Portable electronic devices including multi-mode matching circuits and methods of operating the same

Portable electronic devices are provided including a housing, an antenna associated with the housing and a multi-mode matching circuit operatively associated with the antenna. The multi-mode matching circuit is configured to operate in a first mode when the housing of the portable electronic device is in a first configuration and in a second mode when the housing of the portable electronic device is in a second configuration. Related methods of operating portable electronic devices including multi-mode matching circuits are also discussed.

FIELD OF THE INVENTION

The present invention relates to portable electronic devices and, more particularly, to adaptive antennas of portable electronic devices and methods of operating the same.

BACKGROUND OF THE INVENTION

Recently, there has been a proliferation in the field of wireless communications. Devices such as cordless and cellular telephones, pagers, wireless modems, wireless email devices, personal digital assistants (PDAs) with communication functions, and other portable electronic devices are becoming commonplace. To preserve the integrity of transmission to and from such devices, it is important to maintain a clear, strong radio signal.

A gain of an antenna of a portable electronic device, such as a pager or a cellular telephone be may be lowered by the presence of certain objects such as metallic objects and/or by ground plane conditions, i.e. the antenna may be detuned. When the antenna is detuned, the portable electronic device may have a shorter operating radius and may experience poor in-building performance or fringe performance, i.e. performance at the edge of a cell.

Embedded antennas are common in conventional portable electronic devices. A signal transmitted from or received by an antenna which is integrated into a portable electronic device may encounter several boundaries, including for example a printed circuit board, a battery, a display screen, a device housing, a device carrying case and any of a multitude of other elements or components associated with the device, in addition to a user's body. All such boundaries may influence the propagation of the signal and the surrounding impedance seen by the antenna.

Furthermore, when a portable electronic device is in operation, it may be turned in different directions and may not be optimally aligned to receive and/or transmit signals. At least a portion of signal power losses associated with antennas in portable electronic devices is due to signal reflection. Ideally, all of the signal power of a signal input to an antenna would be converted into an electromagnetic signal and radiated. Likewise, ideally all electromagnetic energy received at the antenna would be converted into an electrical signal and provided to receive electronics. However, in reality the characteristic impedance of the portable electronic device interacts with the characteristic impedance of the antenna and unless these impedances are equal, some signal reflection will likely occur.

Accordingly, some conventional portable electronic devices may include an impedance matching circuit between communication circuitry of the portable electronic device and an antenna. Impedance matching circuits typically include an LC circuit with inductance and capacitance elements connected in any one of a number of standard matching circuit topologies. However, some conventional impedance matching circuits may be configured during manufacture of the portable electronic device and may not provide for adjustments in the field. Thus, the matching circuit may not adapt to environmental conditions that may influence the impedance affecting the antenna. For example, over the air signals transmitted and received by an antenna of a portable electronic device may encounter such dielectric boundaries as the housing of device, printed circuit boards, electronic components in the housing, batteries for powering the device, display, input device and the body of a device user, all of which may influence the impedance seen by the antenna. Such impedances can be estimated, but are dependent upon the orientation of the device with respect to its surroundings. Thus, even the best estimates of impedance matching requirements may not remain accurate for all device operating conditions.

To address possible problems with matching circuits discussed above, adaptive antenna assemblies have been provided in some conventional portable electronic devices such that the antenna may adapt to environmental conditions. For example, adaptive antennas are discussed in U.S. Pat. No. 6,570,462 to Edmonson et al., U.S. Pat. No. 5,778,308 to Sroka et al. and U.S. Pat. No. 5,564,086 to Cygan et al. However, improved antenna matching circuits may be desirable.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide portable electronic devices including a housing and an antenna associated with the housing. The portable electronic device also includes a multi-mode matching circuit operatively associated with the antenna. The multi-mode matching circuit is configured to operate in a first mode when the housing of the portable electronic device is in a first configuration and in a second mode when the housing of the portable electronic device is in a second configuration.

In some embodiments of the present invention, the portable electronic device may further include a sensor operatively associated with the multi-mode matching circuit. The sensor may be configured to detect the first configuration of the housing of the portable electronic device and/or the second configuration of the housing of the portable electronic device. The multi-mode matching circuit may be configured to adjust at least one parameter of the multi-mode matching circuit responsive to the first and/or second detected configurations of the housing of the portable electronic device.

In further embodiments of the present invention, the multi-mode matching circuit may include an impendence matching circuit. The at least one parameter of the multi-mode matching circuit may include a resistance, a capacitance and/or an inductance and may be stored in a lookup table.

In still further embodiments of the present invention, the portable electronic device may further include a processor operatively associated with the sensor. The processor may be configured to locate the at least one parameter in the lookup table using the first and/or second detected configuration of the housing of the portable electronic device as a pointer for an entry in the lookup table.

