JP3776806B2 - Portable wireless device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable radio device that can reduce interaction with a human body having been caused in a conventional antenna so as to make stable communication. SOLUTION: The portable radio device comprises a 1st device body provided with a speaker, a 2nd device body provided with an antenna, and a turning mechanism that interconnects the 1st and 2nd device bodies and axis-supports the 1st device body or the 2nd device body freely turnably in a fan-like motion and the antenna is positioned at an upper end of the 2nd device body.

Description

[0001]
[Industrial application fields]
The present invention relates to a portable wireless device including an antenna.
[0002]
[Prior art]
Conventionally, a whip antenna is usually used as an antenna provided in a portable wireless device, for example, a portable wireless device having a function of receiving information transmitted through radio waves or a function of performing wireless communication. . However, since this whip antenna is provided so as to protrude from the radio device main body, it may be damaged during carrying or operation.
[0003]
As an antenna that compensates for the drawbacks of such a whip antenna, an antenna in which a linear element is added to the top of the monopole antenna to reduce the height of the antenna is known. For example, there are an L-shaped antenna and an inverted F antenna with a folded structure added thereto. However, it is known that such an antenna has a narrow band.
[0004]
Therefore, as an antenna for solving this problem, there is an antenna in which a top element is formed into a plate shape, and one of them is a plate-like inverted F antenna. However, it is known that even such an antenna becomes narrower as the size of the antenna is further reduced.
[0005]
Furthermore, as a method for improving this, an S-shaped antenna obtained by forming a linear T-shaped antenna into a plate shape has been proposed. Looking at the structure of this antenna, the top element is shaped like a combination of two inverted F or L antennas when viewed from the feed point, and this structure is one of the factors that make the S antennas a broadband characteristic. It is believed that there is.
[0006]
However, the following problems arise when using such a T-shaped antenna in a very low profile. This problem has been revealed for the first time by the present inventors.
[0007]
That is, in such an antenna having a capacitive load attached to its top, it is generally considered that the shortened current of the monopole antenna is a component contributing to radiation. Therefore, the radiation resistance is reduced by reducing the total sum of currents on the monopole due to the low attitude of the antenna, thereby increasing the Q value at the time of resonance of the antenna and at the same time narrowing the band characteristics of the antenna. It is expected to be.
[0008]
Further, in an antenna that is generally used for a portable wireless device, not only the current on the antenna but also the current on the wireless device housing contributes to radiation. That is, in the above-mentioned linear antenna, the antenna element and the casing usually form a kind of dipole antenna and radiate in many cases. The same applies to L-shaped or T-shaped antennas.
[0009]
Here, in the T-shaped antenna, the top element can be considered as a simple capacitive element, but by lowering the posture, it can be considered that the antenna is a combination of two L-shaped antennas. Therefore, if the junction point between the monopole and the linear element is shifted and the length from the junction point to the tip of the linear element is different, the antenna has resonance points at two different frequencies. That is, at this time, the radiation characteristic of the L-shaped antenna is shown at each frequency. Such a phenomenon is caused by a slight deviation when Q at each of the two resonance points is high. That is, the lower the posture, the more the phenomenon described above occurs.
[0010]
On the other hand, when the antenna height is high, the top linear element that worked only as a capacitive element gradually appears to be a line having a kind of half-wavelength as the position of the antenna is lowered. The monopole part works as a feed line for feeding power to the line.
[0011]
Accordingly, the linear element itself resonates as a half-wave resonator. In such a half-wave resonance mode, the currents flowing on the housing are considered to cancel each other. As a result, the radiation from the housing is reduced, and the radiation resistance of the entire wireless device is lowered. However, since a current flows on the linear element and on the casing below the linear element, the conductor loss is relatively large.
[0012]
Therefore, in such a state, even if the matching with the feeder line is apparent, the current component that causes the conductor loss or the like may actually be larger than the radiated current component. Here, when the antenna is very low and the radiation resistance is low, or when there is no resonance in the radiation mode at this frequency, the conductor loss cannot be ignored, and the radiation efficiency decreases greatly.
[0013]
Therefore, in general, in a T-shaped low-profile antenna, the resonance frequency of the half-wave resonator generated by the low-profile and the two resonance frequencies generated by the above-described deviation are very close to each other. Therefore, when the two resonance frequencies caused by the deviation between the linear element and the feed line are relatively far apart from the bandwidth of each element, the half wavelength on the linear element is between the two resonance frequencies. The resonance state becomes dominant, and at this time, the radiation efficiency of the antenna decreases.
[0014]
For these reasons, in the T-shaped antenna, keeping the distance from the feeding point to the tip of the linear element the same prevents deterioration of the antenna performance.
[0015]
However, in practice, even when the antenna is mounted on the portable wireless device by adjusting the physical distance in this way, the asymmetry of the shape of the wireless device housing relative to the position where the antenna is mounted and the arrangement of other circuit components Due to the asymmetry, the electrical distance from the plurality of end portions of the linear element to the feeding point of the antenna is not the same.
[0016]
In general, the equivalent circuit at the end of the antenna is represented as a capacitive element. This capacitive characteristic occurs between the tip portion of the antenna and the ground plate to which the antenna is attached. This time, in an antenna that has a low profile with the target linear element attached, and there are multiple antenna tips, each tip is uniformly capacitive with the entire ground plane. It is considered that the characteristic is not generated, but is strongly coupled with the ground plane in the vicinity of the tip thereof to generate the capacitive characteristic.
[0017]
Therefore, the value of the capacitance generated between the tip of each of the tips and the vicinity of the ground plane changes depending on the state of the ground plane in the vicinity of the tip, and the capacitance value varies depending on each element. If it changes, the electrical length of those elements will change. As a result, the radiation efficiency lowering phenomenon as described above occurs.
[0018]
In addition, this time, in the target wireless device, the chassis serves as a ground plane, and the current on the chassis also contributes to radiation. In order to reduce the influence of the hand of the human body that holds the chassis on the characteristics of the antenna, the antenna is placed above the chassis of the wireless device, and the antenna and the chassis are asymmetrical. become. As a result, although the pattern of the linear element itself is symmetric with respect to the feeding point, the radiation efficiency of the antenna is deteriorated on the housing due to the above-described causes.
