Patent Application
20140118196
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
1. Technology Field
The present disclosure relates generally to antenna apparatus for use in electronic devices such as wireless radio devices, and more particularly in one exemplary aspect to a spatially compact antenna apparatus useful on e.g., a base station or access point, and methods of manufacturing and utilizing the same.
2. Description of Related Technology
Radio frequency antennas are now pervasive in modern electronics, due to the widespread adoption of wireless interfaces for communication. Typical wireless applications often include some form of base station or access point, which is in data communication with a broader network, as well as one or more client or mobile devices. Alternatively, a one-way architecture may be employed (such as in the case of a GPS or GLONASS receiver receiving signals from one or more satellites).
Depending on the host device form factor (e.g., base station, mobile user device, etc.) and performance requirements, various physical configurations of antennas are utilized. Such configurations employ mechanical components to, inter alia, support the antenna radiating element(s) and related electrical/electronic components, provide environmental protection, etc. In prior art solutions, such mechanical components are typically customized for each specific antenna configuration. This approach is not optimal, in that a custom design and manufacturing cycle is typically required for each different configuration. This results in comparatively high tooling costs, and longer design cycles; the possibility of reuse of the components on any other design project/configuration is minimal as well.
Moreover, the logistics of supporting such customized configurations is not optimized. For example, different part numbers, storage/inventory, assembly lines/manufacturing equipment, materials, specifications and drawings, etc. are necessitated to support such a wide array of sui generis designs, thereby increasing labor and other costs, and ultimately the cost of the product to the host device manufacturer.
Accordingly, there is a salient need for an improved antenna solution that can provide the required electrical and other performance attributes, along with a higher degree of commonality and “reuse” opportunity, at a lower cost and complexity.
The present invention satisfies the foregoing needs by providing, inter alia, improved apparatus and methods for modular and low-cost antenna design, construction and implementation, and methods associated therewith.
In a first aspect of the invention, an antenna element is disclosed. In one embodiment, the element includes: a cover element having a cavity formed therein; a main radiating element disposed substantially within the cavity; and a coupling element configured to at least electrically couple the antenna element to a host radio frequency device.
In one variant, a parasitic radiating element is formed substantially on or within the cover element; the parasitic radiating element comprises e.g., a laser direct structured (LDS) element formed on an exterior surface of the cover element.
In another variant, the element further includes an out layer disposed over the exterior surface and at least a portion of the parasitic radiating element, the outer layer selected so as to not substantially degrade the electrical performance of at least the parasitic element.
In a further variant, the antenna element further includes a back housing element configured to cooperate with the cover element so as to substantially enclose the cavity, and a ground plane disposed on the back housing.
In another variant, the antenna element comprises a substantially modular construction that is configured to enable the antenna element to be mated with at least one other similar or identical antenna element so as to form an array.
In a second aspect, an antenna array is disclosed. In one embodiment, the array includes: a plurality of substantially identical antenna elements each having: a cover element having a cavity formed therein; a main radiating element disposed substantially within the cavity; a parasitic radiating element formed substantially on or within the cover element; and a coupling element configured to at least electrically couple the antenna element to a host radio frequency device; and a feed structure configured to commonly feed each of the antenna elements.
In one variant, the array comprises the plurality of antenna elements arranged in a substantially planar array.
In another variant, the array comprises the plurality of antenna elements arranged in a substantially three-sector radial array.
In a further variant, the antenna array further includes a circuit board disposed proximate each of the antenna elements, the circuit board further comprising at least one radio frequency transceiver configured to provide a radio frequency signal to the feed network so as to drive each of the individual antenna elements.
In a third aspect of the invention, a method of manufacturing an antenna element is disclosed. In one embodiment, the method includes forming a parasitic radiator on at least a portion of a surface of an antenna radome, with a main radiator disposed substantially within an interior region of the radome. Laser direct structuring (LDS) is used in one variant to form the parasitic radiator (as well as a feed network on the back portion of the antenna element) so as to economize on space and simplify manufacturing.
In a fourth aspect of the invention, an LDS-based antenna element is disclosed. In one embodiment, a “two-shot” modling process is used to form a radome and back cover element of the antenna element, each having specifically identified areas that contain LDS-suitable polymer so as to enable formation of an antenna or conductive trace thereon. The remaining portions of the radome/back cover are formed from a non-LDS enabled polymer such as ABS.
In a fifth aspect of the invention, a simplified antenna feed arrangement is disclosed. In one embodiment, the arrangement includes a conductive clip (e.g., C-shaped) such that custom or expensive connectors or cables used in prior art antenna feeds are obviated; the clip may merely be soldered to (or simply maintain frictional contact) with a trace or other component of the host device when the element is placed in its mounting disposition. In one variant, the clip is coupled to an LDS feed network on the antenna element, which further simplifies the feed structure.