In some embodiments of the present invention, the portable electronic device may further include a timer circuit operatively associated with the sensor. The sensor may be further configured to detect the first and/or second configuration of the housing of the portable electronic device responsive to expiration of the timer circuit. The timer, for example, may be configured to trigger periodic detection of the housing configuration.

In further embodiments of the present invention, the portable electronic device may be a portable electronic device having a flip configuration. The portable electronic device may be in the first configuration when the portable electronic device is open and the portable electronic device may be in the second configuration when the portable electronic device is closed.

While the present invention is described above primarily with reference to portable electronic devices, methods of operating portable electronic devices are also provided.

DETAILED DESCRIPTION

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. In the drawings, the relative sizes of regions or features may be exaggerated for clarity. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It will be understood that when an element is referred to as being “coupled” or “connected” to another element, it can be directly coupled or connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly coupled” or “directly connected” to another element, there are no intervening elements present. Like numbers refer to like elements throughout. As used herein the term “and/or” includes any and all combinations of one or more of the associated listed items.

Embodiments of the present invention will now be described below with respect toFIGS. 1 through 6. Embodiments of the present invention provide portable electronic devices including multi-mode matching circuits. The multi-mode matching circuit may operate in a first mode when the housing of the portable electronic device and/or the antenna is in a first configuration and a second mode when the housing of the portable electronic device and/or the antenna is in a second configuration. In particular, a sensor may be provided that is configured to detect the configuration of the housing of the portable electronic device and/or the antenna and adjust the mode of the multi-mode matching circuit responsive to the detected configuration of the housing of the portable electronic device and/or the antenna. Accordingly, an impedance of multi-mode matching circuits according to embodiments of the present invention may be adjusted based on the configuration of the housing of the portable electronic device and/or the antenna and, therefore, portable electronic devices may be provided having improved transmission characteristics, i.e., more radiation and less reflection of the signal. Receive characteristics of the portable electronic device may also be improved.

The present invention is described below with reference to schematic and block diagrams of mobile terminals including multi-mode matching circuits according to some embodiments of the present invention. Although multi-mode matching circuits are discussed herein as being included as part of a mobile terminal, for example, mobile terminal22ofFIG. 1, embodiments of the present invention are not limited to this configuration. Multi-mode matching circuits according to embodiments of the present invention may be included in any portable electronic device that utilizes an antenna suitable for operation with one or more matching circuits without departing from the scope of the present invention.

FIG. 1illustrates an exemplary radiotelephone communication system, in accordance with embodiments of the present invention, which includes the mobile terminal22and a base station transceiver24of a wireless communications network. The mobile terminal22includes a portable housing23and may include a man machine interface26, a display28, a timer circuit30, a speaker32, a microphone34, a transceiver36, and a memory38, any of which may communicate with a processor42. Furthermore, mobile terminals22according to embodiments of the present invention may further include a multi-mode matching circuit27according to embodiments of the present invention and a sensor29operatively associated with the multi-mode matching circuit27, which also communicate with a controller/processor42. The processor42can be any commercially available or custom microprocessor.

The transceiver36typically includes a transmitter circuit44and a receiver circuit46, which respectively transmit outgoing radio frequency signals to the base station transceiver24and receive incoming radio frequency signals, such as voice signals, from the base station transceiver24via an antenna48. The antenna48may be an embedded antenna, a retractable antenna or any antenna known to those having skill in the art without departing from the scope of the present invention. The radio frequency signals transmitted between the mobile terminal22and the base station transceiver24may comprise both traffic and control signals (e.g., paging signals/messages for incoming calls), which are used to establish and maintain communication with another party or destination. The processor42may support various functions of the mobile terminal22, including processing detected configurations of the housing of the mobile terminal22and/or the antenna48.

As used herein, the term “portable electronic device” or “mobile terminal” may include: a cellular radiotelephone with or without a multi-line display; a Personal Communications System (PCS) terminal that may combine a cellular radiotelephone with data processing, facsimile and data communications capabilities; a Personal Data Assistant (PDA) that can include a radiotelephone, pager, Internet/intranet access, Web browser, organizer, calendar and/or a global positioning system (GPS) receiver; a gaming device, an audio video player, and a conventional laptop and/or palmtop portable computer that may include a radiotelephone transceiver.

In some embodiments of the present invention, the base station transceiver24comprises the radio transceiver(s) that defines an individual cell in a cellular network and communicates with the mobile terminal22and other mobile terminals in the cell using a radio-link protocol. Although only a single base station transceiver24is shown, it will be understood that many base station transceivers may be connected through, for example, a mobile switching center and other devices to define a wireless communications network.

