JP2010074842A - Antenna module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extremely small-sized antenna module which has multi-resonance and widens a transmission/reception band. <P>SOLUTION: The present invention includes: antennas 2, 3; a connection conductor 8 provided mutually between antennas for connecting the antennas 2, 3 in series; a power feeding unit 10 provided at a terminal 4 that is not connected to the connection conductor 8 at the antennas 2, 3 connected in series; an additional conductor 9 provided at the other terminal not connected to the connection conductor 8; and a capacitive conductor 20 conducted to the additional conductor 9. The connection conductor 8 approximately linearly connects the antennas 2, 3 and the additional conductor 9 has an open end. The capacitive conductor 20 is then extended from the additional conductor 8 to a mount surface opposite to at least one of the antennas 2 and 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an antenna module that is suitably used for electronic devices that perform wireless communication such as mobile communication and personal computers.

  In recent years, there has been an increase in the number of mobile terminals equipped with a whip antenna and a built-in antenna for making calls, and a chip antenna for performing wireless data communication with other electronic devices in addition to each antenna. Yes.

  Also, in portable mobile electronic devices such as notebook personal computers, the number of devices that perform data communication wirelessly using a wireless LAN or the like is increasing, and the number of devices equipped with chip antennas is increasing. .

  Furthermore, recent cellular phones and notebook personal computers are required to be downsized and have low power consumption, and downsizing of the antenna device is desired. In addition, with an increase in transmission capacity in recent years, there has been a demand for a broadband antenna. Further, in the multicarrier system such as OFDM (Orthogonal Frequency Modulation Multiplexing), a wider band is required more and more.

  Here, in order to increase the load capacity of the antenna in order to realize a wide band of the antenna, an antenna module in which an additional conductor is added to the tip of the antenna has been studied (see, for example, Patent Document 1 and Patent Document 2). ). 17 and 18 are top views of an antenna module according to the prior art, and show a case where an additional conductor is added to the tip of the antenna element.

  Reference numeral 100 denotes an antenna module, 101 denotes a meander antenna, 102 denotes a power feeding unit, and 103 denotes an additional conductor. The meander antenna 101 is formed of a substrate pattern or the like. The additional conductor 103 is formed at the tip of the meander antenna 101, and the tip is an open end. A signal current is supplied from the power feeding unit 102, and the supplied signal is radiated according to the resonance frequency of the meander antenna 101. The same applies to reception. At this time, the additional conductor 103 becomes a load capacity, the load impedance viewed from the power supply unit 102 increases, the peak of the frequency curve becomes gentle, and the frequency band is expanded.

  FIG. 18 shows a state in which two meander antennas 101 are arranged in parallel to cope with multiple resonances, and an additional conductor 103 is separately formed at each tip.

JP 2002-124812 A JP-A-10-247806

  However, when an additional conductor at the tip of a pattern antenna such as a meander antenna is formed, the pattern antenna itself requires a large area, which causes a problem that the antenna module becomes large.

In recent mobile terminals, notebook personal computers, and the like, a multi-resonant antenna module needs to be required in order to support a plurality of frequency standards in one terminal. For this reason, when a plurality of antennas are arranged in parallel, a separate additional conductor is required for each, and the antenna module becomes large, and there is a problem that it is difficult to reduce the size of the device in which the antenna module is incorporated. .

  In particular, when separate additional conductors are provided, it is necessary to increase the bandwidth of each antenna with each additional conductor, and there is a problem that the antenna module further increases in size due to the large size of each additional conductor itself. It was.

  An object of the present invention is to provide an antenna module that enables transmission and reception in a wide band while realizing miniaturization.

  The present invention is provided on one of a plurality of antennas, a connection conductor provided between the antennas connecting the plurality of antennas in series, and a terminal portion not connected to the connection conductor in the plurality of antennas connected in series. A power supply section, an additional conductor provided on the other side of the terminal section not connected to the connection conductor, and a capacitive conductor connected to the additional conductor, the connection conductor connecting a plurality of antennas in a substantially straight line. The additional conductor is an open end, and the capacitive conductor extends from the additional conductor to a mounting surface facing at least one of the plurality of antennas.

