The subject matter herein generally relates to the field of filters, and more particularly to a cavity filter.
The conventional cavity filter is provided with a coupling adjustment structure for adjusting the coupling frequency between the filter and the cavity, such as a resonant adjustment screw and a coupling adjustment screw. The resonant adjustment screw and the coupling adjustment screw are mostly mounted on the cover plate. In order to install the resonant adjustment screw and the coupling adjustment screw, the cover plate needs to have a certain thickness, which increases the overall size of the cavity filter. The installation of the resonant adjustment screw and the coupling adjustment screw cause the upper surface of the cover plate to be uneven, and the space of the cover plate is occupied. It is not convenient to use, and affects the appearance of the cavity filter.
Many aspects of the present disclosure are better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements.
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments described herein. However, it will be understood by those of ordinary skill in the art that the exemplary embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the exemplary embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the present disclosure.
Several definitions that apply throughout this disclosure will now be presented.
The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “inside” indicates that at least a portion of a region is partially contained within a boundary formed by the object. The term “substantially” is defined to be essentially conforming to the particular dimension, shape, or other feature that the term modifies, such that the component need not be exact. For example, “substantially cylindrical” means that the object resembles a cylinder, but can have one or more deviations from a true cylinder.
The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like.
Referring to
The partition wall 143 has a lower portion resisted to the adjustment passage 153, two sides resisted to the partitioning portion 152 and a upper portion resisted to the inner side of the cover plate 110. In this exemplary embodiment, the resonant tube 133 is integrally formed with the bottom wall 154 of the housing 150. In other embodiments, the partition wall 143 can be welded to the bottom of the adjustment passage 153, the bottom of the resonant tube 133 can be welded to the bottom wall 154 of the housing 150.
The cover plate 110 and the housing 150 are connected by a screw (not shown).
For example, in one embodiment, a fixing ear (not shown) can be drawn out from the housing 150, a threaded hole (not shown) and a positioning post (not shown) may be provided on the fixing ear. Correspondingly, a threaded hole (not shown) and a positioning hole (not shown) are provided at the corresponding positions of the cover plate 110. The cover plate 110 and the housing 150 are accurately aligned by the engagement of the positioning post with the positioning hole, and finally the screw is attached to the threaded holes of the fixing ear and the cover plate 110, thus the cover plate 110 is fixed to the housing 150.
In order to facilitate the installation and adjustment of the resonant adjustment screw 131 and the coupling adjustment screw 142, the resonant tube 133 and the partition wall 143 are provided with threaded holes (not shown). After the resonant tube 133 and the partition wall 143 are mounted on the housing 150, the threaded holes of the resonant tube 133 and the partition wall 143 are exposed to the bottom of the housing 150. The resonant adjustment screw 131 and the coupling adjustment screw 142 are screwed into the resonant tube 133 and the partition wall 143 from the bottom of the housing 150, respectively. In another exemplary embodiment, the position of the resonant tube 133 and the partition wall 143 provided at the bottom of the housing 150 have a recessed structure, and the threaded holes of the resonant tube 133 and the partition wall 143 are exposed in the recessed structure. As such, it is easy to install the resonant adjustment screw 131 and the coupling adjustment screw 142 on the resonant tube 133 and the partition wall 143.
When the coupling adjustment assembly 140 is assembled, the gasket 145 is placed on the first fixing base 1432. The third opening 1415 of the electrical coupling sheet 141 is buckled into the positioning post 1435 and the bottom plate 1410 is placed on the gasket 145. The fastener 144 is successively passed through the fourth opening 1416 and the gasket through hole 1451 and engaged with the threaded hole 1436 to secure the electrical coupling sheet 141 and the partition wall 143 together. After assembly is completed, the coupling adjustment screw 142 is located between the two flakes 1412 and is located below the first opening 1413. In the embodiment, the fastener 144 is a screw. The fastener 144 and the gasket 145 include insulating materials such as plastic, rubber, ceramic, etc.
When the resonant assembly 130 is assembled, the resonant tube 133 is passed through the through hole 1323 and engaged with the step 1324. The resonant tube 133 and the through hole 1323 are in an interference fit to secure the resonant tube 133 to the resonant cap 132. The resonant adjustment screw 131 is passed through the through hole 1323 and is freely to stretched from the through hole 1323. In other embodiments, the resonant cap 132 is welded with the resonant tube 133.
Referring to
Referring to
The notches 1624 of the two resonance caps 162 are arranged symmetrically about the coupling adjustment screw 172. The notch 1624 is arc-shaped. The arc center of the notch 1624 is in the axial direction of the coupling adjustment screw 172. In the embodiment, the resonance frequency of the single resonant cavity 151 is changed by only one percent by setting the cap body 1621 of the resonant cap 162 into a circular shape and providing a notch 1624 on edge of the resonant cap 162, while the coupling band width is almost doubled to facilitate the production of the cavity filter 100. Thus it is convenient to adjust the return loss and the bandwidth of the cavity filter 100 to the specified range. For a filter using a circular resonant cap 162, the coupling adjustment screw 161 can only mobilize 5.5 MHz in a stroke range of 6 mm, but the coupling bandwidth can be increased to 10 MHz, while the resonant frequency of the single resonant cavity 151 rises from 2170 MHz To 2190 MHz, an increase only about 1% (20 MHz). Such variables can be adjusted by adjusting the adjustment screw 161 or modify the size of resonant cavity or other components to overcome the increase of the resonant frequency.
In summary, in the cavity filter 100 of the present application, the resonating assembly 130 and 160, and the coupling adjustment components 140 and 170 are embedded into the bottom of the housing 150, such that the outer surface of the housing 150 has no exposed adjustment structure. The bottom of the housing 150 is kept flat so as to reduce the size of the cavity filter 100 and easy to adjust. The cover plate 110 provides without any adjustment structure to reduce the thickness of the cover plate, with small size, less material and low cost. The frequency debugging range of the coupling adjustment screws 142 and 172 can be increased by changing the shape of the resonance cap 162 and the provision of the electrical coupling sheet 141 to improve the performance of the cavity filter 100.
The exemplary embodiments shown and described above are only examples.
Many details are often found in the art such as the features of cavity filter and cover mechanism thereof. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the exemplary embodiments described above may be modified within the scope of the claims.
Number | Date | Country | Kind |
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106109773 | Mar 2017 | TW | national |