The present invention relates to the field of communications, and, more particularly, to wireless communications and related methods.
Cellular communication systems continue to grow in popularity and have become an integral part of both personal and business communications. Cellular telephones allow users to place and receive phone calls almost anywhere they travel. Moreover, as cellular telephone technology is improved, so too has the functionality of cellular devices. For example, many cellular devices now incorporate Personal Digital Assistant (PDA) features such as calendars, address books, task lists, calculators, memo and writing programs, etc. These multi-function devices usually allow users to wirelessly send and receive electronic mail (email) messages and access the Internet via a cellular network and/or a wireless local area network (WLAN), for example.
As the functionality of cellular devices continues to increase, so too does demand for smaller devices that are easier and more convenient for users to carry. Nevertheless, the move towards multi-functional devices makes miniaturization more difficult as the requisite number of installed components increases. Indeed, the typical cellular device may include several antennas, for example, a cellular antenna, a global positioning system antenna, and a WiFi IEEE 802.11g antenna. These antennas may comprise external antennas and internal antennas.
Generally speaking, internal antennas allow cellular devices to have a smaller footprint. Moreover, they are also preferred over external antennas for mechanical and ergonomic reasons. Internal antennas are also protected by the cellular device's housing and therefore tend to be more durable than external antennas. External antennas may be cumbersome and may make the cellular device difficult to use, particularly in limited-space environments. Yet, one potential drawback of typical internal antennas is that they are in relatively close proximity to the user's head when the cellular device is in use, thereby increasing the specific absorption rate (SAR). Yet more, hearing aid compatibility (HAC) may also be affected negatively. Also, other components within the cellular device may cause interference with or may be interfered by the internal antenna.
The present description is made with reference to the accompanying drawings, in which embodiments are shown. However, many different embodiments may be used, and thus the description 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. Like numbers refer to like elements throughout.
Generally speaking, a mobile wireless communications device may include a housing, at least one wireless transceiver carried by the housing, and a multiple-band antenna carried by the housing and coupled to the at least one wireless transceiver. Example mobile wireless communications devices may include portable or personal media players (e.g., music or MP3 players, video players, etc.), remote controls (e.g., television or stereo remotes, etc.), portable gaming devices, portable or mobile telephones, smartphones, tablet computers, etc. The multiple-band antenna may include a first radiator comprising a radiator element and a parasitic element adjacent thereto, the parasitic element being selectively switchable between floating and grounded states, and a second radiator insulated from the first radiator.
More specifically, the multiple-band antenna may comprise a dielectric substrate supporting the first and second radiators. The dielectric substrate may have a non-planar shape, for example. The dielectric substrate may be carried by a bottom of the housing, and the first and second radiators may be carried by respective opposing first and second sides of the dielectric substrate.
Additionally, the second radiator may comprise first and second branches coupled together with a T-shaped slot therebetween. The second radiator may comprise a feed connection on the first branch, and a reference voltage connection on the second branch. For example, the T-shaped slot may open outwardly and between the first and second branches.
Moreover, the radiator element may comprise a first branch extending alongside the parasitic element, and a second branch extending outwardly from the first branch. The second branch may have a bend in a medial portion thereof. The radiator element may comprise a feed connection on the first branch. For example, the parasitic element may have a rectangular shape.
Another aspect is directed to a method of making a mobile wireless communications device. The method may comprise forming a multiple-band antenna to comprise a first radiator comprising a radiator element and a parasitic element adjacent thereto, the parasitic element being selectively switchable between floating and grounded states, and a second radiator insulated from the first radiator. The method may also include coupling at least one wireless transceiver to be carried by a housing, and coupling the multiple-band antenna to be carried by the housing and to the at least one wireless transceiver.
Referring initially to
In particular, the parasitic element 35 is aligned substantially parallel to the radiator element 36. The parasitic element 35 may be selectively switchable between floating and grounded states, i.e. it is coupled to a plurality of differing impedances. The parasitic element 35 is switched to change the capacitive load of the radiator element 36 and to control the resonance frequency of the same, thereby improving antenna performance. For example, the parasitic element 35 illustratively has a rectangle shape, but may comprise different shapes in other embodiments, such a triangle shape, a trapezoid shape, a curved shape, etc.
