Microwave feeding module and circuit board structure

The present disclosure relates to a satellite signal feeding module and circuit board structure. The circuit board includes a dielectric substrate, a plurality of grounding sheets, a plurality of top feed sheets, a plurality of bottom feed sheets, and a conductive layer. The dielectric substrate includes a main segment having an opening, a rib segment extending across a full width of the opening, and a plurality of extending segments connected to the main segment. The grounding sheets cover the rib segment and a majority portion of the main segment. The top feeding sheets and the bottom sheets cover the extending segments. The conductive layer is disposed in first holes disposed in the main segment and the rib segment for electrically coupling the grounding sheets. The conductive layer is further disposed in second holes in the extending segments for electrically coupling the top and bottom feeding sheets.

TECHNICAL FIELD

The present disclosure relates to a feeding module and a circuit board structure thereof, and more particularly, to a satellite signal feeding module and circuit board structure thereof.

DISCUSSION OF THE BACKGROUND

The use of satellite antennas for reception of television transmission from satellites has increased rapidly in recent years. The use of satellite antennas allows households to have access to hundreds of television channels, which is usually many more than are available through local cable television systems.

Conventionally, satellite signals transmitted by the satellite are received by a satellite antenna and processed by a particular device, such as low-noise block converter, prior to application to a conventional home television. It is common knowledge that minimizing an insertion loss of the satellite antenna can be achieved by using a printed circuit board with a low dielectric loss (also called “loss tangent” or “dissipation factor”), e.g., a printed circuit board having a dielectric loss not greater than 0.002. However, the printed circuit board having the low dielectric loss is expensive and is not well-suited for integration with the satellite antenna and a back-stage signal-processing circuit.

SUMMARY

One aspect of the present disclosure provides a circuit board structure. The circuit board structure includes a dielectric substrate, a plurality of grounding sheets, a plurality of top feeding sheets, a plurality of bottom feeding sheets, and a conductive layer. The dielectric substrate includes a main segment having an opening, a rib segment extending across a full width of the opening, and a plurality of extending segments extending inward from the main segment. A first gap is disposed between the rib segment and each of the extending segments. The grounding sheets are disposed on a top surface of the dielectric substrate and a bottom surface opposite to the top surface, and cover the rib segment and a majority portion of the main segment. The top feeding sheets are placed on the top surface and cover the extending segments. The bottom feeding sheets are placed on the bottom surface and cover the extending segment. The top feeding sheets and the bottom feeding sheets are electrically isolated from the grounding sheets. The conductive layer is disposed in a plurality of first holes, disposed in the main segment and the rib segment, for electrically coupling the grounding sheets, and the conductive layer is further disposed in a plurality of second holes disposed in the extending segments, and configured for electrically coupling the top feeding sheets to the bottom feeding sheets.

In some embodiments, extending centerlines of the first extending segment and the second extending segment are respectively perpendicular to the rib segment.

In some embodiments, a distance between two adjacent first holes is substantially greater than a distance between two adjacent second holes.

In some embodiments, each of the grounding sheets includes a central portion placed on the rib segment, and a plurality of peripheral portions placed on the main segment and spaced away from the central portion.

In some embodiments, a distance between two peripheral portions gradually decreases at positions of increasing distance from the central portion.

In some embodiments, the circuit board structure further includes a plurality of lead-out sheets connected to the top feeding sheets and the bottom feeding sheets and placed on the main segment where the peripheral portions are not placed.

In some embodiments, each of the peripheral portions has a curving inner edge and a straight outer edge.

In some embodiments, the circuit board structure further comprises a plurality of metal sheets disposed in the dielectric substrate and electrically connected to the feeding sheets through the conductive layer disposed in the second holes.

In some embodiments, a dielectric loss of the dielectric substrate is greater than 0.01.

In some embodiments, a diameter of each of the first holes is greater than that of each of the second holes.