[0019]
Furthermore, in the state as described above, non-radiative current distribution is generated on the antenna, and it has been clarified through experiments that the radiation performance of the antenna is deteriorated. FIG. 26 shows experimental results of the locus on the Smith chart and the standing wave ratio of the input impedance of the antenna on the housing simulating the portable wireless device performed by the inventors. As shown in FIG. 26, when the feeding point is positioned so that the antenna pattern is symmetric at the center of the antenna, the impedance of the antenna is shown in the Smith chart of FIG. A loop occurs in the locus, and double resonance occurs. At this time, in the figure, it seems that it is apparently matched with the feeder line at the frequency f0, but the operation efficiency at this time is as shown in the figure comparing the radiation efficiency of the portable radio apparatus of FIG. It is deteriorated by about 6 dB at the maximum from the frequency band of other portions where the matching is not achieved.
[0020]
In consideration of convenience such as carrying around, it is desirable that the portable wireless device is small. However, it is known that the user's hand and head holding the casing are further brought closer to the antenna and affect the radiation field of the antenna by downsizing in this way.
[0021]
In this regard, "Analysis of dipole antenna near dielectric loss using FDTD method" presented at the 1990 IEICE Spring National Conference B-100, and 89 IEEJ Autumn National Conference “Estimation of UHF band bioabsorbed power distribution by thermography” announced at B-153, and “Electrical Proximity Characteristics in Shoulder-Type Portable Wireless Devices” also announced at B-59 Autumn Meeting of the Institute of Electronics, Information and Communication Engineers in 1989 Analysis method "and also" A problem of radio wave protection for the eye "announced at the 89th National Conference of the Institute of Electronics, Information and Communication Engineers SB-2-6 or at the 1991 National Conference of the Institute of Electronics, Information and Communication Engineers B-311 Introduced “Numerical calculation of intraocular SAR by FDTD method”, etc. It was presented at the National Convention B-108, detailed in such as "radiation efficiency of the antenna placed in the lossy dielectric pillar near".
[0022]
As one of the methods for reducing the interaction between the human body and the antenna, it can be considered not to emit radiation in the direction of the human body. Thus, in order not to have directivity in the human body direction, the antenna must have directivity. As an antenna having such characteristics, there is a simple configuration in which an antenna and a parasitic element are arranged in the vicinity thereof to form an array. Arbitrary radiation directivity can be obtained by setting the arrangement of the antenna and the parasitic element. However, since the human head also has a certain degree of conductivity in terms of high frequency, when the antenna is placed on the top like a normal wireless device housing, this antenna is placed on the surface of the human head. An electric image is generated, and the radiation field obtained by setting the arrangement between the antenna elements described above may vary greatly depending on the image on the head, and the desired directivity characteristics may not be obtained. .
[0023]
In addition, even if the radiation field is not directed toward the human body, there is a problem that the hand and the head in contact with the casing directly interact with the current on the casing. In particular, in antennas such as monopole antennas with a quarter-wavelength of Annate and plate-like inverted F antennas, the high-frequency current flowing on the housing is relatively large, and this current is relatively large in the radiation field as seen from the whole radio apparatus Because it contributes, the influence of the human body cannot be ignored. As a method for solving this problem, a method of separating the housing to which the antenna is joined and the housing directly touching the human body in high frequency is conceivable, but in a small wireless device, the housing is divided as described above. Therefore, it is relatively difficult to cut it at a high frequency. Further, there has been a problem that the radio apparatus casing becomes considerably large in order to perform this high-frequency cutting.
[0024]
Conventionally, a sleeve monopole antenna with a balun as shown in FIG. 46 has been proposed as an antenna used in a portable radio apparatus. This antenna has a choke effect on a high-frequency current due to a cylindrical conductor 217a having a length of about a quarter wavelength (here, this cylindrical portion is called a balun). Therefore, compared with other antennas, there is a feature that a high-frequency current does not flow so much on the casing of the wireless device, and it has been regarded as a promising antenna for reducing the influence of the human body in the vicinity of the casing. However, in order to maintain the structure of this antenna when actually used, a cylindrical dielectric 217b is placed on the outside of the coaxial feed line, and a cylindrical conductor of about a quarter wavelength, that is, a balun 217a. It becomes a covered structure, resulting in a complicated structure. As a result, it becomes difficult to give flexibility to the antenna element itself, so that there are problems that the antenna is easily damaged during carrying and the like and that it is difficult to reduce the size.
[0025]
One way to simplify the structure of the sleeve antenna is to remove the balun. A change in the radiation field at this time will be described with reference to FIG.
[0026]
FIG. 43 shows the radiation pattern of the antenna when the balun is removed from the sleeve antenna. Here, the antenna is simply connected to a quarter-wave feed line and a quarter-wave antenna line on the case on the case, and this antenna is joined to the case made of a conductor. Is. In terms of length, the feed line and the antenna element correspond to a half-wave length dipole antenna. However, it can be seen that the radiation field of the dipole antenna shown in FIG. 44 and the pattern of FIG. 43 are quite different. This is because the current that flows from the feed point at the junction of the feed line and the antenna element to the outside of the outer conductor of the feed line does not stop at the junction of the feed line and the case, but flows into the case. This is considered to be due to the radiation from the current on the housing affecting the radiation field of the antenna. Here, since the length of the case is almost one wavelength, the radiation from the antenna and the case is similar to the two-third-wavelength dipole antenna shown in FIG.
[0027]
From the above, by removing the balun, the radiation field of the wireless device is not only significantly different from the desired radiation field of the half-wave dipole antenna shown in FIG. 44, but also high-frequency current flows into the housing. Therefore, the human head and hands that are in close contact with each other affect each other.
[0028]
[Problems to be solved by the invention]
As described above, the antenna with the top capacitive load has a problem that the antenna characteristics are deteriorated when the shape of the wireless device housing is asymmetric with respect to the mounting position of the antenna, such as a portable wireless device. There was a point.