With the above configuration, the present invention can realize downsizing and further widening by making the antenna and the capacitive conductor very close to each other and capacitively coupling the capacitance between the antenna and the capacitive conductor. .

The perspective view of the antenna module in Embodiment 1 of this invention Configuration diagram of antenna module according to Embodiment 1 of the present invention 1 is an equivalent circuit diagram of the antenna module shown in FIG. Configuration diagram of antenna module according to Embodiment 1 of the present invention Configuration diagram of antenna module according to Embodiment 1 of the present invention Configuration diagram of antenna module according to Embodiment 1 of the present invention Equivalent circuit diagram of the antenna module shown in FIG. (A) Mounting diagram of the antenna module of the present invention on a cellular phone, (b) VSWR diagram of the antenna module of the present invention, (c) List view showing the gain of the antenna module of the present invention, (d) Antenna module of the present invention Directivity diagram (A) Conventional antenna module mounting diagram of cellular phone, (b) VSWR diagram of conventional antenna module, (c) List diagram showing gain of conventional antenna module, (d) Directivity diagram of conventional antenna module (A) Conventional antenna module mounting diagram of cellular phone, (b) VSWR diagram of conventional antenna module, (c) List diagram showing gain of conventional antenna module, (d) Directivity diagram of conventional antenna module Configuration diagram of antenna module according to Embodiment 2 of the present invention Configuration diagram of antenna module according to Embodiment 2 of the present invention Configuration diagram of antenna module according to Embodiment 2 of the present invention 12 is an equivalent circuit diagram of the antenna module of FIG. Configuration diagram of electronic apparatus according to Embodiment 3 of the present invention Configuration diagram of diversity apparatus in embodiment 4 of the present invention The perspective view of the antenna module in a prior art Top view of antenna module in the prior art

  According to the first aspect of the present invention, a plurality of antennas, a connection conductor provided between the antennas connecting the plurality of antennas in series, and a plurality of antennas connected in series are connected to the connection conductors. A power supply portion provided on one of the non-terminal portions, an additional conductor provided on the other side of the terminal portion not connected to the connection conductor, and a capacitive conductor conducted to the additional conductor, the connection conductor comprising a plurality of connection conductors An antenna characterized in that the antenna is connected in a substantially straight line, the additional conductor is an open end, and the capacitive conductor extends from the additional conductor to a mounting surface facing at least one of the plurality of antennas. In the module, the antenna and the capacitive conductor can be made very close to each other, and further widening can be realized by capacitively coupling the capacitance between the antenna and the capacitive conductor. In addition, it realizes multi-resonance by resonance that uses only a part of multiple antennas and resonance of different frequencies by using the whole antenna. Therefore, the antenna module can be miniaturized by increasing the bandwidth and realizing the substantial use efficiency of the capacitive component with respect to the conductor area.

  The invention according to claim 2 of the present invention is the antenna module according to claim 1, wherein the width of the additional conductor and the connection conductor is larger than the width of the antenna connected to each of the additional conductor and the connection conductor, Mounting area is reduced.

  According to a third aspect of the present invention, there is provided a first antenna, a second antenna, a connection conductor connecting the first antenna and the second antenna in series, and a connection in the first antenna. A feeding portion provided at a terminal portion facing a terminal portion to which a conductor is connected, an additional conductor provided at a terminal portion facing the terminal portion to which a connection conductor is connected in the second antenna, and the additional conductor And the connection conductor connects the plurality of antennas substantially linearly, the additional conductor is an open end, and the capacitance conductor extends from the additional conductor to the first antenna. And an antenna module extending to a mounting surface facing at least one of the second antennas, wherein the antenna and the capacitive conductor are placed in close proximity to each other. Capacitance between can be realized and further broadband due to capacitive coupling. In addition, it realizes multi-resonance by resonance using only the first antenna and resonance of different frequencies by using two, and the capacity of the connection conductor at a certain resonance frequency is also at the case of another resonance frequency. The capacity of the antenna module can be shared to realize a wide band, and the antenna module can be downsized by increasing the efficiency of the substantial use of the capacity component with respect to the conductor area.

