Patent Application
20170352944
Embodiments pertain to wireless networks and wireless communication devices. Some embodiments relate to wireless local area networks (WLANs) and Wi-Fi networks including networks operating in accordance with the IEEE 802.11 family of standards, such as the IEEE 802.11ac standard, the IEEE 802.11ax study group (SG) (named DensiFi) and WiGig. Other embodiments pertain to mobile wireless communication devices such as the 5G standard. The embodiments herein particularly relate to the efficient transmission and reception of millimeter wave electromagnetic signals.
Wireless communication has been evolving toward ever increasing data rates (e.g., from IEEE 802.11a/g to IEEE 802.11n to IEEE 802.11ac). Currently, 5G and WiGig standards are being introduced for mobile wireless devices and Wireless Local Area Networks (WLAN) respectively. In high-density deployment situations, the utilization of available bandwidth becomes increasingly important. In response to this, an effort has been made to utilize higher frequency bands extending into the millimeter wave range. However, at this frequency, the radiation and transmission line properties for millimeter wave radio become very significant and even the smallest of transmission line discontinuities and parasitics become significant. Efficient methods are needed to transmit and receive millimeter wave signals that are both economical and robust.
Embodiments relate to systems, devices, apparatus, assemblies, methods, and computer-readable media to enhance wireless communications, and particularly to communication systems using phased array antennas. The following description and the drawings illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments can incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments can be included in, or substituted for, those of other embodiments, and are intended to cover all available equivalents of the elements described.
Waveguides are single-conductor transmission lines that can guide the flow of electromagnetic energy. The shape and size of the waveguide determines the frequency or frequencies which can propagate through the waveguide and those which cannot. The cutoff frequency is the minimum frequency which the waveguide can operate and under that frequency radiation will not propagate. In this manner, the waveguide behaves as a high pass filter. Waveguides can operate in a number of different modes, specifically designated by these general categories: Transverse Electro-Magnetic (TEM), Transverse Electric (TE) and Transverse Magnetic (TM). Two-conductor transmission lines can support TE, TM and TEM modes. Single-conductor lines can only support TE and TM modes. The transverse designation refers to the fact that the electric field or magnetic field is entirely contained within the plane transverse to that which the electromagnetic wave is travelling. In a TE mode, the electric field vector is always transverse to the direction of propagation. In a TM mode, the magnetic field vector is always transverse to the direction of propagation. Waveguides are also categorized by their cross sectional shape. For example, a rectangular waveguide has a rectangular cross section. The operating mode number indicates the number of half wavelengths along a side of the cross sectional rectangle. The electromagnetic field pattern inside the waveguide depends on the operating mode. The electromagnetic field pattern is defined by the direction and strength of the electric and magnetic fields inside the waveguide. Each operating mode also has a different cutoff frequency (generally higher mode numbers have higher cutoff frequencies.) The dominant mode is defined as the operating mode with the lowest cutoff frequency. For rectangular waveguides, the dominant mode is the TE10 mode; for circular waveguides, the dominant mode is the TE11 mode. Note that it is possible for a waveguide to simultaneously support electromagnetic waves propagating in different operating modes. This condition, however, is generally considered undesirable and can be avoided by exciting the waveguide above the cutoff frequency of the dominant mode but below the cutoff frequency of all other operating modes.
A patch antenna comprises a flat “patch” of metal mounted over a ground plane and separated by some dielectric material. The flat metal patch will resonate with the ground plane at certain frequencies, specifically at frequencies where the length of the metal patch can be expressed as an integer multiple of half the wavelength. It is also possible for the patch antenna to resonate along the width of the metal patch where the width can be expressed as an integer multiple of half the wavelength. The electric field is maximum at the edge of the patch where it can radiate and the direction of radiation is orthogonal to the patch. The magnetic field of the patch is directed along the surface of the patch and between the patch and the ground plane. Since the magnetic field is transverse to the direction of the wave propagation, the operating mode is Transverse Magnetic. The antenna feed can be connected to the patch in such a way as to only resonate in one dimension (for example along the length). If that dimension is one half wavelength, then the operating mode is TM10, indicating one half wave length resonating along the length and with no resonance along the width.
