An antenna includes a CPW transmission line and a radiating portion. The radiating portion is coupled to the CPW transmission line and is substantially coplanar with the CPW transmission line. The radiating portion is configured to produce a first linear polarization at a first frequency, a circular polarization at a second frequency, and a second linear polarization at a third frequency. The radiating portion includes a conductive material extending from the CPW transmission line and forming a plurality of openings in the radiating portion. The openings are asymmetric with respect to a first region of the radiating portion that is disposed on a first side of the CPW transmission line and a second region of the radiating portion that is disposed on a second side of the CPW transmission line.

TECHNICAL FIELD

The technical field generally relates to antennas, and, more particularly, to antennas with multiple functions, for example for use in vehicles.

BACKGROUND

Antennas are used in vehicles, among other applications. A typical vehicle may use several antennas, such as, by way of example only, a cellular antenna, a personal communications service (PCS) antenna, a global positioning system (GPS) antenna, and a satellite radio antenna, among others. Typically, the vehicle has a different antenna performing each of these functions. Such multiple antennas may be mounted together on a vehicle, for example on a roof of the vehicle. However, such use and/or mounting of multiple antennas can be costly to manufacture and/or install on vehicles, and may occupy more than desired space on the vehicles.

Accordingly, it is desirable to provide an improved antenna, such as for use in connection with a vehicle, for example that provides increased functionality and/or reduced manufacturing and/or installation costs and/or that occupies reduced space on the vehicle. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

SUMMARY

In accordance with one example, an antenna is provided. The antenna comprises a coplanar waveguide (CPW) transmission line and a radiating portion. The radiating portion is coupled to the CPW transmission line, and is configured to produce a linear polarization at a first frequency and a circular polarization at a second frequency.

In accordance with another example, an antenna is provided. The antenna comprises a CPW transmission line and a radiating portion. The radiating portion is coupled to the CPW transmission line and is substantially coplanar with the CPW transmission line. The radiating portion is configured to produce a first linear polarization at a first frequency, a circular polarization at a second frequency, and a second linear polarization at a third frequency. The radiating portion comprises a conductive material extending from the CPW transmission line and forming a plurality of openings in the radiating portion. The plurality of openings are asymmetric with respect to a first region of the radiating portion that is disposed on a first side of the CPW transmission line and a second region of the radiating portion that is disposed on a second side of the CPW transmission line.

In accordance with a further example, an antenna is provided. The antenna comprises a CPW transmission line and a radiating portion. The radiating portion is coupled to the CPW transmission line, and is substantially coplanar with the CPW transmission line. The radiating portion is configured to produce a first linear polarization at a first frequency, a circular polarization at a second frequency, and a second linear polarization at a third frequency. The radiating portion comprises a conductive material extending from the CPW transmission line and forming a first strip of the radiating portion in contact with and perpendicular to the waveguide, a second strip of the radiating portion in contact with and perpendicular to the first strip, a third strip of the radiating portion in contact with the first strip and parallel to the second strip, a fourth strip of the radiating portion in contact with the second strip and the third strip and parallel to the first strip, and a first rectangular conductive region connected to the first strip and the second strip in a first region that is disposed on a first side of the CPW transmission line but not in a second region that is disposed on a second side of the CPW transmission line.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature, and is not intended to limit the disclosure or the application and uses thereof. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, or the following detailed description.

With reference toFIG. 1, there is shown a non-limiting example of a communication system10that may be used together with examples of the systems disclosed herein. The communication system generally includes a vehicle12, a wireless carrier system14, a land network16and a call center18. It should be appreciated that the overall architecture, setup and operation, as well as the individual components of the illustrated system are merely exemplary and that differently configured communication systems may also be utilized to implement the examples of the method disclosed herein. Thus, the following paragraphs, which provide a brief overview of the illustrated communication system10, are not intended to be limiting.

