Patent Publication Number: US-2022216580-A1

Title: Waveguide junction for splitting and/or combining radio frequency energy and method for manufacture

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to waveguides of radio frequency (RF) energy. More specifically, the present invention relates to waveguide junctions for splitting and/or combining RF energy. 
     BACKGROUND OF THE INVENTION 
     Waveguides are routinely used to convey radio-frequency (RF) energy through a predefined path and may be used with RF applications including for example telecommunications, radar and the like. 
     As known in the art, waveguides are commonly structured as hollow pipes having a polygonal (e.g., rectangular) cross section, where at least one dimension (e.g., a width of the pipe) is set according to the working RF wavelength. 
     In some commercially available implementations, a ridge may be placed along a side of the rectangular pipe, thus accommodating an internal pathway for the conveyed RF energy around the circumference of the ridge. As known in the art, a ridged waveguide implementation that is utilized to convey RF energy of a specific wavelength may have a reduced dimensionality (e.g., a shorter width) in relation to an equivalent, ridge-less waveguide, conveying RF energy of the same wavelength. 
     As known in the art, waveguide junctions may be used to propagate RF energy through a first waveguide that may be referred herein as a ‘base’ waveguide and spilt the RF energy to two or more branching waveguides that may be referred herein as ‘arm’ waveguides. Similarly, waveguide junctions may be used to combine RF energy from the two or more arm waveguides into the base waveguide. 
     As known in the art, gapped or slotted waveguides may include a set of gaps, slots, holes or apertures, placed at a predefined location and/or spatial frequency, to allow emittance of RF energy from the waveguide in a direction that is substantially perpendicular to the direction of RF energy propagation within the waveguide. Such gapped waveguides may be employed, for example, in an RF antenna, and may be configured to emit RF energy through the set of apertures. 
     The location and/or spatial frequency of the apertures may be set according to the wavelength of the working RF energy. For example, as the RF frequency is increased, so would the spatial frequency of the apertures, to match the decreased RF wavelength. 
     As known in the art, integrity of a signal that is emitted through a gapped waveguide may be dependent upon the number of apertures in the waveguide and upon the distances between the RF feeding point and the respective emittance apertures. For example, the signal&#39;s integrity may be reduced as the number of apertures is increased and/or as the distance between the RF feeding point and each respective aperture is increased. 
     SUMMARY OF THE INVENTION 
     A waveguide junction that may exploit structural benefits of ridged waveguides (e.g., having a reduced dimensionality), and evenly split and/or combine the propagation of conveyed RF energy between a central feeding point and a pair of arm waveguides (e.g., to produce an emitted signal of improved integrity) is therefore desired. 
     Embodiments of the present invention may include a waveguide junction that may include: a dual-ridged base waveguide; a single-ridged first arm waveguide, connected to the base waveguide; and a single-ridged, second arm waveguide, connected to the base waveguide and to the first arm waveguide. 
     According to some embodiments, the base waveguide, the first arm waveguide and the second arm waveguide may be aligned in a perpendicular T-shaped junction. Alternately, or additionally the base waveguide may be connected to at least one of the first arm waveguide and second arm waveguide so as to form a Y-shaped junction. 
     According to some embodiments, at least one of the base waveguide, the first arm waveguide and the second arm waveguide may be characterized by one of a polygonal (e.g., rectangular) cross section and a circular cross section. 
     According to some embodiments, a ridge of the first arm waveguide may meet a first ridge of the base waveguide in a first position, such that a cross-section of the waveguide junction at the first position may include a first profile. Additionally, or alternately, a ridge of the second arm waveguide may meet a second ridge of the base waveguide in a second position, such that a cross-section of the waveguide junction at the second position may include a second profile. 
     One or more of the first profile and the second profile may be or may include: a right-angled corner profile, a non-overlapping stair-shaped profile, a partially-overlapping stair-shaped profile, a trimmed right-angled corner profile, a rounded right-angled corner profile and a combination thereof. 
