Patent Grant
7256741
This invention relates generally to the field of antennas. More specifically, a multiple-band antenna is provided that is particularly well-suited for use in wireless mobile communication devices, generally referred to herein as “mobile devices”, such as Personal Digital Assistants, cellular telephones, and wireless two-way email communication devices.
Mobile devices having antennas that support multi-band communications are known. Many such mobile devices utilize helix or retractable structures, which are typically installed outside of a mobile device, although embedded antennas installed inside of a case or housing of a device are also known. Generally, embedded antennas are preferred over external antennas for mobile communication devices for mechanical and ergonomic reasons. Embedded antennas are protected by the mobile device case or housing and therefore tend to be more durable than external antennas. Whereas external antennas may physically interfere with the surroundings of a mobile device and make a mobile device difficult to use, particularly in limited-space environments, embedded antennas present fewer such challenges.
In some types of mobile devices, however, known embedded structures and design techniques provide relatively poor communication signal radiation and reception, at least in certain operating positions of the mobile devices. One of the biggest challenges for mobile device antenna design is to ensure that the antenna operates effectively in different positions, since antenna position changes as a mobile device is moved.
In addition, where operation of a mobile device in multiple operating frequency bands is desired or required, physical space limitations often preclude the use of separate antennas for each operating frequency band.
According to an aspect of the invention, an antenna having a plurality of operating frequency bands comprises a first plurality of structures configured for operation in respective ones of the plurality of operating frequency bands, and a second plurality of structures, each configured for operation in more than one of the plurality of operating frequency bands.
A multiple-band antenna according to another aspect of the invention has first, second, and third operating frequency bands, and comprises a first patch structure associated with the first operating frequency band, a second patch structure connected to the first patch structure and associated with the second operating frequency band and the third operating frequency band, a first slot structure disposed between a first portion of the first patch structure and the second patch structure and associated with the first operating frequency band and the second operating frequency band, a second slot structure disposed between a second portion of the first patch structure and the second patch structure and associated with the second operating frequency band, and a third slot structure disposed between a third portion of the first patch structure and the second patch structure and associated with the first operating frequency band and the third operating frequency band.
Further features and aspects of the invention will be described or will become apparent in the course of the following detailed description.
Structures in antennas described herein are sized and shaped to tune an antenna for operation in multiple frequency bands. As described in further detail below, an antenna includes multiple-band antenna structures, each configured for operation in multiple operating frequency bands. In an embodiment of the invention described in detail below, an antenna includes a plurality of structures which are primarily associated with one of a first operating frequency band, a second operating frequency band, and a third operating frequency band, as well as a plurality of “shared” multiple-band structures associated with more than one of the first, second, and third operating frequency bands. This enables the antenna to function as the antenna in a multi-band mobile device. For example, an antenna may be adapted for operation at the Global System for Mobile communications (GSM) 900 MHz frequency band, the GSM-1800 (1800 MHz) frequency band, also known as the Digital Cellular System (DCS) frequency band, and the GSM-1900 (1900 MHz) frequency band, sometimes referred to as the Personal Communication System (PCS) frequency band. Those skilled in the art will appreciate that the GSM-900 band includes a transmit sub-band of 880-915 MHz and a receive sub-band 925-960 MHz, the DCS frequency band similarly includes a transmit sub-band of 1710-1785 MHz and a receive sub-band of 1805-1880 MHz, and the PCS frequency band includes a transmit sub-band a transmit sub-band of 1850-1910 MHz and a receive sub-band of 1930-1990 MHz. It will also be appreciated by those skilled in the art that these frequency bands are for illustrative purposes only. Such an antenna may be designed to operate in different, and possibly more than three, operating frequency bands.
The antenna 10 includes patch structures 12 and 14, slot structures 16, 17, and 18, and tuning structures 20 and 24. Patch antennas are popular for their low profile, virtually unlimited possible shapes and sizes, and inherent flexibility which allows them to be made to conform to most surface profiles. Patch antenna polarizations can be linear or elliptical, with a main polarization component parallel to the surface of the patch. Slot antennas are used to enhance the field strength in required directions by changing their orientations. Operating characteristics of patch and slot antennas are established by antenna shape and dimensions. Principles of operation of patch and slot antennas are well-known to those skilled in the art to which the present application pertains.
