WO2007013723A1

WO2007013723A1 - Inductive waveguide iris for adaptable tuning

Info

Publication number: WO2007013723A1
Application number: PCT/KR2006/000781
Authority: WO
Inventors: So-Hyeun Yun; Man-Seok Uhm; In-Bok Yom
Original assignee: Electronics And Telecommunications Research Institute
Priority date: 2005-07-26
Filing date: 2006-03-07
Publication date: 2007-02-01
Also published as: WO2007013723A8; GB2442900A; GB0801490D0; GB2442900B

Abstract

An inductive waveguide iris for adaptable tuning is disclosed. The inductive waveguide iris has a predetermined shaped cross-section to insert a tuning screw inside thereof. Also, the inductive waveguide iris has an asymmetric structure, or has an embossed portion or an intaglio portion while having variable electric characteristics according to a height and a width of the iris, a distance from a waveguide wall, a height and a width of the embossed portion or a height and a width of the intaglio portion. The disclosed waveguide iris provides similar electric characteristics compared to a symmetric iris and sufficient space for a tuning screw.

Description

INDUCTIVE WAVEGUIDE IRIS FOR ADAPTABLE TUNING

Technical Field

[1] The present invention relates to an inductive waveguide iris; and, more particularly, to an inductive waveguide iris structurally designed for adaptable tuning. Background Art

[2] A waveguide filter is a filter performing a multistage filtering by controlling an iris between resonators formed inside a waveguide. An inductive iris of the waveguide filter is generally formed by an obstacle having a constant thickness and a corner parallel to electric field, such as TE mode of a rectangular waveguide. Such a wave guide is manufactured by a milling machine.

[3] Fig. 1 is a perspective view of a rectangular waveguide filter using an inductive symmetric iris.

[4] As shown in Fig. 1, the waveguide filter 100 includes a resonator 110 and an iris

120. An input port and an output port are connected to other devices using a waveguide flange 130. As shown in Fig. 2, the iris of the waveguide filter is generally designed to have a symmetric structure. A length 210 and a width 220 of the iris 120 are controlled to obtain target electric characteristics.

[5] A waveguide filter is mainly used in microwave bands. Generally, the higher, a frequency of electric wave becomes, the shorter, a wavelength is obtained. Also, a manufacturing error becomes greater relative to the wavelength. Therefore, the manufacturing error significantly influences electric performance of the waveguide filter.

[6] In case of manufacturing a waveguide filter operated in high frequency, for example, higher than 30GHz, it is hard to produce a waveguide filter having electric performance identical to that estimated in a design. In order to obtain similar electric performance planed at the design, a tuning screw is required to finely compensate the performance degradation caused by the manufacturing error.

[7] Since a waveguide filter operated in high frequency such as 30GHz is generally extremely small, it is too difficult to provide a space for the tuning screw. Furthermore, it becomes more complicated to provide the space for the tuning screw if a waveguide filter includes a heat panel in order to use the waveguide filter for high output power.

Disclosure of Invention Technical Problem

[8] It is, therefore, an object of the present invention to provide an inductive waveguide iris structurally designed to provide a space for a tuning screw that reduces performance variation caused by a manufacturing error. Technical Solution

[9] In accordance with an aspect of the present invention, there is provided a plurality of resonators internally formed to have a rectangular shape and an iris formed between adjacent resonators and having a characteristic definition portion to meet target electric characteristics of the waveguide filter.

[10] The waveguide iris may be an asymmetric iris having variable characteristics according to a distance from a waveguide wall and according to a length and a width of the iris.

[11] The waveguide iris may include an embossed portion and have variable electric characteristics according to a height and a width of the iris, and according to a height and a width of the embossed portion.

[12] The waveguide iris may include an intaglio portion and have variable electric characteristics according to a height and a width of the iris, and according to a height and a width of the intaglio portion.

Advantageous Effects

[13] The present invention provides an inductive waveguide iris structurally designed to provide a space for a tuning screw that reduces performance variation caused by a manufacturing error. Brief Description of the Drawings

[14] The above and other objects and features of the present invention will become better understood with regard to the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:

[15] Fig. 1 is a perspective view of a rectangular waveguide filter using an inductive symmetric iris;

[16] Fig. 2 is a cross-sectional view of the rectangular waveguide filter shown in Fig. 1;

[17] FIG. 3 is a cross-sectional view of a waveguide iris in accordance with a first embodiment of the present invention;

[18] FIG. 4 is a cross-sectional view of a waveguide iris in accordance with a second embodiment of the present invention;

[19] FIG. 5 is a cross-sectional view of a waveguide iris in accordance with a third embodiment of the present invention;

[20] FIG. 6 is a cross-sectional view of a waveguide iris in accordance with a fourth embodiment of the present invention;

[21] FIG. 7 is a cross-sectional view of a waveguide iris in accordance with a fifth embodiment of the present invention;

[22] FIG. 8 is a graph showing reflection coefficient characteristics of the waveguide iris shown in Figs. 3 to 7 and that for an inductive symmetric iris; [23] FIG. 9 is a graph showing transmission coefficient characteristics of the waveguide iris shown in Figs. 3 to 7 and that of an inductive symmetric iris; and

[24] FIG. 10 is a graph showing the phases of reflection S and transmission S with respect to the waveguide irises shown in Figs. 3 to 7 and in the inductive symmetric iris. Best Mode for Carrying Out the Invention

[25] Hereinafter, an inductive waveguide iris for adaptable tuning in accordance with a preferred embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

[26] FIG. 3 is a cross-sectional view of a waveguide iris in accordance with a first embodiment of the present invention.