     At least one of the first profile and the second profile may be selected so as to transfer RF energy, at a working frequency of the waveguide junction (e.g., at a frequency that is above the waveguide&#39;s cutoff frequency, as known in the art), between the base waveguide and a respective arm waveguide, at a required transfer ratio as elaborated herein. 
     According to some embodiments, the first profile may be dissimilar from the second profile, to produce a non-symmetrical junction, configured to operate as at least one of: an RF energy splitter having a non-equal splitting ratio and an RF energy combiner having a non-equal combining ratio. 
     Embodiments of the present invention may include a waveguide junction, that may include: a base waveguide; a first arm waveguide, connected to the base waveguide; and a second arm waveguide connected to the base waveguide. The base waveguide may include a first ridge placed along a first side of the base waveguide and a second ridge placed along a second side of the base waveguide. The first arm waveguide may include a third ridge placed along a side of the first arm waveguide and the second arm waveguide may include a fourth ridge placed along a side of the second arm waveguide. 
     The base waveguide may be connected to at least one of the first arm waveguide and second arm waveguide and the first arm waveguide may be perpendicular to the base waveguide and colinear with the second arm waveguide so as to form a perpendicular T-shaped junction. Alternately, or additionally, the base waveguide may be connected to at least one of the first arm waveguide and second arm waveguide so as to form a Y-shaped junction. 
     According to some embodiments, one or more of the base waveguide, the first arm waveguide and the second arm waveguide may have one of a circular cross section and a polygonal (e.g., rectangular) cross section. 
     According to some embodiments, the third ridge may meet the first ridge in a first position and the fourth ridge meets the second ridge in a second position. 
     The first ridge may be juxtaposed with the third ridge at the first position such that a cross-section of the waveguide junction at the first position may include a first profile and wherein the first profile may be selected from a list consisting: a right-angled corner profile, a non-overlapping stair-shaped profile, a partially-overlapping stair-shaped profile, a trimmed right-angled corner profile, a rounded right-angled corner profile and a combination thereof. 
     Alternately, or additionally, the second ridge may be juxtaposed with the fourth ridge at the second position such that a cross-section of the waveguide junction at the second position may include a second profile and wherein the second profile may be selected from a list consisting: a right-angled corner profile, a non-overlapping stair-shaped profile, a partially-overlapping stair-shaped profile, a trimmed right-angled corner profile, a rounded right-angled corner profile and a combination thereof. 
     According to some embodiments, the first profile may be dissimilar from the second profile, to produce a non-symmetrical junction, configured to operate as at least one of an RF energy splitter, with non-equal splitting ratio and an RF energy combiner, with non-equal combining ratio. 
     The first ridge may be juxtaposed with the third ridge at the first position such that at least a portion of a width of the first ridge may be manifested by a first stair in the first profile and at least a portion of a width of the third ridge may be manifested by a second stair in the first profile. Alternately, or additionally, the second ridge may be juxtaposed with the fourth ridge at the second position such that at least a portion of a width of the second ridge may be manifested by a first stair in the second profile and at least a portion of a width of the fourth ridge may be manifested by a second stair in the second profile. 
     According to some embodiments, the waveguide junction may include a cover, positioned at a side of the first arm waveguide and second arm waveguide that may be opposite to the base waveguide. The cover may include one or more apertures, so as to allow emittance of RF energy through the apertures, and wherein the emittance of RF energy through the apertures may be symmetric in relation to a center-line of the base waveguide. 
     Embodiments of the present invention may include a method of producing a waveguide junction. Embodiments of the method may include: 
     connecting a first single-ridged arm waveguide to a dual-ridged base waveguide in a first position; and 
     connecting a second single-ridged arm waveguide to the dual-ridged base waveguide in a second position where each of the first arm waveguide, second arm waveguide and base waveguide may be adapted to carry RF energy at a frequency that may be equal to or higher than a selected cutoff frequency. 
