(12) United States Patent
`Werling et al.
`
`USOO6456856B1
`(10) Patent No.:
`US 6,456,856 B1
`(45) Date of Patent:
`Sep. 24, 2002
`
`(54) MOBILE RADIO EQUIPMENT FORMING
`ANTENNA PATTERN TO PROJECT USER
`FROM RADATION
`
`(75) Inventors: Thierry B. F. Werling; Raul A.
`Bruzzone, both of Le Mans (FR)
`(73) Assignee: Koninklijke Philips Electronics N.V.
`(NL)
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(*) Notice:
`
`(21) Appl. No.: 09/361,074
`(22) Filed:
`Jul. 26, 1999
`(30)
`Foreign Application Priority Data
`Jul. 28, 1998
`(FR) ............................................ 98 O9651
`(51) Int. Cl." .................................................. H04B 1/38
`(52) U.S. Cl. ................
`... 455/550; 455/129
`(58) Field of Search ................................. 455/129, 121,
`455/125,550, 90
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`5,229.975 A 7/1993 Truesdell et al. ........... 367/107
`5,274,844. A * 12/1993 Harrison et al. .....
`... 342/368
`5,541,609 A * 7/1996 Stutzman et al. ........... 343/702
`
`5,729.238 A 3/1998 Walton et al. .............. 343/704
`5,805,067 A * 9/1998 Bradley et al. ............. 340/552
`5,924,020 A * 7/1999 Forssen et al. ............. 342/373
`5.956,626 A * 9/1999 Kaschke et al. ............ 340/552
`5,995,862 A * 11/1999 Gallorini .................... 250/372
`FOREIGN PATENT DOCUMENTS
`
`1/1997 ............ HO1O/1/24
`
`O752735 A1
`EP
`* cited by examiner
`Primary Examiner Daniel Hunter
`ASSistant Examiner Nick Corsaro
`(74) Attorney, Agent, or Firm-Dicran Halajian
`(57)
`ABSTRACT
`A radio communication apparatus includes a transceiver
`coupled to an antenna Structure with many directional anten
`nas that form a radiation pattern. The antenna Structure gives
`greater importance to certain directions of transmission. A
`power regulation device is controlled by a control element
`for modifying the radiation pattern. The control element
`includes Switches for Selectively activating/deactivating the
`directional antennas to modify the radiation pattern. A
`proximity detection device measures at least one proximity
`parameter and feeds the control element with a proximity
`indication for controlling the power regulation device to
`reduce the radiation pattern in the direction of the radio
`communication apparatus user. The proximity detection
`device includes a humidity and/or a temperature detector.
`
`12 Claims, 3 Drawing Sheets
`
`
`
`ZTE, Exhibit 1005-0001
`
`

`

`U.S. Patent
`US. Patent
`
`Sep. 24, 2002
`Sep. 24, 2002
`
`Sheet 1 of 3
`Sheet 1 0f3
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`US 6,456,856 B1
`US 6,456,856 B1
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`
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`
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`ZTE, Exhibit 1005-0002
`
`ZTE, Exhibit 1005-0002
`
`

`

`U.S. Patent
`US. Patent
`
`Sep. 24, 2002
`Sep. 24, 2002
`
`Sheet 2 of 3
`Sheet 2 0f3
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`US 6,456,856 B1
`US 6,456,856 B1
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`30-Y
`
`31 V
`
`V
`
`32
`
`34. -
`E'-
`39 -
`E 35
`' EleX/Rx
`32
`33-Y - 37 I
`E'-
`
`36
`
`- N
`
`Tx|Rx
`
`H. pc
`
`39
`39
`
`F.G.3
`FIG. 3
`
`ZTE, Exhibit 1005-0003
`
`ZTE, Exhibit 1005-0003
`
`

`

`U.S. Patent
`US. Patent
`
`Sep. 24, 2002
`Sep. 24, 2002
`
`Sheet 3 of 3
`Sheet 3 0f3
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`US 6,456,856 B1
`US 6,456,856 B1
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`
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`
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`ZTE, Exhibit 1005-0004
`
`ZTE, Exhibit 1005-0004
`
`