[0029]
The portable wireless device has a problem in that communication performance is significantly deteriorated due to an interaction between the antenna that holds the hand or the head that is in close contact with the antenna. In addition, a sleeve antenna has been proposed as an antenna for a portable radio apparatus to reduce this interaction, but it has a relatively complicated structure, so that there is a problem that actual application is difficult.
[0030]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a portable wireless device that can reduce the interaction with a human body that has occurred in an antenna and thereby can perform stable communication.
[0031]
[Means for Solving the Problems]
In order to achieve the above object, the present invention connects a first casing having a speaker, a second casing having an antenna, the first casing and the second casing, It is composed of a rotation mechanism that pivotally supports the first housing or the second housing in a fan shape, and the antenna is arranged at the upper end of the second housing. To do.
[0032]
[Action]
The portable wireless device of the present invention has two housings, a second housing through which a high-frequency current is installed, and a first housing in which a speaker that is in close contact with the human body is disposed at the upper end. ing. Further, since the rotation mechanism unit pivotally supports the first housing or the second housing in a fan shape, the human body is separated from the antenna, the high-frequency current on the housing, and the electromagnetic waves radiated from the antenna. In addition, when the pocket is stored, it is possible to determine the turning angle according to the convenience of the user and to set the size of the entire wireless device by folding the rotating mechanism portion. In addition, by displaying the maximum directivity gain characteristics, etc. obtained by calculating or measuring in advance on this rotating mechanism, etc., using the distance between the antenna and the human body as a parameter, how much you influence the radiation field during use. It is possible to know what is being given.
[0033]
Desirably, only a quarter wavelength from the contact point with the housing of the feeder line having a half-wavelength length is arranged in parallel to the housing, thereby forming a choke portion for high-frequency current, thereby providing a wireless device. Suppresses high-frequency currents that flow into the housing. Furthermore, a dipole antenna is equivalently formed by the antenna element of the quarter wavelength of the remaining portion of the feeder line. As a result, the position of the maximum amplitude of the high-frequency current can be separated from the human body. From the above, the same effect can be obtained with a simple structure as compared with the sleeve monopole antenna with balun.
[0034]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the main configuration of the appearance of a portable radio apparatus according to the present invention.
[0035]
As shown in FIG. 1, the portable wireless device 1 of this embodiment includes a wireless device housing 3 made of a conductor, and a first element as a first element that is arranged in parallel with the wireless device housing 3. The antenna 5 which consists of a 2nd strip | belt-shaped conductor element and the 2nd strip | belt-shaped conductor element as a 2nd element is provided.
[0036]
Further, the antenna 5 is provided with a feeding point 7 at the junction or boundary between the first strip-shaped conductor element and the second strip-shaped conductor element, and is connected to the feeding point 7 and extends from the wireless device housing 3. Power is supplied via
[0037]
Furthermore, the distance from the feeding point 7 on the housing to the tips of the first and second strip conductor elements is about a quarter wavelength of the frequency to be used. The height from the casing 3 is one-eighth wavelength or less, and at least one of the first strip conductor element and the second strip conductor element includes the first strip conductor element and the second strip conductor element. Means are provided for making the electrical length of the strip conductor element the same.
[0038]
As shown in FIG. 1, the double resonance is eliminated by positioning the feeding point 7 offset from the center of the antenna 5 as shown in FIG. 2, but as shown in FIG. The radiation efficiency is improved by about 5 dB as compared with the case of the double resonance. That is, by correcting the electrical length from the center to the two ends a and b of the antenna element when the feeding point 7 is centered on the feeding point 7 by positioning the feeding point 7 offset from the center of the antenna 5, Double resonance is eliminated to prevent a decrease in radiation efficiency.
[0039]
FIG. 5 is a schematic diagram showing a transmission / reception unit of the portable radio apparatus 1. The radio wave received by the antenna 5 is sent to the receiving circuit 13 by the duplexer 11, and after demodulation, the information signal is sent to the output device 15 such as a speaker or CRT. Conversely, a signal input from the input device 7 such as a microphone or a keyboard is transmitted to the transmission circuit 19 and is transmitted from the antenna 5 through the duplexer 11 after modulation and amplification. Although the portable wireless device 1 uses the antenna 5 for both transmission and reception, an antenna may be provided for each reception and transmission, and the duplexer 11 can be omitted at that time. Of course, an antenna may be directly attached to the transmission system and the reception system, and only each system may be configured in a housing to form a portable transmitter or a portable receiver.
[0040]
Next, a second embodiment of the portable radio apparatus according to the present invention will be described with reference to FIG. In the second embodiment, a short-circuit line 27a as shown in FIG. 6 is provided between the grounding point at the feeding point 7 of the antenna 5 shown in FIG. is there. In this case as well, the same phenomenon as in the case of the feeding point 7 described above occurs. Similarly, the resonance phenomenon is avoided by offsetting the short-circuit line 27a of the folded portion in the same direction as the feeding point 7 and the performance of the antenna is reduced. Deterioration can be prevented.
[0041]
This will be specifically described below. In the embodiment shown in FIG. 6, a drawer type antenna 25A is added to the outside of the antenna 25. By providing this drawer type antenna 25A, antenna switching diversity is possible. Further, by pulling out the pull-out antenna 25A, if the antenna power supply is automatically switched from the antenna 25 to the pull-out antenna 25A, the antenna 25 which is a small antenna in the strong electric field region and the antenna 25 in the weak electric field region are used. By pulling out and using the pull-out antenna 25A, stable communication can be performed while switching the antenna.
[0042]
The antenna 25 is manufactured by cutting a copper foil film formed on the dielectric substrate 29 by etching. The band-shaped element formed into a ribbon shape by this cutting has a peripheral length of about one wavelength and an electric length of almost half wavelength. For example, in this case, a 0.8 mm thick Teflon substrate may be used as the dielectric substrate.
[0043]
In addition, as shown in FIG. 6B, the antenna 25 is installed so that the center of the feeding point 27b and the short-circuit line 27a is located by being shifted from the center line a by a distance b in the right hand direction in the drawing. Furthermore, the length of the cut is configured to be different between the two elements viewed from the feeding point. This corrects the electrical length of both elements from the feeding point to the two ends to the same length, thereby eliminating double resonance.