In the antenna 10, the patch structure 12 is a first structure associated primarily with one frequency band in which the antenna 10 operates. The patch structure 12 is generally C-shaped, including two end portions, at the left- and right-hand sides of the antenna 10 in the view shown in
The patch structure 14 is a second structure that, unlike the first patch structure 12, is a shared multiple-band structure. Operating characteristics of the antenna 10 in the frequency bands associated with the patch structure 14, including frequency and gain, for example, are affected by the size and shape of the patch structure 14. Adjustment of the dimensions of the patch structure 14 has a more balanced effect on its operating frequency bands. As those skilled in the art will appreciate, the patch structure 14 has a relatively wide bandwidth encompassing its operating frequency bands, and is tuned to optimize either one or more than one of its operating frequency bands.
The slot structure 16 is also a shared multiple-band structure, associated with more than one operating frequency band. The length and the width of the slot structure 16 not only sets the frequency bands of the slot structure 16, but also affects the gain and match of the antenna 10 in these frequency bands. For example, changing the width and length of the slot structure 16 may improve antenna match but sacrifice its gain in the operating frequency bands associated with the slot structure 16.
Although the slot structure 17 is connected to the slot structure 16, the slot structure 17 is primarily associated with a single operating frequency band. The dimensions of the slot structure 17 have a dominant effect on performance of the antenna 10 in one frequency band. For example, the slot structure 17 has a different polarization than the slot structure 16, and enhances the transmit gain primarily in one operating frequency band. In one embodiment of the invention, the operating frequency band of the slot structure 17 is also a highest operating frequency band of the patch structure 14. Adding the slot structure 17 to the slot structure 16 reduces the size of the patch structure 14 and thereby further enhances this operating frequency band.
The slot structure 18 is another shared structure, in that it is positioned in the antenna 10 and dimensioned to affect antenna operation in multiple frequency bands. Whereas each of the structures 12 and 16 has a dominant effect on one corresponding operating frequency band, the length, width, and location of the slot structure 18 have a more distributed effect in multiple frequency bands. For example, adjustment of the position and dimensions of the slot structure 18 affects the gain and match of the multiple-band antenna in more than one frequency band.
The patch structures 12 and 14 are shorted along the line 39 in
Tuning structures 20 and 24 are used for fine-tuning the antenna 10. Although connected to the first patch structure 12, the tuning structure 20 may form a tuning tab for a different frequency band that the operating frequency band of the first patch structure 12. As described below, the left-hand end portion of the first patch structure 12 is connected to a feeding point of the antenna 10 and as such is used whenever the antenna 10 is operating in any of its frequency bands. The tuning structure 20 can thus be adapted to have a dominant effect on any of the operating frequency bands of the antenna 10. Fine tuning of such an operating frequency band is accomplished by setting the dimensions of the fine tuning tab 20.
The tuning structure 24, however, at the right-hand end portion of the antenna 10, has a dominant effect on the operating frequency band of the first patch structure 12. The tuning tab forming the tuning structure 24 affects the overall electrical length, and thus the operating frequency band, of the first patch structure 12.
In one embodiment of the invention, the antenna 10 is a tri-band antenna having first, second, and third operating frequency bands. The first patch structure 12 is associated with the first operating frequency band, the second patch structure 14 is associated with the second and third operating frequency bands, the slot structure 16 is associated with the first and third operating frequency bands, the slot structure 17 is associated with the third operating frequency band, and the slot structure 18 is associated with the first and second operating frequency bands. The first operating frequency band is fine tuned using tuning structure 24, and the tuning structure 20 is used to fine tune the second operating frequency band. For an antenna intended for use in a GSM/GPRS mobile device, for example, the first, second and third frequency bands may be GSM-900, DCS, and PCS, respectively.
Those skilled in the art will appreciate that the invention is in no way limited to the GSM, DCS, and PCS operating frequency bands, or to any specific inter-relation between the frequency bands associated with each structure in the antenna 10. For example, the first operating frequency band could be common between the first and second patch structures 12 and 14. In this case, the first patch structure 12 is configured for the first operating frequency band, as above, and the second patch structure 14 is configured for the first frequency band and another frequency band. Other associations between structures and frequency bands are also possible.
Referring now to
Signals in the operating frequency bands, established as described above, are received and radiated by the antenna 10. An electromagnetic signal in one of the operating frequency bands is received by the antenna 10 and converted into an electrical signal for a corresponding receiver or transceiver coupled to the feeding point 38 and the ground point 40. Similarly, an electrical signal in one of the operating frequency bands input to the antenna 10 via the feeding point 38 and the ground point 40 by a transmitter or transceiver is radiated from the antenna 10.