  According to a fourth aspect of the present invention, the width of the additional conductor is larger than the width of the second antenna, and the width of the connection conductor is larger than the widths of the first antenna and the second antenna. The antenna module according to claim 3, wherein a mounting area is reduced.

  The invention according to claim 5 of the present invention is the antenna module according to claim 3, wherein the first antenna and the second antenna have different resonance frequencies, and easily realizes multiple resonances. Therefore, it is possible to easily determine the frequency to be transmitted with multiple resonances.

  The invention according to claim 6 of the present invention is the antenna module according to claim 5, wherein the resonance frequency of the first antenna is higher than the resonance frequency of the second antenna. It is possible to easily realize two resonances in which high frequency is realized with one antenna and low frequency is realized with the first antenna and the second antenna.

The invention according to claim 7 of the present invention is the antenna module according to any one of claims 1 to 6, characterized in that the capacitive conductor is integral with the additional conductor. Can be realized.

  In the present specification, the additional conductor, the connection conductor, and the capacitive conductor have different names for explanation, and are all formed in the same manner, for example, a pattern formed on the substrate. And land surfaces, metal films, etc., which generate capacitance components.

  Hereinafter, it demonstrates using drawing.

(Embodiment 1)
First, an antenna module in which two antennas, a first antenna and a second antenna, are connected to realize multiple resonance, a wide band, and a small size will be described with reference to FIGS.

  1 is a perspective view of an antenna module according to Embodiment 1 of the present invention. FIGS. 2, 4 and 5 are configuration diagrams of the antenna module according to Embodiment 1 of the present invention. FIG. 3 is shown in FIG. FIG. 6 is an equivalent circuit diagram of the antenna module.

  In addition, although all are demonstrated with the helical antenna, it is the same also with other pattern antennas.

  1 is an antenna module, 2 and 3 are helical antennas, the helical antenna 2 is a first antenna, the helical antenna 3 is a second antenna, 4, 5, 6, and 7 are terminal portions, and 8 is a connection conductor. , 9 is an additional conductor, 10 is a feeding portion, 11 and 12 are spiral grooves, and 13 is a feeding point. L1 and L2 are inductor components, and C1 and C2 are capacitance components.

  First, the helical antennas 2 and 3 will be described.

  The helical antennas 2 and 3 are manufactured by forming a conductive film on the surface of the base, forming a pair of terminal portions on the base, and forming spiral grooves 11 and 12 by trimming a part of the conductive film with a laser or the like. Is done.

  The substrate is formed by subjecting an insulator or dielectric such as alumina or a ceramic material mainly composed of alumina to a pressing process, an extrusion method, or the like. In addition, as a constituent material of the substrate, ceramic materials such as forsterite, magnesium titanate, calcium titanate, zirconia / tin / titanium, barium titanate, lead / calcium / titanium may be used, A resin material such as an epoxy resin may be used. In the first embodiment, alumina or a ceramic material mainly composed of alumina is used from the viewpoints of strength, insulation, and ease of processing. In addition, a single layer or a plurality of conductive films made of a conductive material such as copper, silver, gold, or nickel are stacked on the base to form a conductive surface. For the conductive film, plating, vapor deposition, sputtering, paste, or the like is used.

  The terminal portions 4, 5, 6, and 7 are formed at both ends of the base, and are at least one of a thin film such as a conductive plating film, a vapor deposition film, and a sputtered film, a silver paste applied, and the like. One is used.

The base body may have a cross section having the same size as the terminal portions 4, 5, 6, and 7, but may be stepped down, and the cross-sectional area of the base body is the terminal portions 4, 5, 6, and 7. It may be smaller than the cross-sectional area. Since the outer periphery of the base body is stepped down, the base body can have a distance from the surface of the antenna mounting substrate during mounting, and deterioration of characteristics can be prevented. At this time, the step-down may be performed only on a part of the surface of the substrate, or may be stepped over the entire surface. When the step is dropped over the entire surface, it is not necessary to pay attention to the selection of the surface in contact with the electronic substrate at the time of mounting, and the cost at the time of mounting can be reduced.

