selectively connect filters to plural antennas such that at a particular time the first and third filters are connected to a first antenna and the second and fourth filters are connected to a second antenna,
wherein the switching system comprises a first portion for selective connection of the first and third filter to the first antenna and a second portion for selective connection of the second and fourth filter to the second antenna; and wherein the first portion is separate from the second portion.
2. The RF front end system according to claim 1 , wherein each of the first and third filters is a duplex filter and each of the second and fourth filters is a simplex filter.
3. The RF front end system according to claim 1 , wherein each of the first and fourth filters is a duplex filter and each of the second and third filters is a simplex filter.
4. The RF front end system according to claim 2 , wherein the simplex filter is configured for signals in the reception direction only.
5. The RF front end system according to claim 2 , wherein the duplex filter is frequency division duplex filter.
6. The RF Front end system according to claim 1 , wherein the switching system is configured to selectively connect at least one of:
the first filter alone to the first antenna,
the second filter alone to the second antenna,
the third filter alone to the first antenna, and
the fourth filter alone to the second antenna.
7. The RF front end system according to claim 1 , comprising:
a first frequency division multiplexer associated with the first and third filter; and
a second frequency division multiplexer associated with the second and fourth filter.
8. The RF front end system according to claim 7 , wherein the switching system comprises:
an antenna switch;
a first single pole switch having:
a pole connected, directly or indirectly, to the first filter,
first contact point connected, directly or indirectly, to the antenna switch; and
a second contact point connected, directly or indirectly, to a first filtered terminal of the first frequency division multiplexer; and
a second single pole switch having:
a pole connected, directly or indirectly, to the third filter,
a first contact point connected, directly or indirectly, to the antenna switch, and
a second contact point connected, directly or indirectly, to a second filtered terminal of the first frequency division multiplexer.
9. The RF front end system according to claim 8 , wherein the switching system comprises:
a second antenna switch;
a third single pole switch having:
a pole connected, directly or indirectly, to the second filter,
a first contact point connected, directly or indirectly, to the second antenna switch; and
a second contact point connected, directly or indirectly, to a first filtered terminal of the second frequency division multiplexer; and
a fourth single pole switch having:
a pole connected, directly or indirectly, to the fourth filter,
a first contact point connected, directly or indirectly, to the second antenna switch, and
a second contact point connected, directly or indirectly to a second filtered terminal of the second frequency division multiplexer.
10. The RF front end system according claim 1 , comprising:
fifth filter for a third frequency band;
sixth filter for the third frequency band, the sixth filtering having a frequency response characteristic that is different from a frequency response characteristic of the fifth filter;
seventh filter for a fourth frequency band; and
eighth filter for the fourth frequency band, the eighth filter having a frequency response characteristic that is different from a frequency response characteristic of the seventh filter;
wherein the switching system is configured to selectively connect filters to plural antennas such that at a particular time the fifth and seventh filter is connected to the first antenna and the sixth and eighth filter is connected to the second antenna.
11. A mobile apparatus comprising:
a radiofrequency (RF) front end system;
a first antenna connected to the RF front end system; and
a second antenna connected to the RF front end system;
wherein the RF front end system comprises:
a first filter for a first frequency band;
a second filter for the first frequency band, the second filter having a frequency response characteristic that is different from a frequency response characteristic of the first filter, where the second filter receives a different signal within the first frequency band than the first filter, the different signals received by the first filter and the second filter being intra-band carrier aggregation (CA) signals within the first frequency band;
a third filter for a second frequency band;
a fourth filter for the second frequency band, the fourth filter having a frequency response characteristic that is different from a frequency response characteristic of the third filter; and
a switching system configured to selectively connect filters to plural antennas such that at a particular lime the first and third filters is connected to the first antenna and the second and fourth filters is connected to the second antenna,
wherein the switching system comprises a first portion for selective connection of the first and third filter to the first antenna and a second portion for selective connection of the second and fourth filter to the second antenna; and wherein the first portion is separate from the second portion.
12. The mobile apparatus of claim 11 , each of the first and third filters is a duplex filter and each of the second and fourth filters is simplex filter.
13. The mobile apparatus of claim 11 , wherein each of the first and fourth filters is a duplex filter and each of the second and third filters is a simplex filter.
14. The mobile apparatus according to claim 12 , wherein the simplex filter is configured for signals in the reception direction only.
15. The mobile apparatus according to claim 12 , wherein the duplex filter is frequency division duplex filter.
16. The mobile apparatus according to claim 11 , wherein the switching system is configured to selectively connect at least one of:
the first filter alone to the first antenna,
the second filter alone to the second antenna,
the third filter alone to the first antenna, and
the fourth filter alone to the second antenna.
17. The mobile apparatus according to claim 11 , wherein the RF front end system further comprises:
a first frequency division multiplexer associated with the first and third filters; and
a second frequency division multiplexer associated with the second and fourth filters.