Moreover, the radiator element 36 illustratively includes a first branch 43 extending alongside the parasitic element 35, and a second branch 44 extending outwardly from the first branch. The radiator element 36 illustratively includes a feed connection 47 on the first branch 43. The portion of the first branch 43 proximal to the feed connection 47 illustratively has a rectangle shape, but may comprise different shapes in other embodiments, such a triangle shape, a trapezoid shape, a curved shape, etc. The radiator element 36 illustratively includes a medial portion coupling the first branch 43 and the second branch 44. The medial portion illustratively includes L-shaped slot 39 on an inner side thereof, and a protruding portion 49 on an outer side thereof. The L-shaped slot 39 may comprise different shapes in other embodiments, such a triangle shape, a trapezoid shape, a curved shape, etc. The protruding portion 49 is substantially rectangle shaped and forms a portion of a speaker receiving recess, but may comprise different shapes in other embodiments, such a triangle shape, a trapezoid shape, a curved shape, etc. The second branch 44 illustratively includes a bend 45 in a medial portion thereof. The distal end of the second branch 44 is substantially rectangle shaped, but may comprise different shapes in other embodiments, such a triangle shape, a trapezoid shape, a curved shape, etc.
The multiple-band antenna 32 illustratively includes a second radiator 34 insulated from the first radiator 33. More specifically, the multiple-band antenna 32 illustratively includes a dielectric substrate 37 supporting the first and second radiators 33-34. For example, the second radiator 34 may comprise a high band radiator operating at a frequency band of 1710-2170 MHz.
As perhaps best seen in
Additionally, the second radiator 34 illustratively includes first and second branches 40-41 coupled together with a medial portion therebetween. The medial portion illustratively includes a T-shaped slot 42 on an inner side thereon. The T-shaped slot 42 may comprise different shapes in other embodiments, such a triangle shape, a trapezoid shape, a curved shape, etc. The medial portion illustratively includes, on an outer side thereof, a curved portion 79 and a protruding portion 69. The protruding portion 69 is illustratively substantially rectangle shaped, but may comprise different shapes in other embodiments, such a triangle shape, a trapezoid shape, a curved shape, etc. The second radiator 34 illustratively includes a feed connection 53 on the first branch 40, and a reference voltage connection 54, for example, a ground connection, on the second branch 41. The T-shaped slot 42 may open outwardly and between the first and second branches 40-41.
The multiple-band antenna 32 illustratively includes a tuning member 59 (
In the typical cellular device, low band resonance may cause performance issues for the high band antenna. Advantageously, the second radiator 34 is electrically insulated from the first radiator 33 and the parasitic element 35 is appropriately switched to enhance the isolation therebetween. For example, if the second radiator 34 (high band) is in use, the first radiator 33 is terminated with an isolation optimizing impedance, both the parasitic element 35 and the radiator element 36. Also, the two radiator approach with an active low band antenna and a passive high band antenna may give enough design freedom to achieve design goals (low and high band can be tuned independently, and coupling between low and high band can be controlled).
Referring now additionally to
Referring now additionally to
Referring now additionally to
The matching network (impedance) block 55 illustratively includes an inductor 300, and a capacitor 301 coupled in parallel. The second radiator feed path 57 illustratively includes a resistor 309 coupling the matching network block 55 and the switch connector block 58, and a capacitor 340 coupling the switch connector block 58 to the ESD protection block 56.
Referring now to
Referring now to
In particular, diagrams 100 and 120 show the shift of the antenna resonance in the low band (frequency range 800-1000 MHz). The active antenna was designed to extend the bandwidth in the low band area.