Vehicle12may be any type of mobile vehicle such as a motorcycle, car, truck, recreational vehicle (RV), boat, plane, and the like, and is equipped with suitable hardware and software that enables it to communicate over communication system10. Some of the vehicle hardware20is shown generally inFIG. 1including a telematics unit24, a microphone26, a speaker28, and buttons and/or controls30connected to the telematics unit24. Operatively coupled to the telematics unit24is a network connection or vehicle bus32. Examples of suitable network connections include a controller area network (CAN), a media oriented system transfer (MOST), a local interconnection network (LIN), an Ethernet, and other appropriate connections such as those that conform with known ISO (International Organization for Standardization), SAE (Society of Automotive Engineers), and/or IEEE (Institute of Electrical and Electronics Engineers) standards and specifications, to name a few.

The telematics unit24is an onboard device that provides a variety of services through its communication with the call center18, and generally includes an electronic processing device38, one or more types of electronic memory40, a cellular chipset/component34, a wireless modem36, a multiple mode antenna70, and a navigation unit containing a GPS chipset/component42. In one example, the wireless modem36includes a computer program and/or set of software routines adapted to be executed within the electronic processing device38. The antenna70is configured to operate at various frequency bands, and produces linear and circular polarization, for example as depicted inFIGS. 2-11and described further below in connection therewith. In one example, the antenna70is preferably mounted against or within a windshield71of the vehicle12

The telematics unit24may provide various services including: turn-by-turn directions and other navigation-related services provided in conjunction with the GPS chipset/component42; airbag deployment notification and other emergency or roadside assistance-related services provided in connection with various crash and/or collision sensor interface modules66and collision sensors68located throughout the vehicle; and/or infotainment-related services where music, internet web pages, movies, television programs, videogames, and/or other content are downloaded by an infotainment center46operatively connected to the telematics unit24via vehicle bus32and audio bus22. In one example, downloaded content is stored for current or later playback. The above-listed services are by no means an exhaustive list of all the capabilities of telematics unit24, but are simply an illustration of some of the services that the telematics unit may be capable of offering. It is anticipated that telematics unit24may include a number of additional components in addition to and/or different components from those listed above. The telematics unit24comprises and/or is implemented in connection with an antenna70, for example as depicted inFIGS. 2-11and described further below in connection therewith.

Vehicle communications may use radio transmissions to establish a voice channel with wireless carrier system14so that both voice and data transmissions can be sent and received over the voice channel. Vehicle communications are enabled via the cellular chipset/component34for voice communications and the wireless modem36for data transmission. In order to enable successful data transmission over the voice channel, wireless modem36applies some type of encoding or modulation to convert the digital data so that it can be communicated through a vocoder or speech codec incorporated in the cellular chipset/component34. Any suitable encoding or modulation technique that provides an acceptable data rate and bit error rate can be used with the present examples. The antenna70services the GPS chipset/component42and the cellular chipset/component34.

Microphone26provides the driver or other vehicle occupant with a means for inputting verbal or other auditory commands, and can be equipped with an embedded voice processing unit utilizing a human/machine interface (HMI) technology known in the art. Conversely, speaker28provides audible output to the vehicle occupants and can be either a stand-alone speaker specifically dedicated for use with the telematics unit24or can be part of a vehicle audio component64. In either event, microphone26and speaker28enable vehicle hardware20and call center18to communicate with the occupants through audible speech. The vehicle hardware also includes one or more buttons and/or controls30for enabling a vehicle occupant to activate or engage one or more of the vehicle hardware20components. For example, one of the buttons and/or controls30can be an electronic pushbutton used to initiate voice communication with call center18(whether it be a human such as advisor58or an automated call response system). In another example, one of the buttons and/or controls30can be used to initiate emergency services.

The audio component64is operatively connected to the vehicle bus32and the audio bus22. The audio component64receives analog information, rendering it as sound, via the audio bus22. Digital information is received via the vehicle bus32. The audio component64provides amplitude modulated (AM) and frequency modulated (FM) radio, compact disc (CD), digital video disc (DVD), and multimedia functionality independent of the infotainment center46. Audio component64may contain a speaker system, or may utilize speaker28via arbitration on vehicle bus32and/or audio bus22.

The vehicle crash and/or collision detection sensor interface66is operatively connected to the vehicle bus32. The collision sensors68provide information to the telematics unit via the crash and/or collision detection sensor interface66regarding the severity of a vehicle collision, such as the angle of impact and the amount of force sustained.

