US-20260128851-A1 - RADIO-FREQUENCY MODULE AND COMMUNICATION DEVICE

US20260128851A1US 20260128851 A1US20260128851 A1US 20260128851A1US-20260128851-A1

Abstract

A radio-frequency module includes first filters, a second filter, a first switch, a second switch, and a first variable circuit element. The first filters have a first pass band that includes a first communication band. The second filter has a second pass band that includes a second communication band. The first switch selects the connection destination of each of a plurality of antenna terminals from among first terminals of the first filters and the second filter. The second switch selects the connection destination of a second terminal of the second filter from among a first power amplifier and a first low-noise amplifier. The first variable circuit element is connected between the second filter and the second switch and shifts an attenuation band on the first pass band side in the second filter.

Inventors

Satoshi Nakamura
Yoshiki Nakagawa
Katsuya IKEGAMI

Assignees

MURATA MANUFACTURING CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20251031
Priority Date: 20241105

Claims (9)

1 . A radio-frequency module configured to process a first time division duplex (TDD) signal in a first communication band and a second TDD signal in a second communication band adjacent to the first communication band, the first communication band being wider than the second communication band, the radio-frequency module comprising: a first filter having a first pass band that includes the first communication band; a second filter having a second pass band that includes the second communication band; a first switch configured to selectively connect each of a plurality of antenna terminals to a first terminal of the first filter or to a first terminal of the second filter; a second switch configured to selectively connect a second terminal of the second filter to a first power amplifier or to a first low-noise amplifier; and a first variable circuit element connected inside the second filter, inside the second switch, or between the second filter and the second switch, and configured to shift an attenuation band in the second filter, the attenuation band being on a first pass band side.
2 . The radio-frequency module according to claim 1 , further comprising: a variable matching network connected between the second filter and the second switch, wherein the first variable circuit element is inside the variable matching network.
3 . The radio-frequency module according to claim 1 , further comprising: a second variable circuit element, wherein the second variable circuit is in the second filter, and wherein the second variable circuit is a variable filter.
4 . The radio-frequency module according to claim 1 , further comprising: a plurality of third filters including at least one low-pass filter and one high-pass filter; a plurality of fourth filters including at least one low-pass filter and at least one high-pass filter; a plurality of low-noise amplifiers including the first low-noise amplifier; and a plurality of power amplifiers including the first power amplifier, wherein each of the plurality of low-noise amplifiers is connected to a corresponding one of the plurality of fourth filters, wherein each of the plurality of power amplifiers is connected to a corresponding one of the plurality of fourth filters, wherein the first switch is configured to selectively connect each of the plurality of antenna terminals to a corresponding one of the plurality of third filters, wherein the second switch is configured to selectively connect the third filter selected by the first switch to one of the plurality of fourth filters, during reception with the second communication band, the second filter is formed by one third filter selected by the first switch, and a fourth filter selected by the second switch and connected to the first low-noise amplifier, during transmission with the second communication band, the second filter is formed by the one third filter selected by the first switch, and a fourth filter selected by the second switch and connected to the first power amplifier, and during transmission or reception with the first communication band, the first filter is formed by another third filter selected by the first switch, and a fourth filter selected by the second switch and connected to a power amplifier other than the first power amplifier or connected to a low-noise amplifier other than the first low-noise amplifier.
5 . The radio-frequency module according to claim 4 , further comprising: a plurality of sets each including the second switch, the first variable circuit element, the plurality of third filters, and the plurality of fourth filters.
6 . The radio-frequency module according to claim 1 , further comprising: a mounting substrate having a first main surface and a second main surface facing each other; wherein the first switch is on the first main surface of the mounting substrate, wherein the second switch is on the second main surface of the mounting substrate and overlaps at least part of the first switch in a plan view in a thickness direction of the mounting substrate, and wherein the first variable circuit element is on or in the mounting substrate.
7 . The radio-frequency module according to claim 6 , wherein the first variable circuit element is inside the mounting substrate and overlaps at least part of the first switch and at least part of the second switch in the plan view.
8 . The radio-frequency module according to claim 6 , wherein the first variable circuit element is on the first main surface or on the second main surface of the mounting substrate.
9 . A communication device comprising: the radio-frequency module according to claim 1 ; and a signal processing circuit connected to the radio-frequency module and configured to perform signal processing on a radio-frequency signal.

