Millimeter-wave chip-lens array antenna systems for wireless networks

Embodiments of chip-lens array antenna systems are described. In some embodiments, the chip-lens array antenna systems (100) may comprise a millimeter-wave lens (104), and a chip-array antenna (102) to generate and direct millimeter-wave signals through the millimeter-wave lens (104) for subsequent transmission.

This application is a U.S. National Stage Filing under 35 U.S.C. 371 from International Application No. PCT/RU2006/000256, filed May 23, 2006 and published in English as WO 2007/136289 on Nov. 29, 2007, which application and publication are incorporated herein by reference in their entireties.

RELATED APPLICATIONS

This patent application relates to International Application No. PCT/RU2006/000257, filed May 23, 2006 and published in English as WO 2007/136290 on Nov. 29, 2007.

TECHNICAL FIELD

Some embodiments of the present invention pertain to wireless communication systems that use millimeter-wave signals. Some embodiments relate to antenna systems.

BACKGROUND

Many conventional wireless networks communicate using microwave frequencies generally ranging between two and ten gigahertz (GHz). These systems generally employ either omnidirectional or low-directivity antennas primarily because of the comparatively long wavelengths of the frequencies used. The low directivity of these antennas may limit the throughput of such systems. Directional antennas could improve the throughput of these systems, but the wavelength of microwave frequencies make compact directional antennas difficult to implement. The millimeter-wave band may have available spectrum and may be capable of providing higher throughput levels.

Thus, there are general needs for compact directional millimeter-wave antennas and antenna systems suitable for use in wireless communication networks. There are also general needs for compact directional millimeter-wave antennas and antenna systems that may improve the throughput of wireless networks.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustrate specific embodiments of the invention to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments of the invention set forth in the claims encompass all available equivalents of those claims. Embodiments of the invention may be referred to herein, individually or collectively, by the term “invention” merely for convenience and without intending to limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed.

FIGS. 1A and 1Billustrate a chip-lens array antenna system in accordance with some embodiments of the present invention. Chip-lens array antenna system100comprises chip-array antenna102and millimeter-wave lens104.FIG. 1Amay illustrate a top-view of chip-lens array antenna system100andFIG. 1Bmay illustrate a side-view of chip-lens array antenna system100. Chip-lens array antenna system100may generate diverging beam110in first plane115and may generate substantially non-diverging beam112in second plane117.

Chip-array antenna102generates and directs an incident beam of millimeter-wave signals through millimeter-wave lens104for subsequent transmission to user devices. Millimeter-wave lens104has inner surface106and outer surface108with curvatures selected to provide diverging beam110in first plane115and substantially non-diverging beam112in second plane117. In these embodiments, the incident beam of millimeter-wave signals directed by chip-array antenna102may be viewed as being squeezed in second plane117and may remain unchanged in first plane115.

In some embodiments, inner surface106may be defined by substantially circular arc126in first plane115and substantially circular arc136in second plane117. In the embodiments illustrated inFIGS. 1A and 1B, outer surface108may be defined by substantially circular arc128in first plane115and by elliptical arc138in second plane117. In these embodiments, inner surface106, when defined by a substantially circular arc in both first plane115and second plane117, may comprise a substantially spherical inner surface, although the scope of the invention is not limited in this respect.

In some embodiments, first plane115may be a horizontal plane, second plane117may be a vertical plane, and diverging beam110may be a fan-shaped beam in the horizontal plane. In some embodiments, chip-array antenna102may generate wider incident beam103in the vertical plane and narrower incident beam113in the horizontal plane for incidence on inner surface106of millimeter-wave lens104. Wider incident beam103may be converted to substantially non-diverging beam112by millimeter-wave lens104, and narrower incident beam113may be converted to diverging beam110by millimeter-wave lens104.

In the embodiments illustrated inFIGS. 1A and 1B, diverging beam110and narrower incident beam113may have approximately equal beamwidths when outer surface108is defined by substantially circular arc128in first plane115. For example, in some embodiments, wider incident beam103in vertical plane117may have a beamwidth of sixty degrees as illustrated inFIG. 1B, while narrower incident beam113in horizontal plane115may have a beamwidth of thirty degrees as illustrated inFIG. 1A, although the scope of the invention is not limited in this respect. In these embodiments, wider incident beam103, and narrower incident beam113, may both be diverging beams. In horizontal plane115, millimeter-wave lens104may have little or no effect on narrower incident beam113, shown as having a beamwidth of thirty degrees, to provide diverging beam110, which may also have a beamwidth of thirty degrees. In vertical plane117, millimeter-wave lens104may convert wider incident beam103to substantially non-diverging beam112.