  Further, each corner of the base may be chamfered. By providing this chamfer, chipping of the substrate is prevented, the conductive film is prevented from being thinned, or damage to the spiral grooves 11 and 12 is prevented.

  Here, the base body and the terminal portion may be formed separately and then integrated by pasting together, or may be formed integrally in advance. Further, the substrate may not be a square shape, but may be a triangular or pentagonal polygon shape, or may be a cylindrical shape. In the case of the columnar shape, there is no merit of the corner portion, so that the impact resistance is improved and the spiral grooves 11 and 12 can be easily formed.

  The spiral grooves 11 and 12 are formed by excavating the surface of a conductive substrate in a spiral shape using trimming with a laser or the like, and have an inductor component. The inductor component formed by the spiral grooves 11 and 12 is electrically connected to the terminal portion, and the inductor component is electrically connected. The helical antennas 2 and 3 are not provided with a spiral groove by laser trimming, but may be one in which a conductor wire such as a copper wire is wound around a base.

  It is also preferable to improve the durability by covering the outer periphery of the helical antennas 2 and 3 with a protective film while avoiding the terminal portions 4, 5, 6 and 7.

  The helical antennas 2 and 3 may be λ / 4 type antennas or λ / 2 type antennas. However, λ / 4 type antennas are often used to further reduce the size. In this case, the transmission / reception gain is ensured by using the image current generated on the ground plane existing in the vicinity of the helical antennas 2 and 3.

  In addition, the helical antennas 2 and 3 are arranged on substantially the same straight line, so that the area in the width direction can be reduced, and the helical antenna is used to shorten the length. The area can be reduced in size as compared with the case where the packaging is efficiently performed in the length direction and arranged in parallel.

  The terminal portion 4 is connected to the power feeding portion 10, the terminal portions 5 and 6 are connected to the connection conductor 8, and the terminal portion 7 is connected to the additional conductor 9.

  In addition, the helical antenna 2 that is first connected to the power supply unit 10 is a helical antenna in which the resonance frequency of the helical antenna alone corresponds to a high frequency, and the resonance frequency of the helical antenna 3 alone is lower than that of the helical antenna 2. It is also preferable that the antenna corresponds to. In other words, this is realized by having more turns of the spiral groove 12 and the conductor wire formed in the helical antenna 3 than the number of turns of the spiral groove 11 formed in the helical antenna 2. This is because, as will be described later, it is possible to efficiently generate a frequency that resonates only with the helical antenna 2 and a frequency that resonates according to the resonance condition in which the helical antennas 2 and 3 are combined. Of course, this may be reversed. Further, when three or more antennas are connected, it is also preferable that the resonance frequency of the antenna itself is changed from a high frequency to a low frequency in order from the antenna close to the power feeding unit 10. When the antenna is a helical antenna, it is preferable that the number of turns of the trimming groove or the winding conductor wire is increased in order from the helical antenna close to the power feeding unit 10. Of course, this need not be the case.

  Next, the connection conductor 8 and the additional conductor 9 will be described.

The connection conductor 8 is a conductor that electrically connects the helical antenna 2 and the helical antenna 3, that is, the first antenna and the second antenna in series, and is formed on a substrate on which the helical antennas 2 and 3 are mounted. At this time, it is also preferable that the terminal portions 5 and 6 are also used as mounting lands. The connection conductor may be a pattern conductor on the substrate, a solder surface, a land surface, or a metal surface. When a plurality of antennas are connected in series, the antennas are formed between the antennas in order to realize mutual electrical connection.

  The additional conductor 9 is formed at the tip of the helical antenna 3, that is, the second antenna, and the additional conductor 9 is an open end. When a plurality of antennas are connected, the additional conductor 9 is formed on the most advanced terminal portion on the side opposite to each power feeding portion 10 and where there is no connection conductor between the connected antennas. The additional conductor 9 may be a pattern conductor on the substrate, a solder surface, a land surface, or a metal surface, like the connection conductor, and may be formed also as a land surface that connects the terminal portion 7 to the substrate.

