Radio-frequency module and communication device
Loss in a low-pass filter is reduced. A radio-frequency module includes an antenna terminal, a power amplifier, a low-noise amplifier, and a low-pass filter. The low-pass filter is disposed on a transmit path between the antenna terminal and the power amplifier and on a receive path between the antenna terminal and the low-noise amplifier. The low-pass filter has multiple paths. Each of the paths forms a part of either one or both of the transmit path and the receive path. The paths include a first path and a second path. The second path has a smaller reactance than the first path.
1. A radio-frequency module comprising:
an antenna terminal;
a power amplifier;
a low-noise amplifier; and
a low-pass filter that is in a transmit path between the antenna terminal and the power amplifier, and in a receive path between the antenna terminal and the low-noise amplifier,
wherein the low-pass filter has a plurality of paths therethrough, each of the plurality of paths forming a part of the transmit path and/or the receive path, and
wherein the plurality of paths comprise:
a first path, and
a second path having a smaller reactance than the first path.
2. The radio-frequency module according to claim 1 , wherein, in the low-pass filter:
a transmit signal that passes through the transmit path passes through the first path, and
a receive signal that passes through the receive path passes through the second path.
3. The radio-frequency module according to claim 1 ,
wherein the low-pass filter comprises:
an inductor, and
a capacitor, and
wherein the capacitor is a digital tunable capacitor.
4. The radio-frequency module according to claim 3 , further comprising:
a mounting substrate that has a first principal surface and a second principal surface that are opposite each other; and
an external connection terminal that is on a second principal surface side of the mounting substrate,
wherein the inductor is on a first principal surface side of the mounting substrate, and
wherein the digital tunable capacitor is on the second principal surface side of the mounting substrate.
5. The radio-frequency module according to claim 4 , further comprising:
an antenna switch configured to switch a path for connection to an antenna,
wherein the digital tunable capacitor and the antenna switch are in a switch integrated circuit (IC).
6. The radio-frequency module according to claim 5 , wherein the inductor overlaps the switch IC in plan view in a thickness direction of the mounting substrate.
7. The radio-frequency module according to claim 6 , wherein the inductor overlaps the digital tunable capacitor in plan view in the thickness direction of the mounting substrate.
8. The radio-frequency module according to claim 1 , wherein a transmit signal that passes through the transmit path and a receive signal that passes through the receive path are time division duplex (TDD) signals.
9. The radio-frequency module according to claim 1 , wherein a transmit signal that passes through the transmit path and a receive signal that passes through the receive path are frequency division duplex (FDD) signals.
10. A communication device comprising:
the radio-frequency module according to claim 1 ; and
a signal processing circuit configured to process a transmit signal that passes through the transmit path and a receive signal that passes through the receive path.
11. A radio-frequency module comprising:
an antenna terminal;
a power amplifier;
a low-noise amplifier; and
a low-pass filter that is in a transmit path between the antenna terminal and the power amplifier, and in a receive path between the antenna terminal and the low-noise amplifier,
wherein the low-pass filter has a plurality of paths therethrough, each of the plurality of paths forming a part of the transmit path and/or the receive path,
wherein the low-pass filter comprises:
an inductor, and
a capacitor, and
wherein the plurality of paths comprise:
a first path that passes through the capacitor, and
a second path that bypasses the capacitor.
12. The radio-frequency module according to claim 11 , wherein, in the low-pass filter:
a transmit signal that passes through the transmit path passes through the first path, and
a receive signal that passes through the receive path passes through the second path.
13. The radio-frequency module according to claim 11 , wherein the capacitor is a digital tunable capacitor.
14. The radio-frequency module according to claim 13 , further comprising:
a mounting substrate that has a first principal surface and a second principal surface that are opposite each other; and
an external connection terminal that is on a second principal surface side of the mounting substrate,
wherein the inductor is on a first principal surface side of the mounting substrate, and
wherein the digital tunable capacitor is on the second principal surface side of the mounting substrate.
15. The radio-frequency module according to claim 14 , further comprising:
an antenna switch configured to switch a path for connection to an antenna,
wherein the digital tunable capacitor and the antenna switch are in a switch integrated circuit (IC).
16. The radio-frequency module according to claim 15 , wherein the inductor overlaps the switch IC in plan view in a thickness direction of the mounting substrate.
17. The radio-frequency module according to claim 16 , wherein the inductor overlaps the digital tunable capacitor in plan view in the thickness direction of the mounting substrate.
18. The radio-frequency module according to claim 11 , wherein a transmit signal that passes through the transmit path and a receive signal that passes through the receive path are time division duplex (TDD) signals.
19. The radio-frequency module according to claim 11 , wherein a transmit signal that passes through the transmit path and a receive signal that passes through the receive path are frequency division duplex (FDD) signals.
20. A communication device comprising:
radio-frequency module according to claim 11 ; and
a signal processing circuit configured to process a transmit signal that passes through the transmit path and a receive signal that passes through the receive path.