The operating mode of the patch antenna determines the electromagnetic field pattern. As already described, one of the parameters which determines the operating mode is the dimensions of the metal patch with respect to the wavelength. The wavelength is largely determined by the thickness and relative permittivity of the dielectric material separating the metal patch with the ground plane. In some embodiments, an example dielectric material has a relative permittivity of between 2.9 and 3.2 and a patch thickness between 0.1 millimeters and 0.2 millimeters for an operation target of 60 GHz. In other embodiments, such characteristics will vary depending on the design. The type and position of the antenna feed also determine the operating mode. A typical antenna feed can be implemented by a via that connects a signal wire underneath the ground plane to the metal patch without making any electrical contact with the ground plane. If the patch antenna feed is connected along a centerline of the width, yet off center with respect to length of the metal patch, then this will tend to excite a resonant mode along the length, producing a TM10 operating mode.
The orientation of the electric field in the adapter is controlled by the position of the antenna feed and by the shape of the patch antenna. As emphasized before, it is important for certain embodiments that the circular waveguide 720 be open-ended so as to allow for electric coupling to the patch antenna. Various other embodiments with differing waveguide or patch antenna shapes may operate differently. The metal patch 730 is connected to the antenna feed 740. The electric field 755 is horizontal (x-direction) as shown in
In other embodiments, the waveguide adapter can take a different structural shape, such as a rectangular waveguide or a square waveguide. The elbow joint may be mitered or square or may have a rounded bend when viewed as a cross section. The waveguide adapter supports (e.g., transmits) the electromagnetic wave at the operating frequency. This places requirements on the size and the relative dielectric constant of the material inside the waveguide such that the operating frequency is above the cutoff frequency. The waveguide can also be shaped to support any bends such as that shown in
In the example shown in
Various embodiments are now described. It will be apparent that, although certain particular embodiments are described below and throughout this description, different combinations and various of the embodiments described herein are possible, including embodiments with elements not described combined with the elements that are described.
Example 1 is an electromagnetic transmission apparatus comprising: a waveguide comprising an open end, wherein the waveguide is associated with a waveguide operating mode and a characteristic cutoff frequency and wherein the characteristic cutoff frequency is less than a transceiver operating frequency; and a patch antenna configured to resonate at the transceiver operating frequency and further configured to electrically couple to the open end of the waveguide; wherein the patch antenna is further configured for a patch antenna operating mode associated with a patch antenna electric field pattern that is compatible with a waveguide electric field pattern associated with the waveguide operating mode.
In Example 2, the subject matter of Example 1 optionally includes, wherein the waveguide comprises a circular-shaped cross section; and wherein the waveguide is configured for transmission of millimeter waves.
In Example 3, the subject matter of Example 2 optionally includes, wherein the patch antenna comprises a square-shaped surface configured to electrically couple to the waveguide.
In Example 4, the subject matter of Example 3 optionally includes, wherein the waveguide comprises a right angle elbow joint and the patch antenna is configured to excite an electric field in a direction that is orthogonal to the plane formed by the right angle elbow joint,
In Example 5, the subject matter of any one or more of Examples 3-4 optionally include, wherein the waveguide operating mode is Transverse Electric 1-1 (TE11) and the patch antenna operating mode is Transverse Magnetic 1-0 (TM10).
In Example 6, the subject matter of any one or more of Examples 1-5 optionally include, where the open end of the waveguide is electrically isolated from an antenna ground plane associated with the patch antenna.
In Example 7, the subject matter of Example 6 optionally includes, wherein the open end of the waveguide is electrically isolated from the patch antenna.
