CN1668930A - Apparatus for and method of measuring local specific absorption range SAR - Google Patents
Apparatus for and method of measuring local specific absorption range SAR Download PDFInfo
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- CN1668930A CN1668930A CNA038169991A CN03816999A CN1668930A CN 1668930 A CN1668930 A CN 1668930A CN A038169991 A CNA038169991 A CN A038169991A CN 03816999 A CN03816999 A CN 03816999A CN 1668930 A CN1668930 A CN 1668930A
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- electromagnetic field
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/12—Supports; Mounting means
- H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
- H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
- H01Q1/241—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM
- H01Q1/242—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use
- H01Q1/245—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
- H04B1/3827—Portable transceivers
- H04B1/3833—Hand-held transceivers
- H04B1/3838—Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
- H04B1/3827—Portable transceivers
- H04B1/3833—Hand-held transceivers
- H04B1/3838—Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use
- H04B2001/3844—Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use with means to alert the user that a certain exposure has been reached
Abstract
A local SAR measurement device capable of estimating a small-size radio device local SAR on a production line with a high accuracy within a short time. The local SAR measurement device includes a plurality of electromagnetic probes (1) for receiving transmission power from a mobile telephone antenna (12) extending from a mobile telephone main body (11) in Fresnels zone, a combining device for combining the reception powers (2), and a signal processor (3) for estimating a local SAR from the combined reception power. A plurality of electromagnetic probes (1) are used to measure the reception powers of a reference mobile telephone whose local SAR value is known by a precision measurement and a mobile telephone to be measured, so as to estimate the SAR value of the mobile telephone to be measured by utilizing that the SAR value is in proportional relationship with the reception power. Thus, it is possible to measure and evaluate SAR values of a plenty of mobile telephones with a high accuracy in a short time.
Description
Technical field
The present invention relates to local absorption rate (Specific Absorption Rate, SAR) measuring equipment and in the small-sized radio devices such as cellular phone, measure the method for local absorptivity.
Background technology
In recent years, the angle that exempts from electromagnetic wave infringement from the protection body considers, and along with the rapid expansion to the demand of the portable radio device such as cellular phone, the irradiation of electromagnetic waves amount is all more and more tended to retrain in the whole world.Especially, near head the user, with cellular phone when their antenna-electromagnetic wave generates the source and uses, illeffects to human body attracts people's attention, therefore, higher limit is set, so that can retrain and manage it at All Countries to local absorptivity.In addition, in the production run of cellular phone, be necessary the local absorption rate of management product before dispatching from the factory, and need promptly and accurately to check the measuring equipment of local absorptivity.
SAR is human body unit weight power absorbed when being exposed in the electromagnetic wave; and; the Ministry of Posts and Telecommunications is in the communication engineering committee report before the Japan; in the protection guide of human body " when the utilizing radiowave to ", pointed out standard; in addition; " method that relates on the temples of human body the measurement absorptivity of using cellular phone terminal etc. " in the same report pointed out; can utilize the human body (manikin) that goes out shape, size and the electrical characteristics of its head tissue according to human body simulation, so that can observe to experience the SAR that may appear in the human body.
In general, utilize the shape and size that go out its head according to human body simulation, with and the manikin of the electrical characteristics of head tissue can observe to experience the user's who derives from portable radio device the electromagnetic local SAR of inferring of head absorption.Here, utilize electric-field probe to measure near the portable radio device, the intensity distributions of the electric field that in manikin, excites, so that can from its measured value, calculate the SAR value according to following expression (1):
SAR＝σE
2/ρ[W/kg] ...(1)
Here, σ is the conductivity of manikin and the density that ρ is tissue.
In addition, as the method for estimating SAR with plain mode, people proposed according to the lip-deep magnetic field intensity H experience of manikin obtain local SAR method (for example, N.Kuster and Q.Balzano, " near the energy absorption mechanism (Energyabsorption mechanism by biological bodies in the near field of dipoleantennas above 300MHz) of biosome the above dipole antenna of 300MHz ", IEEE Trans.Veh.Tech., Vol.41, no.1, pp.17-23, Feb.1992).Can confirm, according to the method, the distribution table that appears at the local SAR of human body surface can be reached following correlated expression formula (2):
Appearing at the electric field strength E in the manikin and appear at magnetic field intensity H that manikin represents may be with the shape of the emission output of portable radio device, antenna, change with the position relation of manikin etc., therefore, utilize manikin assessment local SAR need measure the distribution of electric field intensity and the distribution of magnetic field intensity.
Form by for example as shown in Figure 7 electric-field probe 62, probe scanning equipment 63 and manikin 64, be considered to the local SAR measuring equipment traditionally so that measure the internal electric field detection type equipment of the portable radio device 61 that supporting member 65 supporting.This equipment makes with other known way and compares, and measuring local SAR in the most accurate mode becomes possibility.
In addition, according to prior art, need not to utilize manikin, wherein for example as shown in Figure 8 electric-field probe 72 is fixed on that local SAR occurs near the part of maximum value, the contiguous electric field detection type local SAR measuring equipment of measuring the contiguous electromagnetic field the free space of portable radio device 71 radiation of supporting from supporting member 75 is considered to another example.This equipment has the simple structure of not carrying out probe scanning, makes short time measurement become possibility, therefore, is suitable for introducing in the large-scale production process.
