Bandpass filter
First Claim
1. A bandpass filter comprising:
- a dielectric block of substantially rectangular prismatic shape having a top surface, a bottom surface, a first portion, a second portion and a third portion, the first portion lying between a first cross-section of the dielectric block and a second cross-section of the dielectric block substantially parallel to the first cross-section and the second and third portions divided by the first portion the first portion being positioned between the second and third portions;
a top metal plate formed on substantially the entire top surface of the dielectric block;
and bottom metal plate formed on substantially the entire bottom surface of the dielectric block;
a metal layer formed on a first and second surface of the dielectric block extending from the top surface to the bottom surface of the entire first portion to electrically couple the top and bottom metal plates to each other at the first portion thereby enabling the first portion of the dielectric block and the metal plates formed thereon to act as an evanescent waveguide;
an electrical isolation region positioned on the first and second surfaces of the dielectric block between the top metal plate and bottom metal plate at the entire second portion of the dielectric block such that the metal plates formed thereon to act as a first resonator, and an electrical isolation region positioned on the first and second surfaces of the dielectric block between the top metal plate and bottom metal plate at the entire third portion of the dielectric block such that the metal plates formed thereon to act as a second resonator and the top and bottom metal plates are electrically isolated from each other at the entire second and third portions.
1 Assignment
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Accused Products
Abstract
A highly compact bandpass filter that has excellent mechanical strength is disclosed. A bandpass filter according to the present invention employs a dielectric block of substantially rectangular prismatic shape constituted of a first portion lying between a first cross-section of the dielectric block and a second cross-section of the dielectric block substantially parallel to the first cross-section and second and third portions divided by the first portion and metal plates formed on surfaces of the dielectric block. The first portion of the dielectric block and the metal plates formed thereon are enabled to act as an evanescent waveguide. The second portion of the dielectric block and the metal plates formed thereon are enabled to act as a first resonator. The third portion of the dielectric block and the metal plates formed thereon are enabled to act as a second resonator. The metal plates include an inductive stub formed on the surface of the first portion of the dielectric block.
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Citations
24 Claims
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1. A bandpass filter comprising:
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a dielectric block of substantially rectangular prismatic shape having a top surface, a bottom surface, a first portion, a second portion and a third portion, the first portion lying between a first cross-section of the dielectric block and a second cross-section of the dielectric block substantially parallel to the first cross-section and the second and third portions divided by the first portion the first portion being positioned between the second and third portions;
a top metal plate formed on substantially the entire top surface of the dielectric block;
and bottom metal plate formed on substantially the entire bottom surface of the dielectric block;
a metal layer formed on a first and second surface of the dielectric block extending from the top surface to the bottom surface of the entire first portion to electrically couple the top and bottom metal plates to each other at the first portion thereby enabling the first portion of the dielectric block and the metal plates formed thereon to act as an evanescent waveguide;
an electrical isolation region positioned on the first and second surfaces of the dielectric block between the top metal plate and bottom metal plate at the entire second portion of the dielectric block such that the metal plates formed thereon to act as a first resonator, and an electrical isolation region positioned on the first and second surfaces of the dielectric block between the top metal plate and bottom metal plate at the entire third portion of the dielectric block such that the metal plates formed thereon to act as a second resonator and the top and bottom metal plates are electrically isolated from each other at the entire second and third portions. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A bandpass filter comprising:
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a dielectric block having a top surface, a bottom surface, first and second side surfaces opposite to each other and third and fourth side surfaces opposite to each other, the dielectric block being constituted of a first portion lying between a first cross-section of the dielectric block substantially parallel to the first side surface and a second cross-section of the dielectric block substantially parallel to the first cross-section, a second portion lying between the first side surface and the first cross-section, and a third portion lying between the second side surface and the second cross-section;
a first metal plate formed on the top surface of the dielectric block;
a second metal plate formed on the bottom surface of the dielectric block;
a first exciting electrode formed on at least one of the first side surface, the third side surface, the fourth side surface, and the bottom surface of the second portion of the dielectric block;
a second exciting electrode formed on at least one of the second side surface, the third side surface, the fourth side surface, and the bottom surface of the third portion of the dielectric block;
a first inductive stub formed on substantially all of the third side surface of the first portion of the dielectric block; and
a second inductive stub formed on substantially all of the fourth side surface of the first portion of the dielectric block; and
an electrical insulation region extending between the first and second metal plates for the entire region between the second and third portions. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A bandpass filter, comprising:
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a dielectric block having a top surface, a bottom surface, first and second side surfaces opposite to each other and third and fourth side surfaces opposite to each other, the dielectric block being constituted of a first portion lying between a first cross-section of the dielectric block substantially parallel to the first side surface and a second cross-section of the dielectric block substantially parallel to the first cross-section, a second portion lying between the first side surface and the first cross-section, and a third portion lying between the second side surface and the second cross-section; and
metal plates formed on the top and bottom surfaces of the dielectric block, and on the third and fourth side surfaces of the first portion to short circuit the metal plates on the top and bottom surfaces to each other; and
an electrical insulation region extending between the first and second metal plates for the entire region between the second and third portions;
whereby a first resonation circuit is established in which the first side surface acts as its open end and the first cross-section acts as its short end and a second resonation circuit is established in which the second side surface acts as its open end and the second cross-section acts as its short end, the bandpass filter further comprising means for providing a π
-type inductive circuit between the first resonation circuit and the second resonation circuit. - View Dependent Claims (19, 20)
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- 21. A bandpass filter comprising first and second quarter-wave dielectric resonators each having an open end and a short end opposite to the open end and having metal plates provided on top and bottom surfaces and a first evanescent waveguide provided between the short end of the first quarter-wave dielectric resonator and the short end of the second quarter-wave dielectric resonator, the bandpass filter being substantially a rectangular prism in overall shape.
Specification