     According to some embodiments, connecting the first arm waveguide to the base waveguide may include juxtaposing a ridge of the first arm waveguide with a first ridge of the base waveguide in the first position, such that a cross-section of the waveguide junction at the first position may include a first profile. Alternately, or additionally, connecting the second arm waveguide to the base waveguide may include juxtaposing a ridge of the second arm waveguide with a second ridge of the base waveguide in the second position, such that a cross-section of the waveguide junction at the second position may include a second profile. 
     Embodiments of the method may include selecting at least one of the first profile and second profile according to a received required RF transfer ratio, wherein each one of the first profile and the second profile may be or may include: a right-angled corner profile, a non-overlapping stair-shaped profile, a partially-overlapping stair-shaped profile, a trimmed right-angled corner profile, a rounded right-angled corner profile and a combination thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which: 
         FIGS. 1A and 1C  are schematic, isometric views of segments of ridged waveguides that may be included in a waveguide junction, according to embodiments of the present invention; 
         FIGS. 1B and 1D  are schematic, front views of segments of ridged waveguides that may be included in a waveguide junction, according to embodiments of the present invention; 
         FIGS. 2A and 2C  are schematic, isometric views of segments of dual-ridged waveguides that may be included in a waveguide junction, according to embodiments of the present invention; 
         FIGS. 2B and 2D  are schematic, front views of segments of dual-ridged waveguides that may be included in a waveguide junction, according to embodiments of the present invention; 
         FIG. 3A  is a schematic cross-section of a waveguide junction, according to embodiments of the present invention; 
         FIG. 3B  is a schematic cross-section of a waveguide junction, according to embodiments of the present invention; 
         FIG. 3C  is a schematic cross-section of a waveguide junction, according to embodiments of the present invention; 
         FIG. 3D  is a schematic cross-section of a waveguide junction, according to embodiments of the present invention; 
         FIG. 4  is an isometric view of a waveguide junction, according to embodiments of the present invention; 
         FIG. 5  is an isometric view of a waveguide junction, according to embodiments of the present invention; and 
         FIG. 6  is a flow diagram, depicting a method of producing a waveguide junction, according to some embodiments of the invention. 
     
    
    
     It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. 
     DETAILED DESCRIPTION OF THE PRESENT INVENTION 
     In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention. Some features or elements described with respect to one embodiment may be combined with features or elements described with respect to other embodiments. For the sake of clarity, discussion of same or similar features or elements may not be repeated. 
     Although embodiments of the invention are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. The term set when used herein may include one or more items. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently. 
     Embodiments of the present invention include a waveguide junction for transferring RF energy between a dual-ridged waveguide and two single-ridged waveguides. 
     Reference is now made to  FIGS. 1A, 1B, 1C and 1D  which are schematic isometric views and schematic front views of a segment of a ridged waveguide that may be included in a waveguide junction, according to embodiments of the present invention. 
     As shown in  FIGS. 1A and 1B , and as known in the art, a single ridged waveguide  10 A may be implemented as a pipe having a polygonal (e.g., rectangular) cross section (except for any ridge or inset that may exist). As known in the art, where at least one dimension (e.g., a width of the pipe, marked as W 1 ) may be set according to the working RF wavelength. For example, as known in the art, a designer may select a cutoff RF frequency, and the at least one dimension may be set so as to accommodate the selected cutoff frequency, such that the waveguide may effectively transfer RF energy that has a frequency equal to, or higher than the cutoff frequency. 
     As also known in the art, a ridge  110  may be placed along a side  11  of waveguide  10 A thus forming a ridged waveguide  10 A. It should be appreciated that a person skilled in the art would understand as known that ridged waveguides may typically be of lesser or smaller dimensionality (e.g., have at least one smaller dimension such as a smaller ‘W 1 ’), in comparison with non-ridged waveguides characterized by the same cutoff frequency. 