  Further, as shown in FIG. 2, the width of the antenna module 1 in the width direction is set so that the width of the connection conductor 8 and the additional conductor 9 is equal to or somewhat larger than the maximum width of the helical antennas 2 and 3. Can be reduced. It is also suitable to be determined in accordance with the board or electronic device to be mounted.

  At this time, when the helical antennas 2 and 3 are arranged on a substantially straight line, the width of the connecting conductor 8 and the additional conductor 9 should be equal to or somewhat larger than the maximum width of the helical antennas 2 and 3. Further reduction of the mounting area in the width direction is further promoted.

  The power feeding unit 10 supplies a signal current to the helical antennas 2 and 3 or transmits the signal current received by the helical antennas 2 and 3 to the receiving circuit. When the helical antenna 2 is connected to the power feeding unit 10 and the helical antenna 3 is electrically connected via the connection conductor 8, a signal current is supplied to both the helical antennas 2 and 3. Of course, even if there are three or more helical antennas, signal feeding to all the antennas is realized in the same way by connecting each with a connecting conductor.

  As described above, it is possible to reduce the mounting area by connecting a plurality of antennas in series via the connection conductors and arranging them on substantially the same straight line.

  Next, the operation of the antenna module 1 will be described.

  When the inductor component and the capacitance component are connected in series, the resonance frequency is determined by (Equation 1).

  That is, it is determined by the square root of the product of the inductor component and the capacitance component.

  FIG. 3 shows an equivalent circuit of the antenna module including the two helical antennas 2 and 3 shown in FIGS. L1 is an inductor component generated by the spiral groove 11, C1 is a capacitance component mainly generated by the connection conductor 8, L2 is an inductor component generated by the spiral groove 12, and C2 is a capacitance component mainly generated by the additional conductor 9.

  In such an antenna module, first, transmission / reception operation at a resonance frequency corresponding to a resonance condition determined from L1 and C1, and transmission / reception at a resonance frequency corresponding to a resonance condition determined from all of L1, L2, C1, and C2. Two resonances of operation are realized. For example, the resonance frequency generated from L1 and C1 is determined from L1 and C1 for the use frequency of about 1.9 GHz corresponding to the use frequency of about 1.8 GHz of the mobile phone standardized by DCS or the GSM1900 standard. One example is the short antenna. On the other hand, with respect to the use frequency 900 MHz of the cellular phone standardized by GSM, a long antenna having a resonance frequency determined from L1, L2, C1, and C2 is an example. Since these are examples, it may be possible to correspond to each frequency of a wireless LAN using 2.4 GHz and 5 GHz, for example.

  As will be described later, if the number of antennas is 3 or more, an antenna module having a resonance frequency of 3 or more can be obtained.

  Also, by forming multiple helical parts by separating trimming grooves in one helical antenna, a frequency that further resonates by generating multiple inductor components and capacitance components in one helical antenna. It is also preferable to increase the number of types. FIG. 4 shows such a case. The helical antenna 3 is provided with a plurality of helical portions.

  Next, the efficient realization of a wide band will be described. The Q value of the antenna is determined by (Equation 2).

  By increasing C, which is a capacitive component, the Q value can be reduced. At this time, by reducing the Q value, the frequency characteristics of the input impedance of the antenna can be flattened, and the transmission / reception bandwidth of the antenna can be increased. In other words, the rise and fall of the peak in the frequency characteristic becomes gentle due to the action of the capacitive component as the load capacity, and as a result, the antenna has a wider bandwidth.

  Here, both the capacitance component C1 generated by the connection conductor 8 and the capacitance component C2 generated by the additional conductor 9 contribute to the formation of the capacitance component. For this reason, the capacitive component C1 of the connection conductor 8 contributes to widening the bandwidth in both cases of the resonance frequency determined from L1 and C1 and the resonance frequency determined from L1, L2, C1, and C2. For this reason, the broadband is further promoted.