Although the present invention may be embodied in communication devices or systems, such as the mobile terminal22, the present invention is not limited to such devices and/or systems. Instead, the present invention may be embodied in any apparatus that may utilize a multi-mode matching circuit according to embodiments of the present invention.

In some embodiments of the present invention, the multi-mode matching circuit27is operatively associated with the antenna48. The multi-mode matching circuit27may be configured to operate in a first mode when the housing of the portable electronic device is in a first configuration and in a second mode when the housing of the portable electronic device is in a second configuration. In certain embodiments of the present invention, the portable electronic device may be a mobile terminal having a flip configuration as illustrated inFIGS. 2A and 2B. The housing of mobile terminal may be in the first configuration200may be when the mobile terminal is open as illustrated inFIG. 2A. Similarly, the housing of the mobile terminal may be in the second configuration205when the mobile terminal is closed as illustrated inFIG. 2B.

As discussed above, a sensor29may be operatively associated with the multi-mode matching circuit. The sensor29may be configured to detect the configuration of the housing of the portable electronic device. The multi-mode matching circuit27may be, for example, an impedance matching circuit and may be configured to adjust one or more parameters or tuning coefficients, for example, a resistance, capacitance and/or an inductance, of the multi-mode matching circuit responsive to the detected configuration of the housing of the mobile terminal22. The sensor29may be a mechanical sensor, an electrical sensor, an acoustic sensor or a combination of any of these without departing from the scope of the present invention. Operations of sensors are known to those having skill in the art and will not be discussed further herein.

It will be understood that although multi-mode matching circuits according to embodiments of the present invention are discussed herein as having first and second modes of operation, multi-mode matching circuits according to embodiments of the present invention are not limited to this configuration. Multi-mode matching circuits according to embodiments of the present invention may have three or more modes without departing from the scope of the present invention. For example, in embodiments of the present invention wherein the mobile terminal has a flip configuration, the mobile terminal may not just be open200or closed205(FIGS. 2A and 2B), the mobile terminal may be a quarter open, half open, three quarters open and the like. Thus, each of the configurations of the mobile terminal may have a corresponding mode of the multi-mode matching circuit27.

In some embodiments of the present invention, the parameters of the multi-mode matching circuit may be stored in a lookup table, for example, the lookup table400illustrated inFIG. 4. The lookup table may be created during calibration of the mobile terminal during manufacturing. The calibration process may be performed on each mobile terminal individually or may be performed on two or more mobile terminals simultaneously without departing from the scope of the present invention. The processor42, operatively associated with the sensor29, may be configured to locate the parameters of the multi-mode matching circuit27in the lookup table400using, for example, the detected configuration of the housing of the mobile terminal as a pointer for an entry in the lookup table.

It will be understood that the lookup table may be predefined and loaded onto a mobile terminal or a plurality of mobile terminals without departing from the scope of the present invention. In other words, the lookup table may not be created during calibration of the mobile terminal during manufacturing, it may be preexisting and simply loaded onto the mobile terminal during manufacturing.

For example, if the mobile terminal is closed, i.e., the angle210between a first portion220of the mobile terminal and a second portion225of the mobile terminal is 0 degrees, the parameters for the matching circuit27may be R1, C1and/or L1. Similarly, if the angle210between a first portion220of the mobile terminal and a second portion225of the mobile terminal is 45 degrees, the parameters for the multi-mode matching circuit27may be R2, C2and/or L2. The parameters for multi-mode matching circuit when the angle210is 90, 135 and 180 degrees are set out in the lookup table400ofFIG. 4.

It will be understood that the angles provided in the lookup table400are provided for exemplary purposes only and embodiments of the present invention should not be limited to these angles. It will be further understood that the angles that change are not limited to the angles provided in, for example,FIG. 2A, any possible angle change between first and second portions of the mobile terminal may be used without departing from the scope of the present invention. Furthermore, details with respect to the parameters (tuning coefficients) of the multi-mode matching circuit27and operations thereof are known to those having skill in the art and will not be discussed further herein.

In some embodiments of the present invention, a timer circuit30may be operatively associated with the sensor29. The sensor29may be further configured to repeatedly detect the configuration of the mobile terminal responsive to expiration of the timer circuit30. It will be understood that although embodiments of the present invention may be discussed herein with respect to mobile terminals having a flip configuration and/or retractable antennas, embodiments of the present invention are not limited to these configurations. Multi-mode matching circuits according to embodiments of the present invention may be used in any portable electronic device having multiple configurations. For example, mobile terminals having ajack-knife configuration or a camera configured to protrude from the mobile terminal during camera functionality and to retract when not in use are within the scope of the present invention.