In Example 8, the subject matter of any one or more of Examples 1-7 optionally include, wherein the waveguide further comprises a second open end configured to radiate energy into free space.
In Example 9, the subject matter of any one or more of Examples 1-8 optionally include, further comprising: a printed circuit board (PCB) wherein the patch antenna is constructed with two metal layers of a plurality of metal layers comprised within the PCB; and a signal line connected to an antenna feed that is constructed within the PCB, wherein the antenna feed is configured to excite the patch antenna in a TM10 operating mode.
In Example 10, the subject matter of Example 9 optionally includes, further comprising radio frequency circuitry connected to the signal line configured to transmit and receive mm-wave signals through the electromagnetic millimeter wave (nun-wave) transmission apparatus.
In Example 11, the subject matter of any one or more of Examples 9-10 optionally include, further comprising a plurality of signal lines, a plurality of patch antennas, and a plurality of waveguides, and further configured to transmit energy from each signal line of the plurality signal lines to one of the waveguides of the plurality of waveguides by exciting one of the patch antennas of the plurality of patch antennas.
In Example 12, the subject matter of Example 11 optionally includes, further comprising radio frequency circuitry connected to the plurality of signal lines configured to transmit and receive mm-wave signals through the electromagnetic millimeter wave (mm-wave) transmission apparatus.
In Example 13, the subject matter of any one or more of Examples 1-12 optionally include, wherein: the waveguide comprises a rectangular-shaped cross section; and the patch antenna comprises a rectangular-shaped surface configured to electrically couple to the waveguide.
In Example 14, the subject matter of Example 13 optionally includes, wherein the waveguide operating mode is Transverse Electric 1-0 (TE10) and the patch antenna operating mode is Transverse Magnetic 1-0 (TM10).
In Example 15, the subject matter of any one or more of Examples 5-14 optionally include, wherein a patch antenna feed is connected to a location on the patch antenna to cause the patch antenna to resonate in a TM10 operating mode and exhibit a scattering reflection coefficient of less than −8 dB at the transceiver operating frequency.
Example 16 is a method of mm-wave signal transmission comprising: exciting a rectangular-shaped patch antenna with a mm-wave signal and resonating the patch antenna in a TM10 operating mode; coupling an electric field of the patch antenna with an open end of a waveguide, the waveguide positioned with the open end over the patch antenna; and launching an electromagnetic wave into the open end of the waveguide wherein a waveguide electric field pattern is compatible with an electric field pattern of the patch antenna and a cutoff frequency of the waveguide is less than a frequency of the mm-wave signal.
In Example 17, the subject matter of Example 16 optionally includes, further comprising: launching an electromagnetic wave into the open end of a waveguide with a circular cross section, propagating the mm-wave signal in a TE11operating mode.
In Example 18, the subject matter of any one or more of Examples 16-17 optionally include, further comprising: launching an electromagnetic wave into the open end of a waveguide with a rectangular cross section, propagating the mm-wave signal in a TE10 operating mode.
In Example 19, the subject matter of any one or more of Examples 16-18 optionally include, further comprising: generating a mm-wave signal with radio frequency circuitry connected to a signal line; and exciting the patch antenna through an antenna teed connected to the signal line wherein the antenna feed is positioned such that the patch antenna is resonating in the TM10 operating mode.
In Example 20, the subject matter of Example undefined optionally includes a non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of a device comprising a wireless communication system, cause the device to: electrically resonate a patch antenna in a TM10 operating mode at an operating frequency of the wireless communication system, producing an electric field which couples to an open end of a waveguide; and launch an electromagnetic wave into the waveguide propagating in a waveguide operating mode wherein an electric field pattern of the waveguide operating mode is compatible with the electric field of the TM10 operating mode of the patch antenna, wherein a cutoff frequency of the waveguide is less than the operating frequency.
In Example 21, the subject matter of Example 20 optionally includes, wherein: the patch antenna comprises a square-shaped surface configured to electrically couple to the waveguide; and the waveguide comprises a circular-shaped cross section and configured for a TE11 operating mode.