Vehicle sensors72, connected to various sensor interface modules44are operatively connected to the vehicle bus32. Exemplary vehicle sensors include but are not limited to gyroscopes, accelerometers, magnetometers, emission detection, and/or control sensors, and the like. Exemplary sensor interface modules44include powertrain control, climate control, and body control, to name but a few.

Wireless carrier system14may be a cellular telephone system or any other suitable wireless system that transmits signals between the vehicle hardware20and land network16. According to an example, wireless carrier system14includes one or more cell towers48, base stations and/or mobile switching centers (MSCs)50, as well as any other networking components required to connect the wireless carrier system14with land network16. As appreciated by those skilled in the art, various cell tower/base station/MSC arrangements are possible and could be used with wireless carrier system14. For example, a base station and a cell tower could be co-located at the same site or they could be remotely located, and a single base station could be coupled to various cell towers or various base stations could be coupled with a single MSC, to list but a few of the possible arrangements. A speech codec or vocoder may be incorporated in one or more of the base stations, but depending on the particular architecture of the wireless network, it could be incorporated within a Mobile Switching Center or some other network components as well.

Land network16can comprise a conventional land-based telecommunications network that is connected to one or more landline telephones, and that connects wireless carrier system14to call center18. For example, land network16can include a public switched telephone network (PSTN) and/or an Internet protocol (IP) network, as is appreciated by those skilled in the art. Of course, one or more segments of the land network16can be implemented in the form of a standard wired network, a fiber or other optical network, a cable network, other wireless networks such as wireless local networks (WLANs) or networks providing broadband wireless access (BWA), or any combination thereof.

Call center18is designed to provide the vehicle hardware20with a number of different system back-end functions and, according to the example shown here, generally includes one or more switches52, servers54, databases56, advisors58, as well as a variety of other telecommunication/computer equipment60. These various call center components are suitably coupled to one another via a network connection or bus62, such as the one previously described in connection with the vehicle hardware20. Switch52, which can be a private branch exchange (PBX) switch, routes incoming signals so that voice transmissions are usually sent to either the live advisor58or an automated response system, and data transmissions are passed on to a modem or other piece of telecommunication/computer equipment60for demodulation and further signal processing. The modem or other telecommunication/computer equipment60may include an encoder, as previously explained, and can be connected to various devices such as a server54and database56. For example, database56could be designed to store subscriber profile records, subscriber behavioral patterns, or any other pertinent subscriber information. Although the illustrated example has been described as it would be used in conjunction with a manned call center18, it will be appreciated that the call center18can be any central or remote facility, manned or unmanned, mobile or fixed, to or from which it is desirable to exchange voice and data.

FIGS. 2 and 3are schematic illustrations of a non-limiting example of an antenna70.FIG. 2depicts the antenna70from a top view, andFIG. 3depicts the antenna from a bottom view that is opposite to or flipped from the view ofFIG. 2. The antenna70preferably corresponds to the antenna70of the communication system10ofFIG. 1, and preferably is used in connection with the communication system10and the telematics unit24ofFIG. 1. The antenna70may be mounted on or within a windshield71of the vehicle12ofFIG. 1, or otherwise on or within the vehicle12. For example, as shown inFIG. 3, the antenna70may be mounted on an inside or interior portion of the windshield71ofFIG. 1. In one preferred example, the antenna70has a size of approximately five centimeters in width and eleven centimeters in length.

The antenna70is a flat, planar, slot type antenna that is fed by a coplanar waveguide (CPW) transmission line210. The CPW transmission line210comprises a signal conductor and ground conductor on both the left and right sides of the signal conductor. The antenna70operates at multiple frequencies, preferably including cellular frequencies, personal communications service (PCS) frequencies, global positioning system (GPS) frequencies, GLONASS (Global Navigation Satellite System) frequencies, and satellite radio frequencies, while also providing for linear and circular polarizations at different frequencies as required by such frequency bands. The antenna70provides these features with a single antenna structure and with a single feed that can help minimize the size and cost of providing such antenna functionality for the vehicle.