Referring now additionally to
The low band antenna (first radiator 33) also shows a 2nd resonance in the range of the high band antenna (second radiator 34). In the illustrated embodiments, the high band and low band antennas 33-34 are close together. The 2nd resonance of the low band antenna 33 will also interact with the 1st resonance of the high band antenna 34. In diagrams 140, 150, 230, the frequency range is extended, and the higher frequencies are shown. The diagrams include the range (800 MHz-2300 MHz), and aid in understanding the control enabled with the active antenna radiator switching state for the isolation between our low band and high band antennas 33-34. Diagram 140 shows return loss of both radiators for the switching state 1 (y-axis in dB, x-axis is frequency in MHz), and this figure shows the 1st and the 2nd resonances of the active antenna (low band radiator 33). The second resonance is overlapping with the resonance of the high band radiator 34 (antenna with T slot). This 2nd resonance causes a coupling between both radiators with impact to antenna isolation. Diagrams 150 and 230 show the coupling/isolation between both radiators, diagram 230 being another format (smith chart) of diagram 150. The antenna isolation impacts the efficiency, HAC and SAR.
Diagrams 170, 180, 220 show the same situation for the switched state 2. It is visible that not only the first resonance is affected, but also the 2nd resonance is shifted. The isolation between both antennas is changed (compare
Diagrams 200, 205 illustrate hearing aid compatibility H-field in first and second switched parasitic states. In particular, peak H-field measurements in A/m for the first switched parasitic state include: grid 1 0.271; grid 2 0.281; grid 30.270; grid 40.272; grid 50.278; grid 60.265; grid 7 0.322; grid 8 0.253; and grid 9 0.205. Peak H-field measurements in V/m for the second switched parasitic state include: grid 1 0.223; grid 2 0.236; grid 3 0.231; grid 4 0.230; grid 5 0.235; grid 6 0.230; grid 7 0.272; grid 8 0.211; and grid 9 0.192. Advantageously, the first and second resonances of the first radiator 33 are managed, thereby mitigating a near field effect for the hearing aid earpiece. Indeed, as shown in diagrams 190, 195, 200, 205, the HAC values are clearly reduced in the second switched parasitic state.
Advantageously, in the mobile wireless communications device 30, the isolation (2nd resonance low band radiator 33 and 1st resonance high band radiator 34) between both antennas is controlled with the different switching states of our active low band antenna. In one case, high isolation is necessary to have the best antenna efficiency (GSM 1800, GSM 1900 RX, W-CDMA Band 1,2,4). This permits the multiple-band antenna 32 to realize this disclosed mechanical arrangement of the antennas being close together in a small volume. But in other cases (GSM 1900 TX (transmit)), the other switching state that gets less isolation can be used, which changes the field distribution on the PCB (printed wire board) and reduces HAC values. Of course, the antenna efficiency is compromised in this case. Nevertheless, mobile wireless communications device 30 does not need an extra HAC reduction structure, as required in typical cellular devices (traditional HAC reduction structures are separate metalized structures(L-stub, for example) mounted close to antenna). The design of the disclosed low band radiator 33 is made so that the 2nd resonance of the low band radiator is in the frequency range where we want to reduce HAC (GSM 1900 TX).
Example components of a mobile wireless communications device 1000 that may be used in accordance with the above-described embodiments are further described below with reference to
The housing 1200 may be elongated vertically, or may take on other sizes and shapes (including clamshell housing structures). The keypad may include a mode selection key, or other hardware or software for switching between text entry and telephony entry.
In addition to the processing device 1800, other parts of the mobile device 1000 are shown schematically in
Operating system software executed by the processing device 1800 is stored in a persistent store, such as the flash memory 1160, but may be stored in other types of memory devices, such as a read only memory (ROM) or similar storage element. In addition, system software, specific device applications, or parts thereof, may be temporarily loaded into a volatile store, such as the random access memory (RAM) 1180. Communications signals received by the mobile device may also be stored in the RAM 1180.
The processing device 1800, in addition to its operating system functions, enables execution of software applications 1300A-1300N on the device 1000. A predetermined set of applications that control basic device operations, such as data and voice communications 1300A and 1300B, may be installed on the device 1000 during manufacture. In addition, a personal information manager (PIM) application may be installed during manufacture. The PIM may be capable of organizing and managing data items, such as e-mail, calendar events, voice mails, appointments, and task items. The PIM application may also be capable of sending and receiving data items via a wireless network 1401. The PIM data items may be seamlessly integrated, synchronized and updated via the wireless network 1401 with corresponding data items stored or associated with a host computer system.