  On the other hand, when an antenna is connected in parallel and an additional conductor is individually formed for each antenna, the additional conductor only contributes individually as a capacitive component in each antenna. That is, even if conductor portions that generate capacitive components of the same area are connected to the antenna, when the antennas are connected in parallel, the ratio of contribution to widening the conductor area is low. On the other hand, in the case of connecting in series, all of the conductor parts that generate a capacitance component (in the present invention, all of the connection conductors that electrically connect the antenna and the additional conductors) contribute to the widening of the band. The ratio of the contribution to the wide band becomes high, and the efficiency of the conductor area versus the wide band is improved.

  In addition, when a plurality of antennas are connected in parallel, the land area for connecting the terminal portions is also required independently for the number of terminal portions, so the area of the antenna module including the margin area increases. . On the other hand, when a plurality of antennas are connected in series, the land portion of the terminal portion connected by the connection conductor is also used as the connection conductor, so that an extra land area and a margin area thereof are unnecessary, Further downsizing is promoted.

  As described above, in an antenna module in which a plurality of antennas are connected to the same power feeding unit in order to realize multiple resonances, a wide band can be achieved with a small conductor area by connecting in series via a connection conductor as in the present invention. It can be realized. That is, the multi-resonance and broadband antenna module can be easily reduced in size.

  At this time, by arranging the antennas on substantially the same straight line, the antenna module 1 having a narrow width direction can be obtained by further utilizing the merit of the effect of shortening the antenna length by using the helical antenna. By making the widths of the conductor 8 and the additional conductor 9 equal to or somewhat larger than the maximum width of the helical antennas 2 and 3, downsizing in the width direction is realized. For this reason, it is possible to realize an antenna module that is suitable when a reduction in the width direction is required as compared with the length direction. The advantage of using an antenna that can shorten the length of a helical antenna is utilized.

  Note that the plurality of antennas may be arranged in a form that is not substantially collinear, and may be determined according to the form of the board to be mounted, other components, and the housing to be stored. Even in this case, downsizing can be realized by sharing a conductor that generates a capacitive component.

  FIG. 5 shows an antenna module in which the helical antennas 2 and 3 are bent at the connection conductor 8. In this way, the connecting conductor 8 is bent, and the antenna module is accommodated in an area where the width direction and the length direction are relatively similar to each other, so that it can be appropriately adapted to other mounting parts, the housing, and the board shape. Is also suitable.

  Next, a case where there are three helical antennas (that is, there are a first antenna, a second antenna, and a third antenna) will be described with reference to FIGS.

  FIG. 6 is a configuration diagram of the antenna module according to Embodiment 1 of the present invention, and FIG. 7 is an equivalent circuit diagram of the antenna module shown in FIG.

  Reference numeral 14 denotes a helical antenna, which is a third antenna. The helical antenna 14 is disposed between the helical antennas 2 and 3, that is, a third antenna is disposed between the first antenna and the second antenna. Reference numerals 15 and 16 denote terminal portions. 8a and 8b are connection conductors, the connection conductor 8a electrically connects the helical antenna 2 and the helical antenna 14, and the connection conductor 8b electrically connects the helical antenna 14 and the helical antenna 3. is there. The connection conductors 8a and 8b are also preferably used as solder lands for mounting the terminal portions 5, 15, 16, and 7, respectively. The connection conductors 8a and 8b are formed of a pattern, a metal surface, a solder surface, or the like. Similarly to the case where the two helical antennas are connected, the connection conductors 8a and 8b and the additional conductor 9 are accommodated within a width that does not exceed the maximum width of the helical antenna or a width that slightly exceeds the width of the antenna module 1. The area in the direction can be reduced.

  Next, the operation of the antenna module 1 will be described using an equivalent circuit shown in FIG.

Since three helical antennas are arranged and each is connected by a connecting conductor, three inductor components and three capacitance components are connected in series. L1 is an inductor component generated from the helical portion due to the trimming groove of the helical antenna 2, L2 is an inductor component generated from the helical portion due to the trimming groove of the helical antenna 14, and L3 is an inductor generated from the helical portion due to the trimming groove of the helical antenna 3. It is an ingredient. C1 is a capacitance component generated from the connection conductor 8a, C2 is a capacitance component generated from the connection conductor 8b, and C3 is a capacitance component generated from the additional conductor 9.