`

`US 6,456,856 B1
`
`1
`MOBILE RADIO EQUIPMENT FORMING
`ANTENNA PATTERN TO PROJECT USER
`FROM RADATION
`
`2
`than those described in cited document. Therefore, an appa
`ratus as mentioned in the opening paragraph is provided,
`characterized in that it comprises a proximity detection
`device for measuring at least one proximity parameter and
`feeding the control element with a proximity indication for
`controlling the power regulation device.
`According to an important characteristic feature of the
`invention, the antenna Structure comprises a plurality of
`directional antennas which have each a transmit power in a
`given direction and the power regulation device comprises
`power control means for regulating the transmit power of the
`directional antennas.
`According to another characteristic feature of the
`invention, the power control means comprise a Switch for
`Selectively activating/deactivating one or various directional
`antennaS.
`According to two particular embodiments of the
`invention, the proximity detection device comprises a tem
`perature detector and/or a humidity detector enabling to
`distinguish, among the various obstacles to the radio
`propagation, the presence of a human being in any obstacle.
`As it is an object of the invention to limit the emission of
`noxious radiation for the benefit of the user's health, it is
`very advantageous to use Such proximity detectors.
`These detectors further feature two additional advantages.
`AS they are passive, they are harmless to the user, because
`they emit no radio wave at all. Moreover, they make both the
`transmit power measurements and the calculations of the
`power differences recommended by the method cited pre
`viously redundant. These detectors are not only energy
`consumers but are also noxious, Since they imply to transmit
`at a certain power level for making the measurements before
`possibly effecting a power level control intended to limit the
`user's absorption of radiation.
`BRIEF DESCRIPTION OF THE DRAWINGS
`These and other aspects of the invention will be apparent
`from and elucidated with reference to the embodiments
`described hereinafter.
`In the drawings:
`FIG. 1 is a block diagram of a communication apparatus
`according to the invention,
`FIG. 2 represents an example of the mobile radio equip
`ment according to the invention,
`FIG. 3 is a block diagram of a particular embodiment of
`the equipment represented in FIG. 2, and
`FIG. 4 is a flow chart for illustrating an example of a
`method of controlling transmit power according to the
`invention.
`
`DESCRIPTION OF PREFERRED
`EMBODIMENTS
`The example represented in FIG.1 may be integrated with
`a radiotelephone using various directional transmitting
`antennas. The communication apparatus comprises a trans
`ceiver device 11 coupled to a plurality of directional anten
`nas 12 to 15 (having a radiation diagram giving greater
`importance to certain directions of transmission). Each
`antenna is electrically connected to a power regulation
`device 16 controlled by a control element 17. Such an
`element may be formed by a Suitably programmed micro
`controller uC which includes a programmable read-only
`memory, a random-acceSS memory, an input/output interface
`having an analog/digital converter and a digital/analog con
`verter and all the devices necessary for the interface with the
`various peripherals.
`
`FIELD OF THE INVENTION
`The invention relates to a radio communication apparatus
`comprising:
`transceiver means coupled to an antenna Structure featur
`ing a radiation diagram which antenna Structure gives
`greater importance to certain directions of transmission
`and
`a power regulation device controlled by a control element
`for modifying Said radiation diagram.
`The invention also relates to mobile radio equipment
`Suitable for communicating with at least one radio base
`Station of a radio telecommunication System, Said equipment
`comprising:
`radio transceiver means coupled to an antenna Structure
`featuring a radiation diagram which antenna Structure
`gives greater importance to certain directions of trans
`mission and
`a power regulation device controlled by a control element
`for modifying Said radiation diagram.
`The invention further relates to a radio base station of a
`radio telecommunication System Suitable for communicating
`with at least one mobile radio terminal, Said Station com
`prising:
`radio transceiver means coupled to an antenna Structure
`featuring a radiation diagram which antenna Structure
`gives greater importance to certain directions of trans
`mission and
`a power regulation device controlled by a control element
`for modifying Said radiation diagram.
`The invention finally relates to a power control method
`for controlling the power radiated in a given direction by a
`plurality of directional antennas which have respective
`transmit powers.
`The invention finds many applications in the field of
`telecommunication by radio channel, notably radiotele
`phony. The invention particularly applies to Systems called
`third generation Systems, operating according to a Universal
`Mobile Telecommunications System (UMTS) standard
`using the technique of Code-Division Multiple AcceSS
`(CDMA). Equipment provided for such systems comprises
`a plurality of directional antennas Suitable for emitting
`noxious radiation absorbed by human tissue situated in the
`proximity of these apparatus.
`
`15
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`25
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`35
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`40
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`45
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`BACKGROUND OF THE INVENTION
`European patent application no. EP 752 735, published in
`the German language, describes an apparatus of the type
`defined in the opening paragraph, comprising means for
`limiting the power of radiation absorbed by human tissue.
`The apparatus comprises an antenna array electrically con
`nected to a control unit for individually regulating the
`transmit power of each antenna as a function of the calcu
`lated variation between the impedance measured at the level
`of the antenna and a reference value corresponding to its
`impedance in the clear field. This difference represents a
`measure of the radiation power absorbed by human tissue.
`SUMMARY OF THE INVENTION
`The present invention proposes means for avoiding the
`emission of radio waves in the direction of human tissue,
`which means are easier to implement and more effective
`
`50
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`ZTE, Exhibit 1005-0005
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`