In some embodiments, the beamwidths of wider incident beam103and narrower incident beam113may refer to the scanning angles over which chip-lens array antenna102may direct an incident beam to millimeter-wave lens104. These embodiments may provide for a wide-angle scanning capability in the horizontal plane. The scanning angle and the beamwidth in the horizontal plane may both be determined by the dimensions of chip-array antenna102, whereas the beamwidth in the vertical plane may be primarily determined by the vertical aperture size of millimeter-wave lens104.

In some embodiments, chip-lens antenna102may scan or steer an incident beam within millimeter-wave lens104to scan or steer beams110and112outside of millimeter-wave lens104, although the scope of the invention is not limited in this respect. These embodiments are discussed in more detail below.

In some embodiments, anti-reflective layer107may be disposed on inner surface106of millimeter-wave lens104to help reduce reflections of incident millimeter-wave signals transmitted by chip-array antenna102. In some embodiments, anti-reflective layer107may be a layer of millimeter-wave transparent material comprising a material that is different than the material of millimeter-wave lens104. The thickness of anti-reflective layer107may be selected so that millimeter-waves reflected from an incident surface of anti-reflective layer107and the millimeter-waves reflected from inner surface106(i.e., behind anti-reflective layer107) may substantially cancel eliminating most or all reflected emissions. In some embodiments, thickness of anti-reflective layer107may be about a quarter-wavelength when the refraction index of anti-reflective layer107is between that of millimeter-wave lens104and the air, although the scope of the invention is not limited in this respect. In some embodiments, the thickness of anti-reflective layer107may be much greater than a wavelength. In some embodiments, one or more anti-reflective layers may be used to further suppress reflections, although the scope of the invention is not limited in this respect. In some embodiments, an anti-reflective layer or anti-reflective coating may be disposed on outer surface108.

In some embodiments, anti-reflective layer107may comprise an anti-reflective coating, although the scope of the invention is not limited in this respect. In some embodiments, the use of anti-reflective layer107may reduce the input reflection coefficient so that when chip-lens array antenna system100is transmitting, any feedback as a result of reflections back to chip-array antenna102is reduced. This may help to avoid an undesirable excitation of the elements of chip-array antenna102. The reduced feedback may also help improve the efficiency of chip-lens antenna system100.

In some embodiments, chip-array antenna102comprises either a linear (i.e., one-dimensional) or planar (i.e., two-dimensional) array of individual antenna elements coupled to a radio-frequency (RF) signal path through control elements. The control elements may be used to control the amplitude and/or the phase shift between elements for steering the incident beam within the millimeter-wave lens. In some embodiments, when chip-array antenna102comprises a planar array of antenna elements, the control elements may set the amplitude and/or the phase shift for the antenna elements (e.g., to achieve a desired scanning angle) although the scope of the invention is not limited in this respect. In this way, wide and narrow incident beams of various beamwidths and scanning angles may be generated. In some embodiments, the rows of antenna elements may be controlled individually to direct the antenna beam.

In some embodiments, a linear phase-shift may be provided across the rows of the antenna elements. In some embodiments, an array-excitation function may be applied to the antenna elements of chip-array antenna102to achieve certain characteristics of the antenna beam, such as a particular power profile and/or side-lobe levels. For example, a uniform amplitude distribution across the array of antenna elements with linear phase shifts in the horizontal directional and with a constant phase in the vertical direction may be used to help achieve some of the characteristics of beams110and112, although the scope of the invention is not limited in this respect. In some other embodiments, a Dolf-Chebyshev distribution or Gaussian power profile may be used for the amplitude and/or phase shifts across the antenna elements of chip-array antenna102, although the scope of the invention is not limited in this respect.

Controlling the amplitude and/or phase difference between the antenna elements of chip-array antenna102may steer or direct the beams within a desired coverage area. It should be noted that the shape of millimeter-wave lens104provides for the characteristics of beams110and112, while controlling and changing the amplitude and/or phase difference between the antenna elements may steer and direct the beams.