     Alternately, as shown in  FIGS. 1C and 1D , and as known in the art, a single ridged waveguide  10 A may be implemented as a pipe having a circular or round cross section (except for any ridge or inset that may exist), where at least one dimension (e.g., a width of the pipe, marked as W 1 ′) may be set according to the working RF wavelength. A ridge  110  may be placed along a side, arc or edge  11 ′ of waveguide  10 A thus forming a ridged waveguide  10 A. 
     Reference is now made to  FIG. 2A, 2B, 2C and 2D  which are schematic isometric views and schematic front views of a segment of a dual-ridged waveguide that may be included in a waveguide junction, according to embodiments of the present invention. 
     As shown in  FIGS. 2A and 2B , and as known in the art, a dual-ridged waveguide  10 B may be implemented as a pipe having a polygonal (e.g., rectangular) cross section, where at least one dimension (e.g., a width of the pipe, marked as W 2 ) may be set according to the working RF wavelength. A first ridge or inset  110  (e.g.,  110 A) may be placed along—e.g. extending along the length of—a first side  11  (e.g.,  11 A) of waveguide  10 B, and a second ridge or inset  110  (e.g.,  110 B) may be placed along a second side  11  (e.g.,  11 B) of waveguide  10 B thus forming a dual-ridged waveguide  10 B. 
     Alternately, as shown in  FIGS. 2C and 2D , and as known in the art, a dual-ridged waveguide  10 B may be implemented as a pipe having a round or circular cross section, where at least one dimension (e.g., a width of the pipe, marked as W 2 ′) may be set according to the working RF wavelength. A first ridge  110  (e.g.,  110 A) may be placed along a first side or arc  11  (e.g.,  11 A′) of waveguide  10 B, and a second ridge  110  (e.g.,  110 B) may be placed along a second side or arc  11  (e.g.,  11 B′) of waveguide  10 B thus forming a dual-ridged waveguide  10 B. 
     Embodiments of the present invention may include a method for producing a waveguide junction, to transfer RF energy having a working frequency that may be equal to or higher than a predefined cutoff frequency between a dual ridge base waveguide and one or more (e.g., two) single ridged arm waveguides. 
     Embodiments of the invention may include: selecting a cutoff RF frequency; selecting a first single-ridged arm waveguide, a second single-ridged arm waveguide and a dual-ridged arm waveguide, each adapted to convey or carry RF energy at a frequency that is equal to or higher than the cutoff frequency, as known in the art; connecting the first single-ridged arm waveguide to the dual-ridged base waveguide in a first position; and connecting the second single-ridged arm waveguide to the dual-ridged base waveguide in a second position. 
     Reference is now made to  FIG. 3A, 3B, 3C and 3D  which are schematic cross-section views of a waveguide junction, according to different embodiments of the present invention. 
     As shown in  FIGS. 3A, 3B, 3C and 3D , a waveguide junction  200  may include: a dual-ridged base waveguide  230 ; a single-ridged first arm waveguide  210 A, connected to the base waveguide; and a single-ridged, second arm waveguide  210 B, connected to base waveguide  230  and to first arm waveguide  210 A. 
     According to some embodiments, dual-ridged base waveguide  230  may have or may be characterized by a polygonal (e.g., a rectangular) cross section (e.g., as depicted in  FIGS. 2A and 2B ). 
     Additionally, or alternately, at least one of first arm waveguide  210 A and second arm waveguide  210 B may have or may be characterized by a polygonal (e.g., a rectangular) cross section (e.g., as depicted in  FIGS. 1A and 1B ). 
     Additionally, or alternately, at least one of dual-ridged base waveguide  230 , first arm waveguide  210 A and second arm waveguide  210 B may have or may be characterized by a circular or round cross section (e.g., as depicted in  FIGS. 2C, 2D, 1C and 1D  respectively). 
     According to some embodiments, dual-ridged base waveguide  230  may be connected perpendicularly to at least one of first arm waveguide  210 A and second arm waveguide  210 B. 