`

`3
`A proximity detector 18 connected to the control element
`17 detects the presence of human tissue in the proximity of
`the apparatus by measuring a proximity parameter, Such as
`temperature or degree of humidity, and transmits a proximity
`coefficient characteristic of the detected object to the control
`element 17. Such a detector is thus capable of differentiating
`between a human body featuring a certain coefficient and
`another body having a different coefficient. The value of this
`coefficient is analyzed by the control element 17 and com
`pared to Set values Stored in, for example, the read-only
`memory to determine, in dependence on their preferred
`directions of transmission, which are the directional anten
`nas whose transmit power is to be reduced and to trigger an
`appropriate control of the power regulation device 16.
`Under the control of the control element 17, the power
`regulation device 16 Selects one or various antennas and
`adjusts their transmit power as a function of the data
`produced by the detector 18.
`On reception, when the generated powers are consider
`ably Smaller than on transmission, all the directions of
`radiation may be used without a danger to the user.
`According to a preferred embodiment of the invention,
`the proximity detector 18 is a passive type of infrared
`thermometer, capable of measuring the temperature of a
`25
`body at a distance of about 20 cm from the detector. A
`variant consists of the use of a humidity detector.
`Preferably, the power regulation device 16 comprises a
`switch (not shown) controlled by the control element 17 for
`individually activating or deactivating the Selected antennas
`and radically Suppressing the contribution of the deactivated
`antennas whose radiation diagram features a lobe in the
`direction of transmission to be avoided.
`FIG. 2 is a perspective view of a radiotelephone com
`prising a structure of an antenna operating in the transceiv
`35
`ing mode whose radiation diagram, Simplified by main
`lobes, is represented by dotted lines. The use of Separate
`antennas for transmission and reception is advocated when
`the frequency bands used for transmission and reception
`respectively, are too far away for them to be compatible with
`the passband of the antennas. On the other hand, the size of
`the apparatus is to be adapted to accommodate a large
`number of antennas, which is actually the case with equip
`ment operating with frequencies in the gigahertz domain.
`The example illustrated by FIG. 2 comprises a housing
`20, a keyboard 21, a control display 22, an earphone 23, a
`microphone 24 and an antenna Structure comprising four
`independent directional transmitting antennas Situated inside
`the housing 20. These antennas are formed by, for example,
`ceramic discs which form a radiation diagram whose main
`lobes 25, 26, 27, 28 point in four orthogonal directions. In
`lieu of a System with various independently controllable
`antennas, one may use an adjustable miniaturized network
`antenna of the “phased-array type” like the one described in
`detail in the manual “Mobile Antenna Systems Handbook',
`K. Fujimoto et al., Artech House Inc., 1994, pp. 436–451.
`FIG. 3 is a block diagram illustrating the operation of the
`radiotelephone represented in FIG. 2. The antennas 30 to 33
`are coupled, on the one hand, to transceiver circuits TX/RX
`by means of a duplexer, and on the other hand to Switches
`34 to 37 controlled by a control element uC as a function of
`data it receives from a proximity detector. The transceiver
`circuits known to a perSon of ordinary skill in the art will not
`be described here. It will be simply recollected that a
`transmitting circuit coupled to an antenna Structure includes
`at least a power amplifier. In the case of a plurality of
`transmitting antennas, the radiotelephone is to comprise as
`
`45
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`US 6,456,856 B1
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`15