Another aspect of the present disclosure provides a microwave feeding module. The microwave feeding module includes a cover, a waveguide, a circuit board structure between the cover and the waveguide, and a septum polarizer fixed in the waveguide. The circuit board structure includes a dielectric substrate, a plurality of grounding sheets, a plurality of top feeding sheets, a plurality of bottom feeding sheets, and a conductive layer. The dielectric substrate includes a main segment having an opening, a rib segment extending across a full width of the opening, and a plurality of extending segments extending inward from the main segment, wherein a first gap is disposed between the rib segment and each of the extending segments. The grounding sheets are placed on a top surface of the dielectric substrate and a bottom surface opposite to the top surface, and cover the rib segment and a majority portion of the main segment. The cover is in contact with the grounding sheet placed on the top surface, and the waveguide is in contact with the grounding sheet placed on the bottom surface. The top feeding sheets are placed on the top surface and cover the extending segments. The bottom feeding sheets are placed on the bottom surface and cover the extending segments. The top feeding sheets and the bottom feeding sheets are electrically isolated from the grounding sheets. The conductive layer is disposed in a plurality of first holes, disposed in the main segment and the rib segment, for electrically coupling the grounding sheets, and in a plurality of second holes, disposed in the extending segments, for electrically coupling the top feeding sheets to the bottom feeding sheets. The septum polarizer is in contact with the grounding sheet placed on the bottom surface.

In some embodiments, the cover comprises a plate, an annular wall disposed on the peripheral portion of the plate, and a rib extending from the plate and connected to the annular wall; wherein the annular wall and the rib are in contact with one of the grounding sheets, and the waveguide and the septum polarizer are in contact with the other one of the grounding sheets.

In some embodiments, the cover further comprises a plurality of notches extending from an outer circumferential surface to an inner circumferential surface of the annular wall.

In some embodiments, the cover further comprises a plurality of flanges protruding from the outer circumferential surface such that each of the notches is surrounded by one of the flanges.

In some embodiments, the waveguide further includes a plurality of protrusions extending outward from an outer circumferential surface of the waveguide, and the protrusions are disposed corresponding to the notches.

In some embodiments, the protrusions are in contact with one of the grounding sheets placed on the bottom surface.

In some embodiments, the circuit board structure further comprises a plurality of lead-out sheets connected to the top feeding sheets and the bottom feeding sheets and placed on the main segment where the peripheral portions are not placed, and the lead-out sheets are disposed in the notches.

In some embodiments, a plurality of curved portions are bent outwardly from the waveguide, and the curved portions are disposed corresponding to the notches.

In some embodiments, the septum polarizer divides an interior of the waveguide in half.

The foregoing has outlined rather broadly the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and technical advantages of the disclosure are described hereinafter, and form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the concepts and specific embodiments disclosed may be utilized as a basis for modifying or designing other structures, or processes, for carrying out the purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit or scope of the disclosure as set forth in the appended claims.

DETAILED DESCRIPTION

FIG. 1is a schematic diagram illustrating a satellite broadcast reception system10in accordance with some embodiments of the present disclosure. Referring toFIG. 1, the satellite broadcast reception system10is configured to receive microwave signals broadcast by a satellite11. In some embodiments, the satellite broadcast reception system10includes a dish reflector12and a low noise block (LNB) downconverter14disposed at the focus of the dish reflector12; the microwave signals are collected by the dish reflector12and focused or concentrated into the LNB downconverter14. In some embodiments, the LNB downconverter14amplifies the low noise of the microwave signals and converts the frequency of the microwave signals down to a low noise intermediate frequency (IF) signal having an adequate level, and the low noise IF signal output from the LNB downconverter14is sent to at least one receiver16, such as a television, through a coaxial cable18, thereby providing a satellite television program to users.

FIGS. 2 and 3are schematic diagrams of a microwave feeding module100in accordance with some embodiments of the present disclosure, andFIG. 4is an exploded view of the microwave feeding module100in accordance with some embodiments of the present disclosure. Referring toFIGS. 2 to 4, in some embodiments, the microwave feeding module100is implemented in the LNB downconverter14shown inFIG. 1, and is utilized to transmit the microwave signal entering the LNB downconverter14to a back-stage signal processing circuit (not shown) for converting the microwave signals to the low noise IF signal. In some embodiments, the microwave feeding module100includes a cover110, a waveguide120, and a circuit board structure130between the cover110and the waveguide120. In some embodiments, the microwave signal received by a feedhorn (not shown) of the LNB downconverter14may transmit through the waveguide120, reflect by the cover110, and receive by the feed sheets of the circuit board structure130will be explained below. In the context of this document, as is popular in the industry, cover110is also referred to as backshort and the terms should be understood to be used interchangeably unless specified otherwise.