     Additionally, or alternately, first arm waveguide  210 A may be colinear with second arm waveguide  210 B. For example, base waveguide  230 , first arm waveguide  210 A and second arm waveguide  210 B may be aligned in a perpendicular (e.g., in a right angle measuring 90 degrees) T-shaped junction, as shown in  FIGS. 3A, 3B, 3C and 3D . 
     Additionally, or alternately, dual-ridged base waveguide  230  may be connected in a non-perpendicular angle to at least one of first arm waveguide  210 A and second arm waveguide  210 B. For example, base waveguide  230 , first arm waveguide  210 A and second arm waveguide  210 B may be connected so as to form a Y-shaped junction. In other words base waveguide  230  may be connected to first arm waveguide  210 A and second arm waveguide  210 B in an obtuse angle (e.g., an angle measuring more than 90 degrees), to form a Y-shaped junction. 
     It would be appreciated that each waveguide of the first single-ridged arm waveguide, second single-ridged arm waveguide and dual-ridged arm waveguide may be connected to another waveguide of the first single-ridged arm waveguide, second single-ridged aim waveguide and dual-ridged arm waveguide in any method as known in the art. For example, a first waveguide (e.g., base waveguide  230 ) may be glued, welded, or held together by any mechanical means at a first end to a second waveguide (e.g., first arm waveguide  210 A) at a second end to form a connection at a connection position (e.g.,  240 A). In another example, parts of waveguide junction  200  may be manufactured as a single, unified physical entity (e.g., by an etching or lathing machine). In such embodiments, the connection of a first waveguide (e.g., base waveguide  230 ) to a second waveguide (e.g., first arm waveguide  210 A) may be inherently done as part of the manufacture process, as known in the art. 
     According to some embodiments, base waveguide  230  may include a first ridge  220 A placed along a first side  23 A of base waveguide  230  and a second ridge  220 B placed along a second, opposite side  23 B of base waveguide  230 . 
     First arm waveguide  210 A may include a third ridge  220 C placed along a side  21 A of first arm waveguide  210 . Third ridge  20 C may meet first ridge  220 A in a first position  240 A and third ridge  220 C may be aligned with first ridge  220 A in a common plane (e.g., the plane of the cross section depicted in  FIGS. 3A, 3B, 3C and 3D ). 
     As shown in  FIGS. 3A, 3B, 3C and 3D , second arm waveguide  220 B may include a fourth ridge  220 D, placed along a side  21 B of second arm waveguide  220 B. Fourth ridge  220 D may meet second ridge  220 B in a second position  240 B and may be is aligned with second ridge  220 B in a common plane (e.g., the plane of the cross section depicted in  FIGS. 3A, 3B, 3C and 3D ), which may align with the plane of ridges  220 A and  220 C. 
     As shown in  FIGS. 3A, 3B, 3C and 3D , first ridge  220 A may meet or may be juxtaposed with third ridge  220 C at first position  240 A such that a cross-section of the waveguide junction  200  at first position  240 A may include or have a first profile or shape, and second ridge  220 B may meet or may be juxtaposed with fourth ridge  220 D at second position  240 B such that a cross-section of the waveguide junction  200  at second position  240 B may include or have a second profile or shape that may or may not be similar or identical to the first profile. 
     The first profile or shape and second profile or shape may be or may include for example: a right-angled corner profile, a non-overlapping stair-shaped profile, a partially-overlapping stair-shaped profile, a trimmed right-angled corner profile and a rounded right-angled corner profile or any combination thereof, as elaborated herein. 
     It will be appreciated that other configurations of may be implemented to produce other types of profiles, as known in the art. 
     In some embodiments, as shown in  FIG. 3A , first ridge or narrow inset  220 A may be juxtaposed with third ridge or narrow inset  220 C at first position  240 A in a right-angled corner configuration, such that a width of first ridge  220 A may fully overlap a width of third ridge  220 C, to create a right-angled corner at position  240 A. In other words, a cross-section of the waveguide junction at first position  240 A may include a right-angled corner profile. 
