Patent Application
20210066830
The present disclosure relates to an apparatus and methods for providing board-to-board radio-frequency (RF) connections and, in particular, to an apparatus and methods for providing a connection interface for board-to-board connections without coaxial connectors.
RF Connectors are currently used to make connections between printed circuit boards (PCBs). Such RF connectors are traditionally precision machined from corrosion resistant materials and, because of this, the RF connectors tend to be one of the largest cost drivers on RF PCBs. In addition, cable interfaces are sometimes required, which drive further costs, and RF connectors are typically installed by a solder reflow process, or manually, which leads to unnecessary processing time and assembly costs. Also, RF connectors are usually attached on the top surface or on the side of a PCB, which prevents those PCBs from being stacked in a spatially efficient manner.
In particular, contemporary RF connections can be expensive, tend to consume valuable space on PCBs and add complexity. Standard RF connector cost is introduced at many levels: the phase during which RF connectors are selected, RF interface design phases, surface mount part assembly phases, inspection phases and mating connector installation phases. In terms of standard RF connectors consuming valuable space, it has been observed that RF connectors tend to set board-to-board spacing in that they can prevent multiple board arrangements and can lead to core PCB stack-ups, they require that space be allocated for connector assemblies and post-assembly inspection. In terms of standard RF connectors adding complexity, it has been observed that they require integrated electrical-mechanical PCB design stages, lead to the provision of multi-core PCBs, can require the use of solder reflow during PCB assembly just for RF connectors and can tend towards high unit cell count line replaceable units (LRUs) that in turn require high yields.
According to an aspect of the disclosure, a stripline radio-frequency (RF) connection interface is provided and includes first and second printed circuit boards (PCBs). The first PCB includes a first trace, ground planes at opposite sides of the first trace, dielectric material interposed between the first trace and the ground planes and a first end. The first end is formed as a first rabbet at which the first trace is exposed. The second PCB includes a second trace, ground planes at opposite sides of the second trace, dielectric material interposed between the second trace and the ground planes and a second end. The second end is formed as a second rabbet, which is substantially identical to the first rabbet, at which the second trace is exposed. The first and second ends are mated in a shiplap joint to electrically couple the first and second traces.
In accordance with additional or alternative embodiments, the ground planes of the first and second PCBs each include conductive material.
In accordance with additional or alternative embodiments, the first and second traces are each formed as striplines.
In accordance with additional or alternative embodiments, a conductive material is electrically interposed between the first and second traces.
In accordance with additional or alternative embodiments, one or more fasteners fasten the first and second ends together.
In accordance with additional or alternative embodiments, one or more magnetic elements magnetically attract the first and second ends together.
In accordance with additional or alternative embodiments, an external mechanical force forces the first and second ends together.
According to another aspect of the disclosure, a radio-frequency (RF) circuit assembly is provided and includes a plurality of printed circuit boards (PCBs). Each PCB of the plurality of PCBs includes a trace, ground planes at opposite sides of the trace, dielectric material interposed between the trace and the ground planes and an end. The end is formed as a rabbet at which the trace is exposed. The end of each PCB of the plurality of PCBs is mated in a shiplap joint with an end formed as a substantially identical rabbet of a neighboring PCB such that the corresponding traces are electrically coupled.
In accordance with additional or alternative embodiments, the plurality of PCBs includes first and second exterior PCBs including lead terminals, first and second interior PCBs mated with one another and including electrical devices and first and second intermediate PCBs mated in sequence with the first and second exterior PCBs, respectively, with one another, respectively, and with the first and second interior PCBs, respectively.
In accordance with additional or alternative embodiments, the ground planes of each PCB of the plurality of PCBs each include conductive material.
In accordance with additional or alternative embodiments, the trace of each PCB of the plurality of PCBs is formed as a stripline.
In accordance with additional or alternative embodiments, a conductive material is electrically interposed between the traces of neighboring PCBs.
In accordance with additional or alternative embodiments, one or more fasteners fasten respective ends of neighboring PCBs together.
In accordance with additional or alternative embodiments, one or more magnetic elements magnetically attract respective ends of neighboring PCBs together.
In accordance with additional or alternative embodiments, an external mechanical force forces respective ends of neighboring PCBs together.
According to another aspect of the disclosure, a method of assembling a stripline radio-frequency (RF) connection interface is provided. The method includes assembling a first printed circuit board (PCB) to comprise a first trace, ground planes at opposite sides of the first trace and dielectric material interposed between the first trace and the ground planes, assembling a second PCB to comprise a second trace, ground planes at opposite sides of the second trace and dielectric material interposed between the second trace and the ground planes, forming complementary ends of the first and second PCBs as first and second substantially identical rabbets, respectively, at which the first and second traces are exposed, respectively, and mating the complementary ends of the first and second PCBs in a shiplap joint to electrically couple the first and second traces.