[0044]
Further, how much the feeding point b is shifted with respect to the center point a of the physical shape of the antenna is determined by the relative relationship between the wavelength of the radio wave used and the size of the antenna. The In the current experiment, for example, when the frequency is 800 MHz and the envelope shape of the antenna is 20 mm × 35 mm, the radiation efficiency is most improved when the antenna is shifted from the center of the physical shape by about λ / 50 to λ / 100. Can do.
[0045]
In addition, since widening the band is a direction of increasing the electrical length, for example, if one of the first element and the second element is a wide element, the feeding point is increased in the direction of the wide element. If the shift is large, the improvement effect can be enhanced.
[0046]
In this example, strip-like conductors are used for the first element and the second element, and the sum of the perimeters is about one wavelength. However, between the first element and the second element and the housing, It is also possible to shorten the physical lengths of the first element and the second element by inserting a dielectric material into the element, and to have the same effect as the present invention.
[0047]
FIG. 7 is a diagram illustrating an example of a shape change for correcting the electrical length of the antenna 25. The antenna 25 is fed from a housing 23 at a feeding point 27b, and is further connected to the housing 23 by a short-circuit wire 27a. The antenna element 25 has a perimeter of about one wavelength by being cut. In FIG. 7, the shape of the antenna 25a shown in FIG. In the antenna 25b shown in FIG. 7B, b1 shown in FIG. 7A is shortened, and in the antenna 25c shown in FIG. 7C, a1 shown in FIG. 7A is shortened. In the antenna 25d shown in FIG. 7 (d), by shortening c1 shown in FIG. 7 (a), the electrical length from the center to both ends of the antenna element when the feeding point 27b of the antenna 25 is centered. Is corrected, the double resonance is eliminated, and the reduction in radiation efficiency is prevented.
[0048]
FIG. 8 is a diagram showing an example in which the electrical length of the antenna 25 in the portable radio apparatus shown in FIG. 6 is corrected by changing the capacity.
[0049]
In the example of the antenna 25e shown in FIG. 8 (a), since the element width a1 on one side of the antenna 25e is wider than the element width a2 on the other side, the capacity of the element on the a1 increases, and the power is equivalently supplied. From the point, the electrical length of the element a1 is longer, and thereby the electrical length of the left and right elements is adjusted to the same length.
[0050]
Further, in the antenna 25f shown in FIG. 8B, the conductor 23 is provided with a conductor projection 29A on the housing 23, and the capacitance at the end A is increased to correct the electrical length. In this case, the conductor protrusion 29A may be another circuit component having a conductor outside. Further, in the antenna 25g shown in FIG. 8C, the capacity is increased by providing a bent portion at the end A on one side of the antenna 25g. At this time, the lower end portion of the end A is connected to the housing 23. It is configured to be separated by a distance L so as not to contact. Furthermore, the antenna 25h shown in FIG. 8E can flexibly cope with the elimination of double resonance by providing the variable capacitor 29B at one end of the antenna 25h.
[0051]
FIG. 9 is a perspective view showing a third embodiment according to the present invention.
[0052]
In this embodiment, the shape of the antenna 35 is configured as an “inverted S-shape” as a whole by combining two J-shapes. Further, the end A on one side of the antenna 35 is capacitively coupled to the conductor protrusion 39B, and the electric capacity of the one end A is increased to increase the electric capacity of the antenna element 35 from the feeding point 37b to the end A. The electrical length is increased. On the other hand, the dielectric 39A is inserted under the end B on the other side of the antenna element 35, thereby increasing the electric capacity of the end B, and the antenna element 35 from the feeding point 37b to the end B is increased. Extends the electrical length. With these, the electrical lengths of both antenna elements 35 are matched to prevent double resonance.
[0053]
Further, at this time, the end portion B and the housing may be separated from each other by a screw, and the thickness of the dielectric 39A may be changed depending on the tightening condition of the screw to change the electric capacity of the end portion B.
[0054]
A fourth embodiment according to the present invention will be described with reference to FIG.
[0055]
The fourth embodiment is an antenna linear element fixed with a gap between a plastic casing 43 and a circuit board 42 via a power supply line 7A and a short-circuit line 27a on the circuit board 42. 45 and a parasitic linear element 45a provided at a position facing the linear element 45 on the back side (inner side) surface of the casing 43. The parasitic element 45a is formed on the back side of the casing 43 by, for example, an epoxy system. It is fixed by a dielectric fixing material 44 such as an adhesive or an adhesive tape. The antenna linear element 45 and the parasitic element 45a slightly change the resonance frequency of each element by slightly changing the electrical length of each of the antenna linear element 45 and the parasitic element 45a. The antenna linear element 45 and the feed line 7A can be matched by changing the distance and thickness between the short-circuit line 27a and the feed line 7A.
[0056]
A fifth embodiment according to the present invention will be described with reference to FIGS.
[0057]
An antenna linear element 45 is provided on the back side (inner side) of the plastic housing 43. A power supply circuit 7 </ b> Aa is provided on the circuit board 42, and power is supplied through the power supply point 7. The antenna linear element 45 is formed on the housing 43 by plating or the like.
[0058]
The feeder circuit 7Aa is composed of two square-shaped linear elements and a linear linear element sandwiched between them, and is terminated to the ground on the circuit board with the feeder point 7 as a starting point. It has become. Further, the feeder circuit 7Aa is made of a spring material, and when a force is applied from the upper side of the circuit, the U-shaped portion is bent. A contact point stable in terms of high frequency can be obtained simply by being pressed against the antenna linear element 45, and the characteristics of the antenna do not change in an unstable manner. In this way, the feeding circuit 45 and the antenna linear element 5 are combined to form an antenna. The matching between the antenna and the feeding point is performed by changing the distance between the two “<"-shaped elements of the feeding circuit and the thickness of the "<-shaped elements".
[0059]
FIG. 13 shows a sixth embodiment. A parasitic linear element 45a is provided on the front surface (outer) surface of the plastic housing 43, and an antenna linear element 45 is provided on the rear surface (inner) surface. A power supply circuit 7Ab is provided on the circuit board 42, and power is supplied through a power supply point. The antenna linear element 45 and the parasitic line element 45a are formed on the housing 43 by plating or the like.