In the above example, when operating in the first frequency band, the structures 12, 16, and 18 of the antenna 10 radiate and receive signals polarized in directions both parallel and perpendicular to the patch structure 12 in a co-operative manner to enhance the gain. Operation of the antenna 10 in the second and third frequency bands is substantially similar. In the second frequency band, the structures 14 and 18 are the major radiating and receiving components, and in the third frequency band, the structures 14, 16, and 17 are the main radiators and receivers.
The antenna 10 offers improved signal transmission and reception relative to known antenna designs, since it uses combined structures of patch and slot antennas which work co-operatively to radiate and receive signals polarized in most popular directions. In this manner, the performance of the antenna 10 is less affected by orientation of a mobile device in which it is installed. Multiple-band operation is also supported in a single antenna with one feeding port.
Performance of the antenna 10 is further enhanced when the antenna is mounted on a mounting structure as shown in
In
The mounting pins 52 and 54 are positioned on the support structure 53 so as to be received in the mounting bores 42 and 44, respectively, when the antenna 10 is positioned for mounting as indicated by the dashed lines 56 and 58. The mounting pins 52 and 54 are then preferably deformed to mount the feeding point 38 and the ground point 40 to the support structure 53 on the mounting structure 50. The mounting pins 52 and 54 may, for example, be heat stakes which are melted to overlay a portion of the feeding point 38 and the ground point 40 surrounding the mounting bores 42 and 44 and thereby retain the feeding point 38 and the ground point 40 in a mounted position.
The top side of the antenna system 70 is shown in
The mounting bores 26, 30, 32, and 34 are surrounded by beveled surfaces, as shown in
The antenna 10 may, for example, be fabricated from a substantially flat conductive sheet of a conductor such as copper, aluminum, silver, or gold, using stamping or other cutting techniques, to form antenna blanks. Mounting bores may be cut or stamped as the blanks are formed, or drilled into the flat antenna blanks. Antenna blanks are then deformed into the shape shown in
As shown in
As those skilled in the art will appreciate, the bent portions 46 and 48 add electrical length to the first and second structures 12 and 14, providing a further means to control antenna gain and frequency for their associated frequency bands. Also, as shown most clearly in
In
Generally, a user holds a lower portion of a mobile device such as 100 with one hand when engaged in a conversation. As such, the top rear portion of the mobile device 100, and thus the antenna 10, is relatively unobstructed when the mobile device 100 is in a voice communication position, thereby providing enhanced performance compared to known antennas and mobile devices.
In a similar manner, the location of the antenna 10 shown in
Thus, the antenna 10, mounted in a mobile device as shown in
Antennas according to aspects of the invention are applicable to different types of mobile device, including, for example, data communication devices, voice communication devices, dual-mode communication devices such as mobile telephones having data communications functionality, personal digital assistants (PDAs) enabled for wireless communications, wireless email communication devices, or laptop or desktop computer systems with wireless modems.
The mobile device 700 is a dual-mode and multiple-band mobile device and includes a transceiver module 711, a microprocessor 738, a display 722, a non-volatile memory 724, a random access memory (RAM) 726, one or more auxiliary input/output (I/O) devices 728, a serial port 730, a keyboard 732, a speaker 734, a microphone 736, a short-range wireless communications sub-system 740, and other device sub-systems 742.
The transceiver module 711 includes a antenna 10, a first transceiver 716, the second transceiver 714, one or more local oscillators 713, and a digital signal processor (DSP) 720.
Within the non-volatile memory 724, the device 700 preferably includes a plurality of software modules 724A-724N that can be executed by the microprocessor 738 (and/or the DSP 720), including a voice communication module 724A, a data communication module 724B, and a plurality of other operational modules 724N for carrying out a plurality of other functions.