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`40
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`4
`many power amplifiers and transmitting circuits as there are
`antennas whose transmit power is to be controlled indepen
`dently of the transmit power of the other antennas.
`According to a preferred embodiment of the invention,
`the detection of human tissue by the proximity detector 39
`triggers the control by the control element uC of the appro
`priate Switches for deactivating the antennas whose radiation
`diagram points to the user's head. In the example with four
`antennas represented in FIG. 2, the antenna producing the
`lobe 27 will generally have to be deactivated.
`For a use in a propagation medium that gives greater
`importance to multiple paths and/or in a region where the
`density of the network of base Stations is high, the Suppres
`Sion of the transmitting antennas featuring their main lobe in
`a given hemisphere does not considerably reduce the vis
`ibility of the base stations located in this hemisphere. In fact,
`in the first case the multiple reflections of the waves increase
`their probability to reach their target and in the Second case
`the communication may be established with another avail
`able base station. Therefore, this embodiment is particularly
`Suitable for a current use in an urban environment. On the
`other hand, for any other use, the addition of an omnidirec
`tional antenna may turn out to be useful to avoid in this case
`losing contact with the only available base Station.
`According to another embodiment, each antenna is con
`nected to its own transmitting circuit and the Switches are
`replaced by attenuators controlled by the control element to
`adjust the transmit power of each antenna as a function of
`the result of the proximity detection. This embodiment
`requires that each antenna be connected to an adjustable
`power amplifier. AS the amplifiers have a high energy
`consumption, this embodiment is reserved to equipment
`whose power consumption is not critical Such as, for
`example, base Stations of a mobile telecommunication Sys
`tem.
`FIG. 4 illustrates a transmit power control method which
`can be realized by the control element 17 represented in FIG.
`1 and integrated with the radiotelephone of FIG. 2 to control
`the power transmitted by a directional antenna Structure.
`The method starts at box K0. In box K1, the power P.
`transmitted by the radiotelephone is read. This power may
`be read, for example, on the output of the power amplifier of
`the transmitting circuit. In box K2, the value read P is
`tested and compared to a Set Value PA representing the
`maximum radiation power considered unharmful to the user.
`If the result of this test PZPA is negative, the method
`proceeds with box K3 where all the antennas are selected
`without a power regulation. If the result of the test is
`positive, the method proceeds with box K4, with a measur
`ing Step for measuring a proximity parameter for detecting
`the presence of a human being in the proximity of the
`apparatus. Depending on the preferred embodiment, this
`Step consists of measuring the ambient temperature T with
`the aid of an infrared Sensor Sensitive to a distance of about
`20 cm. The test carried out in box K5 constitutes a com
`parison Step between the measurement T. carried out in the
`preceding Step and Set Values Ty and T.A.. If the equation
`Tv-T-TA is Verified, Step K6 is proceeded to for
`Selecting Suitable antennas and regulating their transmit
`power. If not, box K3 is returned to.
`With the aid of examples a communication apparatus,
`telephony equipment, a base Station and a power control
`method for modifying the radiation diagram of an antenna
`Structure as a function of a proximity parameter have been
`described and illustrated. Of course it will be possible to
`provide variants of embodiment without leaving the Scope of
`
`ZTE, Exhibit 1005-0006
`
`