     Additionally, or alternately, second ridge  220 B may be juxtaposed with fourth ridge  220 D at second position  240 B such that a width of second ridge  220 B may fully overlap a width of fourth ridge  220 D, to create a right-angled corner at second position  240 B. In other words, a cross-section of the waveguide junction at second position  240 B may include a right-angled corner profile. 
     Additionally, or alternately, as shown in  FIG. 3B , first ridge  220 A may be juxtaposed with third ridge  220 C at the first position  240 A in a non-overlapping configuration, such that a cross-section of the waveguide junction at first position  240 A may include a non-overlapping stair-shaped profile, where, for example, first ridge  220 A may be manifested as a first stair and third ridge  220 C may be manifested as a second stair. 
     Additionally, or alternately, second ridge  220 B may be juxtaposed with fourth ridge  220 D at second position  240 B in a non-overlapping configuration, such that a cross-section of the waveguide junction at second position  240 B may include a non-overlapping stair-shaped profile, where, for example, second ridge  220 B may be manifested as a first stair and fourth ridge  220 D may be manifested as a second stair. 
     Additionally, or alternately, as shown in  FIG. 3C , first ridge  220 A may be juxtaposed with third ridge  220 C at first position  240 A in a partially-overlapping configuration, such that a cross-section of the waveguide junction at first position  240 A may include a partially-overlapping stair-shaped profile, where, for example at least a portion of a width of first ridge  220 A (marked as Δω 1 ) may be manifested by a first stair and at least a portion of a width of third ridge  220 C (marked as Δω 3 ) may be manifested by a second stair. 
     Additionally, or alternately, second ridge  220 B may be juxtaposed with fourth ridge  220 D at second position  240 B in a partially-overlapping configuration, such that a cross-section of the waveguide junction at second position  240 B may include a partially-overlapping stair-shaped profile, where, for example, at least a portion of a width of second ridge  220 B may be manifested by a first stair and at least a portion of a width of fourth ridge  220 D may be manifested by a second stair. 
     Additionally, or alternately, as shown in  FIG. 3D , first ridge  220 A may be juxtaposed with third ridge  220 C at first position  240 A in a trimmed right-angled corner configuration, to create a trimmed right-angled corner at position  240 A. In other words, a cross-section of the waveguide junction at first position  240 A may include a trimmed right-angled corner profile. 
     Additionally, or alternately, second ridge  220 B may be juxtaposed with fourth ridge  220 D at second position  240 B, to create a trimmed right-angled corner at second position  240 B. In other words, a cross-section of the waveguide junction at second position  240 B may include a trimmed right-angled corner profile. 
     Additionally, or alternately, first ridge  220 A may be juxtaposed with third ridge  220 C at first position  240 A in a rounded right-angled corner configuration, to create a rounded right-angled corner at position  240 A. In other words, a cross-section of the waveguide junction at first position  240 A may include a rounded right-angled corner profile. 
     Additionally, or alternately, second ridge  220 B may be juxtaposed with fourth ridge  220 D at second position  240 B, to create a rounded right-angled corner at second position  240 B. In other words, a cross-section of the waveguide junction at second position  240 B may include a rounded right-angled corner profile. 
     It should be known that embodiments may further include any combination of the profiles as elaborated herein, including for example, a combination of a rounded right-angled corner profile and an overlapping stair-shaped profile and the like. 
     According to some embodiments, the profile at first position  240 A may be similar or equivalent to the profile at second position  240 B. For example, the profiles of first position  240 A and second position  240 B may both include a trimmed right-angled corner profile. 
     Alternately, the profile at first position  240 A may be dissimilar from the profile at second position  240 B, to produce a non-symmetrical junction, acting as an RF energy splitter and/or combiner with non-equal ratio. 