Description

CROSS REFERENCE TO RELATED APPLICATION This application claims priority from Japanese Patent Application No. 2024-193858, filed on November 5, 2024. The content of these applications are incorporated herein by reference in its entirety. BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure The present disclosure generally relates to a radio-frequency module and a communication device, and more particularly relates to a radio-frequency module that processes a first TDD signal in a first communication band and a second TDD signal in a second communication band, and a communication device including the radio-frequency module. 2. Description of the Related Art A multiplexer described in Japanese Unexamined Patent Application Publication No. 2023-65416 includes a plurality of switches, a plurality of filters, a plurality of power amplifiers, and a plurality of low-noise amplifiers. BRIEF SUMMARY OF THE DISCLOSURE In a front-end module such as the multiplexer described in Japanese Unexamined Patent Application Publication No. 2023-65416, the plurality of filters generally includes a filter for band 77 (n77, first communication band) and a filter for band 79 (n79, second communication band). The bands n77 and n79 are adjacent communication bands. Therefore, when transmission using n77 and reception using n79 are performed simultaneously, the transmission signal of n77 leaks into the reception path for n79, thereby degrading the reception sensitivity of n79. Furthermore, when communication is performed solely using n79, it is desirable to reduce degradation in the communication quality of n79. In light of the above problems, a possible benefit of the present disclosure is to provide a radio-frequency module and a communication device that can realize reduced interference between adjacent first and second communication bands and reduced degradation of communication quality. A radio-frequency module according to an aspect of the present disclosure processes a first TDD signal in a first communication band and a second TDD signal in a second communication band adjacent to the first communication band. A communication band of the first communication band is wider than a communication band of the second communication band. The radio-frequency module includes a first filter, a second filter, a first switch, a second switch, and a first variable circuit element. The first filter has a first pass band that includes the first communication band. The second filter has a second pass band that includes the second communication band. The first switch selects a connection destination for each of a plurality of antenna terminals from among first terminals of the first filter and the second filter. The second switch selects a connection destination for a second terminal of the second filter from among a first power amplifier and a first low-noise amplifier. The first variable circuit element is connected inside the second filter, inside the second switch, or between the second filter and the second switch, and shifts an attenuation band on the first pass band side in the second filter. A communication device according to an aspect of the present disclosure includes the above-described radio-frequency module and a signal processing circuit. The signal processing circuit is connected to the radio-frequency module and performs signal processing on a radio-frequency signal. The radio-frequency module and communication device according to the present disclosure have an advantage in that reduced interference can be realized between adjacent first and second communication bands while also realizing reduced degradation of communication quality. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a block diagram of a radio-frequency module and a communication device according to Embodiment 1; FIG. 2 is an explanatory diagram illustrating frequency characteristics of a second filter included in the radio-frequency module according to Embodiment 1; FIG. 3 is a block diagram of a radio-frequency module and a communication device according to Embodiment 2; FIG. 4 is a block diagram of a radio-frequency module and a communication device according to Embodiment 3; FIG. 5 is an enlarged view of a main part of the radio-frequency module according to Embodiment 3; FIG. 6 is a block diagram of a radio-frequency module and a communication device according to Embodiment 4; FIG. 7 is a block diagram of a radio-frequency module and a communication device according to a modification of Embodiment 4; FIG. 8 is a cross-sectional view of a radio-frequency module according to Embodiment 5; and FIG. 9 is a plan view of a first main surface of a mounting substrate of the radio-frequency module according to Embodiment 5 as viewed in a direction perpendicular to the first main surface. DETAILED DESCRIPTION OF THE DISCLOSURE 1 Embodiment 1 A radio-frequency module 1 according to Embodiment 1 will be described in detail with reference to the drawing