[0060]
The power feeding circuit 7Ab is composed of two linear elements and a “V” -shaped linear element sandwiched between them, and further on the circuit board starting from a power feeding point at one end of the power feeding circuit 7Ab. It is supposed to be terminated to the ground. Further, the feeder circuit 7Ab is made of a spring material, and the U-shaped portion is bent. Therefore, the feeder circuit 7Ab is only pressed against the antenna linear element 45 to increase the frequency. A stable contact can be obtained, and the characteristics of the antenna do not change unstable. In this manner, the antenna is configured by combining the power feeding circuit 7Ab and the antenna linear element 45. Further, here, the parasitic element 45a is arranged on the back surface across the housing of the antenna element 45. By slightly changing the electrical length of the antenna linear element 45 and the parasitic element 45a, the resonance frequency of each element slightly changes, and the operating band of the antenna can be widened.
[0061]
14, 15 and 16 show a seventh embodiment. Antenna linear element 45, feeding point 27b, short-circuit line 27a, dielectric substrate 29, antenna ground 41, circuit board 42, circuit element 43, groove 46, coaxial line feeding line 47, and projection for fixing the antenna element 49 is provided.
[0062]
On the antenna linear element 45 and the ground 41, a ring-shaped hole (through hole) near the feeding point is formed on the dielectric substrate 29 by etching or the like. In addition, a groove 46 is drilled in advance in the dielectric substrate 29 toward the feeding point 27b, and is also plated. The groove 46 accommodates a coaxial power supply line 47. The core wire of the coaxial line 46 is fixed to the feeding point 27b by soldering or the like. The feeding point 27 b and the short-circuit line 27 a are formed in the dielectric substrate 29 by through holes.
[0063]
17 and 18 show an eighth embodiment.
[0064]
Feed point 7, short-circuit line 27a, feed line 27b, dielectric substrate 29, antenna ground 41, circuit board 42, antenna linear element 45, antenna element fixing protrusion 49, coplanar microstrip line 51 and It is composed of a feeder line connector 53.
[0065]
The feeding line of the antenna linear element 45 and the coplanar microstrip line 51 on the ground 41 is formed on the dielectric substrate 29 by etching or the like. In addition, a connection connector 53 is connected to an end of the coplanar microstrip line 51 in advance by soldering or the like, and the power supply line on the circuit board 42 and the power supply line 51 are connected via the connector 53. Further, the dielectric is peeled off by etching or the like around the place where the dielectric substrate 29 is disposed on the circuit board 42, particularly where the feeder line 51 passes, so that the feeder line is a coplanar microstrip line. Can work as. The feeder line 27b and the short-circuit line 27a are formed in the dielectric substrate 29 by through holes.
[0066]
19 and 20 show a ninth embodiment. The housing 3, the antenna linear element 5, the cylindrical conductor 51, the connector 52 that fixes the antenna to the casing, the linear antenna element 53 that can be expanded and contracted, the electrical contact 54, and the feeder line 55 are configured.
[0067]
First, when the linear element 5 is accommodated, the contact 54 a is connected to the connector 52 and serves as a feeding point for the antenna linear element 5. At this time, the contact 54 b is short-circuited in high frequency by contacting the convex portion of the conductor cylinder 51. Here, by setting the distance from the connector 52 to the convex portion in the conductor cylinder 57 to be a quarter wavelength, the input impedance when the conductor cylinder 57 side is viewed from the connector 52 is substantially open. It will be. Therefore, the conductor cylinder 57 is ignored in terms of high frequency when stored. Here, by setting the distance from the contact 54a to the linear element 5 to be one-sixteenth wavelength or more, the antenna can be matched with the feed line without a matching circuit.
[0068]
When the linear element 53 is pulled out, the contact 54 c is connected to the connector 52, and this is a feeding point for the antenna linear element 5 and the linear element 53. Here, by setting the length of the linear element 53 to a half wavelength from the connector 52, the input impedance of the antenna is matched with the feeder line even in the extended state. In this way, the linear element 53 is stored when the pocket is stored or in a strong electric field region, and the linear element 53 is pulled out and used in a weak electric field region.
[0069]
FIG. 21 shows a tenth embodiment. The housing 3, the antenna linear element 5, the short-circuit line 27 a, the feeder line 27 b, the keyboard 63, the speaker 61, and the microphone 65.
[0070]
The antenna linear element is fixed to a recess provided on the top side of the housing 3 by a short-circuit line 27a and a power supply line 27b. The keyboard 63, the speaker 61, and the microphone 65 are arranged away from the place where the antenna linear element 5 is arranged. By taking such a configuration, radiation toward the human body is reduced.
[0071]
FIG. 22 shows an eleventh embodiment. The housing 3, the housing arm 3 </ b> A, the antenna linear element 5, the keyboard 63, the display 67, the pin 69, the speaker 61, and the microphone 65 are configured.
[0072]
The housing arm portion 3A has an antenna linear element 5 and a microphone 65 at its tip. By comprising in this way, an antenna part can be separated from a human body rather than the housing | casing 3 in which the speaker 61 with which a human body head closely_contact | adheres is arrange | positioned, and the influence on the antenna characteristic by a human body can be reduced. In addition, such a configuration makes it possible to reduce the size of the wireless device, which is convenient to carry.
[0073]
FIG. 23 shows a twelfth embodiment. The antenna linear element 5, the short-circuit line 27 a, the feeder line 27 b, the circuit board 42, and the circuit component 43 are included. The antenna linear element 5 can be formed in an arbitrary shape as shown in the drawing in accordance with the mounting state of other circuits.
[0074]
The means for preventing the characteristic deterioration of the antenna of the present invention can be used by appropriately combining the above embodiments. The present invention is not limited to a portable wireless device, but a wireless device in which the antenna as described above is used in combination with a metal housing, such as a wireless card, a wireless personal computer, various multimedia devices, a wireless LAN terminal, The present invention can be applied to various small radio base stations and antennas used for mobile objects such as automobiles.