For example No. the 2737661st, Jap.P. and Jap.P. disclose for No. 2790103 according to the electromagnetic field from aerial radiation in addition, and detection is from the configuration of the contiguous magnetic field detection type equipment in the magnetic field of manikin surface reflection.In this configuration,, measure DISTRIBUTION OF MAGNETIC FIELD accurately by moving and rotating electromagnetic probe, and, according to the Distribution of Magnetic Field of measuring, estimate local SAR.In view of the above, simple configuration just can be estimated local SAR relatively.
In addition, JP-A-11-133079 discloses the example of being furnished with as (electromagnetic wave coupled mode) electromagnetic coupled equipment of lower member: the electromagnetic field that one group of antenna is collected carries out the synthetic compositor of phase place, and wherein several travelling-wave aerials are positioned at the shielding box on the residing interior wall of radio wave absorber; With read the parts of addition electromagnetic field as radiation power.This electromagnetic wave coupled mode equipment makes in process of production, and stably measuring from the electromagnetic wave as the portable radio device aerial radiation of object to be measured becomes possibility.
But, according to prior art, in above-mentioned internal electric field detection type, contiguous electric field detection type and contiguous magnetic field detection type local SAR measuring equipment, there is such problem, promptly owing to must measure the local SAR value of manikin, the utmost point that the probe member is in antenna nearby, therefore because as the position and the modes of emplacement of the portable radio device of object to be measured, and the position of antenna and direction, deviation appears in measurement data easily.
Here, will be in antenna utmost point SAR nearby measures the measurement data main cause that occurs deviation easily be described below.Fig. 9 is the figure that illustrates from as the component of the electromagnetic field of the miniature dipole antenna radiation of the elementary cell of antenna.When the wave source of miniature dipole antenna is arranged to initial point, be that the electromagnetic field of the position C of R can be expressed as following expression (3)-(7) away from the distance of initial point:
E
＝0 ...(5)
H
R＝H
θ＝0 ...(6)
Here, λ is a wavelength, and k is a wave number, and I is the electric current through miniature dipole antenna, and L is the length of miniature dipole antenna, and ε is the specific inductive capacity of communication space, and μ is the magnetoelectricity rate of communication space.
According to top expression formula, along with from the electromagnetic field of aerial radiation more and more away from the antenna proximity, the component (radially electromagnetic field) that is inversely proportional to distance R plays a leading role, and plays a leading role in the little place of distance R with the item (induction field) that square is inversely proportional to of distance with cube item (quasi-static field) that is inversely proportional to of distance.Therefore, under the situation of general management electromagnetic field, in each regional separated mode, the quasi-static electric field component is played a leading role, is called as utmost point near field with antenna at a distance of the zone in about λ/100, the electromagnetic radiation field component is played a leading role, is called as long-range with antenna at a distance of the zone outside about 5 λ, and zone between the two is called as Fresnel (Fresnel) district.
With the utmost point near field of antenna in about λ/100 in, play a leading role with cube quasi-static electric field component that is inversely proportional to of distance, therefore, when in such zone, measuring, exist the atomic little difference of relative position just may cause the problem that the electromagnetic field measurements error is very big.
λ/100 that generally are used in the frequency in the 800MHz frequency band in the cellular telephone system are about as much as 0.4cm.In the contiguous electric field detection type equipment of the internal electric field detection type equipment of Fig. 7 and Fig. 8 and in contiguous magnetic field detection type local SAR measuring equipment, in order to measure local SAR, in the utmost point near field of probe member with regard to sd so.This is because the fuselage and the antenna of portable radio device just uses nearby at the utmost point of human body under actual behaviour in service, therefore, when the generation source of the surface of manikin and electromagnetic field very near the time, the necessary local SAR of assessing.In addition, cause induction current from the electromagnetic field of aerial radiation on the surface of manikin, generate electric field in manikin inside in secondary mode with this electric current, therefore, be necessary to measure the electromagnetic field of manikin near surface, so that measure this secondary electric field, so, in utmost point near field, measure.
In the internal electric field detection type equipment of Fig. 7, positional precision guarantees by the probe scanning equipment that utilizes industrial robot etc., so that the measuring error that the low precision that dips causes, simultaneously, become the position of scanning in the great zone more than at local SAR, thereby improve measuring accuracy.But in this configuration, in order to improve measuring accuracy, the measuring position is many more, and the time that measurement is spent is just long more, and this is not suitable for being applied in the large-scale production process.
In addition, in the contiguous electric field detection type equipment of Fig. 8 and in No. the 2737661st, Jap.P. and No. 2790103 described contiguous magnetic field detection type equipment of Jap.P., there is such problem, although only measure a place usually, shortened Measuring Time, but, appear at error in the measurement result because measuring position mobile causes or the fine difference of the radiation mode of antenna causes, be difficult to guarantee measuring accuracy.
In addition, the electromagnetic wave coupled mode equipment of describing in JP-A-11-133079 is used for measuring and long-range electromagnetic field as the antenna wide apart of object to be measured, therefore, is difficult near the SAR that this equipment is used for the antenna is measured.