  As is apparent from the equivalent circuit, in this antenna module, the highest frequency resonance frequency based on the resonance condition determined from L1 and C1, and the resonance frequency that is an intermediate frequency based on the resonance condition determined from L1, L2, and C1C2. , L1, L2, L3 and three resonance frequencies of the resonance frequency which is the lowest frequency based on the resonance condition determined from C1, C2, and C3. Furthermore, since the connection conductors 8a and 8b and the additional conductor 9 are shared as a conductor that generates a capacitive component in common, the capacitive component necessary for widening the bandwidth can be increased efficiently. Thereby, compared with the case where the helical antennas are connected in parallel to achieve multiple resonance and the additional conductors are independently connected to the respective helical antennas, the efficiency of the conductor area and the generated capacitance component becomes higher. Therefore, the capacity component generated by a small conductor area can be maximized, and the multi-resonance and wideband antenna module can be very miniaturized. In addition, by arranging the helical antennas 2, 3, and 14 on substantially the same straight line, it is suitable for incorporation in a device having a low mounting margin in the width direction compared to the length direction. Of course, when the mounting margin in the length direction is low, it is also preferable to cope by connecting the helical antennas 2, 3, and 14 by bending them at the positions of the respective connection conductors 8a and 8b.

  Next, FIG. 8 shows a comparison of the experimental results with the conventional antenna module in the case where the connection conductor is connected in series through such a connection conductor, and the connection conductor is shared as a capacitance component to achieve a reduction in size and a wider band. This will be described with reference to FIGS.

  8A is a mobile phone mounting diagram of the antenna module of the present invention, FIG. 8B is a VSWR diagram of the antenna module of the present invention, and FIG. 8C is a list showing the gain of the antenna module of the present invention. FIG. 8D is a directivity diagram of the antenna module of the present invention. Similarly, FIG. 9A and FIG. 10A are mounting diagrams of a conventional antenna module on a mobile phone, FIG. 9B and FIG. 10B are VSWR diagrams of the conventional antenna module, and FIG. FIG. 10C is a list showing gains of the conventional antenna module, and FIG. 9D and FIG. 10D are directivity diagrams of the conventional antenna module.

  9 shows the results when the performance is improved by increasing the size of the antenna, and FIG. 10 shows the results when the area is the same as that of the present invention.

  As is apparent from FIG. 8A, the antenna module of the present invention connects two helical antennas in series via a connecting conductor to realize two resonances and a broad band. On the other hand, in the conventional antenna module, two helical antennas are connected in parallel, and additional conductors are formed individually to realize two resonances and a broad band. As is clear from the comparison between FIG. 8A and FIG. 9A, the mounting area of the antenna module of the present invention is small, which is about 60% of that of the conventional antenna module.

As is clear from FIGS. 8B and 9B, there are two frequency peaks, and two resonances are realized. Furthermore, almost the same bandwidth is realized at the same VSWR value. Further, as is clear from FIGS. 8C and 9C, the gain at a certain frequency is almost the same between the antenna module of the present invention and the conventional antenna module. Further, as is apparent from FIGS. 8D and 9D, the directivity between the antenna module of the present invention and the conventional antenna module is comparable. That is, it can be seen that the antenna module of the present invention that can achieve downsizing of nearly 40% is not inferior to the conventional antenna module in performance, and is rather high in gain and the like.

  Further, as is apparent from FIGS. 10A to 10D, when the present invention is downsized to the same extent, the gain is not sufficient in the frequency band, and the bandwidth cannot be sufficiently increased. I understand that. As is clear from the VSWR diagram of FIG. 10B, the frequency band at the positions where the VSWR values are 1 to 3 is very small compared to the case of the present invention shown in FIG. 8B. It can be seen that the desired broadband is not sufficient. Also, the gain itself is insufficient.

  As is clear from the experimental results, the antenna module of the present invention can be miniaturized in order to achieve multiple resonances and achieve the same or higher gain, directivity, and bandwidth. It is clear that downsizing of the electronic equipment incorporating the can also be realized.