[0075]
In the above-described embodiment, the case where the entire casing is configured with a conductor has been described as an example. However, the present invention is not limited to this, and for example, only one surface or a part of the casing is configured with a conductor. The present invention can be applied to a portable wireless device of an appropriate system such as a configuration. For example, a portable wireless device configured by a device main body mounted on a vehicle and an antenna attached to the vehicle is applicable.
[0076]
Furthermore, in the above embodiment, the case where the antenna is configured by two elements has been described as an example. However, the present invention is not limited to this, and any number of elements may be used as long as the number is two or more, and the shape is linear. It can be applied to the configuration of an antenna having an arbitrary shape such as a U-shape, J-shape, O-shape, T-shape, triangle shape, fan shape, loop shape, spiral shape, etc. composed of a strip or plate-like body. Needless to say.
[0077]
27 and 28 show an embodiment according to the fourth invention. It includes a housing 110, a speaker 111, a microphone 115, an antenna 117L, and a parasitic element 117R.
[0078]
Thus, by arranging the antenna 117L and the parasitic element 117R on the back surface facing the front surface where the speaker 111 is disposed, and configuring the array antenna by these, the directivity of the array antenna is in the direction of the human head. The direction is as shown in FIG. The antenna 117L and the parasitic element 117R are arranged in the normal direction with respect to the back surface. In such a case, the high-frequency current drawn from the feeding point of the antenna generates a relatively large current distribution on the antenna 117L and on the back surface of the housing 110, but compared to the current distribution distributed on the back surface on the front surface. Only small things occur. The current generated on the front surface causes an interaction with the human body in close contact. However, as mentioned above, since this current is small, there is no problem. On the other hand, the current on the antenna is separated from the human body by the thickness of the housing and further extends in a direction away from the human body surface. For this reason, the projected image on the human body surface induced by this current is smaller than the current on the antenna. This is because the human body is not a good conductor. The projected image on the surface of the human body due to the current on the back surface has a relatively small distribution because the back surface is separated from the human body by the thickness of the casing and the human body is not a good conductor. From the above, the projected image on the human body can thereby obtain a desired radiation directivity, and the interaction between the electromagnetic wave radiated from the antenna and the human head can be reduced.
[0079]
29 and 30 show another embodiment according to the fourth invention.
[0080]
As shown here, by arranging the antenna 117D and the parasitic element 117U as an array, the directivity of the array antenna becomes the two directions shown in the figure. Even in such a configuration, the effect is equal to the embodiment shown in FIG.
[0081]
In this embodiment, the antenna 117D is a quarter-wave monopole antenna, a plate-like inverted F antenna shortened from the antenna, a normal mode helical antenna, a microstrip antenna, etc. Should be used. Furthermore, by using a half-wave monopole antenna or a half-wave sleeve antenna with a balun, the current flowing into the housing can be reduced, the influence of the human body on the antenna characteristics is reduced, and the human body and the high frequency that are in close contact with the housing Interaction with current can also be reduced. The parasitic element 117U uses an antenna of the same type as the antenna 117D, and further inserts a load at the feeding point, and can change the radiation directivity by setting the value of this load as desired.
[0082]
FIG. 31 shows an embodiment of a configuration in which the distance between the speaker and the housing according to the fifth invention can be changed. A bellows 110c is provided between the housing 110a and the housing 110b, and an antenna 117, a speaker 111, and a microphone 115 are further provided. Specifically, a speaker 111 and a microphone 115 are disposed in the housing 110a, and an antenna 117 is disposed in the housing 110b. The casing 110b is covered with a conductor to shield internal components. The housing 110a and the housing 110b are connected by a signal line longer than the length of the bellows 110c, and have a structure that can withstand expansion and contraction of the bellows. Further, by collecting high-frequency circuit portions in the housing 110b, the housing 110a and the housing 110b can be connected by a low-frequency signal line.
[0083]
Here, since the low-frequency signal line has less impedance fluctuation due to the deformation of the signal line due to expansion and contraction than the high-frequency signal line, it is advantageous to connect the two housings with the low-frequency signal line in this way. It is. As shown in FIG. 31, the bellows is extended during communication (a) and shortened during standby (b). By configuring in this way, it is possible to reduce the amount of electromagnetic waves radiated to the human body during communication without interfering with storage.
[0084]
FIG. 32 shows another embodiment of the configuration according to the fifth aspect of the invention which can change the distance between the speaker and the housing. The housing 121 can be stored in the housing 110. The housing 121 can be expanded and contracted from the inside of the housing 110. The antenna 117 is provided in the housing 121. A speaker and a microphone are provided in the housing 110. The scale 123 is provided on the side surface of the housing 121 and the amount of the scale 123 is easily determined. That is, the scale 123 indicates the maximum directivity gain with the position of the casing 121 and the human body as parameters, and is displayed on the side surface of the casing 121 as confirmed by calculation or experiment in advance. By reading the scale 123 at a location that matches the casing 110, the amount of change in the radiation field due to the human body at that time can be easily confirmed.
[0085]
FIG. 33 and FIG. 34 show another embodiment of the constitution that can change the distance between the speaker and the housing according to the fifth invention.
[0086]
With respect to the casing 125A having a predetermined length, the casing 125B having a substantially half length is pivotally supported by the rotation mechanism unit 127 at a position that is approximately half the length of the casing 125A. In addition, an antenna 117 is provided at one end of the housing 125A, a microphone 115 is provided on the front surface (inside surface) of the other side, and a speaker 111 is provided on the front surface (inside surface) of the housing 125B. It is done. At the time of a call, as shown in FIG. 33B with the rotation mechanism portion 127 as the center, the housing 125B is expanded in a fan shape with respect to the housing 125A and fixed. As shown in FIG. 34, the distance between the speaker 111 arranged in the housing 125B and the microphone 115 in the housing 125A in this unfolded state is formed to be substantially equal to the distance between the human ear and the mouth. The distance can be changed by changing the turning angle according to the shape and preference of the face of the user. Further, since the ear is in close contact with the speaker 111, the feeding point of the antenna 117 is set away from the human head. Therefore, by configuring as described above, the interaction between the antenna, the high-frequency current on the housing and the human body is reduced. Further, when carrying, as shown in FIG. 33A, the protruding portion is eliminated by folding the housing 125B, and the size can be reduced.