The mobile device 700 is preferably a two-way communication device having voice and data communication capabilities. Thus, for example, the mobile device 700 may communicate over a voice network, such as any of the analog or digital cellular networks, and may also communicate over a data network. The voice and data networks are depicted in
The transceiver module 711 is used to communicate with the networks 719, and includes the first transceiver 116, the second transceiver 114, the one or more local oscillators 713, and the DSP 720. The DSP 720 is used to send and receive signals to and from the transceivers 714 and 716 and to provide control information to the transceivers 714 and 716. If the voice and data communications occur at a single frequency, or closely-spaced sets of frequencies, then a single local oscillator 713 may be used in conjunction with the transceivers 714 and 716. Alternatively, if different frequencies are utilized for voice communications versus data communications or communications in different networks or types of network, for example, then a plurality of local oscillators 713 can be used to generate a plurality of frequencies corresponding to the voice and data networks 719. Information, which includes both voice and data information, is communicated to and from the transceiver module 711 via a link between the DSP 720 and the microprocessor 738.
The detailed design of the transceiver module 711, such as frequency bands, component selection, power level, etc., is dependent upon the communication networks 719 in which the mobile device 700 is intended to operate. For example, the transceiver module 711 may include transceivers 714 and 716 designed to operate with any of a variety of communication networks, such as the Mobitex™ or DataTAC™ mobile data communication networks, AMPS, TDMA, CDMA, PCS, and GSM. Other types of data and voice networks, both separate and integrated, may also be utilized where the mobile device 700 includes a corresponding transceiver and the antenna 10 is configured to operate in a corresponding operating frequency band.
Depending upon the type of network 719, the access requirements for the mobile device 700 may also vary. For example, in the Mobitex and DataTAC data networks, mobile devices are registered on the network using a unique identification number associated with each mobile device. In GPRS data networks, however, network access is associated with a subscriber or user of a mobile device. A GPRS device typically requires a subscriber identity module (“SIM”), which is required in order to operate a mobile device on a GPRS network. Local or non-network communication functions (if any) may be operable, without the SIM device, but a mobile device will be unable to carry out any functions involving communications over the data network 719, other than any legally required operations, such as ‘911’ emergency calling.
After any required network registration or activation procedures have been completed, the mobile device 700 may then send and receive communication signals, including both voice and data signals, over the networks 719. Signals received by the antenna 10 from the communication network 719 are routed to one of the transceivers 714 and 716, which provides for such functions as signal amplification, frequency down conversion, filtering, channel selection, and analog to digital conversion. Analog to digital conversion of the received signal allows more complex communication functions, such as digital demodulation and decoding to be performed using the DSP 720. In a similar manner, signals to be transmitted to the network 719 are processed by the DSP 720, which modulates and encodes the signals, for example, and then provides the processed signals to one of the transceivers 714 and 716, which perform such operations as digital to analog conversion, frequency up conversion, filtering, amplification, and transmission to the communication network 719 via the antenna 10.
In addition to processing the communication signals, the DSP 720 also provides for transceiver control. For example, the gain levels applied to communication signals in the transceivers 714 and 716 may be adaptively controlled through automatic gain control algorithms implemented in the DSP 720. Other transceiver control algorithms could also be implemented in the DSP 720 in order to provide more sophisticated control of the transceiver module 711.
The microprocessor 738 preferably manages and controls the overall operation of the dual-mode mobile device 700. Many types of microprocessors or microcontrollers could be used here, or, alternatively, a single DSP 720 could be used to carry out the functions of the microprocessor 738. Low-level communication functions, including at least data and voice communications, are performed through the DSP 720 in the transceiver module 711. Other, high-level communication applications, such as a voice communication application 724A, and a data communication application 724B may be stored in the non-volatile memory 724 for execution by the microprocessor 738. For example, the voice communication module 724A provides a high-level user interface operable to transmit and receive voice calls between the mobile device 700 and a plurality of other voice or dual-mode devices via the network 719. Similarly, the data communication module 724B provides a high-level user interface operable for sending and receiving data, such as e-mail messages, files, organizer information, short text messages, etc., between the mobile device 700 and a plurality of other data devices via the networks 719.
The microprocessor 738 also interacts with other device subsystems, such as the display 722, the non-volatile memory 724, the RAM 726, the auxiliary input/output (I/O) subsystems 728, the serial port 730, the keyboard 732, the speaker 734, the microphone 736, the short-range communications subsystem 740, and any other device subsystems generally designated as 742.
