Front-End Circuit for Simultaneous Transmission and Reception Operation

A front-end circuit comprising:

• a first antenna connection;
• a first signal path with a first tunable filter arranged therein and coupled to the first antenna connection;
• a second signal path with a second tunable filter arranged therein and coupled to the first antenna connection;
• a third signal path with a third tunable filter arranged therein and coupled to the first antenna connection;
• at least one phase shifter arranged in at least one of the signal paths between a respective filter and the first antenna connection;
• and
• a control circuit configured to tune frequency bands of the filters,
• wherein the filters are operable in a FDD operating mode or a TDD operating mode, and
• wherein the front-end circuit is simultaneous operable in at least one transmission band and at least one reception band using all three filters and the associated signal paths.

A front-end circuit comprising:

• a first antenna connection and a second antenna connection to each of which a group of three signal paths is connected, each signal path connecting an RF chip to one of the antenna connections, wherein the following is arranged in each signal path:
• a tunable power amplifier or a tunable LNA;
• a tunable filter whose input and output impedances are tunable;
• a phase shifter circuit;
• the two groups of the three signal paths covering two different frequency ranges selected from the group consisting of a range of less than 700 MHz, a range of 700 MHz to 1000 MHz, a range of 1000-1400 MHz, a range of 1400-1700 MHz, a range of 1700-2200 MHz, a range of 2200-2700 MHz, and a range above 2700 MHz;
• and
• each group comprises at least one tunable Tx filter and one tunable Rx filter;
• and
• a diplexer connected between an antenna and the first and second antenna connections, wherein the diplexer is configured to separate two selected frequency ranges.