[0087]
FIG. 35 shows another embodiment of the structure according to the fifth aspect of the invention which can change the distance between the speaker and the housing. This embodiment has substantially the same configuration as the portable radio apparatus shown in FIG. In the embodiment shown in FIG. 35, one half of the casing 125Aa is configured to be half of the thickness of the other, and the half-thickness of the casing 125Ba is formed by the rotation mechanism portion 127 in the half-thickness portion. Swings and is housed. Note that the speaker 111 is provided in the case 125Ba that is a movable case, the antenna 117 is provided at one end of the case 125Aa that is the main body side case, and the microphone 115 is provided on the front surface on the other side. It is done.
[0088]
FIG. 36 shows another embodiment. The configuration is almost the same as that of the embodiment shown in FIG. 35, and in this example, the method of development at the time of a call is the back side. The effect is substantially the same as in the case of FIG.
[0089]
That is, the casing 125Ab and the casing 125Bb are connected by the rotation mechanism unit 127. As shown in FIG. 36B, the casing 125Bb is fanned out and fixed to the rear of the casing 125Ab as shown in FIG. Since the speaker 111 is disposed in the housing 125Ab and the ear is in close contact therewith, the feeding point of the antenna 117 is separated from the human head.
[0090]
With the configuration described above, the interaction between the current on the antenna and the housing and the human body is reduced. Similarly to the embodiment of the previous invention, when carrying, it can be miniaturized by folding.
[0091]
Another embodiment will be described with reference to FIGS. It is comprised of a housing 110, an antenna 117b, and a feeder line 117a.
[0092]
As shown in FIGS. 37 and 38, the feeder line 117a first rises perpendicularly from a certain surface on the housing 110, and then bends substantially at a right angle, so that the distance d from the previous surface is about several tenths of a wavelength. (Refer to FIG. 38 (c)) while maintaining parallel, and parallel to the housing 110 over a quarter-wavelength from point n to point m in FIGS. At the point m, the feeder line 117a is also bent substantially vertically and extends in the extending direction of the radio equipment case 110 in the longitudinal direction. Further, the feed line 117a ends at a point p extended by a quarter wavelength, and a quarter-wavelength antenna linear element 117b is attached to the end thereof.
[0093]
In such a configuration, the antenna linear element 117b and the subsequent outer portion of the quarter-wave feed line 117a work in the same manner as a half-wave dipole antenna having a feed line at the junction p. This is because the housing 110 functions to choke the high-frequency current from the point m to the point n of the feeder line 117a connected to this portion. The explanation of this function is as follows.
[0094]
A portion from the point n to the point m of the feeder line 117a is short-circuited to the housing 110 at a quarter wavelength as viewed from the point m. Accordingly, when the U-shaped portion formed by the feeder line 117A and the surface of the housing 110 is viewed from the point m, the impedance is considerably high. As a result, the U-shaped portion functions to choke at the point m for the current flowing out of p and flowing outside the outer conductor of the feeder line 117a. This choke prevents the previous current from flowing into the housing 110. As a result, the interaction between the human head closely contacting the casing 110 and the current on the casing and the antenna is reduced. According to this configuration, a sleeve is not necessary for the outer conductor. Therefore, the structure of the antenna can be simplified as compared with the sleeve antenna, and equivalent performance can be realized.
[0095]
FIG. 39 shows a radiation pattern of the radio having the configuration of the above embodiment. Unlike the pattern shown in FIG. 43, it is close to the pattern of a half-wave dipole antenna. This shows that the current flowing into the housing is considerably reduced. Further, FIG. 40 shows a pattern when the length of the choke performed by the housing and the power supply line is set to one-fifth wavelength. Also in this pattern, it can be seen that the radiation field is remarkably improved and the current on the casing is reduced as compared with the pattern shown in FIG.
[0096]
FIG. 41 shows another embodiment. 41, a conductive conductor cylinder 129 having a length of about a quarter wavelength is embedded in one surface of the housing 110, for example, one corner of the upper surface, and the antenna 117b is embedded in the conductor cylinder 129. And a feeder line 117a. The conductor cylinder 129 is electrically short-circuited to the feeder line 117a at the bottom portion n.
[0097]
Further, the feeder line 117a is electrically short-circuited with the conductor cylinder 129 at n points ahead of the quarter wavelength as seen from the junction point m between the casing 110 and the conductor cylinder 129. Therefore, the impedance when looking from the junction point m to the point n becomes very large, and the high-frequency current drawn from the junction point p between the feeder line 117a and the antenna element 117b is choked at the point m. Here, the antenna element 117b is formed by winding a wire of about a quarter wavelength in a coil shape in order to suppress the height of the antenna.
[0098]
With the above configuration, the interaction between the human body that is in close contact with the housing 110 and the current on the antenna and the housing is reduced as in the above-described invention.
[0099]
FIG. 42 shows another embodiment. The portable wireless device shown in FIG. 42 is obtained by cutting out part of the housing 110 to form a stepped portion, and providing the antenna 117b on the stepped portion.
[0100]
The length between the point m that is the same height as the upper surface of the housing 110 and the point n that is the point at the bottom of the stepped portion is about a quarter wavelength. Further, since the feeder line 117a is electrically short-circuited with the casing 110 at the n point at the bottom, the impedance when viewed from the junction point m to the point n becomes very large. Therefore, the high-frequency current that has run out from the junction point p between the feeder line 117a and the antenna element 117b is choked at the point m. Here, the antenna element 117b and the feeder line 117a between the point p and the point m are wound in a coil shape in order to suppress the height of the antenna.
[0101]
By adopting such a configuration, the interaction between the human body in close contact with the casing 110 and the current on the antenna and the casing is remarkably reduced, as in each of the embodiments described above.
[0102]
【The invention's effect】
As described above, the portable radio apparatus according to the present invention can reduce the interaction with the human body that has occurred in the antenna, thereby achieving an effect such that stable communication can be performed.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a configuration of a position example of a portable radio apparatus according to the present invention.
