Front end circuit and method of operating a front end circuit

Patent metadata

Field	Value
Publication number	US-2016359506-A1
Application number	US-201315102858-A
Country	US
Kind code	A1
Filing date	Dec 11, 2013
Priority date	Dec 11, 2013
Publication date	Dec 8, 2016
Grant date	—

Abstract

The present invention concerns a front end circuit ( 1 ) which comprising a first tunable duplexer ( 5 ) comprising a first tunable RX bandpass filter ( 9 ) and a first tunable TX bandpass filter ( 10 ), wherein the first tunable duplexer ( 5 ) is configured to support a first FDD mode in a first FDD frequency band and a first TDD mode in a first TDD frequency band. Furthermore, the present invention concerns a method of operating the front end circuit.

First claim

1 . Front end circuit,
comprising a first tunable duplexer comprising a first tunable RX bandpass filter and a first tunable TX bandpass filter, wherein the first tunable duplexer is configured to support a first FDD mode in a first FDD frequency band and a first TDD mode in a first TDD frequency band.

2 . Front end circuit according to claim 1 ,
wherein, in the first TDD mode, the first tunable duplexer is configured to alternate between a TX setting and a RX setting.

3 . Front end circuit according to claim 2 ,
wherein, in the RX setting, the first tunable RX bandpass filter is optimized to the first TDD frequency band, and the first tunable TX bandpass filter is detuned such that it does not have a passband in the first TDD frequency band.

4 . Front end circuit according to claims 2 ,
wherein, in the TX setting, the first tunable TX bandpass filter is optimized to the first TDD frequency band, and the first tunable RX bandpass filter is detuned such that it does not have a passband in the first TDD frequency band.

5 . Front end circuit according to claim 1 ,
wherein the first tunable duplexer is configured such that, in the first FDD mode, the first tunable RX bandpass filter and the first tunable TX bandpass filter is optimized to the first FDD frequency band.

6 . Front end circuit ( 1 ) according to claim 1 ,
wherein the first tunable duplexer is configured to support at least a second FDD mode in a second FDD frequency band.

7 . Front end circuit ( 1 ) according to claim 1 ,
wherein the first tunable duplexer is configured to support at least a second TDD mode in a second TDD frequency band.

8 . Front end circuit ( 1 ) according to claim 1 ,
further comprising a second tunable duplexer comprising a second tunable RX bandpass filter and a second tunable TX bandpass filter, wherein the front end circuit is configured to support a TDD interband carrier aggregation mode wherein a signal is received simultaneously in the first TDD frequency band and in an aggregated TDD frequency band, wherein the second tunable RX bandpass filter is optimized to the aggregated TDD frequency band in the TDD interband carrier aggregation mode.

9 . Front end circuit ( 1 ) according to claim 8 ,
wherein, in the TDD interband carrier aggregation mode, one of the first tunable RX bandpass filter and the first tunable TX bandpass filter is optimized to the first TDD frequency band and the other of the first tunable RX bandpass filter and the first tunable TX bandpass filter is detuned such that it does not have a passband in the first TDD frequency band.

10 . Method of operating a front end circuit,
wherein the front end circuit comprises a first tunable duplexer comprising a first tunable RX bandpass filter and a first tunable TX bandpass filter, the method comprising the steps of:
determining a mode of operation,
if the mode of operation is a first FDD mode in a first FDD frequency band, tuning the first tunable RX bandpass filter and the first tunable TX bandpass filter to the first FDD frequency band,
if the mode of operation is a first TDD mode in a first TDD frequency band, tuning one of the first tunable RX bandpass filter and the first tunable TX bandpass filter to the first TDD frequency band and detuning the other one of the first tunable RX bandpass filter and the first tunable TX bandpass filter away from the first TDD frequency band such that it does not have a passband in the first TDD frequency band.

11 . Method according to claim 10 ,
wherein if the mode of operation is a first TDD mode in a first TDD frequency band, for sending signals in a TX mode of the first TDD mode, the method comprises the step of:
tuning the first tunable TX bandpass filter to the first TDD frequency band and detuning the tunable RX bandpass filter away from the first TDD frequency band such that it does not have a passband in the first TDD frequency band, and
for receiving signals in a RX mode of the first TDD mode, the method comprises the step of:
tuning the first tunable RX bandpass filter to the first TDD frequency band and detuning the tunable TX bandpass filter away from the first TDD frequency band such that it does not have a passband in the first TDD frequency band.

12 . Method according to claim 10 ,
wherein if the mode of operation is a second FDD mode in a second FDD frequency band, for sending and receiving signals, the method comprises the step of:
tuning the first tunable RX bandpass filter and the first tunable TX bandpass filter to the second FDD frequency band.

13 . Method according to claim 10 ,
wherein if the mode of operation is a second TDD mode in a second TDD frequency band, for sending and receiving signals, the method comprises the step of:
tuning one of the first tunable RX bandpass filter and the first tunable TX bandpass filter to the second TDD frequency band and detuning the other one of the first tunable RX bandpass filter and the first tunable TX bandpass filter away from the second TDD frequency band such that it does not have a passband in the second TDD frequency band.

14 . Method according to claim 10 ,
wherein the front end circuit further comprises a second tunable duplexer comprising a second tunable RX bandpass filter and a second tunable TX bandpass filter, the method comprising the steps of:
if the mode of operation is a TDD interband carrier aggregation mode wherein a signal is received simultaneously in the first TDD frequency band and in an aggregated TDD frequency band, tuning the second tunable RX bandpass filter to the aggregated TDD frequency band and tuning one of the first tunable RX bandpass filter and the first tunable TX bandpass filter to the first TDD frequency band and detuning the other one of the first tunable RX bandpass filter and the first tunable TX bandpass filter away from the first TDD frequency band such that it does not have a passband in the first TDD frequency band.

15 . Method according to claim 10 ,
wherein the front end circuit comprises a first phase shifter and a second phase shifter, wherein the first phase shifter is connected between an antenna port and the first tunable RX bandpass filter, and wherein the second phase shifter is connected between the antenna port and the first tunable TX bandpass filter.

16 . Method according to claim 15 ,
wherein the first and the second phase shifter are realized using a fixed, not-tunable network.

17 . Front end circuit according to claim 1 ,
wherein the front end circuit comprises a first phase shifter and a second phase shifter, wherein the first phase shifter is connected between an antenna port and the first tunable RX bandpass filter, and wherein the second phase shifter is connected between the antenna port and the first tunable TX bandpass filter.

18 . Front end circuit according to claim 17 ,
wherein the first and the second phase shifter are realized using a fixed, not-tunable network.

19 . Front end circuit,
comprising a first tunable duplexer comprising a first tunable RX bandpass filter and a first tunable TX bandpass filter, wherein the first tunable duplexer is configured to support a first FDD mode in a first FDD frequency band and a first TDD mode in a first TDD frequency band, further comprising a second tunable duplexer comprising a second tunable RX bandpass filter and a second tunable TX bandpass filter, wherein the front end circuit is configured to support a TDD interband carrier aggregation mode wherein a signal is received simultan

Assignees

• Epcos Ag

Inventors

• Ellae Juha
• Schmidhammer Edgar

Classifications

• H04B1/52

  Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa · CPC title

• H04L5/14

  Two-way operation using the same type of signal, i.e. duplex · CPC title

• H04B1/0057 Primary

  using diplexing or multiplexing filters for selecting the desired band · CPC title