In some embodiments, the antenna elements of chip-array antenna102may comprise dipole radiating elements, although the scope of the invention is not limited in this respect as other types of radiating elements may also be suitable. In some embodiments, the antenna elements of chip-array antenna102may be configured in any one of a variety of shapes and/or configurations including square, rectangular, curved, straight, circular, or elliptical shapes.

In some embodiments, millimeter-wave lens104may be spaced apart from chip-array antenna102to provide cavity105therebetween. In some embodiments, cavity105may be air filled or filled with an inert gas. In other embodiments, cavity105may comprise a dielectric material having a higher permittivity and/or higher index of refraction at millimeter-wave frequencies than millimeter-wave lens104. Due to the lower permittivity and/or lower index of refraction of the dielectric material that may be within cavity105, less millimeter-wave reflections from inner surface106may result. In these embodiments, one or more foci may be implemented to help provide multiple antenna sectors, although the scope of the invention is not limited in this respect.

In some embodiments, millimeter-wave lens104may be made of a solid millimeter-wave dielectric material, such as a millimeter-wave refractive material having a relative permittivity ranging between 2 and 3 for a predetermined millimeter-wave frequency, although the scope of the invention is not limited in this respect. In some embodiments, cross-linked polymers, such as Rexolite, may be used for the millimeter-wave refractive material, although other polymers and dielectric materials, such as polyethylene, poly-4-methylpentene-1, Teflon, and high density polyethylene, may also be used. Rexolite, for example, may be available from C-LEC Plastics, Inc., Beverly, N.J., USA. In some embodiments, gallium-arsenide GaAs, quartz, and/or acrylic glass may be used for millimeter-wave lens104. Any of these materials may also be selected for anti-reflective layer107provided that it is a different material and has a higher index of refraction than the material used for millimeter-wave lens104. In some other embodiments, millimeter-wave lens104and/or anti-reflective layer107may comprise artificial dielectric materials and may be implemented, for example, as a set of metallic plates or metallic particles distributed within a dielectric material, although the scope of the invention is not limited in this respect.

In some embodiments, millimeter-wave lens104may comprise two or more layers of millimeter-wave dielectric material. In these embodiments, the millimeter-wave dielectric material of a first layer closer to chip-array antenna102may have a higher permittivity than the millimeter-wave dielectric material of a second layer, although the scope of the invention is not limited in this respect.

In some embodiments, the millimeter-wave signals transmitted and/or received by chip-lens antenna system100may comprise multicarrier signals having a plurality of substantially orthogonal subcarriers. In some embodiments, the multicarrier signals may comprise orthogonal frequency division multiplexed (OFDM) signals, although the scope of the invention is not limited in this respect. The millimeter-wave signals may comprise millimeter-wave frequencies between approximately 60 and 90 Gigahertz (GHz). In some embodiments, the millimeter-wave signals transmitted and/or received by chip-lens antenna system100may comprise single-carrier signals, although the scope of the invention is not limited in this respect.

FIGS. 2A and 2Billustrate a chip-lens array antenna system in accordance with some embodiments of the present invention. Chip-lens array antenna system200comprises chip-array antenna202and millimeter-wave lens204.FIG. 2Amay illustrate a top-view of chip-lens array antenna system200andFIG. 2Bmay illustrate a side-view of chip-lens array antenna system200. Chip-lens array antenna system200may generate diverging beam210in first plane215and may generate substantially non-diverging beam212in second plane217.

In the embodiments illustrated inFIGS. 2A and 2B, outer surface208may be defined by elliptical arc228in first plane215and by elliptical arc238in second plane217. Inner surface206may be defined by substantially circular arc226in first plane215and substantially circular arc236in second plane217.

In the embodiments illustrated inFIGS. 2A and 2B, diverging beam210may have a substantially narrower beamwidth than narrower incident beam213when outer surface208is defined by elliptical arc228in first plane215. In these embodiments, the incident beam of millimeter-wave signals directed by chip-array antenna202may be viewed as being squeezed in both second plane217and first plane215, although the incident beam may be viewed as being squeezed less in first plane215. In this way, chip-lens array antenna system200may provide a higher antenna gain with a smaller scanning angle in first plane215as compared to chip-lens array antenna system100(FIGS. 1A and 1B).

