Patent Application
20110026194
The present invention relates to signal amplifiers and, more particularly, to signal amplifiers having aluminum housing bodies.
Cable television networks are communications networks that are used to transmit cable television signals, broadband Internet service, video-on-demand services, digital telephone service and/or a variety of other information between one or more service providers (e.g., a cable television company) and a plurality of subscribers (e.g., individual homes, apartments, hotels, businesses, etc.). Most conventional cable television networks comprise hybrid fiber-coaxial networks. In these networks, fiber optic cables are typically used to carry radio frequency (“RF”) signals between the headend facilities of the service provider and various distribution points, while less expensive coaxial cable may be used, for example, to carry the signals between the distribution points and individual homes and businesses.
The RF signal received from the service provider at each subscriber premise may be a relatively low power signal (e.g., 5 dBmV/channel) that may require amplification in order to properly service the various communication ports maintained by a subscriber. As such, an RF signal amplifier is typically provided at each subscriber premise that is used to amplify the signals received from the service provider. In some cases, the RF signal amplifier may also amplify return signals that are passed from the subscriber premises to the service provider. In many cases, these signal amplifiers may be mounted outdoors, and hence can be subject to extreme environmental conditions.
Signal amplifiers are known in the art that include two-piece aluminum housings comprising a housing body and a back plate.
As shown in
Signal amplifiers are also known in the art that include a two-piece zinc housing comprising a housing body and a back plate. The zinc housing pieces may be plated with other metals, so that the back plate may be soldered to the housing body. This may allow elimination of the weather gasket, RFI gasket and the locking screws.
Pursuant to embodiments of the present invention, RF signal amplifiers are provided that have a housing that includes a first aluminum housing piece and a second housing piece. The housing also includes an input port, an output port and a power port. A first coaxial connector is mounted in the input port. A second coaxial connector is mounted in the output port. A third coaxial connector is mounted in the power port. A power amplifier is mounted within the housing, and is used to amplify an input signal received through the first coaxial connector. At least a portion of the housing has at least one metal plated thereon. The first aluminum housing piece is soldered, welded or brazed to the second housing piece.
In some embodiments, the first, second and third coaxial connectors may each be a female F-style coaxial connector having brass connector housings. The housing may comprise an aluminum housing body and a back plate. The metal plating may comprise copper that is flash coated onto the housing. In some embodiments, a nickel-based layer, a tin-based layer and/or a nickel and tin alloy based layer may be plated on the copper flash coat. The first aluminum housing piece may be mounted directly to the second housing piece without an intervening gasket. The first housing piece may be soldered, or welded or otherwise permanently adhered to the second housing piece. In embodiments that use solder, a non-lead or lead-based solder may be used to solder the first housing piece to the second housing piece.
Pursuant to further embodiments of the present invention, methods of manufacturing a signal amplifier are provided. Pursuant to these methods, a housing body having a bottom and sidewalls that define a compartment is formed via an aluminum casting process. A back plate is also formed. The back plate may comprise, for example, an aluminum, brass, iron or steel back plate. At least a portion of the housing body is plated with copper. At least a portion of the back plate is likewise plated with copper. At least one metal or metal alloy is plated on the copper plating on the housing body. At least one metal or metal alloy is plated on the copper plating on the back plate. At least one input connector, at least one output connector and at least one power connector are installed in the housing body. The signal amplifier is installed within the housing body. Finally, the back plate is soldered to the housing body.
In some embodiments, the input, output and power connectors may be coaxial connectors having a brass connector housing. The metal or metal alloy that is plated on the copper plating on the housing body and/or back plate may be nickel and/or tin. The back plate may be soldered to a lip that is formed in an interior surface of the sidewalls so as to extend around substantially the entire periphery of the housing body. Moreover, the back plate may be mounted directly to the housing body without any intervening gasket. The back plate may be soldered to the housing body using a lead-based or a non-lead-based solder.
Embodiments of the present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that when an element is referred to as being “connected” or “mounted” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly mounted” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (i.e., “between” versus “directly between”, etc.).