The present invention makes after having considered above-mentioned situation, the purpose of this invention is to provide local SAR measuring equipment and the method that can assess local SAR along the production line of the small-sized radio devices such as cellular phone in the short time accurately.
Summary of the invention
Be furnished with according to local SAR measuring equipment of the present invention: several electromagnetic probes are used for measuring from the electromagnetic wave of the wireless device radiation electromagnetic field level (electromagnetic fieldlevel) at Fresnel region; Signal processing is used to handle the electromagnetic field level that electromagnetic probe obtains; And position regulator, be used to adjust the relative position relation between above-mentioned probe and the wireless device, it is characterized in that, in electromagnetic probe, measure benchmark wireless device that its local SAR value knows in advance respectively and as the electromagnetic field level of the wireless device of object to be measured, with in above-mentioned signal processing, the relation of utilizing the SAR value to be directly proportional with electromagnetic field level is by obtaining the local SAR value as the wireless device of object to be measured in the local SAR value of estimating to be engaged in the benchmark wireless device of knowing earlier.
In above-mentioned configuration, in Fresnel region, measure electromagnetic field level away near the utmost point near field the wireless device antenna, so as to utilize and benchmark wireless device that the local SAR value is known between proportional relation, can estimate the local SAR value by computing, thereby, can by assessment, obtain local SAR in the short time accurately along the production line of making the portable radio device such as cellular phone as the wireless device of object to be measured.Therefore, can along production line the local SAR value of a large amount of wireless devices be measured at short notice.
In addition, the local SAR measuring equipment is characterised in that position regulator moves one of above-mentioned electromagnetic probe and wireless device at least by the electromagnetic field radiation pattern (pattern) according to above-mentioned wireless device, adjusts relative position relation between the two.
In above-mentioned configuration, can position that measure electromagnetic field level be adjusted to the optimum position according to radiation mode from the electromagnetic field of wireless device radiation, thereby, can measure accurately.
In addition, the local SAR measuring equipment is characterised in that, according to transmission frequency, existence is more than under the situation from the electromagnetic field radiation pattern of above-mentioned wireless device, position regulator is by one of the mobile at least electromagnetic probe of transmission frequency and wireless device, so that change relative position relation between the two.
In above-mentioned configuration, can be according to the electromagnetic field radiation pattern different with transmission frequency, the position of measuring electromagnetic field level is adjusted to the optimum position, when measuring the wireless device that uses a plurality of frequency bands etc. with box lunch, in each frequency band, can measures accurately.
Local SAR measuring method of the present invention is characterised in that, contains to have the following steps: at the electromagnetic field level of measuring the benchmark wireless device that its local SAR value knows in advance from the electromagnetic Fresnel region of wireless device radiation; At the electromagnetic field level of from the electromagnetic Fresnel region of wireless device radiation, measuring as the wireless device of object to be measured; With the relation of utilizing the SAR value to be directly proportional, according to above-mentioned measured electromagnetic field level, by obtaining local SAR value in the local SAR value of estimating to be engaged in the benchmark wireless device of knowing earlier as the wireless device of object to be measured with electromagnetic field level.
According to said process, can by assessment, obtain local SAR in the short time accurately along the production line of making the small portable wireless device such as cellular phone as the wireless device of object to be measured.
In addition, the local SAR measuring method is characterised in that, further contain and have the following steps: according to transmission frequency, existence is more than under the situation from the electromagnetic field radiation pattern of wireless device, measure one of the electromagnetic probe of above-mentioned electromagnetic field level and above-mentioned wireless device by moving at least, change relative position relation between the two according to transmission frequency.
At said process, can be according to the electromagnetic field radiation pattern different with transmission frequency, the position of measuring electromagnetic field level is adjusted to the optimum position, when measuring the wireless device that uses a plurality of frequency bands etc. with box lunch, in each frequency band, can measures accurately.
Description of drawings
Fig. 1 is the figure that illustrates according to the configuration of the local SAR measuring equipment of one embodiment of the invention;
Fig. 2 is the concept map that the mode on the antenna of cellular phone that electricity is added to from radio circuit is shown;
Fig. 3 illustrates the process flow diagram of process that the local SAR measuring equipment that utilizes present embodiment is estimated the local SAR of cellular phone to be measured;
Fig. 4 is the figure that the relation between the direction of the position of electromagnetic probe and electromagenetic wave radiation is shown;
Fig. 5 is illustrated in the local SAR measuring equipment that utilizes present embodiment, under the situation about in position, measuring with the very big direction of electromagnetic field radiation pattern, and the performance diagram of the related data between received power and the local SAR;
Fig. 6 is illustrated in the local SAR measuring equipment that utilizes present embodiment, with offset with the very big direction of electromagnetic field radiation pattern under the situation about measuring in the position of 60mm, the performance diagram of the related data between received power and the local SAR;
Fig. 7 is the figure that illustrates according to the configuration of the internal electric field detection type SAR measuring equipment of prior art;
Fig. 8 is the figure that illustrates according to the configuration of the contiguous electric field detection type SAR measuring equipment of prior art; Know
Fig. 9 is the figure that illustrates from the component of the electromagnetic field of miniature dipole antenna radiation.
