Patent Application
20150207194
Existing wireless base stations utilize deep drawn resonators (DDR) as a part of an amplification system. In general, there are two types of DDRs; integral and non-integral. In an integral, DDR a resonator and a filter body are formed as one component that makes up a cavity filter. Conversely, in a non-integral DDR the resonator and filter body are separate components making up a cavity filter.
Referring now to
Yet further, the bottom portion 1b of the DDR 1 may deflect (e.g., bend) due to the force applied to the bottom portion 1b of the DDR 1 by a locked washer 3a as the washer 3a is forced against the bottom portion 1b by the screw 3b. The resulting force on the bottom portion lb causes over compression of a portion of the bottom portion 1b of the DDR 1 around area 2b which, in turn, may cause the DDR 1 lose contact with the body 2 across, or at, contact point 2a.
In either case, once the DDR 1 is no longer in contact with the body 2 across, or at, area 2a DDR 1 may become “ungrounded” which in turn may cause the frequency transmitted by the cavity filter to “drift” or vary which has adverse effects on the expected operation and performance of the amplification system. It is therefore desirable to provide methods and devices for grounding DDRs that minimizes or substantially eliminates a non-integral DDR from losing contact across, or at, a grounding contact area, which in turn minimizes or substantially eliminates frequency drift.
Exemplary embodiments of methods and devices for grounding DDRs are provided.
According to an embodiment, a cavity filter may comprise a filter body, a resonator connected to the filter body to ground the resonator, and a compression plate and stop limiter positioned to substantially eliminate movement of the resonator away from a contact area of the filter body. By reducing or eliminating movement of the resonator away from the contact area the resonator remains grounded to the filter body which, in turn, substantially eliminates frequency drift. The resonator may be a DDR in one embodiment of the invention.
The cavity filter may be part of a tower mounted amplifier or antenna.
In embodiments of the invention, the compression plate may comprises a metallic material, such as a non-ferrous, metallic material for example while the stop limiter may be configured as a stepped stopped limiter, or, alternatively, as an embossed concentric ring, stop limiter to name just two examples.
The resonator may operate over a range of frequencies selected from at least 698 MHz to 960 MHz and 1700 MHz to 2700 MHz, for example.
In addition to the inventive cavity filters and other devices, the present invention also provides for related methods. For example, in one embodiment a method may comprise grounding a resonator to a filter body by connecting a filter body and resonator to ground the resonator, and positioning a compression plate and stop limiter to substantially eliminate movement of the resonator away from a contact area of the filter body.
As described above, the cavity filter may be a part of a tower mounted amplifier or antenna, and the so-grounded resonator may comprise a deep drawn resonator that may operate over a range of frequencies selected from at least 698 MHz to 960 MHz and 1700 MHz to 2700 MHz, for example.
Similarly, the compression plate may comprise a metallic material, such as a non-ferrous metallic material. The method may further comprise configuring the stop limiter as a stepped stopped limiter, or, alternatively, as an embossed concentric ring, stop limiter.
Additional features of the inventions will be apparent from the following detailed description and appended drawings.
Exemplary embodiments for grounding DDRs are described herein and are shown by way of example in the drawings. Throughout the following description and drawings, like reference numbers/characters refer to like elements.
It should be understood that, although specific exemplary embodiments are discussed herein there is no intent to limit the scope of present invention to such embodiments. To the contrary, it should be understood that the exemplary embodiments discussed herein are for illustrative purposes, and that modified and alternative embodiments may be implemented without departing from the scope of the present invention. Further, though specific structural and functional details may be disclosed herein, these are merely representative for purposes of describing the exemplary embodiments.
It should be noted that one or more exemplary embodiments may be described as a process or method. Although a process/method may be described as sequential, it should be understood that such a process/method may be performed in parallel, concurrently or simultaneously. In addition, the order of each step within a process/method may be re-arranged. A process/method may be terminated when completed, and may also include additional steps not included in a description of the process/method.
As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As used herein, the singular forms “a,” “an” and “the” are not intended to include the plural form, unless the context indicates otherwise.
As used herein, the term “embodiment” refers to an embodiment of the present invention.
In the embodiment shown in
The compression plate may be made of a metallic material, such as a non-ferrous metallic material. Alternatively, the plate may be made from another suitable material. The plate may have a thickness that varies depending on the specific requirements of a particular cavity filter. In one embodiment the thickness may be 1 millimeter.
It should be understood that though component 50a is described as a compression “plate” that other equivalent structure(s) may be substituted, provided, such structure functions to distribute some of force being supplied by a screw and washer, such as screw 30b and washer 30a, over the surface of a bottom portion of a DDR, such as DDR 10. In addition the plate may be substantially flat or may be conical in shape, for example.
Further, though described as a stop limiter 50b, other equivalent structure(s) may be substituted, provided, such a structure functions to eliminate or substantially minimize over compression of the bottom portion of a DDR, such as DDR 10, which, in turn, eliminates or substantially minimizes the movement (e.g., deflection) of a DDR away from a grounding contact area. Still further, the “stepped” form of the limiter 50b depicted in
While exemplary embodiments have been shown and described herein, it should be understood that variations of the disclosed embodiments may be made without departing from the spirit and scope of the claims that follow.