In accordance with embodiments of the present invention, signal amplifiers are provided that have a multi-piece metal-plated aluminum housing. The plated-aluminum housing pieces are soldered together to provide a weather-proof housing structure. In some embodiments, no weather gaskets or RFI gaskets are required. As discussed herein, the signal amplifiers according to embodiments of the present invention may be lightweight, extremely durable, and less expensive than comparable prior art signal amplifiers. Moreover, the signal amplifiers according to embodiments of the present invention may exhibit improved electrical performance and/or may have improved thermal conductivity. The aluminum housing may comprise a pure aluminum housing or an aluminum alloy housing such as 360 aluminum.
As shown in
As is also shown in
The housing body 120 may include a plurality of internal support structures 128 that may be used to support the internal circuitry 140 and/or to facilitate making electrical connections between the internal circuitry 140 and the input connector 150 and/or the output connector 160. The internal support structures 128 may also act as heat sinks that transfer heat away from active components of the internal circuitry 140. The inner, top portions of the longitudinal and lateral sidewalls 122, 123 may be thinned to create an internal lip 129 that extends around the internal periphery of the housing body 120. As discussed below, the back plate 130 may rest on and be soldered to this internal lip 129.
As shown best in the exploded perspective view of
The internal circuitry 140 may comprise any circuit components that are used to implement the functionality of a signal amplifier such as, for example, a signal amplifier that is used to amplify signals transmitted over a cable television network. U.S. patent application Ser. No. 12/208,675, filed Sep. 11, 2008 and now published as U.S. Patent Publication No. 2009/0047917, the contents of which are incorporated herein by reference, illustrates the designs for a number of signal amplifiers that could be incorporated into housings according to embodiments of the present invention. It will be appreciated, however, that the present invention may be used with any signal amplifier such as, for example, signal amplifiers that do not include dedicated Voice over IP bypass paths, signal amplifiers that do not include a power amplifier in the forward and/or return path, signal amplifiers with different numbers of input and/or output ports, amplifiers with different circuit designs (e.g., signal amplifiers that support MOCA), etc.
The input connector 150 may comprise, for example, a female F-style coaxial connector. Thus, for example, in some embodiments, the input connector 150 may have the design shown in U.S. Pat. No. 6,299,479, the contents of which are incorporated herein by reference as if set forth fully herein. The output and power connectors 160, 170 may also each comprise a female F-style coaxial connectors and may be identical to the input connector 150. The input, output and power connectors 150, 160, 170 are mounted within their respective input and output ports 125, 126, 127. In some embodiments, the power connector 170 may be used solely to provide a direct current (“DC”) power signal to the signal amplifier 100. In other embodiments, the power connector 170 may comprise a dual radio frequency/DC power port. In such embodiments, the power connector 170 may serve as both a power input and, for example, as a second output connector 160.
As shown best in
As noted above, the housing body 120 and the back plate 130 may be formed of aluminum. However, as known to those of skill in the art, aluminum generally cannot be soldered. Thus, as discussed above with respect to
Nickel (“Ni”) and/or tin (“Sn”) may then be plated on top of the copper flash coat 112. In some embodiments, a nickel layer 114 may be plated onto the copper flash coat 112, and then a tin layer 116 is plated on top of the nickel plating 114. As is known to those of skill in the art, solder has good adhesion characteristics to both nickel and tin; thus, the plated nickel and tin layers 114, 116 allow the back plate 130 to be soldered to the housing body 120. The nickel plating may be applied, for example, using nickel electroplating techniques. If the copper flash coat 112 is not applied, the nickel plating 114 may be applied using electroless nickel (“EN”) plating techniques.
As the back plate 130 may be soldered to the housing body 120, the overall size of the housing 110 may be reduced as compared to conventional aluminum signal amplifier housings, as the interior of conventional aluminum housings include a number of locking screws (e.g., four) about the internal periphery of the housing that increase the overall footprint of the housing (see
It will be appreciated that the back plate may be permanently adhered to the housing body by welding or brazing in addition to by soldering.
In one specific embodiment of the present invention, the housing body 120 may comprise an aluminum housing body (e.g., a 360 aluminum alloy), and the back plate 130 may comprise a brass back plate. An electroless nickel plating may be applied to the aluminum housing body 120, and a copper flash coat may be plated on the brass back plate 130, followed by a nickel plating. A liquid paint coat may be applied to the exterior of the housing body 120 as well.