[27] As shown in FIG. 3, the waveguide iris according to the first embodiment has an asymmetrical structure, and the electric characteristics thereof are controlled by controlling a length of the iris 310a and a width of the iris 320a. In this configuration, the waveguide iris according to the first embodiment may have electric performance identical to a symmetric iris according to a distance 330a or 340a from a waveguide wall.

[28] FIG. 4 is a cross-sectional view of a waveguide iris in accordance with a second embodiment of the present invention.

[29] Referring to FIG. 4, embossments are formed at the waveguide iris according to the second embodiment. Herein, target electric performance can be obtained by controlling a height 310b of the iris, heights 320b and 330b of embossments and widths 340b and 350b of the iris. It is preferable to form the embossment to have a wider width 350b than a tuning screw for obtaining better electric characteristics.

[30] FIG. 5 is a cross-sectional view of a waveguide iris in accordance with a third embodiment of the present invention.

[31] As shown in FIG. 5, intaglios are formed at the waveguide iris according to the third embodiment of the present invention. In this configuration, target electric performance can be obtained by controlling a height 310c of the iris, heights 320c and 330c of the intaglios and widths 340c and 350c of the iris.

[32] FIG. 6 is a cross-sectional view of a waveguide iris in accordance with a fourth embodiment of the present invention.

[33] Referring to FIG. 6, one embodiment is formed at one side of the waveguide iris according to the fourth embodiment. The waveguide iris according to the fourth embodiment can have similar electric characteristics to a symmetric iris by controlling the height 310d and the width 32Od of the iris as well as the height 330d and the width [34] FIG. 7 is a cross-sectional view of a waveguide iris in accordance with a fifth embodiment of the present invention. [35] As shown in FIG. 7, an intaglio is formed at one side of the waveguide iris according to the fifth embodiment. The waveguide iris according to the fifth embodiment can have similar electric characteristics to a symmetric iris by controlling the height 310e and the width 32Oe of the iris as well as the height 330e and the width

34Oe of the intaglio while providing a sufficient space for the tuning screw. [36] FIG. 8 is a graph showing reflection coefficient characteristics of the waveguide iris shown in Figs. 3 to 7 and that for an inductive symmetric iris. [37] Referring to FIG. 8, a characteristic curve 410 denotes the reflection coefficient characteristics of the inductive symmetric iris and characteristic curves 420 to 460 denote the reflection coefficient characteristics of the waveguide irises shown in Figs.

3 to 7, respectively. [38] As shown in graph of FIG. 8, the waveguide irises according to the present invention have similar reflection coefficient characteristics to that of the inductive symmetric iris. [39] FIG. 9 is a graph showing transmission coefficient characteristics of the waveguide iris shown in Figs. 3 to 7 and that of an inductive symmetric iris. [40] Referring to FIG. 9, a characteristic curve 510 denotes the transmission coefficient characteristics of the inductive symmetric iris, and the characteristic curves 520 to 560 denote the transmission coefficient characteristics of the waveguide irises shown in

Figs. 3 to 7. [41] As shown in FIG. 9, the waveguide irises according to the present invention have similar transmission coefficient characteristics compared to the inductive symmetric iris. [42] FIG. 10 is a graph showing the phase of reflection S and transmission S with respect to the waveguide irises shown in Figs. 3 to 7 and in the inductive symmetric iris. [43] Referring to FIG. 10, a characteristic curve 610 denotes the phase of reflection S and transmission S with respect to the inductive symmetric iris, and characteristics curves 620 to 660 denote the phase of reflection S and transmission S with respect ^r 11 21 ^r to the waveguide irises shown in Figs. 3 to 7.

[44] As shown in FIG. 10, the waveguide irises according to the present invention have similar the phase of reflection S and transmission S compared to the inductive

11 21 symmetric iris. [45] As described above, the irises according to the present invention have various shapes to provide similar electric characteristics compared to the inductive symmetric iris and provide a space for the tuning screw. Therefore, electric characteristics variation caused by the manufacturing error can be corrected without re-manufacturing the microwave iris.

[46] The present application contains subject matter related to Korean patent application

No. KR 2005-0067836, filed in the Korean patent office on July 26, 2005, and Korean patent application NO. KR 2005-0096403, filed in the Korean patent office on October 13, 2005, the entire contents of which being incorporated herein by reference.

[47] While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirits and scope of the invention as defined in the following claims.

Claims

[1] A waveguide filter comprising:

A plurality of resonators internally formed to have a rectangular shape; and an iris formed between adjacent resonators and having a characteristic definition portion to meet target electric characteristics of the waveguide filter.

[2] The waveguide filter as recited in claim 1, wherein the iris is an asymmetric iris having variable characteristics according to a distance from a waveguide wall and according to a length and a width of the iris.

[3] The waveguide filter as recited in claim 1, wherein the iris includes an embossed portion and has variable electric characteristics according to a height and a width of the iris, and according to a height and a width of the embossed portion.

[4] The waveguide filter as recited in claim 1, wherein the iris includes an intaglio portion and has variable electric characteristics according to a height and a width of the iris, and according to a height and a width of the intaglio portion.