In accordance with additional or alternative embodiments, the method further includes electrically interposing conductive material between the first and second traces.
In accordance with additional or alternative embodiments, the method further includes fastening the complementary ends of the first and second PCBs together.
In accordance with additional or alternative embodiments, the method further includes magnetically attracting the complementary ends of the first and second PCBs together.
In accordance with additional or alternative embodiments, the method further includes applying an external mechanical force to force the complementary ends of the first and second PCBs together.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with the advantages and the features, refer to the description and to the drawings.
For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts:
As will be described below, a stripline SNAP-RF connection interface is provided and enables board-to-board RF connections without the use of RF connectors, electroplating and vias. The stripline SNAP-RF connection reduces costs and complexity of RF panels by eliminating the need for traditional connectors, one of the main cost drivers of traditional RF panels. The stripline SNAP-RF connection does not require solder reflow, and can be easily integrated into the PCB manufacturing processes without a placement line. In addition, while traditional connectors tend to have significant losses and tend to have relatively high height profiles above board surfaces and thus pose packaging problems in tight areas, the stripline SNAP-RF connection exhibits reduced loss characteristics and has a flat profile.
With reference to
The first PCB 110 includes a first circuit trace 111, first and second ground planes 112 and 113 (see
The second PCB 120 includes a second circuit trace 121, first and second ground planes 122 and 123 at opposite sides of the second circuit trace 121, dielectric material 124 interposed between the second circuit trace 121 and the first and second ground planes 122 and 123 at the opposite sides of the second circuit trace 121 and a second end 125. The second circuit trace 121 can be formed of conductive material (e.g., copper, tin, etc.) and can be formed with a stripline shape 126 having a relative small thickness in the thickness dimension TD, a width in the width dimension WD that exceeds the relatively small thickness and a length in the length dimension LD that exceeds the width. The first and second ground planes 122 and 123 can be formed with conductive material (e.g., copper, tin, etc.) and can be substantially flat and planar. The dielectric material 124 electrically isolates the second circuit trace 121 between the first and second ground planes 122 and 123. The second end 125 is characterized in that an end of the first ground plane 122 and the dielectric material 124 between the first ground plane 122 and the second circuit trace 121 are recessed from respective corresponding ends of the second circuit trace 121 and the second ground plane 123 to thus form the second end 125 into a second rabbet 127 and to thus expose the second circuit trace 121 along a length LR of the second rabbet 127.
It is to be understood that the first and second PCBs 110 and 120 can also include additional ends formed as rabbets opposite or adjacent to the first end 115 and the second end 125, respectively. This will be described below with reference to
With continued reference to
As shown in
As shown in
With reference to
The plurality of PCBs 510 can include first and second exterior PCBs 5101 and 5102 that each include lead terminals 521, first and second interior PCBs 5103 and 5104 that are mated with one another along stripline SNAP-RF connection interface 10134 and include electrical devices 522, first intermediate PCBs 5105, 5106 and 5107 and second intermediate PCBs 5108, 5109 and 51010. First intermediate PCB 5105 is mated with first exterior PCB 5101 along stripline SNAP-RF connection interface 10115, first intermediate PCB 5107 is mated with first interior PCB 5103 along stripline SNAP-RF connection interface 10173 and first intermediate PCB 5106 is mated with first intermediate PCB 5105 along stripline SNAP-RF connection interface 10156 and with first intermediate PCB 5107 along stripline SNAP-RF connection interface 10167. Second intermediate PCB 5108 is mated with second exterior PCB 5102 along stripline SNAP-RF connection interface 10128, second intermediate PCB 51010 is mated with second interior PCB 5104 along stripline SNAP-RF connection interface 101104 and second intermediate PCB 5109 is mated with second intermediate PCB 5108 along stripline SNAP-RF connection interface 10189 and with second intermediate PCB 51010 along stripline SNAP-RF connection interface 101910. Circuit traces proceed from the lead terminals 521 and external inputs through each of the PCBS 510 and each of the stripline SNAP-RF connection interfaces 101 to the electrical devices 522.
With reference to
In accordance with embodiments, the method can further include electrically interposing conductive material between the first and second circuit traces 605 prior to or during the mating of operation 604 and one or more of fastening the complementary ends of the first and second PCBs together 606, magnetically attracting the complementary ends of the first and second PCBs together 607 and applying an external mechanical force to force the complementary ends of the first and second PCBs together 608.
With reference to
Technical effects and benefits of the present invention are the provision of a low-cost stripline SNAP-RF connection that can be made with reduced process steps and equipment requirements as compared to traditional connectors, can be relatively easily integrated into PCB manufacturing processes and can be relatively easily assembled and maintained in the field, has excellent electrical performance and a reduced/zero height profile and exhibits increased connection densities as compared to traditional RF connectors.
The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
While the preferred embodiments to the invention have been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described.