It will be further understood that although embodiments of the present invention are discussed herein with respect to configurations of the housing of the portable electronic device, embodiments of the present invention are not limited to this configuration. For example, in some embodiments of the present invention the multi-mode matching circuit27may switch between first and second modes responsive to a position of the antenna relative to the housing of the mobile terminal. For example, the multi-mode matching circuit27may operate in a first mode when a retractable antenna is in a first retracted position300relative to the housing of the mobile terminal as illustrated inFIG. 3A. Similarly, the multi-mode matching circuit may operate in a second mode when the retractable antenna is in a second extended position305relative to the housing of the mobile terminal as illustrated inFIG. 3B.

Over the air signals transmitted and received by an antenna48of a portable electronic device may encounter such electromagnetic boundaries as the housing of device, printed circuit boards, electronic components in the housing, batteries for powering the device, display, input device and the body of a device user, all of which may influence the impedance seen by the antenna. Portable electronic devices including multi-mode matching circuits27according to embodiments of the present invention may provide the ability to change the impedance of the multi-mode matching circuit based on the configuration of the housing and/or the antenna so that a strong signal may be transmitted and/or received regardless of the orientation of the portable electronic device with respect to its surroundings. Accordingly, portable electronic devices including multi-mode matching circuits according to embodiments of the present invention may have relatively higher gains and higher proportions of signal radiation. Thus, embodiments of the present invention may provide portable electronic devices having improved radio performance characteristics.

Referring now toFIG. 5, operations of portable electronic devices including multi-mode matching circuits according to some embodiments of the present invention will be discussed. Operations begin at block500by detecting a configuration of a housing of the portable electronic device. Detection of the configuration may be performed when the portable electronic device is powered on and may be periodically detected when a change of configuration is detected or a timer circuit expires. In embodiments of the present invention where the housing of the portable electronic device includes a mobile terminal having a flip configuration, the configuration of the mobile terminal may be open, closed and/or partially open/closed. The configuration of the housing of the portable electronic device may be detected by a sensor operatively associated with a multi-mode matching circuit. One or more parameters of the multi-mode matching circuit may be adjusted based on the detected configuration of the housing of the portable electronic device (block510).

Referring now to the flowchart ofFIG. 6, operations of portable electronic devices including multi-mode matching circuits according to further embodiments of the present invention will be discussed. Operations begin at block600by detecting a configuration of a housing of the portable electronic device. The configuration of the mobile terminal may be detected by a sensor operatively associated with a multi-mode matching circuit of the portable electronic device. One or more parameters of the multi-mode matching circuit may be located in a lookup table (block610). The lookup table may be created during calibration of the portable electronic device during manufacturing. The calibration process may be performed on each portable electronic device individually or may be performed on two or more portable electronic devices simultaneously without departing from the scope of the present invention. The detected configuration of the housing of the portable electronic device may be used as a pointer for an entry in the lookup table. In some embodiments of the present invention, the sensor may be operatively associated with a processor, which may be configured to locate the one or more parameters in the lookup table.

The one or more parameters located in the lookup table may be used to adjust the multi-mode matching circuit to adapt the impedance of the antenna to environmental conditions (block620). It is determined if the configuration of the phone has changed or a timer has expired (block630). If it is determined that the configuration has changed and/or a timer has expired (block630), operations return to block600and repeat. If it is determined that the configuration has not changed and/or the timer has not expired (block630), operations remain at block630until the configuration of the mobile terminal changes and/or the timer expires.

It will be understood that although the methods discussed with respect to the flowcharts ofFIGS. 5 and 6are discussed with respect to detection of a configuration of the housing of a portable electronic device at block500and600, respectively, embodiments of the present invention are not limited to this configuration. In some embodiments of the present invention operations of block500and/or600may include detecting a position of an antenna relative to the housing of the portable electronic device as discussed above without departing from the scope of the present invention.

As briefly discussed above with respect toFIGS. 1 through 6, embodiments of the present invention provide portable electronic devices having multi-mode matching circuits. One or more parameters of the multi-mode matching circuit may be adjusted based on a detected configuration of the housing of the portable electronic device and/or position of the antenna relative to the housing of the portable electronic device. Adjusting the parameters of the matching circuit may provide the ability to change the impedance of the multi-mode matching circuit based on the configuration of the housing and/or the antenna so that a strong signal may be transmitted and/or received regardless of the orientation or configuration of the portable electronic device with respect to its surroundings. Accordingly, portable electronic devices including multi-mode matching circuits according to embodiments of the present invention may experience higher gains and/or less reflection due to the adaptability of the antenna.

In the drawings and specification, there have been disclosed typical illustrative embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.