Some of the subsystems shown in
Operating system software used by the microprocessor 738 is preferably stored in a persistent store such as the non-volatile memory 724. In addition to the operating system, which controls all of the low-level functions of the mobile device 700, the non-volatile memory 724 may include a plurality of high-level software application programs, or modules, such as a voice communication module 724A, a data communication module 724B, an organizer module (not shown), or any other type of software module 724N. The non-volatile memory 724 also may include a file system for storing data. These modules are executed by the microprocessor 738 and provide a high-level interface between a user and the mobile device 700. This interface typically includes a graphical component provided through the display 722, and an input/output component provided through the auxiliary I/O 728, the keyboard 732, the speaker 734, and the microphone 736. The operating system, specific device applications or modules, or parts thereof, may be temporarily loaded into a volatile store, such as RAM 726 for faster operation. Moreover, received communication signals may also be temporarily stored to RAM 726, before permanently writing them to a file system located in a persistent store such as the non-volatile memory 724. The non-volatile memory 724 may be implemented, for example, as a Flash memory component or a battery backed-up RAM.
An exemplary application module 724N that may be loaded onto the mobile device 700 is a personal information manager (PIM) application providing PDA functionality, such as calendar events, appointments, and task items. This module 724N may also interact with the voice communication module 724A for managing phone calls, voice mails, etc., and may also interact with the data communication module 724B for managing e-mail communications and other data transmissions. Alternatively, all of the functionality of the voice communication module 724A and the data communication module 724B may be integrated into the PIM module.
The non-volatile memory 724 preferably provides a file system to facilitate storage of PIM data items on the device. The PIM application preferably includes the ability to send and receive data items, either by itself, or in conjunction with the voice and data communication modules 724A, 724B, via the wireless networks 719. The PIM data items are preferably seamlessly integrated, synchronized and updated, via the wireless networks 719, with a corresponding set of data items stored or associated with a host computer system, thereby creating a mirrored system for data items associated with a particular user.
The mobile device 700 may also be manually synchronized with a host system by placing the device 700 in an interface cradle, which couples the serial port 730 of the mobile device 700 to the serial port of the host system. The serial port 730 may also be used to enable a user to set preferences through an external device or software application, or to download other application modules 724N for installation. This wired download path may be used to load an encryption key onto the device, for example, to provide a more secure method than exchanging such encryption information via the wireless networks 719. Interfaces for other wired download paths may be provided in the mobile device 700, in addition to or instead of the serial port 730. For example, a USB port provides an interface to a similarly equipped personal computer.
Additional application modules 724N may be loaded onto the mobile device 700 through the networks 719, through an auxiliary I/O subsystem 728, through the serial port 730, through the short-range communications subsystem 740, or through any other suitable subsystem 742, and installed by a user in the non-volatile memory 724 or RAM 726. Such flexibility in application installation increases the functionality of the mobile device 700 and may provide enhanced on-device functions, communication-related functions, or both. For example, secure communication applications enable electronic commerce functions and other such financial transactions to be performed using the mobile device 700.
When the mobile device 700 is operating in a data communication mode, a received signal, such as a text message or a web page download, is processed by the transceiver module 711 and provided to the microprocessor 738, which preferably further processes the received signal for output to the display 722, or, alternatively, to an auxiliary I/O device 728. A user of mobile device 700 may also compose data items, such as email messages, using the keyboard 732, which is preferably a complete alphanumeric keyboard laid out in the QWERTY style, although other styles of keyboards, such as the known DVORAK style or a telephone keypad, may also be used. User input to the mobile device 700 is further enhanced with a plurality of auxiliary I/O devices 728, which may include a thumbwheel input device, a touchpad, a variety of switches, a rocker input switch, etc. The composed data items input by the user may then be transmitted over the communication networks 719 via the transceiver module 711.
When the mobile device 700 is operating in a voice communication mode, the overall operation of the mobile device is substantially similar to the data mode, except that received signals are output to the speaker 734 and voice signals for transmission are generated by the microphone 736. Alternative voice or audio I/O subsystems, such as a voice message recording subsystem, may also be implemented on the mobile device 700. Although voice or audio signal output is preferably accomplished primarily through the speaker 734, the display 722 may also be used to provide an indication of the identity of a calling party, the duration of a voice call, or other voice call-related information. For example, the microprocessor 738, in conjunction with the voice communication module 724A and the operating system software, may detect the caller identification information of an incoming voice call and display it on the display 722.
A short-range communications subsystem 740 is also included in the mobile device 700. For example, the subsystem 740 may include an infrared device and associated circuits and components, or a short-range RF communication module such as a Bluetooth™ module or an 802.11 module to provide for communication with similarly-enabled systems and devices. Those skilled in the art will appreciate that “Bluetooth” and “802.11” refer to sets of specifications, available from the Institute of Electrical and Electronics Engineers, relating to wireless personal area networks and wireless local area networks, respectively.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The invention may include other examples that occur to those skilled in the art.