As depicted inFIGS. 2 and 3, the antenna70includes an upper region202and a lower region204. Both the upper region202and the lower region204are flat and co-planar with one another, and include a conductive material206disposed on top of a substrate208. In one example, the conductive material206comprises copper, and the substrate208comprises a thin film substrate, such as a thin film substrate sold under the trademark Kapton, which has the dielectric constant of approximately 3.4 to 3.5 and loss tangent (tan δ=0.0015). Also in one example, the conductive material206has a thickness of between 0.2 and 1.0 mils (preferably approximately 0.5 mils), and the substrate208has a thickness of between one mil and three mils (preferably approximately two mils).

The upper region202is a non-radiating portion of the antenna70. The upper region202includes the above-referenced coplanar waveguide transmission line210that is at least substantially flat and coplanar with the lower region204. The CPW transmission line210is electrically coupled between the lower region204and a coaxial cable212. In certain examples, the coaxial cable212may also be considered to be part of the antenna70. In other examples, the coaxial cable212may be considered to be a separate component that is electrically coupled to the antenna70.

Turning briefly toFIGS. 4 and 5, an exemplary interface between the coaxial cable212and the CPW transmission line210is illustrated, in accordance with one example. Specifically, as shown inFIGS. 4 and 5, the coaxial cable212has an end400having a connector (e.g., an SMA connector, a Fakra connector, or the like) that can be connected to other components or systems, such as a receiver or a system that includes a receiver. The coaxial cable212also includes an outer jacket402(preferably made of PVC) that provides protection for the coaxial cable212.

In addition, the coaxial cable212includes a braided shield404, an insulator406, and a center conductor408. The CPW transmission line has a ground conductor510and a signal conductor512. The braided shield404of the coaxial cable212is soldered onto the ground conductor510of the CPW transmission line210. The center conductor408of the coaxial cable212is soldered onto the signal conductor512of the coplanar ground plane210, and the signal conductor512is electrically coupled and connected to the lower region204of the antenna70.

In certain examples, the interface between the coaxial cable212and the CPW transmission line210may vary. For example, if a clear conductive material206is desired, then the coaxial cable212may be interfaced with the CPW transmission line210in a manner such as that described in commonly assigned U.S. patent application Ser. No. 12/622,683, entitled “Connector Assembly and Method of Assembling a Connector Arrangement Utilizing the Connector Assembly”, filed on Nov. 20, 2009, and incorporated herein by reference.

Returning now toFIGS. 2 and 3, the lower region204of the antenna70comprises a radiating portion204of the antenna70. Although the radiating portion204utilizes a single CPW transmission line210and a single electrical feed therefrom, the radiating portion radiates at different frequencies, and provides linear and circular polarization as required at such various frequencies. The radiating portion204preferably operates in this manner for one or more cellular, PCS, GPS, GLONASS, and satellite radio frequency bands. In one example, the radiating portion204provides (i) vertical, linear polarization at one or more cellular bands (e.g., 824-894 MHz) and one or more PCS bands (e.g., 1850-1990 MHz); (ii) right hand circular polarization at one or more GPS bands (e.g., 1574.4-1576.4 MHz) and GLONASS (Global Navigation Satellite System) bands (e.g., 1598-1605 MHz); and (iii) left hand circular polarization at one or more satellite radio bands (e.g., 2332.5 to 2345 MHz).

Also as depicted inFIGS. 2 and 3, the conductive material206defines an outer periphery of the radiating portion204that comprises a first strip214, a second strip216, a third strip218, and a fourth strip220of the radiating portion204. As used herein, a strip includes an outer boundary or later of the conductive material206. The first strip214of the radiating portion204is in contact with and is perpendicular to the CPW transmission line210. The second strip216of the radiating portion204is in contact with and is perpendicular to the first strip214. The third strip218of the radiating portion204is in contact with the first strip214and is parallel to the second strip216. The fourth strip220of the radiating portion204is in contact with the second strip216and the third strip218, and is parallel to the first strip214. In the depicted example, a length246of the radiating portion204along the second strip216or the third strip218is within a range of 50 millimeters to 90 millimeters (most preferably approximately equal to 69 millimeters), and a width of the radiating portion204along the first strip214or the fourth strip220is within a range of 30 millimeters to 70 millimeters (and most preferably approximately equal to 50 millimeters).