Here, the symbol among the relevant figure, 1 expression electromagnetic probe, 2 expression compositors, 3 expression signal processings, the fuselage of 11 expression cellular phones, the antenna of 12 expression cellular phones, 13 expression radio circuits, 14,14a and 14b represent the electromagnetic field radiation pattern, 15 expression probe movable parts.
Embodiment
Hereinafter embodiment of the invention will be described with reference to drawings.
Present embodiment shows as the equipment of measuring local SAR in small-sized radio devices, along the production line of cellular phone, according near the tolerance of the received power antenna, estimates the configuration of local SAR measuring equipment of local SAR and the example of operation.
At first, the overview of measuring the method for local SAR according to present embodiment is described.
Place at the identical large-tonnage product of production standard, for example, in the production run of cellular phone, under the situation of the value that can obtain local SAR for a cellular phone, the factor that makes a difference by understanding and by carrying out relatively can be estimated the local SAR value of another product.Therefore, at first the factor that makes a difference between the cellular phone of being produced is described with reference to Fig. 2.
Fig. 2 is the concept map that the mode on the antenna of cellular phone that electricity is added to from radio circuit is shown, and the antenna of cellular phone is made up of antenna element 91, match circuit 92 and transmitter 93.The equivalent electrical circuit of antenna comprises match circuit 92, and encouraged by the power supply Vg that contains internal driving Zg in the transmitter 93.If antenna element 91 is seen the input impedance Zin in the past and the mutual conjugate impedance match of internal driving Zg of power supply from input end, so, draw Zin=Zg
*Here, (
*) the expression complex conjugate.
Under this situation, the power input Pin that is supplied to antenna element 91 is expressed as following expression 8):
Here, I
1Be the electric current that flows through antenna element 91, be expressed as: I
1=Vg/ (Zg+Zin).
In addition, therefore all power that are input to antenna, use following expression (9) and (10) all from power supply Vg supply:
Here, the real part of Re (X) expression X and the available horsepower that Pin represents power supply.In addition, S represents to be supplied to the power of antenna and the ratio of the available horsepower of power supply, under the situation of conjugate impedance match, and S=1.
In addition, the power P r from the aerial radiation to the space expresses with following expression (11):
P
r＝P
av-(P
a+P
c+P
m) ...(11)
In the above in the expression formula, P
aBe to form the power attenuation that the alternating-current resistance (highfrequency resistance) of the metal wire of antenna element 91 causes, P
cBe the power attenuation that the loss resistance of match circuit causes, and P
mBe the power attenuation that causes owing to impedance (impedance) mismatch, and be expressed as P
m=(1-S) P
AvoIntroduce following expression (12) according to these expression formulas:
When the difference factor considering to cause in process of production between the product, P
cAnd P
aBe taken as the small factor of the difference that causes between the product.Therefore, cause the main factor of the difference between the product of producing to be considered to the deviation of the available horsepower of the power supply that difference that the adjustment owing to the difference between each parts in the transmitter and each parts causes occurs.Therefore, derive the power P that is radiated antenna space
rWith the electric current I in the antenna element
1Between the relation expressed of usefulness following expression (13):
Electric current I in the antenna element
1Generate magnetic field H near it is own, according to Amp, the relation in electric current and magnetic field is H ∝ I.Here, as long as the structure of antenna element and the distribution form of electric current do not change, nigh DISTRIBUTION OF MAGNETIC FIELD form occurs and also can not change.Therefore, derive following expression (14):
P
r∝H
2 ...(14)
Then, from above-mentioned expression formula (7) and (14), draw relation in the following expression (15);
SAR∝R
r ...(15)
That is to say control radiation power P under the situation that the distribution form at the structure of antenna element and electric current does not change
rSituation under, can control the deviation of local SAR.
Although radiation power P
rObtained the total intensity that is used as radiation direction in long-range, still, in order to measure long-range in actual production process, large space is inevitably in measuring equipment, and this is infeasible.Therefore, a large amount of electromagnetic probes may be arranged in the Fresnel region that is easier to guarantee high measurement accuracy than utmost point near field, so that can receive a part of radiation power P
r
For incoming level (level) P that makes electromagnetic probe
xWith radiation power P
rHave high correlation, shown in the electromagnetic wave Coupling device among the JP-A-11-133079, the technology of placing the power of several electromagnetic probes and synthetic each electromagnetic probe is useful.But, in order to carry out more high-precision measurement, electromagnetic probe must be placed on radiation power and become great direction, the person is not at incoming level P
xWith radiation power P
rBetween can not guarantee high correlation, cause and can't measure with the high precision that can control local SAR.
By conscientiously checking under the situation of the description on consider, the inventor designs such layout: can measure the electromagnetic field level in the Fresnel region that may measure electromagnetic field level relatively accurately, replace the electromagnetic field level in the utmost point near field, in local SAR in the small-sized radio devices of measuring such as cellular phone, electromagnetic probe can be positioned at radiation power and become great direction.As a result, can realize to estimate the local SAR measuring equipment of local SAR at short notice accurately, so that can be along production line application.
