Circuit module including a splitter and a mounting substrate

Patent metadata

Field	Value
Publication number	US-9252476-B2
Application number	US-201314057000-A
Country	US
Kind code	B2
Filing date	Oct 18, 2013
Priority date	Apr 21, 2011
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

In a circuit module, even if a transmission signal output from a transmission electrode of a mounting substrate to a transmission terminal of a splitter leaks into a ground electrode, the transmission signal that has leaked into the ground electrode flows into via conductors that are connected along an edge portion of the ground electrode close to the transmission electrode and connected to a ground line of a motherboard. Therefore, the transmission signal that has been output from the transmission electrode and leaked into the ground electrode is prevented from traveling along an edge portion of the ground electrode toward a reception electrode side. Thus, characteristics of isolation between the transmission electrode and the reception electrode provided on the mounting substrate on which the splitter is mounted are improved.

First claim

What is claimed is:

1. A circuit module comprising:
a splitter that includes a transmission filter and a reception filter with different pass bands from each other; and
a mounting substrate on which the splitter is mounted; wherein
the splitter includes a transmission terminal that allows input to the transmission filter, a reception terminal that allows output from the reception filter, and a ground terminal;
the mounting substrate includes a transmission electrode that is connected to the transmission terminal, a reception electrode that is connected to the reception terminal, and a ground electrode that is arranged between the transmission electrode and the reception electrode when viewed in plan and is connected to the ground terminal;
a plurality of via conductors are connected to the ground electrode along an edge portion of the ground electrode that is close to the transmission electrode when viewed in plan; and
the mounting substrate includes a plurality of dielectric layers, and a layer of the plurality of dielectric layers at which the ground electrode is provided is different from a layer of the plurality of dielectric layers at which the transmission electrode, the reception electrode, and the common electrode are provided.

2. The circuit module according to claim 1 , wherein the plurality of via conductors are connected to the ground electrode along edge portions of the ground electrode from an edge portion of the ground electrode close to the transmission electrode to an edge portion of the ground electrode close to the reception electrode when viewed in plan.

3. The circuit module according to claim 1 , wherein the transmission electrode and the reception electrode are provided adjacent to or in an area of an edge of a mounting surface of the mounting substrate and the ground electrode is provided between that edge and the transmission electrode when viewed in plan.

4. The circuit module according to claim 1 , wherein the ground electrode is provided across a plurality of layers of the mounting substrate and individual portions of the ground electrode are connected to each other through the via conductors.

5. The circuit module according to claim 4 , wherein the individual portions of the ground electrode provided across the plurality of layers in the mounting substrate have the same shape.

6. The circuit module according to claim 1 , wherein the ground electrode includes a first extended portion that extends towards an outside of the splitter when viewed in plan.

7. The circuit module according to claim 6 , wherein the ground electrode further includes a second extended portion that extends from an end portion of the first extended portion in at least one of a direction toward the transmission electrode and a direction toward the reception electrode.

8. The circuit module according to claim 1 , wherein the ground electrode surrounds at least the transmission electrode when viewed in plan.

9. The circuit module according to claim 1 , wherein at least one of the transmission electrode and the reception electrode includes a rectangular or substantially rectangular land on a mounting surface of the mounting substrate and the ground electrode surrounds at least three sides of the transmission electrode or the reception electrode when viewed in plan.

10. The circuit module according to claim 1 , wherein
the splitter includes a common terminal that is connected to an output side of the transmission filter and an input side of the reception filter;
the transmission electrode, the reception electrode, and a common electrode, which is connected to the common terminal, include rectangular or substantially rectangular lands located on the mounting surface of the mounting substrate; and
the ground electrode surrounds at least three sides of each of the transmission electrode, the reception electrode and the common electrode when viewed in plan.

11. The circuit module according to claim 10 , wherein a shape of the common electrode is one of rectangular, substantially rectangular, circular and substantially circular.

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

13. The circuit module according to claim 1 , wherein each of the transmission filter and the reception filter includes at least one of a surface acoustic wave device, a dielectric filer and a bulk acoustic wave device.

14. The circuit module according to claim 1 , wherein the splitter is a first splitter, the circuit module including a second splitter mounted on the substrate.

15. The circuit module according to claim 14 , wherein the ground electrode is located between the transmission electrodes and the reception electrodes of the first and second splitters.

16. The circuit module according to claim 1 , wherein
the splitter includes a common electrode that is connected to an output side of the transmission filter and an input side of the reception filter; and
the transmission electrode and the reception electrode are arranged in a central portion of the ground electrode and the common electrode is arranged on an upper edge side of the ground electrode.

17. The circuit module according to claim 1 , wherein a shape of each of the transmission electrode and the reception electrode is one of rectangular, substantially rectangular, circular and substantially circular.

18. A mobile communication terminal comprising the circuit module according to claim 1 .

19. A mobile information terminal comprising the circuit module according to claim 1 .

20. The circuit module according to claim 1 , wherein the transmission electrode and the reception electrode are provided at an uppermost layer of the plurality of dielectric layers, and the layer at which the ground electrode is provided is one layer below the uppermost layer.

21. The circuit module according to claim 1 , wherein an end portion of the ground electrode on an edge side thereof extends in both directions along an edge of the mounting substrate so as to be substantially T-shaped, such that the ground electrode is arranged between the edge of the mounting substrate and the transmission and reception electrodes.

Assignees

• Murata Manufacturing Co

Inventors

• Onodera Syuichi

Classifications

• H05K1/0233

  Filters, inductors or a magnetic substance · CPC title

• H01P5/12 Primary

  Coupling devices having more than two ports (H01P5/04 takes precedence) · CPC title

• H05K2201/09618

  Via fence, i.e. one-dimensional array of vias · CPC title

• H04M1/0202

  Portable telephone sets, e.g. cordless phones, mobile phones or bar type handsets (constructional features of telephone transmitters or receivers, e.g. of speakers or microphones H04M1/03) · CPC title

• H05K1/0227

  Split or nearly split shielding or ground planes · CPC title