The conductive material206also defines a conductive border222surrounding each of the first, second, third, and fourth strips214,216,218and220. In a preferred example, the conductive border222is approximately 5 mm wide. However, this may vary.

In addition, the conductive material206defines a first rectangular conductive region224, a second rectangular conductive region226, and a non-rectangular conductive region228, all within the radiating portion204of the antenna70(i.e., within the area encompassed by the first, second, third, and fourth strips214,216,218, and220). The first rectangular conductive region (or box)224is connected to the first strip214(or the conductive border222thereof) and the second strip216(or the conductive border222thereof). The first rectangular conductive region224is disposed in a second region243(depicted on the right hand side of the radiating portion204inFIG. 2) that is located on a second side of the CPW transmission line210, but is not disposed in a first region241(depicted on the left hand side of the radiating portion204inFIG. 2) that is located on a second side of the CPW transmission line210. This asymmetry with respect to the first and second regions241,243helps to generate desired circular polarization by providing a phase difference of approximately 90°, for example at GPS, GLONASS, and satellite radio frequency bands. In the depicted example, the first rectangular conductive region224has a length250that is within a range of 15 millimeters to 35 millimeters (and most preferably equal to approximately 18 millimeters). The first rectangular conductive region224provides the necessary phase difference required for CP and helps the antenna structure resonate at broader frequencies by making the slot size smaller in the right side region, and is particularly important for making the antenna broadband in general.

The second rectangular conductive region226extends from the first strip214(or the conductive border222thereof) along a centerline251of the radiating portion204. The second rectangular conductive region226is preferably longer and narrower than the first rectangular conductive region224, and is preferably adjacent to the first rectangular conductive region224. In the depicted example, the second rectangular conductive region226has a length within a range of 25 millimeters to 50 millimeters (and most preferably equal to approximately 37 millimeters). The second rectangular conductive region226extends closer to the fourth strip220than does the first rectangular conductive region224. The second rectangular conductive region226is a transition region from the CPW210to asymmetric slot regions and excites the entire antenna structure. The second rectangular conductive region226is particularly important for creating vertical, linear polarization at the cellular frequency bands in conjunction with the bent strip230,232,234.

The non-rectangular conductive region228is disposed by branching off the fourth strip220. The non-rectangular conductive region228forms a bent in order to fit the long conducting path, which includes a first portion (or segment)230, a second portion (or segment)232, and a third portion (or segment)234, within the conductive border222.

The first portion230extends linearly from the fourth strip220(or the conductive border222thereof), and is perpendicular to the fourth strip220. In the depicted example, the first portion230has a length that is within a range of 23 millimeters to 25 millimeters (and most preferably equal to approximately 24 millimeters), and a width that is within a range of 4.5 millimeters to 5.5 millimeters (and most preferably equal to approximately 4.8 millimeters).

The second portion232extends from the first portion230, and is parallel to the fourth strip220. In the depicted example, the second portion232has a length that is within a range of 12.5 millimeters to 13.5 millimeters (and most preferably equal to approximately 12.8 millimeters), and a width that is within a range of 5 millimeters to 6 millimeters (and most preferably equal to approximately 5.5 millimeters).

The third portion234extends from the second portion232, and is parallel to the first portion230. In the depicted example, the third portion234has a length that is within a range of 22 millimeters to 24 millimeters (and most preferably equal to approximately 23 millimeters), and a width that is within a range of 4.5 millimeters to 5.5 millimeters (and most preferably equal to approximately 4.8 millimeters).

Together, the first, second, and third portions230,232, and234form a bent microstrip shape for the non-rectangular conductive region228. The non-rectangular conductive region228extends the antenna's resonance at cellular frequency bands, and is particularly important for creating vertical linear polarization at the cellular frequency bands.