According to the present invention, be equipped with the level that two or more electromagnetic probes, synthetic each electromagnetic probe measure and read the result as the part of electromagnetic field level with change electromagnetic probe and as the part of relative position relation between the wireless device of object to be measured, thereby, can be along the great orientation measurement received power level of radiation power, and, as received power level P
xThe received power level P of the benchmark wireless device of knowing in advance with its local SAR value
0Between result relatively, estimate local SAR value as the wireless device of object to be measured.
Fig. 1 is the figure that illustrates according to the configuration of the local SAR measuring equipment of one embodiment of the invention.
The local SAR measuring equipment comprises electromagnetic probe 1, compositor 2 and signal processing 3, so that measure from the electromagnetic wave as cellular phone antenna 12 radiation of the cellular phone of object to be measured.Radio-circuit 13 in the fuselage 11 of cellular phone antenna 12 and cellular phone is connected, so that supply through-put powers from radio-circuit 13.
Electromagnetic probe 1 can be used as electric field detection type antenna by detecting electromagnetic antenna configuration example such as miniature dipole antenna, miniature unipole antenna, normal mould spiral antenna or inverted-F antenna.In addition, micro-circuit antenna, shield loop antenna, slot aerial etc. can be used as magnetic field detection type antenna.Alternatively, also can use travelling-wave aerial of arranging several antenna elements etc.In the present embodiment, be equipped with the electromagnetic probe 1 more than, Fig. 1 shows the mode of electromagnetic radiation 14 corresponding examples that are equipped with two electromagnetic probes with cellular phone antenna 12.
The electromagnetic received power that compositor 2 synthetic electromagnetic probes 1 detect.By for example utilizing the dual signal coupling mechanism of several synthetic power that received by two electromagnetic probes 1, the input and output in the combination tournament (tournament diagram) can be synthesized quantity and be the power that the electromagnetic probe 1 of 2 multiple receives.
In the present embodiment, the received power of the benchmark cellular phone that will know in advance as the received power of the cellular phone of Devices to test and its local SAR value is compared, thereby, estimate the local SAR value in the Devices to test.In for example received power when the benchmark cellular phone is P
0With the received power of measuring as the cellular phone of object to be measured be P
xThe time, the local SAR value is SAR
0Situation under, can obtain local SAR value SAR in the following expression (16) this moment from above-mentioned expression formula (15)
x:
Several electromagnetic probes 1 all are positioned at the fuselage 11 with respect to cellular phone, are in the position in the Fresnel region.The through-put power that several electromagnetic probes 1 in the Fresnel region receive from 12 radiation of cellular phone antenna.Compositor 2 is 1 that receive with each electromagnetic probe, synthesize into output power based on the electromagnetic received power from cellular phone, then with in the output power input signal processing section 3, so that carry out the processing relevant with the estimation of local SAR.
Here, Fresnel region is in the active zone of electromagnetic radiation field component from wave electromagnetic radiation source, the electromagnetic radiation field component that is inversely proportional to distance, or with cube not active zone of the quasi-static electric field component that is inversely proportional to of distance; It is square active basically zone of the inductive electromagnetic field component that is inversely proportional to distance; With the zone that comprises with the distance of the wave electromagnetic radiation source point in about λ/100 to 5 λ scopes.
Transmission frequency at cellular phone is under the situation of for example 800MHz frequency band, the about 38cm of its wavelength, therefore, Fresnel region comprise with the distance of cellular phone antenna 12 at the about 0.38cm point in the 190cm scope.In addition, be under the situation of for example 1.5GHz frequency band in the transmission frequency of cellular phone, wavelength become about 20cm and Fresnel region comprise with the distance of cellular phone antenna 12 at the about 0.2cm point in the 100cm scope.
In example as shown in Figure 1, supposed that 800MHz frequency band and 1.5GHz frequency band both are as service band, be used for situation as the cellular phone of object to be measured, therefore, several electromagnetic probes 1 be positioned at cellular phone antenna 12 at a distance of 1cm to the position of 5cm.Two electromagnetic probes 1 are arranged in than long-range field more near the zone of antenna, thereby, can form the whole measuring system of the about 20cm * 20cm of size * 50cm, therefore, dwindled the space that measuring equipment is monopolized, make this measuring equipment can be applicable to production line.
For the received power P that exports acquisition separately that synthetic electromagnetic probe 1 is received
xAs much as possible near radiation power P
r, preferably electromagnetic probe 1 is positioned at electromagenetic wave radiation pattern 14 great directions.Find out that from from the electromagnetic field component of miniature dipole antenna radiation, can know shown in expression formula (3) to (7) the electromagnetic field radiation pattern in the Fresnel region needn't be consistent with the electromagnetic field radiation pattern in long-range.But the electromagnetic field radiation pattern in the Fresnel region is than the electromagnetic field radiation pattern in the more approaching long-range field, utmost point near field, and distance is far away more, and the greatest irradiation direction is just consistent more.So, different with the measurement in the utmost point near field, by placing electromagnetic probe 1, can in Fresnel region, carry out stably measured along the great direction of electromagenetic wave radiation pattern.
In addition, the local SAR measuring equipment of present embodiment is furnished with probe movable part 15, as by the relative position relation between the fuselage 11 that changes electromagnetic probe 1 and cellular phone, adjusts the position regulator of position.Can use in the mode identical with this probe movable part 15, move the position regulator of two electromagnetic probes 1 respectively with respect to the fixed main body 11 of cellular phone, in addition, can use in a parallel manner, move the part of several electromagnetic probes 1 along equidirectional simultaneously.And, can fix two electromagnetic probes 1, as member with the fuselage 11 of parallel mode mobile honeycomb phone.