In the embodiments illustrated inFIGS. 2A and 2B, wider incident beam203and narrower incident beam213may both be diverging beams. In these embodiments in horizontal plane215, millimeter-wave lens204may convert narrower incident beam213, shown as having a beamwidth of approximately thirty degrees, to diverging beam210of a substantially reduced beamwidth, shown as having a beamwidth of approximately fifteen degrees. In vertical plane217, millimeter-wave lens204may convert wider incident beam203, shown as having a beamwidth of approximately sixty degrees, to substantially non-diverging beam212. The selection of a particular elliptical arc in a particular plane may determine the beamwidth of a transmitted beam in that plane and whether the transmitted beam is diverging or non-diverging in that plane. In some embodiments, wider incident beam203and narrower incident beam213may refer to the scanning angles over which chip-lens array antenna202may direct an incident beam to millimeter-wave lens204, although the scope of the invention is not limited in this respect.

In some embodiments illustrated inFIGS. 2A and 2B, outer surface208may be defined by first elliptical arc228in first plane215and defined by a second elliptical arc238in second plane217. In these embodiments, first elliptical arc228may have a greater radius of curvature than second elliptical arc238, and diverging beam210may be less diverging than incident beam213generated by chip-array antenna202in first plane215as a result of first elliptical arc228having a greater radius of curvature than second elliptical arc238, although the scope of the invention is not limited in this respect. Elliptical arcs with a greater radius of curvature may refer to ellipses having foci that have a greater separation to provide a ‘flatter’ elliptical arc.

In some embodiments, cavity205may be provided between millimeter-wave lens204and chip-array antenna202. As discussed above in reference to chip-lens array antenna system100(FIG. 1), cavity205may also be filled with either air or an inert gas, or alternatively, cavity205may comprise a dielectric material having a higher permittivity and/or higher index of refraction at millimeter-wave frequencies than millimeter-wave lens204, although the scope of the invention is not limited in this respect. In some embodiments, millimeter-wave lens204may also comprise two or more layers of millimeter-wave dielectric material.

FIG. 3illustrates a chip-lens array antenna system in accordance with some secant-squared (sec2) embodiments of the present invention.FIG. 3illustrates a side-view of chip-lens array antenna system300. Chip-lens array antenna system300comprises millimeter-wave lens304and chip-array antenna302. Chip-array antenna302may generate and direct an incident beam of millimeter-wave signals through millimeter-wave lens304for subsequent transmission to user devices. In these embodiments, millimeter-wave lens304may have substantially spherical inner surface306and may have outer surface308comprising first and second portions318A and318B. First and second portions318A and318B of outer surface308may be selected to provide a substantially omnidirectional pattern in first plane315and substantially secant-squared pattern314in second plane317.

In some embodiments, inner surface306may be defined by substantially circular arc336in both horizontal plane315and vertical plane317, and secant-squared pattern314may provide an antenna gain pattern that depends on elevation angle303to provide user devices with substantially uniform signal levels substantially independent of range. In these embodiments, the curve of outer surface308may represent a solution to a differential equation and may have neither a spherical, an elliptical, nor a parabolic shape. In some embodiments, the curve of outer surface308may be a generatrix curve in which a parameterization has been assigned based on the substantially secant-squared314, although the scope of the invention is not limited in this respect.

In some embodiments, millimeter-wave lens304may be symmetric with respect to vertical axis301. In other words, the shape of millimeter-wave lens304may be obtained by revolving around vertical axis301, although the scope of the invention is not limited in this respect.

In some embodiments, first plane315may be a horizontal plane and second plane317may be a vertical plane. In these embodiments, a substantially omnidirectional pattern in the horizontal plane and substantially secant-squared pattern314in the vertical plane may provide one or more user devices with approximately the same signal power level substantially independent of the distance from millimeter-wave lens304over a predetermined range. In these embodiments, the substantially omnidirectional pattern in the horizontal plane and substantially secant-squared pattern314in the vertical plane may also provide one or more user devices with approximately the same antenna sensitivity for reception of signals substantially independent of the distance from millimeter-wave lens304over the predetermined range. In other words, user devices in the far illumination zone may be able to communicate just as well as user devices located in the near illumination zone.

In some embodiments, cavity305may be provided between millimeter-wave lens304and chip-array antenna302. As discussed above in reference to chip-lens array antenna system100(FIG. 1), cavity305may also be filled with either air or an inert gas, or alternatively, cavity305may comprise a dielectric material having a higher permittivity and/or higher index of refraction at millimeter-wave frequencies than millimeter-wave lens304, although the scope of the invention is not limited in this respect. In some embodiments, millimeter-wave lens304may also comprise two or more layers of millimeter-wave dielectric material.