In a sixth aspect of the invention, a method of reconfiguring an antenna array is disclosed. In one embodiment, the method includes selectively removing one or more modular antenna elements from an existing array, and placing the removed elements in a second, different configuration so as to provide different electrical and/or antenna physical (e.g., azimuthal coverage) properties.
In a seventh aspect of the invention, a method of manufacturing a low-cost, simplified antenna element is disclosed. In one embodiment, the method includes: forming a front cover element and a rear cover element, at least one of the front and rear cover elements formed using first and second types of material; activating relevant portions of at least one of the front and rear covers containing the first type of material; utilizing an electroless process so as to accrete a plurality of conductive elements on the activated portions; disposing a ground plane onto the back cover element; disposing a main radiator element on the back cover element; affixing a feed conductor to at least one of the accreted conductive elements; and joining the front and rear cover elements.
Further features of the present invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description.
The features, objectives, and advantages of the disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, wherein:
All Figures disclosed herein are ©Copyright 2012-2013 Pulse Finland Oy. All rights reserved.
Reference is now made to the drawings wherein like numerals refer to like parts throughout.
As used herein, the terms “antenna,” and “antenna system,” refer without limitation to any system that incorporates a single element, multiple elements, or one or more arrays of elements that receive/transmit and/or propagate one or more frequency bands of electromagnetic radiation. The radiation may be of numerous types, e.g., microwave, millimeter wave, radio frequency, digital modulated, analog, analog/digital encoded, digitally encoded millimeter wave energy, or the like. The energy may be transmitted from location to another location, using, or more repeater links, and one or more locations may be mobile, stationary, or fixed to a location on earth such as a base station.
As used herein, the terms “board” and “substrate” refer generally and without limitation to any substantially planar or curved surface or component upon which other components can be disposed. For example, a substrate may comprise a single or multi-layered printed circuit board (e.g., FR4), a semi-conductive die or wafer, or even a surface of a housing or other device component, and may be substantially rigid or alternatively at least somewhat flexible.
The terms “frequency range”, “frequency band”, and “frequency domain” refer without limitation to any frequency range for communicating signals. Such signals may be communicated pursuant to one or more standards or wireless air interfaces.
As used herein, the terms “portable device”, “mobile device”, “client device”, “portable wireless device”, and “host device” include, but are not limited to, personal computers (PCs) and minicomputers, whether desktop, laptop, or otherwise, set-top boxes, personal digital assistants (PDAs), handheld computers, personal communicators, tablet computers, portable navigation aids, J2ME equipped devices, cellular telephones, smartphones, personal integrated communication or entertainment devices, or literally any other device capable of interchanging data with a network or another device.
Furthermore, as used herein, the terms “radiator,” and “radiating element” refer without limitation to an element that can function as part of a system that receives and/or transmits radio-frequency electromagnetic radiation; e.g., an antenna.
The terms “RF feed,” “feed” and “feed conductor” refer without limitation to any energy conductor and coupling element(s) that can transfer energy, transform impedance, enhance performance characteristics, and conform impedance properties between an incoming/outgoing RF energy signals to that of one or more connective elements, such as for example a radiator.
As used herein, the terms “top”, “bottom”, “side”, “up”, “down”, “left”, “right”, “back”, “front”, and the like merely connote a relative position or geometry of one component to another, and in no way connote an absolute frame of reference or any required orientation. For example, a “top” portion of a component may actually reside below a “bottom” portion when the component is mounted to another device (e.g., to the underside of a PCB).
As used herein, the term “wireless” means any wireless signal, data, communication, or other interface including without limitation Wi-Fi, Bluetooth, 3G (e.g., 3GPP, 3GPP2, and UMTS), HSDPA/HSUPA, TDMA, CDMA (e.g., IS-95A, WCDMA, etc.), FHSS, DSSS, GSM, PAN/802.15, WiMAX (802.16), 802.20, narrowband/FDMA, OFDM, PCS/DCS, Long Term Evolution (LTE) or LTE-Advanced (LTE-A), analog cellular, NFC/RFID, CDPD, satellite systems such as GPS, millimeter wave or microwave systems, optical, acoustic, and infrared (i.e., IrDA).
The present disclosure provides, in one salient aspect, a spatially compact and modular antenna element that can be used either alone or as a basic “building block” for larger arrays and sectorial antennas (i.e., by joining needed number of elements together). Thus, the same parts can be reused for various complete product designs, thereby advantageously reducing the need for customized parts (and the attendant disabilities associated therewith, as discussed supra). Moreover, multiple antenna elements can be readily joined together via a common feed network (in one implementation, via the back portion of each element). The antenna gain and beam width are also adjustable through configuration of the array (and the construction of the antenna elements themselves).