Also as depicted inFIGS. 2 and 3, the radiating portion204includes various asymmetric openings (or gaps) that are formed, defined, and/or surrounded by the conductive material206. The gaps represent regions in which the substrate208is present but the conductive material206is not present (and, specifically, include regions in which the substrate208is not directly covered, but that the regions are directly surrounded by, the conductive material206). For example, during manufacture, the conductive material206may be scraped off or otherwise removed to leave the bare substrate208to form the open spaces (or gaps). The various openings (or gaps) are asymmetric, for example with respect to the first region241and the second region243of the radiating portion204of the antenna70. The asymmetric configuration of the shapes, sizes, and locations of the various openings (or gaps) results in openings (or gaps) that resonate at different frequencies (as described in greater detail below) and introduce a ninety degree phase difference between two current paths from a signal strip of the CPW transmission line210, and thereby generates desired circular polarizations at appropriate frequencies (such as, right hand circular polarization at GPS and GLONASS frequency bands and left hand circular polarization at satellite radio frequency bands).

Specifically, as depicted inFIGS. 2 and 3, a first opening (or gap)236is formed between a bottom portion of the second rectangular conductive region226and the second portion232of the non-rectangular conductive region228. In the depicted example, the first gap236is within a range of 2 to 4 millimeters wide (most preferably equal to approximately 3 millimeters wide).

In addition, also as depicted inFIGS. 2 and 3, a second opening (or gap)238is formed between a bottom portion of the third portion234of the non-rectangular conductive region228and the fourth strip220(or the conductive barrier222thereof). In the depicted example, the second gap238is within a range of 0.5 to 1.5 millimeters wide (most preferably equal to approximately 1.3 millimeters wide).

A third opening (or gap)240is disposed within the first region241of the radiating portion204of the antenna70. The third gap240is generally bounded by the second strip216(or the conductive border222thereof), the first strip214(or the conductive border222thereof), the second rectangular conductive region226, the non-rectangular conductive region228, and the fourth strip220or the conductive border222thereof). The third gap240is significantly larger than all of the other gaps, including the first and second gaps236,238(described above) and the fourth and fifth gaps242,244(described below). In the depicted example, the third opening240is within a range of 17 to 19 millimeters wide (most preferably equal to approximately 18.3 millimeters wide), and is within a range of 58 to 60 millimeters long (most preferably equal to approximately 59 millimeters long). The third opening240together with the base antenna structure222provides resonances at mid frequencies including the GPS frequency band.

A fourth opening (or gap)242is disposed within the second region243of the radiating portion204of the antenna70. The fourth gap242is generally bounded by a bottom portion of the first rectangular conductive region224, the third strip218(or the conductive border222thereof), the fourth strip220(or the conductive border222thereof), the non-rectangular conductive region234, and the second rectangular conductive region226. The fourth gap242is significantly larger than all of the other gaps, including the first and second gaps236,238(described above) and the fifth gap244(described below), but is smaller than the third gap240(described above). In the depicted example, the fourth gap242is within a range of 17 to 19 millimeters wide (most preferably equal to approximately 18.3 millimeters wide), and is within a range of 39 to 41 millimeters long (most preferably equal to approximately 40 millimeters long). The fourth opening242together with the base antenna structure222provide resonances at higher frequencies including the XM frequency band.

In addition, a fifth opening (or gap)244is disposed near the centerline251of the radiating portion204of the antenna70. The fifth gap244is generally bounded by the first, second, and third portions230,232,234of the non-rectangular conductive region228and the by the fourth strip220(or the conductive border222thereof). In the depicted example, the fifth gap244is within a range of 2 to 4 millimeters wide (most preferably equal to approximately 3.2 mm wide), and is within a range of 18 to 20 millimeters long (most preferably equal to approximately 18.7 millimeters long).

The fabricated antenna70can be installed or integrated onto the windshield71or window glass by applying dielectric adhesive on the non-conductor side of the antenna70and pressing the antenna70against the glass. In various examples, there may be multiple ways of integrating and/or installing the antenna on or within the windshield71or window glass. The antenna70can also be designed and fabricated for a standard non-flexible PCB. In one example, the antenna70can be housed in a non-conducting package and then installed onto the windshield71or window glass surface. In accordance with the example ofFIG. 3, the fabricated antenna70was installed just behind the rear view mirror on the windshield71glass of a convertible type passenger vehicle.

