High frequency device

• US 5,406,235 A
• Filed: 04/08/1994
• Issued: 04/11/1995
• Est. Priority Date: 12/26/1990
• Status: Expired due to Term

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Hayashi, Katsuhiko
• Primary Examiner(s): Nelli, Raymond A.
• Application Number:
  US08/225,341
• Time in Patent Office: 368 Days
• Field of Search: 333/202, 333/204, 333/222, 333/246, 333/33, 333/321
• US Class Current: 333/204
• CPC Class Codes: H01P 1/203 Strip line filters
• CPC Class Codes: H01P 1/20345 Multilayer filters
• CPC Class Codes: H01P 1/2039 Galvanic coupling between Input/Output
• CPC Class Codes: H01P 1/2056 Comb filters or interdigital filters with metallised resonator holes in a dielectric block
• CPC Class Codes: H01P 3/088 Stacked transmission lines
• CPC Class Codes: H01P 7/04 Coaxial resonators
• CPC Class Codes: H01P 7/082 Microstripline resonators H01P7/088 takes precedence
• CPC Class Codes: H01P 7/084 Triplate line resonators H01P7/088 takes precedence
• CPC Class Codes: H03B 5/1847 the active element in the amplifier being a semiconductor device
• CPC Class Codes: H05K 1/0237 High frequency adaptations H05K1/0216 takes precedence
• CPC Class Codes: H05K 3/4676 Single layer compositions

Abstract

The present invention relates to high frequency devices, such as a high frequency transmission line, a high frequency filter, and a resonator, and has an object to realize a reduction in size of the high frequency devices without decreasing Q thereof. In order to achieve this object, the high frequency device is structured such that an inner conductor (5) used in a resonator is sandwiched by high dielectric layers (2, 3) of a material with a high dielectric constant, both sides of the high dielectric layers are sandwiched by low dielectric layers (1, 4) of a material with a low dielectric constant, and both sides of the low dielectric layers are sandwiched by GND electrode (6, 7).

Claims

1. A high frequency device comprising:

a multi-layer substrate constructed by laminating a plurality of dielectric layers, each with different dielectric constants;

at least one inner conductor, acting as a signal transmission line for propagating a high frequency signal, provided inside said multi-layer substrate; and

outer conductors for providing a ground potential,

wherein top and bottom surfaces of said at least one inner conductor are sandwiched by first dielectric layers formed of a dielectric material with a first dielectric constant, top and bottom surfaces of said first dielectric layers are sandwiched by second dielectric layers formed of a dielectric material with a second dielectric constant which is lower than said first dielectric constant, and outer surfaces of said second dielectric layers are sandwiched by said outer conductors.

2. A high frequency filter comprising:

a laminated body constructed by laminating at least first, second, third and fourth dielectric layers;

first and second resonant conductors being formed at intervals of a predetermined distance between said second and third dielectric layers, said first and second resonant conductors being located inside said laminated body, said first and second resonant conductors acting as strip line resonators in signal transmission lines for propagating high frequency signals;

GND electrode patterns formed, at intervals of a predetermined distance, on lateral sides of said first and second resonant conductors; and

GND electrodes being formed on outer surfaces of said first and fourth dielectric layers,

wherein said second and third dielectric layers are made of a material with a first dielectric constant, and the first and fourth dielectric layers are made of a material with a second dielectric constant which is lower than said first dielectric constant of said second and third dielectric layers.

3. A high frequency filter comprising:

a laminated body constructed by laminating at least first, second, third, fourth, fifth, sixth, seventh and eighth dielectric layers;

a first GND electrode being formed on an outer surface of said first dielectric layer;

a first resonant conductor being formed between the second and third dielectric layers, said second and third dielectric layers being located below the first GND electrode;

first GND electrode patterns being formed at intervals of a predetermined distance on lateral sides of said first resonant conductor;

a second GND electrode being formed between the fourth and fifth dielectric layers, said fourth and fifth dielectric layers located below said third dielectric layer;

a second resonant conductor being formed between the sixth and seventh dielectric layers, said sixth and seventh dielectric layers formed below said fifth dielectric layer, said first and second resonant conductors acting as strip line resonators in signal transmission lines for propagating high frequency signals;

second GND electrode patterns being formed at intervals of a predetermined distance on lateral sides of said second resonant conductor; and

a third GND electrode being formed on an outer surface of said eighth dielectric layer, said eighth dielectric layer is formed below said seventh dielectric layer,

wherein the second, third, sixth and seventh dielectric layers, which are formed on top and bottom surfaces of the respective first and second resonant conductors, are made of a material with a first dielectric constant and the first, fourth, fifth and eighth dielectric layers are made of a material with second dielectric constant lower than said first dielectric constant.

4. A dielectric resonator comprising:

a laminated dielectric block constructed by laminating a plurality of second dielectric layers and a plurality of first dielectric layers;

at least one resonant conductor formed inside the dielectric block, said at least one resonant conductor acting as at least one strip line resonator in at least one signal transmission line for propagating at least one high frequency signal; and

a GND electrode being formed on an entire external circumferential surface of the dielectric block except for one side surface thereof,

wherein the plurality of first dielectric layers are formed on top and bottom surfaces of said at least one resonant conductor, and the plurality of second dielectric layers are formed on outer surfaces of said first dielectric layers, said first dielectric layers having first dielectric constants which are higher than second dielectric constants of the second dielectric layers.

5. A dielectric filter comprising:

a laminated body constructed by laminating a plurality of first dielectric layers and a plurality of second dielectric layers, said second dielectric layers having a second dielectric constant higher than a first dielectric constant of the first dielectric layers;

a plurality of resonant conductors acting as strip line resonators having different resonance frequencies, said resonant conductors formed inside the laminated body; and

a GND electrode provided on an entire external circumferential surface of the laminated body except for one side surface thereof,

wherein the plurality of second dielectric layers are formed on top and bottom surfaces of said plurality of resonant conductors, the plurality of first dielectric layers are formed on outer surfaces of the second dielectric layers.

6. A dielectric filter according to claim 5, wherein between lateral sides of said plurality of resonant conductors, first dielectric strips are formed, respectively, said first dielectric strips have a dielectric constant lower than said second dielectric constant of the second dielectric layers which are formed on top and bottom surfaces of the plurality of resonant conductors.

7. A dielectric filter according to claim 5, wherein a plurality of holes are formed in the second dielectric layers which are disposed on top and bottom surfaces of the resonant conductors, said holes are formed at positions corresponding to areas between the resonant conductors, and the holes are filled with a dielectric having a dielectric constant lower than said second dielectric constant of said second dielectric layers.

8. An oscillator module comprising:

a resonant conductor constructed of a strip line resonator acting as a signal transmission line for propagating a high frequency signal;

a plurality of first dielectric layers sandwiching top and bottom surfaces of the resonator conductor, said first dielectric layers having a first dielectric constant;

a plurality of second dielectric layers sandwiching outer surfaces of the first dielectric layers, said second dielectric layers having a second dielectric constant which is lower than said first dielectric constant; and

a plurality of GND patterns being formed between surfaces of the second dielectric layers except for a certain part,

wherein a first GND pattern of said plurality of GND patterns is located beneath the resonant conductor, and at least two other of said plurality of second dielectric layers are formed on an upper side of the resonant conductor and at a portion of said at least two other of said plurality of second dielectric layers having none of said GND patterns formed thereon.