RF device and communication apparatus using the same

• US 20030068998A1
• Filed: 08/26/2002
• Published: 04/10/2003
• Est. Priority Date: 08/27/2001
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ishizaki, Toshio, Yamada, Toru, Yamakawa, Takehiko
• Granted Patent: US 6,985,712 B2
• Time in Patent Office: Days
• US Class Current: 455/339
• CPC Class Codes: H01P 1/15 by semiconductor devices
• CPC Class Codes: H01P 1/20345 Multilayer filters
• CPC Class Codes: H01P 1/213 combining or separating two or more different frequencies H01P1/215 takes precedence

Abstract

An RF device, has a first substrate made of a material with a lower relative dielectric constant and having a high frequency circuit formed therein or on a surface thereof; and

a second substrate made of a material with a higher relative dielectric constant,

wherein at least a part of a filter is provided in, on a surface of or in the vicinity of the second substrate and connected to the high frequency circuit, and

the high frequency circuit is composed of an element other than the part of the filter.

Claims

1. An RF device, comprising:

a first substrate made of a material with a lower relative dielectric constant and having a high frequency circuit formed therein or on a surface thereof; and

a second substrate made of a material with a higher relative dielectric constant,

wherein at least a part of a filter is provided in, on a surface of or in the vicinity of said second substrate and connected to said high frequency circuit, and

said high frequency circuit is composed of an element other than said part of the filter.

2. The RF device according to claim 1, wherein said at least a part of the filter forms a high frequency circuit for a CDMA mode.

3. The RF device according to claim 1, wherein said second substrate is partially overlaid on said first substrate, a semiconductor device or passive device is provided on a region in the surface of said first substrate on which said second substrate is not overlaid, and a multilayered wiring pattern made of copper or silver is formed in said first substrate, whereby said high frequency circuit is formed.

4. The RF device according to claim 3, wherein said semiconductor device includes any one of a PIN diode device, a GaAs semiconductor device, a field effect transistor (FET) device and a varactor diode device, and switching among a plurality of frequency bands is realized by an operation of any one of said devices.

17. A communication apparatus, comprising the RF device according to any one of claims 1 to 16, a transmitting circuit, a receiving circuit and an antenna which are connected to said RF device.

5. An RF device, comprising:

a first substrate made of a material with a lower relative dielectric constant and having a first high frequency circuit for a lower frequency band formed therein or on a surface thereof; and

a second substrate made of a material with a higher relative dielectric constant,

wherein at least a part of a filter of a second high frequency circuit for a higher frequency band is provided in, on a surface of or in the vicinity of said second substrate, and said first high frequency circuit and said second high frequency circuit are connected to each other.

6. The RF device according to claim 5, wherein said second substrate is overlaid on said first substrate, and said part of the filter is sandwiched between said first substrate and said second substrate.

7. The RF device according to claim 6, wherein said second substrate is partially overlaid on said first substrate, a semiconductor device or passive device is provided on a region in the surface of said first substrate on which said second substrate is not overlaid, and a multilayered wiring pattern made of copper or silver is formed in said first substrate, whereby said first high frequency circuit is formed.

8. The RF device according to claim 7, wherein said second substrate comprises a plurality of substrates disposed on said first substrate with spaced apart from each other, one of said plurality of substrates constitutes a transmitting filter, and another of said plurality of substrates constitutes a receiving filter.

9. The RF device according to claim 5, wherein said lower frequency band is a frequency band for a TDMA mode, and said higher frequency band is a frequency band for a CDMA mode.

10. The RF device according to claim 5, wherein each of said first and second substrates is composed of a multilayered and integrally molded ceramic.

11. The RF device according to claim 5, wherein said first substrate is made of a low temperature cofired ceramic and said second substrate is made of a high temperature cofired ceramic.

12. The RF device according to claim 6, wherein a part of said filter is a resonator electrode, and said resonator electrode is constituted by a metal foil.

13. The RF device according to claim 12, wherein the RF device is integrated by filling a space defined by said first substrate, said second substrate and said resonator electrode with a thermosetting resin.

14. The RF device according to claim 7, wherein said semiconductor device includes any one of a PIN diode device, a GaAs semiconductor device, a field effect transistor (FET) device and a varactor diode device, and switching between said first high frequency circuit and said second high frequency circuit is realized by an operation of any one of said devices.

15. The RF device according to claim 5, wherein whole or a part of said second substrate is covered with a shielding electrode.

16. The RF device according to claim 7, wherein said passive device includes a SAW filter with an electrode hermetically sealed.