`

`S
`the invention, notably as regards the choice of the proximity
`parameter to be detected and the choice of the antenna
`Structure used.
`What is claimed is:
`1. A radio communication apparatus comprising:
`a transceiver coupled to an antenna Structure featuring a
`radiation diagram, Said antenna Structure giving greater
`importance to certain directions of transmission;
`a power regulation device controlled by a control element
`for modifying Said radiation diagram; and
`a proximity detection device for measuring at least one
`proximity parameter and feeding the control element
`with a proximity indication for controlling the power
`regulation device, wherein the proximity detection
`device comprises a humidity detector.
`2. An apparatus as claimed in claim 1, wherein the
`antenna Structure comprises a plurality of directional anten
`nas which have each a transmit power in a given direction
`and the power regulation device comprises power control
`means for regulating the transmit power of the directional
`antennaS.
`3. An apparatus as claimed in claim 2, wherein the power
`control means comprise a Switch for Selectively activating/
`deactivating one or various directional antennas.
`4. An apparatus as claimed in claim 1, wherein the
`proximity detection device comprises a temperature detec
`tor.
`5. Mobile radio equipment Suitable for communicating
`with at least one radio base Station of a radio telecommu
`nication System, Said equipment comprising:
`a radio transceiver coupled to an antenna Structure fea
`turing a radiation diagram which antenna Structure
`gives greater importance to certain directions of trans
`mission;
`a power regulation device controlled by a control element
`for modifying Said radiation diagram; and
`a proximity detection device for measuring at least one
`proximity parameter and applying to the control ele
`ment an indication of proximity for controlling the
`power regulation device, wherein the proximity detec
`tion device comprises a humidity detector.
`6. A radio base Station of a radio telecommunication
`System Suitable for communicating with at least one mobile
`radio terminal, Said radio base Station comprising:
`a radio transceiver coupled to an antenna Structure fea
`turing a radiation diagram which antenna Structure
`gives greater importance to certain directions of trans
`mission;
`a power regulation device controlled by a control element
`for modifying Said radiation diagram; and
`a proximity detection device for measuring at least one
`proximity parameter and applying to the control ele
`
`15
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`25
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`35
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`40
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`US 6,456,856 B1
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`6
`ment a proximity indication for controlling the power
`regulation device, wherein the proximity detection
`device comprises a humidity detector.
`7. A power control method for controlling the power
`radiated in a given direction by a plurality of directional
`antennas which have respective transmit powers compris
`ing:
`measuring of at least one proximity parameter including
`a humidity detector for forming a measured result to
`detect a presence of a human being in the proximity of
`the apparatus,
`comparing Said measured result to Set values to form a
`comparison result, and
`Selecting at least one directional antenna for regulation of
`its transmit power as a function of the comparison
`result.
`8. A radio communication apparatus comprising:
`a transceiver coupled to a plurality of antennas having a
`radiation pattern;
`a control element;
`a power regulation device controlled by Said control
`element for modifying Said radiation pattern; and
`a proximity detector which measures at least one proX
`imity parameter, Said proximity detector including a
`humidity detector and Said at least one proximity
`parameter including a humidity parameter which indi
`cateS proximity of a user of Said radio communication
`apparatus in a direction;
`wherein Said control element controls Said power regula
`tion device in response to said humidity parameter So
`that Said radiation pattern is reduced in Said direction.
`9. The radio communication apparatus of claim 8,
`wherein Said control element includes at least one Switch for
`each one of Said plurality of antennas for Selectively deac
`tivating at least one of Said plurality of antennas that forms
`Said radiation pattern in Said direction.
`10. The radio communication apparatus of claim 8,
`wherein Said control element includes Switches for Selec
`tively deactivating at least one of Said plurality of antennas
`that forms said radiation pattern in Said direction.
`11. The radio communication apparatus of claim 8,
`wherein Said control element includes attenuators for Selec
`tively attenuating at least one of Said plurality of antennas
`that forms said radiation pattern in Said direction.
`12. The radio communication apparatus of claim 8, fur
`ther comprising a plurality of adjustable gain amplifiers
`coupled to Said plurality of antennas, Said control element
`controlling at least one of Said plurality of adjustable gain
`amplifiers to reduce Said radiation pattern in Said direction.
`
`ZTE, Exhibit 1005-0007
`
`