In some embodiments, the cover110includes a plate112, an annular wall114disposed on the peripheral portion of the plate112, and a space115defined by the plate112and the annular wall114. In some embodiments, the cover110further includes a rib116extending from the plate112and connected to the annular wall114. In some embodiments, the annular wall114has an outer circumferential surface1142, an inner circumferential surface1144, and a plurality of notches118extending from the outer circumferential surface1142to the inner circumferential surface1144. In some embodiments, the notches118are formed at locations where the rib116is not connected. In some embodiments, the cover110further includes a plurality of flanges119protruding from the outer circumferential surface1142such that each of the notches118is surrounded by one of the flanges119. In some embodiments, the plate112has a circular shape. In some embodiments, the cover110is made of metal. In some embodiments, the plate112, the annular wall114, the rib116, and the flange119may be integrally formed.

In some embodiments, the waveguide120has cylindrical wall124including an outer circumferential surface1242and an inner circumferential surface1244. In some embodiments, the waveguide120further includes a plurality of protrusions127a,127bextending outward from the outer circumferential surface1242. In some embodiments, the waveguide120is made of metal, and the protrusions127a,127bare integral with the waveguide120.

In some embodiments, the microwave feeding module100further includes a septum polarizer126fixed in the waveguide120and divides an interior125of the waveguide120in half.

In some embodiments, the circuit board structure130comprises a dielectric substrate140, a top grounding sheet150, a bottom grounding sheet160, a plurality of top feeding sheets175, and a plurality of bottom feeding sheets195. Referring toFIG. 4, in some embodiments, the dielectric substrate140includes a top surface1402and a bottom surface1404opposite to the top surface1402. In some embodiments, a dielectric loss of the dielectric substrate140is greater than 0.01. In some embodiments, the dielectric loss of the dielectric substrate140is substantially equal to 0.02. In some embodiments, the dielectric substrate140is made of epoxy-glass composite material. In some embodiments, the dielectric substrate140is a flame retardant4(FR4) substrate. In some embodiments, the dielectric substrate140is symmetrical with respect to an axis A.

FIG. 5is a top view of the dielectric substrate140in accordance with some embodiments of the present disclosure.

Referring toFIG. 5, in some embodiments, the dielectric substrate140includes a main segment142having a rectangular or a square shape, a rib segment144, a first extending segment146, and a second extending segment148. The main segment142has an opening1422extending from the top surface1402to the bottom surface1404shown inFIG. 4. Referring again toFIG. 5, in some embodiments, the opening1422, arranged in a circular shape, is disposed at a center of the main segment142. The rib segment144is disposed inside the opening1422and extends across a full width of the opening1422.

In some embodiments, the first extending segment146and the second extending segment148, formed as rectangles, extend inward from the main segment142. In some embodiments, the first extending segment146and the second extending segment148are disposed in the opening1422and located at two opposite sides of the rib segment144. In some embodiments, an extending centerline1462of the first extending segment146and an extending centerline1482of the second extending segment148are perpendicular to the rib segment144. In some embodiments, the first extending segment146and the second extending segment148do not connect to the rib segment144; in other words, there is a gap G1formed between the rib segment144and each of the first extending segment146and the second extending segment148. In some embodiments, the first extending segment146and the second extending segment148are respectively symmetric with respect to the rib segment144.

In some embodiments, a plurality of first holes145are formed in the rib segment144and the main segment142. In some embodiments, the first holes145disposed in the main segment142partially encircle the opening1422. In some embodiments, the first holes145are disposed in locations of the main segment142where the first extending segment146and the second extending segment148are not connected. In some embodiments, a plurality of second holes149, in an equal-pitch arrangement, are formed in the first extending segment146and the second extending segment148. In some embodiments, a distance D1between two adjacent first holes145disposed in the main segment142is substantially greater than a distance D2between two adjacent second holes149, and a distance D3between two adjacent first holes145disposed on the rib segment144may be substantially equal to or less than the distance D1. In some embodiments, a diameter of each of the first holes145is greater than that of each of the second holes149. In some embodiments, the first holes145and the second holes149are formed at the same time. In some embodiments, the first holes145and the second holes149extend from the top surface1402to the bottom surface1404shown inFIG. 4.

Referring again toFIGS. 2 to 4, in some embodiments, the top grounding sheet150is placed on the top surface1402, and the bottom grounding sheet160is placed on the bottom surface1404. In order to provide better performance, a total area of the top grounding sheet150and the bottom grounding sheet160should be as large as possible. In some embodiments, the top grounding sheet150and the bottom grounding sheet160are disposed over the rib segment144and a majority portion of the main segment142. In some embodiments, portions of the main segment142where the first extending segment146and the second extending segment148are connected are exposed to the top grounding sheet150and the bottom grounding sheet160.