     For example, the profile of first position  240 A may be a partially-overlapping stair-shaped profile, where (a) a first portion (e.g., 80%) of the width of first ridge  220 A and third ridge  220 C may be respectively manifested by the first and second stairs of the profile of first position  240 A, and (b) a second portion (e.g., 20%) of the width of second ridge  220 B and fourth ridge  220 D may be respectively manifested by the first and second stairs of the profile of second position  240 B. 
     The relative positioning of the ridges  220  (e.g.,  220 A in relation to  220 C,  220 B in relation to  220 D) may be set so as to accommodate specifically required ratios of RF energy transfer through the junction. Pertaining to the same example, it has been shown experimentally, that in such configuration, where the profile of first position  240 A resembles a right-angled corner profile and the profile of second position  240 B resembles a non-overlapping stair-shaped profile, the ratio of transferred RF energy from base waveguide  230  to second waveguide  210 B may be higher than the ratio of transferred RF energy from base waveguide  230  to first waveguide  210 A. 
     According to some embodiments, a designer may define at least one of a first requirement for an RF transfer ratio (e.g., an RF transfer ratio above a first percentage) between base waveguide  230  and first arm waveguide  210 A and a second requirement for an RF transfer ratio (e.g., an RF transfer ratio above a second percentage) between base waveguide  230  and second arm waveguide  210 B. The designer may calculate the ratio of transferred RF energy by a commercially available tool for numerical simulation of RF energy propagation, as known in the art, to design and produce a junction that may accommodate the first and/or second requirements for RF transfer ratios. 
     The designer may set the position and/or shape of at least one ridge (e.g., the way ridges are met or juxtaposed as elaborated herein), so as to select at least one of the first profile and second profile at a respective at least one meeting point  240  (e.g.,  240 A,  240 B), so as to transfer RF energy, at a working frequency of the waveguide junction, between base waveguide  230  and a respective arm waveguide  210  (e.g.,  210 A,  210 B) at a required transfer ratio. 
     According to some embodiments, the first profile (e.g., at point  240 A) may be dissimilar from the second profile (e.g., at point  240 B), to produce a non-symmetrical junction. The non-symmetrical junction may be configured to operate for example, as an RF energy splitter having a non-equal splitting ratio or an RF energy combiner having a non-equal combining ratio. 
     According to some embodiments, the design process elaborated herein may include one or more iterations of design change (e.g., change in a location, position or size of one or more ridges) and RF propagation calculation (e.g., by a commercially available numeric simulation tool), until the at least one of first and second requirements for RF transfer ratios is met. 
     In other words, embodiments may include: 
     receiving a requirement for at least one RF transfer ratio (e.g., as part of a design of an RF system design); and 
     selecting at least one of the first profile and second profile according to the received requirement (e.g., of the at least one RF transfer ratio), wherein each one of the first profile and the second profile may be, for example: a right-angled corner profile, a non-overlapping stair-shaped profile, a partially-overlapping stair-shaped profile, a trimmed right-angled corner profile, a rounded right-angled corner profile and a combination thereof. The at least one of the first profile and second profile may be selected by the designer by the iterative designing process as elaborated herein, where properties of waveguide junction  200  such as RF transfer ratio are calculated numerically (e.g., by commercially available dedicated software), and the design of the junction (e.g., positioning of the ridges) is altered until the at least one received requirement is met. 
     Reference is now made to  FIG. 4  which is an isometric view of a waveguide junction, according to embodiments of the present invention. In  FIG. 4 , a portion of a side of first arm waveguide  210 A and a portion of a side of second arm waveguide  210 B opposite the base waveguide has been removed, to enable an isometric view of first positions  240 A and  240 B in a partially-overlapping configuration, as elaborated herein in relation to  FIG. 3C . It may be appreciated by a person skilled in the art that RF energy that may be fed into base waveguide  230  (e.g., at a feed point marked ‘X’, between ridge  220 A and ridge  220 B), may propagate along base waveguide  230  at the direction of ridge  220 A and ridge  220 B, and may be split between first arm waveguide  210 A (e.g., along ridge  220 C) and second arm waveguide  210 B (e.g., along ridge  220 D), as shown by the dotted arrow lines of  FIG. 4 . 
