KR0131539B1 - Dielectric resonator filters with i/o ports - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency dielectric filter based on a dielectric coaxial resonator, and more particularly to a dielectric filter having input and output terminals for surface mounting (SMD).

The present invention provides a dielectric filter in which a hole for an inner conductor does not penetrate to an open surface of a dielectric resonator, and forms an electrode on the open surface, thereby implementing a capacitor. It is characterized in that the single electrode to perform the role of the capacitor and the input and output terminals at the same time

Description

Dielectric filter with electrodes for input and output terminals

1 illustrates a conventional dielectric structure.

2 is a cross-sectional view taken along the line AA ′ of the dielectric filter of FIG.

3 is an equivalent circuit diagram of the dielectric filter of FIG.

4 is a diagram showing the structure of a dielectric filter having an electrode for input and output terminals of the present invention.

5 is a view showing a state in which the dielectric filter of FIG. 4 is mounted on a substrate.

* Explanation of symbols for main parts of the drawings

1: dielectric block 2: open face of dielectric coaxial resonator

3: capacitor electrode 4: coupling adjustment groove

5: Conductor wire for I / O terminal 6: Outer conductor of coaxial line

7 Coaxial line inner conductor 8 Filter I / O capacitor

9: Electrode for capacitor and input / output terminal 10: Electrode removal part

11 substrate 12 printed circuit electrode

13: soldering

FIELD OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency dielectric filter based on a dielectric ipsilateral resonator, and more particularly to a dielectric filter having input and output terminals for a surface mount (SMD).

[Prior art]

UHF band dielectric filter is generally used in RF transmitter and receiver of mobile phone, and due to the advantage of miniaturization, TEM mode 1/4 wavelength coaxial line using high dielectric constant microwave dielectric is used.

FIG. 1 is a diagram showing the structure of a conventional dielectric filter having input and output terminals, and FIG. 2 is a cross-sectional view taken along the line AA 'of FIG.

As shown in Figs. 1 and 2, by forming a hole for the coaxial resonator in one dielectric block 1, by leaving a dielectric having a constant thickness on the open face 2 side of the coaxial resonator, A filter is implemented by forming a capacitor between the electrode 3 on the open surface 2 and the inner conductor 7 of the coaxial line.

However, in the conventional electrode structure, since a predetermined size electrode is formed only at the upper end of the inner conductor 7 like the electrode for capacitor 3 of FIG. 1, a separate conductive wire is used for electrical contact between the electrode and the substrate when the filter is mounted. (5) has to be used, and mounting on a substrate has a complicated problem.

[Problem to solve in the present invention]

Recently, due to the miniaturization and high functionality of the mobile communication terminal, miniaturization of components and high density of mounting are required.

However, in the conventional dielectric filter, when the filter is implemented by combining the dielectric coaxial resonator, the electrode for the input / output capacitor is formed and the input / output terminal for the connection with the external circuit must be attached to the electrode, resulting in a large volume and unsuitable for surface mounting. have.

[Purpose of invention]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a dielectric filter suitable for surface mount (SMD) requiring miniaturization and high density of components by implementing the input / output capacitor and the input / output terminal as a single electrode formed in the dielectric resonator itself. There is a purpose.

[Summary of invention]

In order to achieve the above object, the present invention provides a dielectric filter in which a hole for an inner conductor does not penetrate to an open surface of a dielectric known device and forms an electrode on the open surface, thereby extending the electrode on the open surface to one end of the open surface. It is characterized in that the role of the input and output terminals by forming a single electrode to perform the role of the capacitor and the input and output terminals at the same time.

EXAMPLE

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a structure of a dielectric filter having a capacitor and an electrode for input / output terminals as an embodiment of the present invention.

In the equivalent circuit of FIG. 3, an electrode 9 is formed on an open surface for implementing two capacitors 8 on both sides thereof, and the inner electrode 7 acts as a capacitor through a dielectric therebetween.

At this time, when the capacitor electrode 9 is formed to extend to one end of the open surface as shown in FIG. 4 to form an input / output terminal, the surface-mount type which does not need to separately use the input / output terminal lead 5 as shown in FIG. Input and output terminals can be implemented.

At this time, the surface perpendicular to the opening surface 2 in the extending direction of the electrode 9 on the open surface 2 is partially removed as shown by reference numeral 10 in FIG. 4 so that the electrode 9 and the external electrode 6 are not short-circuited. Or selective plating so that the part is excluded during the plating process.

FIG. 5 is a diagram illustrating a structure in which a dielectric filter having a capacitor and an electrode for input / output terminals 9 implemented as shown in FIG. 4 is mounted on a printed circuit electrode 12 on the substrate 11 by soldering 13.

[Effects of the Invention]

As described above, when the input and output terminals of the dielectric filter are formed according to the present invention, the capacitor and the input and output terminals of the filter circuit can be solved with one electrode, so that the filter can be manufactured without attaching a separate terminal or capacitor to the outside. It has the effect of miniaturization, simplification of manufacturing process, ease of mounting, and increase of packing density.

Claims (2)

A dielectric filter using a dielectric coaxial resonator in which a hole is formed through the inner conductor so that the inner conductor hole is not penetrated, and a capacitor is formed between the inner conductor and the electrode on the open surface. A dielectric filter having an input / output terminal electrode, wherein the electrode extends to one end of the open surface and is used as an input / output terminal for connection with a surface mount substrate. The method of claim 1, wherein a part of the electrode on the surface perpendicular to the opening surface in the direction in which the electrode on the opening surface extends to the end is removed to prevent a short circuit between the electrode on the opening surface and the outer conductor. A dielectric filter having an electrode for input / output terminals, which is selectively plated.