Aforesaid position regulator can realize that for example several electromagnetic probes 1 integrally are in the framework that forms with circle or rectangle along circular or rectangular peripheral direction with such configuration, be in the center of this framework with the fuselage 11 of cellular phone, so that can the whole framework of move left and right or the fuselage 11 of cellular phone.In addition, supporting the movable support element of the fuselage 11 of cellular phone for example be configured to can automatic mobile movable support element by computer control the position, thereby can make whole measuring task robotization.
Here, each electromagnetic probe 1 is on fuselage 11 equidistant positions with cellular phone or parallel with the fuselage 11 of cellular phone, only require that each cellular phone 1 is in the scope of Fresnel region, so that be on optimum position or the optimum orientation according to the form of electromagnetic field radiation pattern 14.
Then, with reference to the process flow diagram of Fig. 3, the process that the local SAR measuring equipment that utilizes present embodiment is estimated the local SAR of cellular phone to be measured is described.In Fig. 3, the equipment of Fig. 1 is carried out the process that enclosed with dashed lines is come.
At first, in step S31, utilization for example has the internal electric field detection type measuring equipment as shown in Figure 7 of high measurement accuracy (for example long Measuring Time) and measures SAR
0-as the local SAR value of the cellular phone of benchmark (benchmark portable radio device).Here, in general, for each frequency band, local SAR is different, therefore, under the situation that exists the cellular phone that is provided as object to be measured more than one frequency band to use, each frequency band is measured.
Then, in step S32, utilize the received power P of the local SAR measuring equipment measuring basis cellular phone (benchmark portable radio device) of Fig. 1
0At this moment, the relative position relation between the electromagnetic probe 1 of local SAR measuring equipment and the fuselage 11 of cellular phone obtains adjusting in advance, so that measure received power P
0The difference that causes becomes as much as possible little.
Subsequently, in step S33, measure the received power P of cellular phone to be measured (portable radio device to be measured)
xAt this moment, be used under the situation of cellular phone to be measured, each frequency band is measured received power P at frequency band more than one
xThen, in step S34, the received power P that benchmark cellular phone and cellular phone to be measured are measured will be respectively
0And P
xIn the substitution expression formula (16), so that, obtain SAR as the local SAR value of cellular phone to be measured by calculating
xThen, in step S35, confirm whether to exist the cellular phone that then will measure, and, under the situation that has another cellular phone to be measured, the process of repeating step S33 and S34.
Said process makes the received power P that measures cellular phone to be measured at the utmost point in the short time
xBecome possibility, therefore, can measure a large amount of cellular phones to be measured at short notice.
Fig. 4 is the figure that the relation between the direction of the position of electromagnetic probe 1 and electromagenetic wave radiation is shown, and it shows the mode that cellular phone antenna 12 generates two kinds of different mode of electromagnetic radiation 14a and 14b.In many cases, depend on the transmission band of cellular phone, the fuselage length of cellular phone and the length of antenna etc., the electromagnetic field radiation pattern that cellular phone generates has various forms.Use at cellular phone under the situation of two frequency bands for example, an antenna is used for diverse two frequency bands mutually, for example, and 800MHz frequency band and 1.5MHz frequency band.Under these circumstances, for the 800MHz frequency band, electromagnetic field radiation pattern 14a for example shown in dotted line occurs and for the 1.5MHz frequency band, the electromagnetic field radiation pattern 14b shown in solid line occurs, their form is different.
In Fig. 4, under the situation of an A, can obtain the stable received power of electromagnetic field radiation pattern 14a in the position of electromagnetic probe 1, but near zero point, observe electromagnetic field radiation pattern 14b, low incoming level is provided, and, because moving of position etc. estimated the repeatable variation of measuring.On the contrary, under the situation of a B, can obtain the stable received power of electromagnetic field radiation pattern 14b, but near zero point, observe electromagnetic field radiation pattern 14a, the low incoming level and the measurement reproducibility of difference are provided in the position of electromagnetic probe 1.In addition, under the situation of a C, for electromagnetic field radiation pattern 14a and 14b each, estimate all variation of the repeatability measured in the position of electromagnetic probe 1.For the above reasons, in the received power of measuring basis cellular phone and each radiation field of cellular phone to be measured, the position of electromagnetic probe 1 becomes most important.Hereinafter, make description according to the example of the data that obtain by actual measurement.
Fig. 5 is the example that the data of received power that the local SAR measuring equipment of utilization present embodiment as shown in Figure 1 measures and the relation between the local SAR are shown.Produce 20 products and be used as cellular phone to be measured,, have a mind to make the available horsepower of transmitter to differ approximately ± 1.5dB in order to make the correlativity easy to understand with same structure.The longitudinal axis of Fig. 5 represents to utilize the data of the local SAR of measuring based on the measuring equipment of prior art as shown in Figure 7 and transverse axis to represent the value of the received power measured by the local SAR measuring equipment of present embodiment.Here, the position of cellular phone 11 is adjusted to electromagnetic probe 1 and is positioned at electromagnetic field radiation pattern 14 great directions.
