Epcos Ag

Infineon Technologies Ag

Snaptrack Incorporated

Juha Ellae

Edgar Schmidhammer

Robert Aigner

Stephan Marksteiner

Pekka Ikonen

Hans-Jörg Timme

The present invention concerns a front end circuit () which 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. Furthermore, the present invention concerns a method of operating the front end circuit.

Front end circuit and method of operating a front end circuit

A duplexer having good insulation, small geometric dimensions and good decoupling of the transmit signal path from an antenna which may have poor matching is specified. To that end, the duplexer comprises two transmit filters, a receive filter and two 90&#xb0; hybrids.

Duplexer

An antenna and RF front-end arrangement include at least one LTE or WCDMA Tx&Rx antenna, one MIMO Rx or diversity antenna adapted for low band LTE or WCDMA and one MIMO Rx or diversity antenna adapted for high band LTE or WCDMA. At least one of the MIMO Rx or diversity antennas is adapted for transmitting and receiving WLAN and/or BlueTooth signals. Therefore, a dedicated WLAN antenna is not required and the number of antennas can be reduced.

Antenna and RF front-end arrangement

A filter circuit comprises a balanced port, an unbalanced port and a substrate. A series circuit of a filter stage and a balun is disposed between the balanced port and the unbalanced port. The balun and the filter stage are formed on the substrate.

Growing community of inventors

Halikko, Finland

Juha Ellae