In Example 22, the subject matter of any one or more of Examples 20-21 optionally include, wherein the waveguide operating mode is Transverse Electric 1-1 (TE11) and the patch antenna operating mode is Transverse Magnetic 1-0 (TM10).
In Example 23, the subject matter of any one or more of Examples 20-22 optionally include, further comprising instructions that cause the device to radiate energy into free space from a second open end of the waveguide.
In Example 24, the subject matter of any one or more of Examples 20-23 optionally include, further comprising instructions that cause the device to receive mm-wave signals at a second open end of the waveguide.
In Example 25, the subject matter of any one or more of Examples 20-24 optionally include, wherein: the patch antenna comprises a square-shaped surface configured to electrically couple to the waveguide; and the waveguide comprises a rectangular-shaped cross section and configured for the TE10 operating mode.
Example 26 is a radio frequency front end module comprising: a radio frequency integrated circuit (RFIC); a plurality of waveguide adapters coupled to the RFIC; a plurality of waveguides associated with a plurality of corresponding radiation patterns, and coupled to a corresponding waveguide adapter of the plurality of waveguide adapters, wherein the plurality of waveguides are associated with a waveguide operating mode and a characteristic cutoff frequency and wherein the characteristic cutoff frequency is less than a transceiver operating frequency; and a plurality of patch antennas corresponding to pairs of waveguide adapters and waveguides of the plurality of waveguide adapters and the plurality of waveguides, the plurality of patch antennas configured to resonate at the transceiver operating frequency and further configured to electrically couple to an open end of a corresponding waveguide of the plurality of waveguides; wherein the plurality of patch antennas are further configured for a patch antenna operating anode associated with a patch antenna electric field pattern that is compatible with a waveguide electric field pattern associated with the plurality of corresponding radiation patterns.
Example 27 is The radio frequency front end module further comprising: a substrate comprising one or more of a printed circuit board, a glass substrate, a ceramic substrate, and a semiconductor substrate; wherein the RFIC and the plurality of waveguide adapters are mounted to the substrate and coupled via a plurality of transmission lines.
In Example 28, the subject matter of any one or more of Examples 26-27 optionally include wherein the plurality of waveguides each comprises a circular-shaped cross section; and wherein each waveguide is configured for transmission of millimeter waves.
In Example 29, the subject matter of any one or more of Examples 26-28 optionally include wherein each patch antenna comprises a square-shaped surface configured to electrically couple to the waveguide.
In Example 30, the subject matter of any one or more of Examples 26-29 optionally include wherein each waveguide comprises a right angle elbow joint and the patch antenna is configured to excite an electric field in a direction that is orthogonal to the plane formed by the right angle elbow joint.
In Example 31, the subject matter of Example 30 optionally includes wherein each waveguide operating mode is Transverse Electric 1-1 (TE11) and each patch antenna operating mode is Transverse Magnetic 1-0 (TM10).
In Example 32, the subject matter of any one or more of Examples 26-31 optionally include, where the open end of each waveguide is electrically isolated from an antenna ground plane associated with the patch antenna.
In Example 33, the subject matter of any one or more of Examples 26-32 optionally include wherein the open end of each waveguide is electrically isolated from the patch antenna.
In Example 34, the subject matter of any one or more of Examples 26-33 optionally include, wherein each waveguide further comprises a second open end configured to radiate energy into free space.
In Example 35, the subject matter of any one or more of Examples 26-34 optionally include wherein each waveguide is associated with a slit or hole in a waveguide metal wall configured for radiation of energy into free space via the slit or hole.
In Example 36, the subject matter of any one or more of Examples 26-35 optionally include further comprising: a printed circuit board (PCB) wherein each patch antenna is constructed with two metal layers of a plurality of metal layers comprised within the PCB; and a plurality of signal line connected to a plurality of antenna feeds that are constructed within the PCB, wherein the plurality of antenna feeds are configured to excite each patch antenna in a TM10 operating mode.
