HF circuit and HF module
An HF circuit is specified, by means of which carrier aggregation is possible with a simple design. The circuit comprises a duplexer, a further filter, and two phase shifters, and can be used in an HF module of a mobile wireless device.
1. A radio frequency (RF) circuit comprising
a first port, a first reception port, a common port, and a third port,
a first duplexer comprising a transmission filter connected between the first transmission port and the common port, and a reception filter connected between the first reception port and the common port,
a third filter connected between the third port and the common port,
a first phase shifter connected between the common port of the first duplexer and the common port of the RF circuit, and
a second phase shifter connected between the third filter and the common port of the RF circuit,
wherein the third filter is a bandpass filter,
wherein the RF circuit is provided to simultaneously transmit signals via the transmission filter and the third filter, or receive signals via the reception filter and the third filter,
wherein at least one of the transmission filter, the reception filter, or the third filter is tunable, and
wherein at least one of the transmission filter, the reception filter, or the third filter comprises a filter topology comprising a parallel inductive element, three serial capacitive elements, and four parallel paths, each of the parallel paths having a parallel circuit with a capacitive element and an inductive element.
2. The RF circuit according to claim 1 , wherein at least one of the first phase shifter or the second phase shifter is tunable.
3. The RF circuit according to one of the preceding claims, further comprising a second transmission port, a second reception port, and a second duplexer having a transmission filter connected between the second transmission port and the common port, and a reception filter, which is connected between the second reception port and the common port.
4. The RF circuit according to one of the preceding claims, further comprising a sixth port and a sixth filter configured as a bandpass filter connected between the sixth port and the common port.
5. The RF circuit according to one of the preceding claims, further comprising
a diplexer having a first filter and a second filter,
wherein the first filter of the diplexer is connected between the first duplexer and the common port and connected between the third filter and the common port,
wherein the second filter of the diplexer is connected to the common port, and
wherein the first filter and the second filter are selected from high-pass filters and low-pass filters.
6. The RF circuit according to one of the preceding claims, further comprising an antenna tuner connected between the first duplexer and the common port.
7. The RF circuit according to one of the preceding claims, further comprising a first impedance matching circuit, a second impedance matching circuit, and a third impedance matching circuit,
wherein the first impedance matching circuit is connected between the first transmission port and the transmission filter of the first duplexer,
wherein the second impedance matching circuit is connected between the first reception port and the reception filter of the first duplexer, and
wherein the third impedance matching circuit is connected between the third port and the third filter.
8. The RF circuit according to the preceding claim, wherein at least one of the first impedance matching circuit, the second impedance matching circuit, or the third impedance matching circuit is tunable.
9. The RF circuit according to one of the preceding claims, further comprising
a transmission amplifier, a reception amplifier, and a third amplifier,
wherein the transmission amplifier is connected between the first transmission port and the common port,
wherein the reception amplifier is connected between the first reception port and the common port, and
wherein the third amplifier is connected between the third port and the common port.
10. The RF circuit according to the preceding claim, wherein at least one of the transmission amplifier, the reception amplifier, or the third amplifier is tunable.
11. The RF circuit according to claim 1 , wherein the filter comprises four or five serial capacitive elements.
12. The RF circuit according to one of claims 1 - 10 and 11 , wherein at least one phase shifter or all phase shifters each comprise a serial capacitive element, two parallel paths, each having an inductive element, and a capacitive element which connects the two parallel paths to ground.
13. The RF circuit according to one of the two preceding claims, wherein the filter comprises a tunable inductive element or a tunable capacitive element.
14. An RF module which combines all the circuit elements of the RF circuit according to one of claims 1 - 10 and 11 - 13 in one component.