Filter unit

A filter unit comprises a cover and a base. The cover includes a number of first grooves, and the base includes a number of second grooves aligned with the first grooves. At least one of the cover or the base includes an alloy of zinc and aluminum, wherein the weight percentage of zinc is greater than that of aluminum.

BACKGROUND OF THE INVENTION

The present invention relates generally to satellite communications and, more particularly, to a filter unit for satellite communications.

In satellite communications, signal quality may be susceptible to communication environments such as terrestrial topology and weather conditions. A filter may usually be used to suppress interference or noise in received signals.

FIG. 1Ais a schematic cross-sectional view of a conventional filter unit1. Referring toFIG. 1A, the filter unit1may include a base11and a number of tuning pins12each corresponding to one of a number of grooves112of the base11. The depth of each groove112may be adjusted by a corresponding one of the tuning pins12so as to filter signals at frequencies of interest. However, the conventional filter unit1may generally include an alloy of aluminum and zinc, in which the weight percentage of aluminum is greater than that of zinc. Such weight percentage may result in undesirable surface roughness of the grooves112, which may adversely affect the function of a filtering space111defined by the grooves112and in turn the performance of the filter unit1.

BRIEF SUMMARY OF THE INVENTION

Examples of the present invention may provide a filter unit that comprises a cover including a number of first grooves, and a base including a number of second grooves aligned with the first grooves.

Some examples of the present invention may also provide a filter unit that comprises a cover including a number of first grooves, and a base including a number of second grooves aligned with the first grooves, wherein the cover includes an alloy of zinc and aluminum, and the weight percentage of zinc is greater than that of aluminum.

Examples of the present invention may further provide a filter unit that comprises a cover including a number of first grooves, and a base including a number of second grooves aligned with the first grooves, wherein the base includes an alloy of zinc and aluminum, and the weight percentage of zinc is greater than that of aluminum.

Other objects, advantages and novel features of the present invention will be drawn from the following detailed embodiments of the present invention with attached drawings, in which:

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the present examples of the invention illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like portions.

FIG. 2Ais an unfolded, perspective view of a filter unit2in accordance with an example of the present invention. Referring toFIG. 2A, a filter unit2may include a base21and a cover22. At least one of the base21or the cover22may include an alloy of aluminum (Al) and zinc (Zn), wherein the weight percentage of zinc may be greater than that of aluminum. Experiments reveal that surface roughness or surface texture of a filter unit comprising an Al—Zn alloy may be improved when zinc is greater than aluminum in weight percentage. The surface roughness or surface texture may be measured by several methods such as roughness average (Ra), root-mean-square (rms) and maximum height of profile (Rmax).

In one example, the weight percentage of zinc is equal to or greater than approximately 90%. In another example, the weight percentage of zinc is equal to or smaller than approximately 99%. In still another example, the weight percentage of aluminum is equal to or greater than approximately 1%. In yet another example, the weight percentage of aluminum is equal to or smaller than approximately 10%. In yet still another example, the alloy may include approximately 90% to 99% of zinc and approximately 1% to 10% of aluminum by weight.

Furthermore, in one example, the weight percentage of zinc is equal to or greater than approximately 95%. In another example, the weight percentage of zinc is equal to or smaller than approximately 96%. In still another example, the weight percentage of aluminum is equal to or greater than approximately 3.9%. In yet another example, the weight percentage of aluminum is equal to smaller than approximately 4.3%. In yet still another example, the alloy may include approximately 95% to 96% of zinc and approximately 3.9% to 4.3% of aluminum by weight.

The base21may include a first support212, a second support213, and a body211between the first and second supports212and213. The body211may include a recessed portion “R” with a bottom surface (not numbered). A number of protrusions2111may protrude from the bottom surface and may be separated from one another by a groove “G1”. The first support212may include a first opening212A for signal input and the second support213may include a second opening213A for signal output.

The cover22may include a raised portion220with a number of grooves “G2”. In the present example, each of the raised portion220and the recessed portion R may have a rectangular shape. When the recessed portion R and the raised portion220engage with one another, the grooves G1and G2may be aligned with one another. Each of the grooves G1and G2may extend in a first direction, which may be orthogonal to a second direction in which a signal to be filtered transmits from the first opening212A to the second opening213A.

FIG. 2Bis a folded, perspective view of the filter unit2illustrated inFIG. 2A. Referring toFIG. 2B, a number of fastening means23such as screws, bolts and rivets may be used to engage the cover22with the base21.

FIG. 2Cis a cross-sectional view of the filter unit2illustrated inFIG. 2Btaken along a line AA′. Referring toFIG. 2C, the grooves G1and G2and a space “S” defined by the engaged base21and the cover22may function as a filter that allows a signal at a frequency within a predetermined range to pass the outlet213A.

FIG. 3is a perspective view of a communication device3in accordance with an example of the present invention. Referring toFIG. 3, the communication device3may include a transceiver module31, a feeding module32coupled to the transceiver module31and a reflection module33. The transceiver module31may include a transducer311, a filter unit322which may be similar to the filter unit2described and illustrated with reference toFIGS. 2A to 2C, and a waveguide323. The transducer311may include an orthogonal mode transducer (OMT) coupled between the filter unit322and the waveguide323.