In Example 37, the subject matter of Example 36 optionally includes, further comprising radio frequency circuitry connected to the signal line configured to transmit and receive mm-wave signals through the RFIC.
In Example 38, the subject matter of any one or more of Examples 36-37 optionally include, wherein: each waveguide comprises a rectangular-shaped cross section; and each patch antenna comprises a rectangular-shaped surface configured to be electrically couple to the waveguide.
In Example 39, the subject matter of Example 38 optionally includes, wherein the waveguide operating mode is Transverse Electric 1-0 (TE10) and the patch antenna operating anode is Transverse Magnetic 1-0 (TM10).
Example 40 is an apparatus for signal transmission comprising: means for exciting a rectangular-shaped patch antenna with a mm-wave signal and resonating the patch antenna in a TM10 operating mode; means for coupling an electric field of the patch antenna with an open end of a waveguide, the waveguide positioned with the open end over the patch antenna; and means for launching an electromagnetic wave into the open end of the waveguide wherein a waveguide electric field pattern is compatible with an electric field pattern of the patch antenna and a cutoff frequency of the waveguide is less than a frequency of the mm-wave signal.
In Example 41, the subject matter of Example 40 optionally includes further comprising: means for launching an electromagnetic wave into the open end of a waveguide with a circular cross section, propagating the mm-wave signal in a TE11 operating mode.
in Example 42, the subject matter of any one or more of Examples 40-41 optionally include further comprising: means for launching an electromagnetic wave into the open end of a waveguide with a rectangular cross section, propagating the mm-wave signal in a TE10 operating mode.
In Example 43, the subject matter of any one or more of Examples 40-42 optionally include further comprising: means for generating a mm-wave signal with radio frequency circuitry connected to a signal line; and means for exciting the patch antenna through an antenna feed connected to the signal line wherein the antenna feed is positioned such that the patch antenna is resonating in the TM10 operating mode.
Example 44 is a storage medium comprising instructions that, when executed by one or more processors, implement any method described above.
Additionally, in some embodiments, the antennas are each associated with a hole, slit, aperture, or other opening in a metal wall. In some embodiments, for example, a waveguide antenna array may have launch and receive signals via these slits or holes in a waveguide metal wall elsewhere than in the open end. In various embodiments, these openings may be made in any shape that enables communication with the corresponding signals, with a signal feed to one end of the waveguide metal wall, a short circuit on the other end, and the slots or openings along the waveguide metal wall.
Example computer system machine 1200 includes a processor 1202 (e.g., a central processing unit (CPU), a graphics processing unit (GPU) or both), a main memory 1204 and a static memory 1206, which communicate with each other via an interconnect 1208 (e.g., a link, a bus, etc.). The computer system machine 1200 can further include a video display unit (device) 1210, an alphanumeric input device 1212 (e.g., a keyboard), and a user interface (UI) navigation device 1214 (e.g., a mouse). In one embodiment, the video display unit 1210, input device 1212 and UI navigation device 1214 are a touch screen display. The computer system machine 1200 can additionally include a storage device 1216 (e.g., a drive unit), a signal generation device 1218 (e.g., a speaker), an output controller 1232, a power management controller 1234, and a network interface device 1220 (which can include or operably communicate with one or more antennas 1230, transceivers, or other wireless communications hardware), and one or more sensors 1228, such as a Global Positioning Sensor (GPS) sensor, compass, location sensor, accelerometer, or other sensor.
The storage device 1216 includes a machine-readable medium 1222 on which is stored one or more sets of data structures and instructions 1224 (e.g., software) embodying or utilized by any one or more of the methodologies or functions described herein. The instructions 1224 can also reside, completely or at least partially, within the main memory 1204, static memory 1206, and/or within the processor 1202 during execution thereof by the computer system machine 1200, with the main memory 1204, static memory 1206, and the processor 1202 also constituting machine-readable media.
