High-frequency module

• US 9,948,276 B2
• Filed: 02/09/2017
• Issued: 04/17/2018
• Est. Priority Date: 08/12/2014
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Yamaguchi, Yukiya
• Primary Examiner(s): Nguyen, Lee
• Application Number:
  US15/428,252
• Publication Number:
  US 20170155376A1
• Time in Patent Office: 432 Days
• Field of Search: 455 73, 333100
• CPC Class Codes: H03H 7/09 Filters comprising mutual inductance
• CPC Class Codes: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H03H 9/0542 consisting of a lateral arrangement H03H9/0566 takes precedence
• CPC Class Codes: H03H 9/0557 the other elements being buried in the substrate
• CPC Class Codes: H03H 9/0576 including surface acoustic wave [SAW] devices
• CPC Class Codes: H03H 9/64 using surface acoustic waves
• CPC Class Codes: H03H 9/725 Duplexers
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

In a high-frequency module, first and second inductors that adjust attenuation characteristics of a first filter of a filter component, are separated from each other such that the first and second inductors readily magnetic field couple with each other. Consequently, an amount of wiring used to define a first wiring electrode inside the filter component is reduced and a number of layers of a package substrate and the profile of the filter component are reduced. Consequently, variations in the attenuation characteristics of the first filter caused by the first wiring electrode electromagnetic-field coupling with another wiring electrode are prevented. The attenuation characteristics of the first filter is easily adjusted and improved by adjusting the inductance value of the second inductor.

Claims

1. A high-frequency module comprising:

a filter component including;

a first terminal to which an RF signal is input;

a first filter through which the RF signal input to the first terminal passes;

a second terminal that outputs the RF signal that has passed through the first filter;

a third terminal; and

a first inductor including one end connected to the first filter and another end connected to the third terminal;

a module substrate on which the filter component is mounted; and

a second inductor that is provided, inside the module substrate, directly below the filter component in plan view and includes one end connected to the third terminal and another end connected to ground;

wherein

the first filter includes;

a plurality of series arm resonators that are arranged in a series arm that connects an input terminal and an output terminal of the first filter; and

a plurality of parallel arm resonators that are connected to the series arm;

wherein

the one end connected to the first filter of the first inductor is connected to at least one of the plurality of the parallel arm resonators; and

a first wiring electrode that defines the first inductor and a second wiring electrode that defines the second inductor at least partially overlap in plan view.

2. The high-frequency module according to claim 1, wherein the first wiring electrode and the second wiring electrode are structured such that currents that flow in portions thereof where the first wiring electrode and the second wiring electrode overlap flow in a same direction.

3. The high-frequency module according to claim 1, wherein the first inductor and the second inductor have a same inductor structure of a spiral or helical shape and the first wiring electrode and the second wiring electrode are wound in a same direction.

4. The high-frequency module according to claim 1, wherein

the filter component includes a filter substrate on which the plurality of series arm resonators and the plurality of parallel arm resonators are located in a prescribed area of one main surface thereof, and a package substrate on which the filter substrate is mounted;

and

the first wiring electrode is provided inside the package substrate.

5. The high-frequency module according to claim 4, further comprising a resin layer provided on the package substrate.

6. The high-frequency module according to claim 4, wherein the first wiring electrode is provided in the package substrate, and the second wiring electrode is provided in the module substrate.

7. The high-frequency module according to claim 1, wherein the filter component includes:

a filter substrate on which the plurality of series arm resonators and the plurality of parallel arm resonators are located in a prescribed area of one main surface thereof;

an insulating layer that surrounds the prescribed area;

a cover layer that is arranged on the insulating layer and covers the plurality of series arm resonators and the plurality of parallel arm resonators; and

a space that is surrounded by the filter substrate, the insulating layer and the cover layer;

the first terminal, the second terminal and the third terminal are exposed at a main surface on a side opposite the surface where the space is located and are connected to mounting electrodes provided on a mounting surface of the module substrate; and

the first wiring electrode is provided inside the cover layer.

8. The high-frequency module according to claim 1, further comprising:

a third inductor that adjusts characteristics of the first filter, the third inductor including a third wiring electrode provided inside the module substrate, including one end thereof connected to at least one of the plurality of parallel arm resonators and another end thereof connected to ground;

wherein

the second wiring electrode and the third wiring electrode are structured such that directions of currents that flow through the second inductor and the third inductor are opposite to each other.

9. The high-frequency module according to claim 1, wherein

the filter component further includes:

a second filter including a plurality of resonators and through which an RF signal input to the second terminal passes; and

a fourth terminal that outputs the RF signal that has passed through the second filter;

wherein

a pass band of the first filter is a frequency band of a transmission signal; and

a pass band of the second filter is a frequency band of a reception signal.

10. The high-frequency module according to claim 9 wherein the second filter is a balanced filter.

11. The high-frequency module according to claim 1, wherein the filter component is a duplexer.

12. The high-frequency module according to claim 1, wherein the high-frequency module is a high-frequency antenna switching module.

13. The high-frequency module according to claim 1, wherein the module substrate includes a multilayer body.

14. The high-frequency module according to claim 13, wherein the multilayer body includes via conductors and in-plane conductor patterns.

15. The high-frequency module according to claim 1, further comprising a matching network including at least one of an inductor and a capacitor.

16. The high-frequency module according to claim 1, wherein the filter component has one of a chip size package structure and a wafer level chip size package structure.

17. The high-frequency module according to claim 1, wherein the first filter includes a plurality of surface acoustic wave resonators.

18. The high-frequency module according to claim 1, further comprising a ground electrode layer on a mounting surface of the module substrate, wherein the ground electrode layer includes a notch at a location where the first and second wiring electrodes at least partially overlap in plan view.

19. A mobile communication terminal comprising:

a mother substrate; and

the high-frequency module according to claim 1 mounted on the mother substrate.

20. The mobile communication terminal according to claim 19, wherein the mobile communication terminal is one of a cellular phone and a mobile information terminal.