Electronic device having printed circuit board joined to cavity resonance filter

• US 6,370,033 B1
• Filed: 02/02/2000
• Issued: 04/09/2002
• Est. Priority Date: 02/02/1999
• Status: Expired due to Fees

• Current Assignee: Toko KK
• Original Assignee: Toko KK
• Inventors: Saegusa, Seiichiro, Nakamura, Naoshi
• Primary Examiner(s): Gandhi, Jayprakash N.
• Assistant Examiner(s): Vigushin, John B.
• Application Number:
  US09/496,423
• Time in Patent Office: 797 Days
• Field of Search: 361/782, 361/783, 361/814, 361/737, 361/818, 361/799, 361/800, 361/753, 361/816, 361/777, 333/185, 333/246, 333/247, 174/35.CE, 174/35.R, 336/200, 336/232
• US Class Current: 361/777
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H03H 2001/0078 comprising spiral inductor on a substrate
• CPC Class Codes: H03H 7/0123 comprising distributed impedance elements together with lumped impedance elements
• CPC Class Codes: H03H 7/1775 Parallel LC in shunt or branch path H03H7/1791 takes precedence
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/1006 Non-printed filter
• CPC Class Codes: H05K 2201/10371 Shields or metal cases

Abstract

An electronic device has a filter function, and enables a communications device to be miniaturized and made thin at reduced cost. A pair of spiral conductive patterns are provided adjacent to each other on a printed circuit board having multiple electronic elements provided thereon, and one end of each of the spiral conductive patterns connects via through holes to a ground pattern provided on the bottom face of the printed circuit board. Then, a cavity case is electrically connected to the ground pattern, and is mounted on the printed circuit board so as to cover the top faces of the spiral conductive patterns, thereby forming a cavity resonance filter joined to the printed circuit board.

Claims

1. An electronic device comprising:

a printed circuit board having multiple electronic elements mounted thereon;

a ground pattern provided on said printed circuit board;

a pair of spiral conductive patterns provided adjacent to each other on said printed circuit board, one end of each pattern connecting to said ground pattern and the other end being open ended; and

a cavity case electrically connected to said ground pattern, and provided so as to cover the top faces of said pair of spiral conductive patterns.

2. The electronic device of claim 1, wherein said pair of spiral conductive patterns has an input or output terminal at an intermediate part thereof.

3. The electronic device of claim 1, wherein said cavity case is configured to create a capacitance with said spiral conductive patterns.

4. An electronic device comprising:

a printed circuit board having multiple electronic elements mounted thereon;

a ground pattern provided on a first face of said printed circuit board;

a pair of spiral conductive patterns provided adjacent to each other at a predetermined position on a second face of said printed circuit board so as to be facing said ground pattern with said printed circuit board there between, one end of each of said spiral conductive patterns connecting via a through hole to said ground pattern; and

a cavity case electrically connected to said ground pattern, and provided so as to cover

the top faces of said pair of spiral conductive patterns.

5. The electronic device of claim 4, wherein said pair of spiral conductive patterns are provided adjacent to each other on said printed circuit board, one end of each pattern connected to said ground pattern and the other end being open-ended.

6. The electronic device of claim 4, wherein said pair of spiral conductive patterns has an input or output terminal at an intermediate part thereof.

7. The electronic device of claim 4, wherein said cavity case is configured to create a capacitance with said spiral conductive patterns.