While the machine-readable medium 1222 is illustrated in an example embodiment to be a single medium, the term “machine-readable medium” can include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more instructions 1224. The term “machine-readable medium” shall also be taken to include any tangible medium that is capable of storing, encoding or carrying instructions (e.g., instructions 1224) for execution by the machine 1200 and that cause the machine 1200 to perform any one or more of the methodologies of the present disclosure or that is capable of storing, encoding or carrying data structures utilized by or associated with such instructions.
The instructions 1224 can further be transmitted or received over a communications network 1226 using a transmission medium via the network interface device 1220 utilizing any one of a number of well-known transfer protocols (e.g., HTTP). The term “transmission medium” shall be taken to include any intangible medium that is capable of storing, encoding, or carrying instructions for execution by the machine, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.
Various techniques, or certain aspects or portions thereof may take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, non-transitory computer-readable storage medium, or any other machine-readable storage medium wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the various techniques. In the case of program code execution on programmable computers, the computing device may include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. The volatile and non-volatile memory and/or storage elements may be a RAM, EPROM, flash drive, optical drive, magnetic hard drive, or other medium for storing electronic data The base station and mobile station may also include a transceiver module, a counter module, a processing module, and/or a clock module or timer module. One or more programs that may implement or utilize the various techniques described herein may use an application programming interface (API), reusable controls, and the like. Such programs may be implemented in a high level procedural or object-oriented programming language to communicate with a computer system. However, the program(s) may be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language, and combined with hardware implementations.
Various embodiments may use 3GPP LTE/LTE-A, IEEE 1002.11, and Bluetooth communication standards. Various alternative embodiments may use a variety of other WWAN, WLAN, and WPAN protocols and standards can be used in connection with the techniques described herein. These standards include, but are not limited to, other standards from 3GPP (e.g., HSPA+, UMTS), IEEE 1002.16 (e.g., 1002.16p), or Bluetooth (e.g., Bluetooth 9.0, or like standards defined by the Bluetooth Special Interest Group) standards families. Other applicable network configurations can be included within the scope of the presently described communication networks. It will be understood that communications on such communication networks can be facilitated using any number of personal area networks, LANs, and WANs, using any combination of wired or wireless transmission mediums.
The embodiments described above can be implemented in one or a combination of hardware, firmware, and software. Various methods or techniques, or certain aspects or portions thereof, can take the form of program code (i.e., instructions) embodied in tangible media, such as flash memory, hard drives, portable storage devices, read-only memory (ROM), random-access memory (RAM), semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)), magnetic disk storage media, optical storage media, and any other machine-readable storage medium or storage device wherein, when the program code is loaded into and executed by a machine, such as a computer or networking device, the machine becomes an apparatus for practicing the various techniques.
A machine-readable storage medium or other storage device can include any non-transitory mechanism for storing information in a form readable by a machine e.g., a computer). In the case of program code executing on programmable computers, the computing device can include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. It should be understood that the functional units or capabilities described in this specification have been referred to or labeled as components or modules in order to more particularly emphasize their implementation independence. For example, a component or module can be implemented as a hardware circuit comprising custom very-large-scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A component or module can also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, or the like. Components or modules can also be implemented in software for execution by various types of processors. An identified component or module of executable code can, for instance, comprise one or more physical or logical blocks of computer instructions, which can, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified component or module need not be physically located together, but can comprise disparate instructions stored in different locations which, when joined logically together, comprise the component or module and achieve the stated purpose for the component or module.
Indeed, a component or module of executable code can be a single instruction, or many instructions, and can even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data can be identified and illustrated herein within components or modules, and can be embodied in any suitable form and organized within any suitable type of data structure. The operational data can be collected as a single data set, or can be distributed over different locations including over different storage devices, and can exist, at least partially, merely as electronic signals on a system or network. The components or modules can be passive or active, including agents operable to perform desired functions.