From the related data of Fig. 5 as can be seen, received power and local SAR are proportional, therefore, can estimate local SAR from the measured value of received power.In these routine data, the related coefficient between received power and the local SAR is 0.94, presents the precision that is enough to estimate easily local SAR in large-scale production process.
On the other hand, Fig. 6 is illustrated in when utilizing the local SAR measuring equipment of present embodiment as shown in Figure 1, the position of cellular phone to be measured with respect to the offset in the electromagnetic field radiation pattern 14 great directions under the 60mm situation, received power P
xAnd the example of the data of the correlativity between the local SAR.In this example, although the cellular phone that is used to measure is identical with the situation of Fig. 5 with the local SAR value since electromagnetic probe 1 with respect to the offset of cellular phone to be measured the direction of electromagnetic field radiation pattern 14 maximums, incoming level is extremely low.And the local SAR value is different with received power, shows that related coefficient is low to moderate 0.53, as can be seen, can not obtain to be enough to measure the precision of local SAR.
Like this, between the fuselage 11 of electromagnetic probe 1 and cellular phone, and the optimal selection of the relative position relation between electromagnetic probe 1 and the cellular phone antenna 12 is that high precision estimates that local SAR institute is indispensable.In order to determine optimum positional relationship, measure in advance that its local SAR value for example knows in advance more than one benchmark cellular phone, and, can check as shown in Figure 5 the position relation that correlativity uprises.Then,, adjust by the position regulator such as probe movable part 15 between the fuselage 11 of electromagnetic probe 1 and cellular phone according to this best value of setting, and the relative position relation between electromagnetic probe 1 and the cellular phone antenna 12.
In addition,, prepare for example as the related data curve map as the curve map among Fig. 5 in advance, so that can obtain scale-up factor SAR in the above-mentioned expression formula (16) according to the slope of the near linear of curve map according to more than one benchmark cellular phone
0Thereby, can estimate the local SAR of cellular phone to be measured accurately.
Here, electromagnetic field radiation pattern 14 can not change, unless flowing through the distribution of the electric current of cellular phone antenna 12 changes, therefore, can determine best relative position relation for each product uniformly, and, in process of production, there is no need to be the relative position relation between the fuselage 11 of each product adjustment electromagnetic probe 1 and cellular phone.So, can measure at short notice, and, large-tonnage product can suitably be measured.
In addition, under the situation of cellular phone use, make the mobile arbitrarily displacement mechanism in position of the fuselage 11 of electromagnetic probe 1 or cellular phone along the production line outfit, as position regulator more than a frequency band, thereby, can be in the position of the most suitable each frequency band assessment received power P
x
As mentioned above, according to present embodiment, can measure the local SAR as the small-sized radio devices of object to be measured in the short time accurately in little space, this is suitable for producing the production line of the small portable wireless device such as cellular phone.In addition, according to for all different electromagnetic field radiation mode adjustment electromagnetic probe of each frequency band and the relative position relation between the Devices to test, thereby, can estimate local SAR accurately more than the wireless device of a frequency band for using.
Although with reference to specific embodiment the present invention has been made detailed description above, those of ordinary skill in the art should be understood that and can carry out various modifications and improvement under situation without departing from the spirit and scope of the present invention.
The application quotes in full, for your guidance hereby based on the Japanese patent application that proposed on May 17th, 2002 2002-143326 number.
Industrial Applicability A
Aforesaid the present invention can provide local SAR measurement device and can be along such as the honeycomb fashion electricity The production line of small-sized radio devices of words and so on is assessed the side of local SAR at short notice accurately Method.
Claims (5)
1. local SAR measuring equipment comprises:
Several electromagnetic probes are used for measuring from the electromagnetic wave of the wireless device radiation electromagnetic field level at Fresnel region;
Signal processing is used to handle the electromagnetic field level that electromagnetic probe obtains; With
Position regulator is used to adjust the relative position relation between electromagnetic probe and the wireless device,
Wherein, electromagnetic probe is measured benchmark wireless device that its local SAR value knows in advance respectively and as the electromagnetic field level of the wireless device of measuring object; With
Signal processing is utilized the proportional relation between SAR value and the electromagnetic field level, is engaged in the local SAR value of estimating in the local SAR value of the benchmark wireless device of knowing earlier as the wireless device of measuring object.
2. local SAR measuring equipment according to claim 1, wherein, position regulator is according to the electromagnetic field radiation pattern from the wireless device radiation, and one of mobile at least electromagnetic probe and wireless device are adjusted the relative position relation between electromagnetic probe and the wireless device.
3. local SAR measuring equipment according to claim 1, wherein, when according to transmission frequency, when having several from the electromagnetic field radiation pattern of wireless device radiation, position regulator is according to one of the mobile at least electromagnetic probe of transmission frequency and wireless device, so that the relative position relation between change electromagnetic probe and the wireless device.
4. a method of measuring local SAR comprises the steps:
At the electromagnetic field level of from the electromagnetic Fresnel region of wireless device radiation, measuring the benchmark wireless device that its local SAR value knows in advance;
At the electromagnetic field level of from the electromagnetic Fresnel region of wireless device radiation, measuring as the wireless device of measuring object; With
Utilize the proportional relation between SAR value and the electromagnetic field level,, be engaged in the local SAR value of estimating in the local SAR value of the benchmark wireless device of knowing earlier as the wireless device of measuring object according to the measured electromagnetic field level.