     Reference is now made to  FIG. 5  which is an isometric view of a waveguide junction  200 , according to embodiments of the present invention. Waveguide junction  200  may include a gapped cover  30 , positioned at a side  11  of first arm waveguide  210 A and second arm waveguide  210 B that is opposite base waveguide  230 . Gapped cover  30  may include a plurality of gaps or apertures  31 , configured to enable or allow emittance of RF energy therethrough. 
     RF energy may be fed into waveguide junction  200  at a feeding position (e.g., marked as ‘X’), and may propagate via base waveguide  230 , and split evenly between arm waveguide  210 A and arm waveguide  210 B. 
     According to some embodiments, the length of arm waveguide  210 A and arm waveguide  210 B may be set so as to enable the propagated RF energy to resonate therein as a standing wave, as known in the art. 
     Arm waveguide  210 A and arm waveguide  210 B may be symmetric in relation to feeding point X, so as to allow symmetric resonance of RF energy between arm waveguide  210 A and arm waveguide  210 B. 
     According to some embodiments, Gapped cover  30  and the plurality of apertures  31  may also be symmetric in relation to feeding point X, so as to enable symmetric emittance of RF energy through apertures  31 , in relation to a center-line (e.g., marked ‘ 0 ’) of base waveguide  230 . 
     Reference is now made to  FIG. 6  which is a flow diagram depicting a method of producing a waveguide junction, according to some embodiments of the invention. 
     As shown in step S 1005 , embodiments may include connecting a first single-ridged arm waveguide (e.g., such as depicted in  FIG. 1A  and/or  FIG. 1C ) to a dual-ridged base waveguide (e.g., such as depicted in  FIG. 2A  and/or  FIG. 2C ) in a first position. 
     As shown in step S 1010 , embodiments may include connecting a second single-ridged arm waveguide (e.g., such as depicted in  FIG. 1A  and/or  FIG. 1C ) to the dual-ridged base waveguide in a second position, so as to produce a waveguide junction (e.g., a T junction, such as depicted, for example, in  FIG. 3A  through  FIG. 3D ). Each of the first arm waveguide, second arm waveguide and base waveguide may be adapted to carry RF energy at a frequency that is equal or higher than a selected cutoff frequency. 
     Embodiments of the present invention may provide an improvement over currently available waveguide junctions, by combining the exploitation of the structural benefits of ridged waveguides (e.g., having a reduced dimensionality) with application of configurable characteristics of the conveyed RF energy. 
     For example, a designer may choose to split and/or combine, for example evenly, the propagation of conveyed RF energy between a central feeding point at the base waveguide and a pair of arm waveguides. This configuration may be advantageous for example, in embodiments where a gapped cover is applied as shown in  FIG. 5 . In such configurations, the central feeding of RF energy and the even split thereof to the two arm waveguides may produce an emitted signal through gapped cover  30  that may be characterized by superior integrity in relation to a commercially available configuration, in which a waveguide of an equivalent length (e.g., of the combined length of arms  210 A and  210 B) may be fed by an RF feeding point located at one extremity of the waveguide of the equivalent length. 
     Moreover, embodiments of the invention may enable a designer to define a first requirement for an RF transfer ratio (e.g., an RF transfer ratio above a first percentage) between base waveguide  230  and first arm waveguide  210 A and a second requirement for an RF transfer ratio (e.g., an RF transfer ratio above a second percentage) between base waveguide  230  and second arm waveguide  210 B, and design a waveguide junction that may accommodate at least one of the first requirement and second requirement, by an iterative numerical simulation process, as elaborated herein. 
     While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. Further, features or elements of different embodiments may be used with or combined with other embodiments.