Radio frequency microwave waveguide structure and method for fabrication thereof

#This invention relates to a radio frequency (RF) microwave waveguide structure and a fabricating method thereof, and in particular to an inaccessible RF microwave waveguide structure.

#Radio frequency (RF) microwave waveguide networks are attractive for numerous applications, where high radiation efficiency is required. The fabrication of the RF microwave waveguide networks is a multi-step process. When such networks include multi-component assemblies, separate fabrication of individual components is usually employed. These components can then be joined using one of numerous techniques, such as brazing, soldering or welding. In particular, dip brazing is considered as the most technically easy and relatively cheap method for fabricating RF microwave waveguide networks. This method employs a submerging of the components to be joined into a molten bath of salt or flux, followed by quenching them slowly in hot water to dissolve the salt or flux. Specifically, the fixtured assembly is preheated in an air furnace to insure uniform temperature of dissimilar masses in the assembly, and then immersed in a bath of molten salt that contains flux (also known as filler metal). The molten flux serves a multi-purpose role: providing heat transfer, supporting the assembly, and fluxing the joints through a capillary action. The immersion time required for dip brazing may vary, but usually it is less than two minutes. The assembly is then removed from the bath, cooled, and cleaned to be ready for further processing.

#FIG. 1 schematically illustrates an example of a typical RF microwave waveguide network 10 that can be fabricated by dip brazing. The RF microwave waveguide network 10 includes a complex array of waveguide components 11 coupled together at joint nodes 12 for effective transferring RF microwave signals. To absorb undesired RF microwave energy, ferrite termination parts, such as dummy loads 13, are used in the network 10.

#In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

#FIG. 1 is an example of a typical RF microwave waveguide network;

#FIG. 2 is a partial magnified view of the RF microwave waveguide network to shown in FIG. 1;

#The principles of the method according to the present invention may be better understood with reference to the drawings and the accompanying description, wherein like reference numerals have been used throughout to designate identical elements. It should be understood that these drawings, which are not necessarily to scale, are given for illustrative purposes only, and are not intended to limit the scope of the invention. Examples of constructions and fabrication processes are provided for selected elements. Those versed in the art should appreciate that many of the examples provided have suitable alternatives which may be utilized.

#Referring to FIG. 3, an exploded partial view of an inaccessible RF microwave waveguide structure 30 is illustrated, according to one embodiment of the present invention. The inaccessible RF microwave waveguide structure 30 comprises a RF microwave waveguide network 100 including an array of tortuous waveguide components 101, a high temperature stable dummy load 103, and a blocking assembly at least partially covering the network 100. In the present not limiting example, the blocking assembly is formed by a front cover 31 and a back block 32. The dummy load 103 is mounted on a surface of the wall of the waveguide components 101 at a required place in the vicinity of an aperture 102 arranged in the wall.

#According to this embodiment, the front cover 31 and the back block 32 are each formed by one or more units and are connected to a front side 33 and a back side 34 of the RF microwave waveguide network 100, respectively. Also, in the present example, the units of the front cover 31 and the back block 32 are plates designed for a planar array antenna, and may be made of aluminum.