In one exemplary application, a base station (e.g., a Small Cell Base Station (SCBS)) unit can be configured (and rapidly reconfigured) with the antenna elements disclosed herein based on individual cell site needs. For instance, the modular antenna elements disclosed herein can be used to configure a 6-sector 360-degree coverage array, or a 3-sector 180-degree coverage array. Likewise, planar or even hybrid (e.g., angular/planar) arrays can readily be formed.
In another aspect, a simplified RF contact configuration is presented to connect the antenna element feed point(s) to the host radio device without need of specific connectors or cables, thereby advantageously further simplifying the use of the element(s) in various applications.
Detailed descriptions of the various embodiments and variants of the apparatus and methods of the disclosure are now provided. While primarily discussed in the context of base stations or access points, the various apparatus and methodologies discussed herein are not so limited. In fact, the apparatus and methodologies of the disclosure may be useful in any number of antennas, whether associated with mobile or fixed devices.
Referring now to
The illustrated antenna elements 100 of
It is noted, however, that even if the mechanical shape of the element cover 104 is square or rectangular as in
In one variant, the radome 104 is snap-fit 115 to the rear cover element 106 so as to provide mechanical stability and ease of assembly/disassembly; however, it will be appreciated that other fastening techniques may be used in place of or in conjunction with the foregoing, including e.g. use of adhesives, fasteners, heat staking of one component to the other, press-fit or other frictional technologies, and so forth, as will be recognized by those of ordinary skill given the present disclosure.
Moreover, it can be appreciated that the radome may take on any number of different shapes, the illustrated outwardly (convex) shapes of
The antenna element 100 of
A conductor (in this embodiment, a “C” shaped clip with some resiliency) 120 is also provided to facilitate electrical connection to a host device (e.g., substrate with radio transceiver circuits 130; shown in
Use of the foregoing C-clip arrangement advantageously (i) allows for positive mechanical (and hence electrical) frictional contact with a host device without necessitating soldering or other bonding, and (ii) obviates the use of specialize connectors or cables (e.g., coaxial or otherwise), thereby reducing cost and increasing simplicity of design and manufacturing. It will be appreciated, however, that other shapes and/or orientations of conductor may be used with equal success, depending on the particular application. For instance, the C-clip may be oriented at 90 degrees to that illustrated (i.e., rotated out of the plane of the antenna element) and elongated as needed so as to facilitate “side” mounting.
It is further appreciated that while the exemplary embodiment only illustrates the use of one RF feed point, and one main radiator element, the present disclosure is not so limited, and may be implemented with any number of RF feed points (e.g. two-feed, three-feed), as well as any number of antenna elements and/or switching elements as may be required by the particular application.
Moreover, while the parasitic element 112 is shown disposed (e.g., printed) on the outer or convex surface of the cover element (radome) 104, the parasitic element may be formed on the interior (concave) surface, or two or more elements formed on both surfaces if desired. In that no electrical connections are required to the parasitic element(s) 112, their number and location may be varied as required by the application and is facilitated through the use of the multi-dimensional LDS process.
In the exemplary embodiment of
In the illustrated element 100 of
In the exemplary embodiment where LDS is used, 2-shot molding can advantageously be used to limit usage of LDS plastic to only within the (parasitic) radiator area of the radome 106, and the feed network area of the back cover element 106.
In an alternative embodiment, the aforementioned “2-shot” molding process is obviated through use of a pad printing technique (or other non-LDS printing technique) to form the parasitic radiator 112 on the radome.
In one variant, the LDS parasitic radiator 112 as described above is generally retained; however, manufacturing time can advantageously be reduced by using a meshed or “raster” surface (instead of consistent metallization as in the prior embodiment). Specifically, instead of fully metallized surface, a fine “mesh” is formed. Pitch size of the mesh in the exemplary embodiment is small enough so that from an electromagnetic point of view, the surface appears consistent. When the entire surface does not require the lasering process, a proportional saving in laser treatment time is achieved. Moreover, the amount of metal used is also advantageously reduced. Such rastering (and/or cross-hatching) can be used also in the pad printing process; in that case, the cost saving stems mainly from the reduced amount of metal required.
In the exemplary embodiment, polarization of the antenna element 100 can be selected by altering the feed coupling element configuration, single port, dual port, vertical, horizontal, slant +/−45-deg. polarizations are possible; see the exemplary configurations of
The ground plane 108 of the exemplary element 100 comprises a metallic (e.g., copper alloy) layer that in the present embodiment is screen-printed onto the exposed portion of the back cover element 106. As is known, screen printing is a printing technique that uses a woven mesh to support an blocking stencil. The attached stencil forms open areas of mesh that transfer printable material which can be pressed through the mesh as a sharp-edged image onto an underlying substrate. Through placement of the ground plane on the back cover element of the antenna element 100, additional ground (GND) clips can be readily added between ground plane and radio board as needed. The ground plane can be alternatively formed using sheet metal, FPC or other metallization technique (rather than screen printing).