FIG. 6includes a graphical representation600illustrating exemplary reflection coefficients of the antenna ofFIG. 2at different frequencies. Specifically, radiation patterns of the installed antenna were measured at various frequencies of the Cell, PCS, GPS and GLONASS bands in an anechoic chamber. OnFIG. 6, the x-axis represents frequency (in GHz), and the y-axis represents the reflection coefficient (in dB). The graphical representation600displays a first resonance602at a cellular frequency band, a second resonance604at a GPS frequency band, a third resonance606at a GLONASS frequency band, a fourth resonance608at a PCS frequency band, a fifth resonance610at a satellite radio frequency band, and a sixth resonance612at a Wi-Fi frequency band. As shown inFIG. 6, the reflection coefficients are less than −10 dB for each of the above-referenced frequency bands, and the antenna70provides an excellent impedance match at each of these frequency bands.

FIG. 7includes a graphical representation700illustrating exemplary phase differences of the antenna ofFIG. 2at different frequencies. Specifically, the graphical representation700represents a simulated phase difference between the two current paths, using finite element method (FEM) based software. The x-axis of the graphical representation700represents frequency (in GHz), and the y-axis represents phase difference (in degrees) between the two current paths. As is shown inFIG. 7, the phase difference is approximately 90 degrees (±15 degrees) at a first point702and a second point704over the GPS and GLONASS bands, respectively. The opposite sense of circular polarization can be obtained by simply exchanging the asymmetric slots, for example for use in connection with a satellite radio frequency band.

FIGS. 8-11provide graphical representations of various polarized radiation patterns of an example of the antenna70at various frequencies. Specifically, (i)FIG. 8provides a graphical representation800of a vertical, linearly polarized radiation pattern802of an example of the antenna70at a cellular frequency band of 869 MHz and an elevation angle of 85 degrees with reference to zenith, along with a reference radiation pattern804of a reference production antenna under the same conditions; (ii)FIG. 9provides a graphical representation900of a vertical, linearly polarized radiation pattern902of an example of the antenna70at a PCS frequency band of 1930 MHz and a reference elevation angle of 85 degrees, along with a reference radiation pattern904of a reference production antenna under the same conditions; (iii)FIG. 10provides a graphical representation1000of a right hand circularly polarized radiation pattern1002of an example of the antenna70at a GPS frequency band of 1.575 GHz and a reference elevation angle of 60 degrees, along with a reference radiation pattern1004of a reference production antenna under the same conditions; and (iv)FIG. 11provides a graphical representation1100of a right hand circularly polarized radiation pattern1102of an example of the antenna70at a GLONASS frequency band of 1.602 GHz and a reference elevation angle of 60 degrees.

The graphical representations ofFIGS. 8-11illustrate that the single, multi-functional antenna70provides antenna performance comparable to that of a production antenna at various different frequency bands with different polarization requirements. The single, multi-functional antenna70performs as well as or better than typical existing vehicle antenna modules having separate, individual antennas for each different frequency band. The single, multi-functional antenna70provides these functions with a single coaxial cable feed and a single CPW transmission line in a relatively flat and compact envelope, thereby providing for potential cost savings in manufacture and installation as well as reduced size and easier placement in vehicles of various types.

It will be appreciated that the disclosed systems and components thereof may differ from those depicted in the figures and/or described above. For example, the communication system10, the telematics unit24, and/or various parts and/or components thereof may differ from those ofFIG. 1and/or described above. Similarly, the antenna70and/or various parts or components thereof may differ from those ofFIGS. 2-5and/or described above, and/or the graphical results may differ from those depicted inFIGS. 6-11.

Similarly, it will be appreciated that, while the disclosed systems are described above as being used in connection with automobiles such as sedans, trucks, vans, and sports utility vehicles, the disclosed systems may also be used in connection with any number of different types of vehicles, and in connection with any number of different systems thereof and environments pertaining thereto.