2 is a diagram showing a positional relationship between feeding points of antenna elements of the portable wireless device shown in FIG. 1. FIG.
FIG. 3 is a diagram showing impedance characteristics of a portable radio apparatus using the antenna shown in FIG.
FIG. 4 is a diagram comparing the radiation efficiency of the present invention and a conventional portable wireless device.
FIG. 5 is a block diagram showing a schematic configuration of the portable radio apparatus shown in FIG. 1;
FIG. 6 is a diagram showing a second embodiment of the portable radio apparatus according to the present invention.
7 is a diagram showing an example of a shape change for correcting the electrical length of an antenna element in the portable wireless device shown in FIG. 6;
8 is a diagram illustrating an example in which the electrical length of the antenna element in the portable wireless device shown in FIG. 6 is corrected by changing the capacitance.
FIG. 9 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 10 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 11 is a diagram showing a third embodiment of the portable radio apparatus according to the invention.
FIG. 12 is a diagram showing a third embodiment of the portable radio apparatus according to the invention.
FIG. 13 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 14 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 15 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 16 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 17 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 18 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 19 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 20 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 21 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 22 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 23 is a diagram showing a third embodiment of the portable radio apparatus according to the present invention.
FIG. 24 is a perspective view showing an appearance of a conventional portable wireless device.
25 is a diagram showing a positional relationship between feeding points of antenna elements of the portable wireless device shown in FIG. 24. FIG.
FIG. 26 is a diagram showing impedance characteristics of the conventional portable wireless device shown in FIG.
FIG. 27 is a diagram showing an embodiment of a portable wireless device according to a fourth invention of the present invention.
FIG. 28 is a diagram showing an embodiment of a portable wireless device according to a fourth invention of the present invention.
FIG. 29 is a diagram showing an embodiment of a portable wireless apparatus according to the fourth aspect of the present invention.
FIG. 30 is a diagram showing an embodiment of a portable wireless device according to a fourth invention of the present invention.
FIG. 31 is a diagram showing an embodiment of a portable wireless apparatus according to the fifth aspect of the present invention.
FIG. 32 is a diagram showing an embodiment of a portable wireless apparatus according to the fifth aspect of the present invention.
FIG. 33 is a diagram showing an example of a portable wireless device according to a sixth invention of the present invention.
FIG. 34 is a diagram showing an embodiment of a portable wireless apparatus according to the sixth aspect of the present invention.
FIG. 35 is a diagram showing an embodiment of a portable wireless apparatus according to the sixth aspect of the present invention.
FIG. 36 is a diagram showing an embodiment of a portable wireless apparatus according to the sixth aspect of the present invention.
FIG. 37 is a diagram showing an example of a portable wireless device according to a sixth invention of the present invention.
FIG. 38 is a diagram showing an example of a portable wireless device according to a sixth invention of the present invention.
FIG. 39 is a diagram showing an embodiment of a portable wireless apparatus according to the sixth aspect of the present invention.
FIG. 40 is a diagram showing an example of a portable wireless device according to a sixth invention of the present invention.
FIG. 41 is a diagram showing an example of a portable wireless device according to a sixth invention of the present invention.
FIG. 42 is a diagram showing an embodiment of a portable wireless apparatus according to the sixth aspect of the present invention.
FIG. 43 is a perspective view of the radiation pattern of the antenna and the appearance of the wireless device when the balun is removed from the sleeve antenna.
FIG. 44 is a pattern diagram showing a radiation field of a dipole antenna.
FIG. 45 is a pattern diagram showing a radiation field of a two-third-wavelength dipole antenna.
FIG. 46 is a perspective view showing an external appearance of a portable wireless device including a conventional sleeve monopole antenna with a balun.
[Explanation of symbols]
1 Portable wireless device
3 Radio equipment housing
5 Antenna
7 Feeding point
7A Feeding line
11 Duplexer
13 Receiver circuit
15 Output device
17 Input device
19 Transmitter circuit
25A Pull-out antenna
27a Short circuit wire
27b Feeding point
29 Derivative substrate
29A conductor convex part
29B variable capacity
39A Dielectric
39B Conductive convex part
40 Power supply line
41 Ground for antenna
42 Circuit board
43 Circuit parts
44 Projection for fixing antenna element
45 Power supply circuit
46 Groove for feeding line
50 Power line connector
51 Cylindrical conductor
52 Connector to fix antenna to housing
53 Stretchable linear antenna element
54 Electrical contacts
63 keyboard
67 display
69 pins
61 Speaker
65 microphone
110 Radio equipment housing
117 Antenna element
110C bellows
111 speakers
115 microphone
123 scales
127 Rotation mechanism
129 Conductor cylinder

Claims (8)

A first housing having a speaker;
A second housing comprising an antenna provided at an end on one side and a microphone provided on the front surface on the other side ;
Provided between the antenna and the microphone of the second housing, said first housing and said second housing and rotatably supported, the second housing with respect to and a rotating mechanism for deploying the first housing to the fan Te,
The portable radio apparatus according to claim 1, wherein the antenna is separated from a rear side of the speaker in a state where the first casing is expanded and a user's ear is attached to the speaker .   The rotation mechanism section is provided at a lower end portion of the first casing, and pivotally supports the first casing and the second casing in a rotatable manner. The portable wireless device described.   The portable wireless device according to claim 1, wherein the shape of the second housing is substantially rectangular.   The second casing includes a first part where the antenna is arranged and a second part where the microphone is arranged, and the thickness of the second part is thicker than the first part. The portable radio apparatus according to claim 1.   5. The portable radio according to claim 4, wherein a thickness of the first part in the second casing is substantially half of a thickness of the second part in the second casing. apparatus.   The portable wireless device according to claim 4, wherein a thickness of the first casing is substantially half of a thickness of the second portion in the second casing.   The upper end portion of the first casing substantially coincides with the lower end portion of the second casing when the first casing and the second casing are folded. The portable wireless device described.   The portable wireless device according to claim 1, wherein the length of the first casing is substantially half of the length of the second casing.

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