Advantages of the exemplary embodiment of the antenna element 100 include: (i) reduced number of physical parts as compared to prior art solutions; (ii) reduced overall thickness (d) of the element 100 as shown in
Moreover, the antenna elements disclosed herein have improved RF properties (resulting from, inter alia, the main radiator 102 being disposed in close proximity to the radome). In such a configuration, electrical performance is improved, since the parasitic radiator (or main radiator in the alternate embodiment referenced above) can be formed on the outer surface of the radome 104. Then radome material losses accordingly have little or no effect on antenna radiating performance. Also, the distance between the reflector (ground plane 108) and main radiator 102 can be maximized for a given mechanical height, since the relevant radiator can be formed onto the outer surface of the radome. In conventional antenna technology, the radiator(s) is/are below the radome, and thus closer to the ground plane.
As indicated above, one salient advantage of the disclosure is its use of identical (or substantially identical) modular antenna elements as “building blocks” which can be joined together in variety of ways to form antenna arrays, panels, columns (cylinders) or other shapes such as polygons. Moreover, various components (e.g., end caps, rear housing element, etc.) can be accommodated into the basic antenna element 100 to form variety of sizes and shapes of antenna assembly, as described in greater detail below. The foregoing capability allows the antenna elements to be largely “commoditized” and have interchangeability, thereby simplifying manufacturing, inventory management, and assembly into antenna arrays.
Moreover, it will be appreciated that the antenna apparatus may be constructed to have at least two-dimensional non-chirality (aka “handedness”), such that its orientation is not critical to its operation. This is particularly useful in manufacturing; i.e., a human or pick-and-place machine may pick up the non-chiral antenna elements as they arrive or are positioned in a source device without having to orient them with respect to the non-chiral dimension(s) before assembly. For instance, considering the round embodiment of
In the exemplary embodiments of the antenna array, the antenna gain and beam width are adjustable by way of the array configuration. For instance, single element 100 can achieve a gain 7 dBi, horizontal 3 dB beam width 65 deg, vertical 3 dB beam width 50 deg. A 1×2 vertical array can achieve a gain 9.5 dBi, horizontal 3 dB beam width 60 deg, vertical 3 dB beam width 30 deg.
In one configuration of the apparatus, a six-sector array 300 with 360-degrees of coverage is formed using six substantially identical antenna elements 100, as shown in
In another configuration, a six-element array 400 is formed, yet with pairs 406 of adjacent elements being coordinated such that three radiating/receiving sectors are formed to cover 360 degrees, as shown in
In another configuration, a two-element planar array 500 is formed as shown in
In yet another configuration, a 3-element hemispherical (180-degree coverage) array is formed, the array having three radiating sectors as shown in
Next, relevant portions of the front and rear covers (i.e., those with LDS plastic) are ablated using a laser according to the prescribed LDS process, so as to activate the dopant material contained therein (step 1004).
Per step 1006, the components 104, 106 are then placed in an electroless process so as to build up the desired conductive traces (e.g., parasitic radiator 112, feed network 114, etc.) on the ablated LDS portions.
After completion of step 1006, the ground plane is screen printed onto the relevant portions of the back cover element 106 per step 1008. Any protective coating 113 desired on the front cover 104 may also now be applied per step 1010.
At step 1012, the main radiator element 102 is heat-staked to the rear cover element at the supports 116 (
It will be appreciated that the modular antenna elements disclosed herein (e.g., those of
It will be recognized that while certain aspects of the disclosure are described in terms of a specific sequence of steps of a method, these descriptions are only illustrative of the broader methods, and may be modified as required by the particular application. Certain steps may be rendered unnecessary or optional under certain circumstances. Additionally, certain steps or functionality may be added to the disclosed embodiments, or the order of performance of two or more steps permuted. All such variations are considered to be encompassed within the disclosure and claims provided herein.
While the above detailed description has shown, described, and pointed out novel features as applied to various embodiments, it will be understood that various omissions, substitutions, and changes in the form and details of the device or process illustrated may be made by those skilled in the art. The foregoing description is of the best mode presently contemplated. This description is in no way meant to be limiting, but rather should be taken as illustrative of the general principles of the disclosure.
This application claims priority to co-owned and co-pending U.S. Provisional Patent Application Ser. No. 61/718,637 filed Oct. 25, 2012 of the same title, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61718637 | Oct 2012 | US |