In some embodiments, the top grounding sheet150comprises a top central portion152and two top peripheral portions154,156spaced away from the central portion152. In some embodiments, gaps G2are formed between the top peripheral portions154,156. In some embodiments, a distance between two top peripheral portions154,156gradually decreases at positions of increasing distance from the central portion152. In some embodiments, the central portion152is placed on the rib segment144, and the top peripheral portions154,156connected to the central portion152are placed on the main segment142. In some embodiments, the top peripheral portions154,156have a shape that substantially corresponds to a shape of the main segment142. In some embodiments, each of the top peripheral portions154,156, formed as an arch, has a curving inner edge1542,1562and a straight outer edge1544,1564. In some embodiments, the top grounding sheet150further includes a plurality of through-holes158penetrating therethrough. In some embodiments, the through-holes158are circular and disposed corresponding to the first holes145.

In some embodiments, the bottom grounding sheet160includes a bottom central portion162placed on the rib segment144and a bottom peripheral portion164placed on the main segment142. In some embodiments, the bottom central portion162is connected to the bottom peripheral portion164and divides the interior of the bottom peripheral portion164in half. In some embodiments, the bottom peripheral portion164, formed as an arch, has a circular inner edge1642and a straight outer edge1644. In some embodiments, the top grounding sheet150and the bottom grounding sheet160are made of metal. In some embodiments, the bottom grounding sheet160further includes a plurality of through-holes168penetrating therethrough. In some embodiments, the through-holes168are circular and disposed corresponding to the first holes145.

In some embodiments, the top feeding sheets175include a first feeding sheet170and a second feeding sheet180placed on the top surface1402, wherein the top feeding sheets175do not come into contact with the top grounding sheet150; the bottom feeding sheets195include a third feeding sheet190and a fourth feeding sheet200, formed as rectangles and placed on the bottom surface1404, wherein the bottom feeding sheets195do not come into contact with the bottom grounding sheet160. In some embodiments, the first feeding sheet170and the third feeding sheet190are disposed on the first extending segment146, and the second feeding sheet180and the fourth feeding sheet200are disposed on the second extending segment148. In some embodiments, a plurality of through holes172,182,192,202are respectively formed in the first feeding sheet170, the second feeding sheet180, the third feeding sheet190, and the fourth feeding sheet200. The through-holes172,182,192,202are circular and disposed corresponding to the second holes149.

In some embodiments, the circuit board structure130further includes a plurality of lead-out sheets174,184extending outward from the first feeding sheet170and the second feeding sheet180. In some embodiments, the lead-out sheets174,184are placed on the main segment142where the top peripheral portions154,156are not placed. In some embodiments, the lead-out sheets174,184are electrically isolated from the top grounding sheet150. In some embodiments, the first feeding sheet170and the lead-out sheet174are integrally formed, and the second feeding sheet180and the lead-out sheet184are integrally formed. In some embodiments, the first feeding sheet170, the second feeding sheet180, the third feeding sheet190, the fourth feeding sheet200, and the lead-out sheets174,184are made of metal.

Referring toFIGS. 4 and 6, in some embodiments, the cover110is in contact with the top grounding sheet150, and the waveguide120and the septum polarizer126are in contact with the bottom grounding sheet160after assembling. Specifically, the rib116is in contact with the top central portion152, and the annular wall114is in contact with the top peripheral portions154,156; the septum polarizer126is in contact with the bottom central portion162, and the waveguide120is in contact with the bottom peripheral portion164. In some embodiments, a conductive layer220is disposed in the first holes145, through-holes158,168for electrically connecting the top grounding sheet150and the bottom grounding sheet160, and the conductive layer220is further disposed in the second holes149, through-holes172,182,192,202for electrically connecting the top feeding sheets175and the bottom feeding sheets195. In some embodiments, the flanges119are in contact with the top peripheral portions154,156of the top grounding sheet150after assembling. In some embodiments, the protrusions127a,127bare disposed corresponding to the first notches118after assembling. In some embodiments, the protrusions127a,127bare in contact with the bottom peripheral portion164of the bottom grounding sheet160after assembling. In some embodiments, an insertion loss of the circuit board structure100made of the material with high dielectric loss is reduced since the top surface1402and the bottom surface1404thereof are provided with the grounding sheets and the feeding sheets.