FIGS. 4A and 4Billustrate a chip-lens array antenna system in accordance with some fully-filled embodiments of the present invention.FIG. 4Amay illustrate a top-view of chip-lens array antenna system400andFIG. 4Bmay illustrate a side-view of chip-lens array antenna system400. In these embodiments, chip-lens array antenna system400includes chip-array antenna402and millimeter-wave refractive material404disposed over chip-array antenna402. Chip-array antenna402generates and directs a beam of millimeter-wave signals within millimeter-wave refractive material404for subsequent transmission to one or more user devices. In these embodiments, millimeter-wave refractive material404has outer surface408, which may be defined by either a substantially circular arc (not shown) or elliptical arc428in first plane415, and elliptical arc438in second plane417. This curvature may generate diverging beam410in first plane415and substantially non-diverging beam412in second plane417.

In these fully-filled embodiments, chip-array antenna402may be at least partially embedded within millimeter-wave refractive material404. Chip-lens array antenna system400may require less space than chip-lens array antenna system100(FIGS. 1A and 1B) or chip-lens array antenna system200(FIGS. 2A and 2B) when configured to achieve similar characteristics and when similar lens material is used. In some embodiments, up to a three times reduction in size may be achieved, although the scope of the invention is not limited in this respect. In some embodiments, the size of chip-array antenna402may be proportionally reduced while the beamwidth within refractive material404may remain unchanged because the wavelength of the millimeter-wave signals may be shorter within refractive material404than, for example, in air. This may help reduce the cost of chip-lens array antenna system400. In these embodiments, the wavefront provided by chip-array antenna402may become more spherical and less distorted near outer surface408. In these embodiments, millimeter-wave refractive material404may reduce distortion caused by the non-zero size of chip-array antenna402providing a more predictable directivity pattern. Furthermore, the absence of reflections from an inner surface may reduce the input reflection coefficient reducing unfavorable feedback to chip-array antenna402.

In some embodiments, a non-reflective coating or layer may be provided over outer surface408to reduce reflections, although the scope of the invention is not limited in this respect. In some embodiments, millimeter-wave dielectric material404may comprise two or more layers of millimeter-wave dielectric material, although the scope of the invention is not limited in this respect.

FIG. 5illustrates a chip-lens array antenna system in accordance with some multi-sector embodiments of the present invention.FIG. 5illustrates a top-view of multi-sector chip-lens array antenna system500. Multi-sector chip-lens array antenna system500may comprise a plurality of millimeter-wave lens sections504and a plurality of chip-array antennas502to direct millimeter-wave signals through an associated one of millimeter-wave lens sections504for subsequent transmission to one or more user devices. In these multi-sector embodiments, each of millimeter-wave lens sections504may comprise inner surface506defined by arcs. Each of millimeter-wave lens sections504may also have outer surface508defined by either a substantially circular arc or an elliptical arc in first plane515and defined by an elliptical arc in a second plane. First plane515may be the horizontal plane and the second plane may be the vertical plane (i.e., perpendicular to or into the page), although the scope of the invention is not limited in this respect.

In some embodiments, the arcs used to define inner surfaces506and outer surfaces508may be elliptical, hyperbolic, parabolic, and/or substantially circular and may be selected to provide diverging beam510in first plane515and a substantially non-diverging beam in the second plane. In some multi-sector embodiments, each chip-array antenna502, and one of millimeter-wave lens sections504may be associated with one sector of a plurality of sectors for communicating with the user devices located within the associated sector, although the scope of the invention is not limited in this respect

In the example embodiments illustrated inFIG. 5, each sector may cover approximately sixty degrees of horizontal plane515, and diverging beams510may have a fifteen-degree beamwidth in the horizontal plane. In these embodiments, chip-array antenna502may steer its beam within a thirty-degree beamwidth within lens504for scanning within a sixty-degree sector as illustrated to provide full coverage within each sector. In some other embodiments, each sector may cover approximately 120 degrees, although the scope of the invention is not limited in this respect.