In other specific embodiments of the present invention, the housing body 120 may comprise an aluminum housing body, and the back plate 130 may comprise one of an aluminum, iron or steel back plate. An electroless nickel plating may be applied to the aluminum housing body 120, and a copper flash coat may be plated on the back plate 130, followed by a nickel plating. A liquid paint coat may be applied to the exterior of the housing body 120 as well.
In further embodiments of the present invention, the housing body 120 may comprise an aluminum housing body, and the back plate 130 may comprise one of an aluminum, iron, brass or steel back plate. A copper flash coat may be plated on the housing body 120, followed by a nickel plating. A copper flash coat may be plated on the back plate 130, followed by a nickel plating. A liquid paint coat or an electrostatic powder coat may be applied to the exterior of the housing body 120. A lacquer coat may be applied to the exterior of the back plate 130.
In still further embodiments of the present invention, the housing body 120 may comprise an aluminum housing body, and the back plate 130 may comprise one of an aluminum, iron, brass or steel back plate. A copper flash coat may be plated on the housing body 120, followed by a nickel plating, followed by a bright tin or tin plating. A copper flash coat may be plated on the back plate 130, followed by a nickel plating, followed by a bright tin or tin plating. A liquid paint coat or an electrostatic powder coat may be applied to the exterior of the housing body 120. A lacquer coat may be applied to the exterior of the back plate 130.
In additional embodiments of the present invention, the housing body 120 may comprise an aluminum housing body, and the back plate 130 may comprise one of an aluminum, iron, brass or steel back plate. A copper flash coat may be plated on the housing body 120, followed by a nickel-tin alloy plating. A copper flash coat may be plated on the back plate 130, followed by a nickel-tin alloy plating.
In yet additional embodiments of the present invention, the housing body 120 may comprise an aluminum housing body, and the back plate 130 may comprise one of an aluminum, iron, brass or steel back plate. A copper flash coat may be plated on the housing body 120, followed by a nickel plating, followed by a bright tin or tin plating. A copper flash coat may be plated on the back plate 130, followed by a nickel plating, followed by a bright tin or tin plating. A liquid paint coat or an electrostatic powder coat may be applied to the exterior of the housing body 120. A liquid paint coat or a powder coat may be applied to the exterior of the back plate 130.
While signal amplifiers that include multi-piece zinc (“Zn”) housings that are soldered together are known in the art, zinc may have a number of disadvantages as compared to the plated-aluminum housings according to embodiments of the present invention. First, aluminum is more electrically conductive than zinc. As such, an aluminum housing may provide a better ground surface than a comparable zinc housing. Second, aluminum has better thermal conductivity than zinc. As noted above, better thermal conductivity can result in better solder joints. Additionally, aluminum housings can equally and/or better dissipate heat generated by the signal amplifier during operation, and hence can provide improved amplifier performance as the performance of a signal amplifier may tend to degrade at elevated temperatures. For example, the thermal conduction of aluminum is typically in the range 160-180 W/(m·0 C), whereas the thermal conduction of zinc is about 113 W/(m·0 C). While aluminum alloys typically have lower thermal conductivity numbers, the same is also true for zinc alloys. Third, while aluminum and zinc typically cost about the same per pound (the five year average in spot price between the two is within five percent), zinc weighs approximately 2.5 times more than aluminum. As the thickness of the housing body 120 and back plate 130 will typically be approximately the same regardless of the metal used to form the housing, an aluminum signal amplifier housing may require substantially less metal (by weight) than a corresponding zinc housing. Consequently, the material costs of a plated-aluminum housing may be substantially less than the material costs of a plated-zinc housing. Moreover, the resulting product is also lighter, which may reduce transportation costs and lighter products may be preferred by installers.
Additionally, most coaxial connectors used in cable television systems including, for example, the F-style coaxial connectors depicted in
The foregoing disclosure is not intended to limit the present invention to the precise forms or particular fields of use disclosed. It is contemplated that various alternate embodiments and/or modifications to the present invention, whether explicitly described or implied herein, are possible in light of the disclosure.