5. the method for measurement local SAR according to claim 4, further comprise the steps: when having several according to transmission frequency from the electromagnetic field radiation pattern of wireless device radiation, according to transmission frequency one of the electromagnetic probe of traverse measurement electromagnetic field level and wireless device at least, so that change between the electromagnetic probe and the relative position relation between the wireless device.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP143326/2002 | 2002-05-17 | ||
| JP2002143326A JP4010869B2 (en) | 2002-05-17 | 2002-05-17 | Local SAR measuring apparatus and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1668930A true CN1668930A (en) | 2005-09-14 |
| CN100360946C CN100360946C (en) | 2008-01-09 |
Family
ID=29545012
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB038169991A Expired - Fee Related CN100360946C (en) | 2002-05-17 | 2003-05-09 | Apparatus for and method of measuring local specific absorption range SAR |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JP4010869B2 (en) |
| CN (1) | CN100360946C (en) |
| AU (1) | AU2003235922A1 (en) |
| CZ (1) | CZ20041124A3 (en) |
| WO (1) | WO2003098238A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011109961A1 (en) * | 2010-03-12 | 2011-09-15 | 中兴通讯股份有限公司 | Mobile terminal for balancing specific absorption rate and total radiated power and method thereof |
| CN102467595A (en) * | 2010-11-12 | 2012-05-23 | 中兴通讯股份有限公司 | Method and device for processing laptop device model |
| CN101170368B (en) * | 2006-10-23 | 2013-01-30 | 株式会社Ntt都科摩 | Absorption rate measurement system and method |
| CN105611610A (en) * | 2015-12-28 | 2016-05-25 | 联想(北京)有限公司 | Information processing method and electronic devices |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100462461B1 (en) * | 2002-08-23 | 2004-12-17 | 주식회사 이레테크 | A standard signal source supply device for effectiveness test of the sar measure system |
| JP2006078237A (en) * | 2004-09-08 | 2006-03-23 | Matsushita Electric Ind Co Ltd | Power measuring method of wireless device |
| JP4657032B2 (en) * | 2005-07-07 | 2011-03-23 | パナソニック株式会社 | Method and apparatus for measuring electromagnetic wave of electronic equipment |
| TWI369084B (en) * | 2008-02-15 | 2012-07-21 | King Yuan Electronics Co Ltd | Automatic detecting device for radio frequency environment |
| CN104702346A (en) * | 2015-02-02 | 2015-06-10 | 深圳市共进电子股份有限公司 | Near-field multi-machine testing system and method |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2630222B2 (en) * | 1993-09-20 | 1997-07-16 | 日本電気株式会社 | SAR measuring device and measuring method |
| US5754054A (en) * | 1996-06-28 | 1998-05-19 | Siemens Rolm Communications Inc. | Apparatus and method for determining the source and strength of electro-magnetic emissions |
| CN1142441C (en) * | 2000-01-19 | 2004-03-17 | 郑宏兴 | Radiation and conduction measuring system |
| JP2001318112A (en) * | 2000-05-10 | 2001-11-16 | Hitachi Ltd | Apparatus or method for measurement of electromagnetic field and manufacturing method for electronic component or electronic device using it |
-
2002
- 2002-05-17 JP JP2002143326A patent/JP4010869B2/en not_active Expired - Fee Related
-
2003
- 2003-05-09 WO PCT/JP2003/005848 patent/WO2003098238A1/en active Application Filing
- 2003-05-09 AU AU2003235922A patent/AU2003235922A1/en not_active Abandoned
- 2003-05-09 CN CNB038169991A patent/CN100360946C/en not_active Expired - Fee Related
- 2003-05-09 CZ CZ20041124A patent/CZ20041124A3/en unknown
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101170368B (en) * | 2006-10-23 | 2013-01-30 | 株式会社Ntt都科摩 | Absorption rate measurement system and method |
| WO2011109961A1 (en) * | 2010-03-12 | 2011-09-15 | 中兴通讯股份有限公司 | Mobile terminal for balancing specific absorption rate and total radiated power and method thereof |
| CN102467595A (en) * | 2010-11-12 | 2012-05-23 | 中兴通讯股份有限公司 | Method and device for processing laptop device model |
| CN102467595B (en) * | 2010-11-12 | 2015-04-01 | 中兴通讯股份有限公司 | Method and device for processing laptop device model |
| CN105611610A (en) * | 2015-12-28 | 2016-05-25 | 联想(北京)有限公司 | Information processing method and electronic devices |
| CN105611610B (en) * | 2015-12-28 | 2019-10-29 | 联想(北京)有限公司 | A kind of information processing method and electronic equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100360946C (en) | 2008-01-09 |
| JP2003332999A (en) | 2003-11-21 |
| WO2003098238A1 (en) | 2003-11-27 |
| CZ20041124A3 (en) | 2005-10-12 |
| AU2003235922A1 (en) | 2003-12-02 |
| JP4010869B2 (en) | 2007-11-21 |
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