In the example embodiments illustrated inFIG. 5, each of chip-array antennas502may illuminate millimeter-wave lens504with a thirty-degree beamwidth. Millimeter-wave lens504may downscale the beamwidth, for example, by a factor of two, to provide diverging beams510with a beamwidth of fifteen degrees external to millimeter-wave lens504. This downscaling of the beamwidth may allow chip-array antennas502to provide a greater-radius coverage area when scanning. For example, chip-array antenna522may scan over scanning angle524(shown as ninety degrees) to cover a larger sector providing scanning angle526(shown as forty-five degrees) outside millimeter-wave lens504(i.e., from scanned beam520to scanned beam521). In this example, a scanning angle of forty-five degrees outside millimeter-wave lens504may be downscaled from a ninety-degree scanning angle inside millimeter-wave lens504. This may allow each chip-array antenna502to provide coverage over one of the sixty-degree sectors with a fifteen-degree beamwidth provided by each diverging beam510. There is no requirement that the same antenna pattern and/or beamwidth be used in each sector. In some embodiments, different antenna patterns and/or beamwidths may be used in different sectors, although the scope of the invention is not limited in this respect.

In some embodiments, one or more cavities may be provided between millimeter-wave lens504and chip-array antennas502. As discussed above in reference to chip-lens array antenna system100(FIG. 1), these cavities may be filled with either air or an inert gas, or alternatively, these cavities may comprise a dielectric material having a higher permittivity and/or higher index of refraction at millimeter-wave frequencies than millimeter-wave lens504, although the scope of the invention is not limited in this respect. In some embodiments, millimeter-wave lens504may also comprise two or more layers of millimeter-wave dielectric material.

Referring toFIGS. 1A,1B,2A,2B,3,4A,4B and5, chip-array antenna102may be suitable for use as chip-array antenna202, chip-array antenna302, chip-array antenna402, and chip-array antenna502. The materials described above for use in fabricating millimeter-wave lens104may also be suitable for in fabricating millimeter-wave lens204, millimeter-wave lens304millimeter-wave lens refractive material404and the sections of millimeter-wave lens504. In some embodiments, an anti-reflective layer or coating, such as anti-reflective layer107, may be provided over the inner and/or outer surfaces of millimeter-wave lens204, the inner and/or outer surfaces millimeter-wave lens304, the outer surface of millimeter-wave lens material404and the inner and/or outer surfaces of the sections of millimeter-wave lens504, although the scope of the invention is not limited in this respect.

FIG. 6illustrates a millimeter-wave communication system in accordance with some embodiments of the present invention. Millimeter-wave communication system600includes millimeter-wave multicarrier base station604and chip-lens array antenna system602. Millimeter-wave multicarrier base station604may generate millimeter-wave signals for transmission by chip-lens array antenna system602to user devices. Chip-lens array antenna system602may also provide millimeter-wave signals received from user devices to millimeter-wave multicarrier base station604. In some embodiments, millimeter-wave multicarrier base station604may generate and/or process multicarrier millimeter-wave signals, although the scope of the invention is not limited in this respect. Chip-lens array antenna system100(FIGS. 1A and 1B), chip-lens array antenna system200(FIGS. 2A and 2B), chip-lens array antenna system300(FIG. 3), chip-lens array antenna system400(FIGS. 4A and 4B), or chip-lens array antenna system500(FIG. 5) may be suitable for use as chip-lens array antenna system602.

As used herein, the terms ‘beamwidth’ and ‘antenna beam’ may refer to regions for either reception and/or transmission of millimeter-wave signals. Likewise, the terms ‘generate’ and ‘direct’ may refer to either the reception and/or transmission of millimeter-wave signals. As used herein, user devices may be a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), or other device that may receive and/or transmit information wirelessly. In some embodiments, user devices may include a directional antenna to receive and/or transmit millimeter-wave signals.

In some embodiments, millimeter-wave communication system600may communicate millimeter-wave signals in accordance with specific communication standards or proposed specifications, such as the Institute of Electrical and Electronics Engineers (IEEE) standards including the IEEE 802.15 standards and proposed specifications for millimeter-wave communications (e.g., the IEEE 802.15 task group 3c ‘Call For Intent’ dated December 2005), although the scope of the invention is not limited in this respect as they may also be suitable to transmit and/or receive communications in accordance with other techniques and standards. For more information with respect to the IEEE 802.15 standards, please refer to “IEEE Standards for Information Technology—Telecommunications and Information Exchange between Systems”—Part 15.