For example, although described above primarily in the context of a tri-band antenna, a multiple-element antenna may also include further antenna elements to provide for operation in more than three frequency bands. Similarly, even though the antenna described herein provides three operating frequency bands, implementations in which fewer operating frequency bands are used are also possible. For example, an antenna that supports GSM-900, DCS and PCS might be used in a mobile device that uses only GSM-900 and PCS.
The mounting structure 50 is shown for illustrative purposes only, and may be shaped differently and include different, further, or fewer cooperating structures than those shown in the drawings and described above, depending on the particular mobile device in which the multiple-band antenna is implemented. It should also be appreciated that the mounting structure could be integral with a mobile device housing or other component of the mobile device instead of a separate component.
Layout of the multiple-band antenna is similarly intended to be illustrative and not restrictive. For example, a multiple-band antenna according to the present invention may include slot structures of a different shape than shown in the drawings, and need not necessarily incorporate fine-tuning structures. Similarly, as is typical in antenna design, the dimensions and positions of antenna structures can be adjusted as necessary to compensate for effects of other mobile device components, including a shield or display, for example, on antenna characteristics.
Although the antenna 10 is mounted on the mounting structure 50 using mounting pins, other types of fasteners, including screws, rivets, and adhesives, for example, will be apparent to those skilled in the art.
In addition, fabrication of the antenna 10 from a planar conductive sheet as described above simplifies manufacture of the antenna 10, but the invention is in no way restricted to this particular, or any other, fabrication technique. Printing or depositing a conductive film on a substrate and etching previously deposited conductor from a substrate are two possible alternative techniques.
Multiple-band patch and slot antenna structures in a single antenna have been described above. Those skilled in the art will appreciate that the invention is in no way restricted to a particular type or number of shared multiple-band structure. In alternative embodiments of the invention, only one type of antenna structure, or more or fewer antenna structures, are shared multiple-band structures. The principles described herein may also be applied to antennas comprising other types of structure than patch and slot structures.
| Number | Date | Country | Kind |
|---|---|---|---|
| 03252987 | May 2003 | EP | regional |
This application is a continuation of U.S. Ser. No. 10/844,685 filed on May 13, 2004 now U.S. Pat. No. 7,023,387, the entirety of which is incorporated herein by reference. This application also claims priority to EP 03252987.7 filed on May 14, 2003.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3521284 | Shelton, Jr. et al. | Jul 1970 | A |
| 3599214 | Altamayer | Aug 1971 | A |
| 3622890 | Fujimoto et al. | Nov 1971 | A |
| 3683376 | Pronovost | Aug 1972 | A |
| 4024542 | Ikawa et al. | May 1977 | A |
| 4074270 | Kaloi | Feb 1978 | A |
| 4403222 | Bitter, Jr. et al. | Sep 1983 | A |
| 4471493 | Schober | Sep 1984 | A |
| 4504834 | Garay et al. | Mar 1985 | A |
| 4543581 | Nemet | Sep 1985 | A |
| 4571595 | Phillips et al. | Feb 1986 | A |