FIG. 7is an exploded view of a microwave feeding module100A in accordance with some embodiments of the present disclosure, andFIG. 8is a cross-sectional view of the microwave feeding module100A in accordance with some embodiments of the present disclosure. Unless specified otherwise, the materials and formation methods of the components in these embodiments are essentially the same as those of the like components, which are denoted by like reference numerals in the embodiments shown inFIGS. 2 through 6. The details of the like components shown inFIGS. 7 and 8may thus be found in the discussion of the embodiments shown inFIGS. 2 through 6.

Referring toFIGS. 7 and 8, in some embodiments, the circuit board structure130A of the feeding module100A further includes a plurality of metal sheets230,240,250,260disposed in the first extending segment146and the second extending segment148. Specifically, the metal sheets230and240are disposed in the first extending segment146, and the metal sheets250and260are disposed in the second extending segment148. In some embodiments, the conductive layer220disposed in the second holes149formed in the first extending segment146is utilized to electrically connect the first feeding sheet170, the third feeding sheet190, and the metal sheets230,240; the conductive layer220disposed in the second holes149formed in the second extending segment148is utilized to electrically connect the second feeding sheet180, the fourth feeding sheet200, and the metal sheets250,260.

FIG. 9is a schematic diagram of a microwave feeding module100B in accordance with some embodiments of the present disclosure,FIG. 10is an exploded view of the microwave feeding module100B in accordance with some embodiments of the present disclosure, andFIG. 11is a cross-sectional view of the microwave feeding module10B in accordance with some embodiments of the present disclosure. Unless specified otherwise, the materials and formation methods of the components in these embodiments are essentially the same as those of the like components, which are denoted by like reference numerals in the embodiments shown inFIGS. 2 through 6. The details of the like components shown inFIGS. 9 to 11may thus be found in the discussion of the embodiments shown inFIGS. 2 through 6.

Referring toFIGS. 9 to 11, a plurality of curved portions128bend outwardly form the waveguide120B, such that an air gap stripline or suspended stripline is formed to reduce the insertion loss of the circuit board100B. In some embodiments, the curved portions128are formed at locations where the septum polarizer126is not connected. In some embodiments, the curved portions128are disposed corresponding to the notches118after assembling.

One aspect of the present disclosure provides a circuit board structure. The circuit board includes a dielectric substrate, a plurality of grounding sheets, a plurality of feed sheets, and a conductive layer. The dielectric substrate includes a main segment having an opening, a rib segment extending across a full width of the opening, and a plurality of extending segments extending inward from the main segment. A gap is disposed between the rib segment and each of the extending segments. The grounding sheets are placed on a top surface of the dielectric substrate and a bottom surface opposite to the top surface. The grounding sheets cover the rib segment and a majority portion of the main segment. The top feeding sheets are disposed on the top surface and cover the extending segments, and the bottom sheets are disposed on the bottom surface and cover the extending segments. The top feeding sheets and the bottom feeding sheets are electrically isolated from the grounding sheets. The conductive layer is disposed in a plurality of first holes, disposed in the main segment and the rib segment, for electrically coupling the grounding sheets. The conductive layer is further disposed in a plurality of second holes, disposed in the extending segments, for electrically coupling the top feeding sheets to the bottom feeding sheets.

One aspect of the present disclosure provides a microwave feeding module. The microwave feeding module includes a cover; a waveguide, a circuit board structure between the cover and the waveguide, and a septum polarizer fixed in the waveguide. The circuit board structure includes a dielectric substrate, a plurality of grounding sheets, a plurality of top feeding sheets, a plurality of bottom feeding sheets, and a conductive layer. The dielectric substrate includes a main segment having an opening, a rib segment extending across a full width of the opening, and a plurality of extending segments extending inward from the main segment, wherein a first gap is disposed between the rib segment and each of the extending segments. The grounding sheets are placed on a top surface of the dielectric substrate and a bottom surface opposite to the top surface, and the grounding sheets cover the rib segment and a majority portion of the main segment. The cover is in contact with the grounding sheet placed on the top surface, and the waveguide is in contact with the grounding sheet placed on the bottom surface. The top feeding sheets are placed on the top surface and cover the extending segments. The bottom feeding sheets are placed on the bottom surface and cover the extending segment. The top feeding sheets and the bottom feeding sheets are electrically isolated from the grounding sheets. The conductive layer is disposed in a plurality of first holes, disposed in the main segment and the rib segment, for electrically coupling the grounding sheets; the conductive layer is further disposed in a plurality of second holes, disposed in the extending segments, for electrically coupling the top feeding sheets to the bottom feed sheets. The septum polarizer is in contact with the grounding sheet placed on the bottom surface.