Communication functions, including data and voice communications, are performed through the communications subsystem 1001, and possibly through the short-range communications subsystem 1020. The communications subsystem 1001 includes a receiver 1500, a transmitter 1520, and one or more antennas 1540 and 1560. In addition, the communications subsystem 1001 also includes a processing module, such as a digital signal processor (DSP) 1580, and local oscillators (LOs) 1601. The specific design and implementation of the communications subsystem 1001 is dependent upon the communications network in which the mobile device 1000 is intended to operate. For example, a mobile device 1000 may include a communications subsystem 1001 designed to operate with the Mobitex™, Data TAC™ or General Packet Radio Service (GPRS) mobile data communications networks, and also designed to operate with any of a variety of voice communications networks, such as Advanced Mobile Phone System (AMPS), time division multiple access (TDMA), code division multiple access (CDMA), Wideband code division multiple access (W-CDMA), personal communications service (PCS), GSM (Global System for Mobile Communications), enhanced data rates for GSM evolution (EDGE), etc. Other types of data and voice networks, both separate and integrated, may also be utilized with the mobile device 1000. The mobile device 1000 may also be compliant with other communications standards such as 3GSM, 3rd Generation Partnership Project (3GPP), Universal Mobile Telecommunications System (UMTS), 4G, etc.
Network access requirements vary depending upon the type of communication system. For example, in the Mobitex and DataTAC networks, mobile devices are registered on the network using a unique personal identification number or PIN associated with each device. In GPRS networks, however, network access is associated with a subscriber or user of a device. A GPRS device therefore typically involves use of a subscriber identity module, commonly referred to as a SIM card, in order to operate on a GPRS network.
When required network registration or activation procedures have been completed, the mobile device 1000 may send and receive communications signals over the communication network 1401. Signals received from the communications network 1401 by the antenna 1540 are routed to the receiver 1500, which provides for signal amplification, frequency down conversion, filtering, channel selection, etc., and may also provide analog to digital conversion. Analog-to-digital conversion of the received signal allows the DSP 1580 to perform more complex communications functions, such as demodulation and decoding. In a similar manner, signals to be transmitted to the network 1401 are processed (e.g. modulated and encoded) by the DSP 1580 and are then provided to the transmitter 1520 for digital to analog conversion, frequency up conversion, filtering, amplification and transmission to the communication network 1401 (or networks) via the antenna 1560.
In addition to processing communications signals, the DSP 1580 provides for control of the receiver 1500 and the transmitter 1520. For example, gains applied to communications signals in the receiver 1500 and transmitter 1520 may be adaptively controlled through automatic gain control algorithms implemented in the DSP 1580.
In a data communications mode, a received signal, such as a text message or web page download, is processed by the communications subsystem 1001 and is input to the processing device 1800. The received signal is then further processed by the processing device 1800 for an output to the display 1600, or alternatively to some other auxiliary I/O device 1060. A device may also be used to compose data items, such as e-mail messages, using the keypad 1400 and/or some other auxiliary I/O device 1060, such as a touchpad, a rocker switch, a thumb-wheel, or some other type of input device. The composed data items may then be transmitted over the communications network 1401 via the communications subsystem 1001.
In a voice communications mode, overall operation of the device is substantially similar to the data communications mode, except that received signals are output to a speaker 1100, and signals for transmission are generated by a microphone 1120. Alternative voice or audio I/O subsystems, such as a voice message recording subsystem, may also be implemented on the device 1000. In addition, the display 1600 may also be utilized in voice communications mode, for example to display the identity of a calling party, the duration of a voice call, or other voice call related information.
The short-range communications subsystem enables communication between the mobile device 1000 and other proximate systems or devices, which need not necessarily be similar devices. For example, the short-range communications subsystem may include an infrared device and associated circuits and components, a Bluetooth™ communications module to provide for communication with similarly-enabled systems and devices, or a NFC sensor for communicating with a NFC device or NFC tag via NFC communications.
Many modifications and other embodiments will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that various modifications and embodiments are intended to be included within the scope of the appended claims.