| 4584709 | Kneisel et al. | Apr 1986 | A |
| 4590614 | Erat | May 1986 | A |
| 4692769 | Gegan | Sep 1987 | A |
| 4730195 | Phillips et al. | Mar 1988 | A |
| 4839660 | Hadzoglou | Jun 1989 | A |
| 4847629 | Shimazaki | Jul 1989 | A |
| 4857939 | Shimazaki | Aug 1989 | A |
| 4890114 | Egashira | Dec 1989 | A |
| 4894663 | Urbish et al. | Jan 1990 | A |
| 4975711 | Lee | Dec 1990 | A |
| 5030963 | Tadama | Jul 1991 | A |
| 5138328 | Zibrik et al. | Aug 1992 | A |
| 5214434 | Hsu | May 1993 | A |
| 5218370 | Blaese | Jun 1993 | A |
| 5227804 | Oda | Jul 1993 | A |
| 5245350 | Sroka | Sep 1993 | A |
| 5257032 | Diamond et al. | Oct 1993 | A |
| 5347291 | Moore | Sep 1994 | A |
| 5373300 | Jenness et al. | Dec 1994 | A |
| 5420599 | Erkocevic | May 1995 | A |
| 5422651 | Chang | Jun 1995 | A |
| 5451965 | Matsumoto | Sep 1995 | A |
| 5451968 | Emery | Sep 1995 | A |
| 5457469 | Diamond et al. | Oct 1995 | A |
| 5489914 | Breed | Feb 1996 | A |
| 5493702 | Crowley et al. | Feb 1996 | A |
| 5541609 | Stutzman et al. | Jul 1996 | A |
| 5684672 | Karidis et al. | Nov 1997 | A |
| 5701128 | Okada et al. | Dec 1997 | A |
| 5767811 | Mandai et al. | Jun 1998 | A |
| 5821907 | Zhu et al. | Oct 1998 | A |
| 5841403 | West | Nov 1998 | A |
| 5870066 | Asakura et al. | Feb 1999 | A |
| 5872546 | Ihara et al. | Feb 1999 | A |
| 5903240 | Kawahata et al. | May 1999 | A |
| 5929813 | Eggleston | Jul 1999 | A |
| 5966098 | Qi et al. | Oct 1999 | A |
| 5973651 | Suesada et al. | Oct 1999 | A |
| 5977920 | Hung | Nov 1999 | A |
| 5990838 | Burns et al. | Nov 1999 | A |
| 6008773 | Matsuoka et al. | Dec 1999 | A |
| 6028568 | Asakura et al. | Feb 2000 | A |
| 6031505 | Qi et al. | Feb 2000 | A |
| 6034639 | Rawlins et al. | Mar 2000 | A |
| 6140966 | Pankinaho | Oct 2000 | A |
| 6329951 | Wen et al. | Dec 2001 | B1 |
| 6335706 | Elliot | Jan 2002 | B1 |
| 6337667 | Ayala et al. | Jan 2002 | B1 |
| 6343208 | Ying | Jan 2002 | B1 |
| 6408190 | Ying | Jun 2002 | B1 |
| 6456249 | Johnson et al. | Sep 2002 | B1 |
| 6515634 | Desclos et al. | Feb 2003 | B2 |
| 6664930 | Wen et al. | Dec 2003 | B2 |
| 6781548 | Wen et al. | Aug 2004 | B2 |
| 6791500 | Qi et al. | Sep 2004 | B2 |
| 7151493 | Wen et al. | Dec 2006 | B2 |
| 20010001554 | Oshiyama | May 2001 | A1 |
| 20010050643 | Egorov et al. | Dec 2001 | A1 |
| 20020101380 | Pruss et al. | Aug 2002 | A1 |
| 20020140607 | Zhou | Oct 2002 | A1 |
| 20030011521 | Edimo et al. | Jan 2003 | A1 |
| 20040201530 | Wen et al. | Oct 2004 | A1 |
| Number | Date | Country |
|---|---|---|
| 101 37 946 | Apr 2003 | DE |
| 0543645 | May 1993 | EP |
| 0571124 | Nov 1993 | EP |
| 0765001 | Mar 1997 | EP |
| 0814536 | Dec 1997 | EP |
| 0892459 | Jan 1999 | EP |
| 1018779 | Jul 2000 | EP |
| 1172885 | Jan 2002 | EP |
| 1189304 | Mar 2002 | EP |
| 1296410 | Mar 2003 | EP |
| 1304765 | Apr 2003 | EP |
| 2330951 | May 1999 | GB |
| 55147806 | Nov 1980 | JP |
| 5007109 | Jan 1993 | JP |
| 5129816 | May 1993 | JP |
| 5267916 | Oct 1993 | JP |
| 5347507 | Dec 1993 | JP |
| 06097712 | Apr 1994 | JP |
| 6204908 | Jul 1994 | JP |
| 9638881 | May 1996 | WO |
| 9733338 | Sep 1997 | WO |
| 9812771 | Mar 1998 | WO |
| 9903166 | Jan 1999 | WO |
| 9925042 | May 1999 | WO |
| 0001028 | Jan 2000 | WO |
| 0171844 | Sep 2001 | WO |
| 0178192 | Oct 2001 | WO |
| 0191236 | Nov 2001 | WO |
| 02054539 | Jul 2002 | WO |
| 03047031 | Jun 2003 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20060125698 A1 | Jun 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10844685 | May 2004 | US |
| Child | 11344753 | US |