  Of course, when the antennas are connected in parallel as in the prior art and the additional conductors are individually formed, if the area is the same as that of the present invention, the bandwidth becomes insufficient, and the performance of the present invention is also reduced. The advantage of the antenna module is clear.

  With the above configuration, it is possible to promote a wide band while realizing an antenna module having multiple resonances in a very small size.

  In addition, although the above was demonstrated about the case where a helical antenna was used, for example, any of a winding type helical antenna in which a copper wire is wound around a base, a meander-shaped pattern antenna, a conductor antenna formed from a conductor, etc. The same applies to an antenna.

(Embodiment 2)
Next, using FIG. 11, FIG. 12, FIG. 13, and FIG.

  11, 12, and 13 are configuration diagrams of the antenna module according to Embodiment 2 of the present invention, and FIG. 14 is an equivalent circuit diagram of the antenna module of FIG.

  Reference numeral 20 denotes a capacitive conductor, and the capacitive conductor 20 is provided on the bottom surface of either or both of the spiral groove 11 and the spiral groove 12 of the helical antennas 2 and 3. For example, in the mounting substrate on which the antenna module is mounted, a conductor that generates a capacitive component such as solder, a substrate pattern, or a metal film is formed in advance on a portion corresponding to the bottom surface of the spiral grooves 11 and 12, and then the helical antenna 2 3 is implemented. In FIG. 11, it is formed on the bottom surface of the spiral groove 11 of the helical antenna 2, in FIG. 12, it is formed on the bottom surface of the spiral groove 12 of the helical antenna 3, and in FIG. 13, the bottom surface of both spiral grooves 11, 12 of the helical antennas 2, 3. Formed. The capacitive conductor 20 extends from the additional conductor 9 and is conductive.

  In this way, by disposing the capacitive conductors on the bottom surfaces of the spiral grooves 11 and 12 that generate the inductor components of the helical antennas 2 and 3, the spiral grooves 11 and 12 and the capacitive conductor 20 are not directly electrically connected. Although it is conductive but very close, it is capacitively coupled to the equivalent circuit diagram shown in FIG.

  C10 is a capacitive component mainly generated from the connecting conductor 8, C11 is a capacitive component mainly generated from the additional conductor 9, C12 is a capacitive component mainly generated from the capacitive conductor 20, L10 is generated from the spiral groove 11, and L11 is generated from the spiral groove 12. This is the inductor component. As apparent from FIG. 14, the capacitive component C12 of the capacitive conductor 20 also contributes as a capacitive component in the whole.

  Here, the total combined capacity is expressed by the following (Equation 3).

  As is clear from (Equation 3), if the value of C12 is increased, the combined capacitance value C is increased, and the increased capacitance value further promotes the broadband. The same applies to the cases of FIGS. 11 and 13.

  As described above, it is possible to realize a wider band by efficiently utilizing the gap portion between the helical antenna and the substrate that is generated when the helical antenna is mounted on the substrate.

  In addition, although the above was demonstrated about the case where a helical antenna was used, for example, any of a winding type helical antenna in which a copper wire is wound around a base, a meander-shaped pattern antenna, a conductor antenna formed from a conductor, etc. The same applies to an antenna.

(Embodiment 3)
FIG. 15 is a configuration diagram of an electronic device according to Embodiment 3 of the present invention. The electronic device shown in FIG. 15 is a notebook personal computer, a mobile terminal, a mobile phone, or the like, and the antenna module described in Embodiments 1 and 2 is incorporated as a communication antenna.

  30 is a housing, 31 is an antenna module, 32 is a high-frequency circuit, 33 is a processing circuit, 34 is a control circuit, and 35 is a power source.

  The housing 30 is, for example, a mobile phone housing or a notebook computer housing. Further, a display unit, a memory unit, a hard disk, an external storage medium, and the like which are not shown in FIG. 15 may be included.

  The antenna module 31 is the antenna module described in the first or second embodiment, and here, a case where a helical antenna is used is shown.

  The high-frequency circuit performs a process of supplying a high-frequency signal current to the antenna module or detecting a high-frequency signal received by the antenna module 31. Power amplifier necessary for transmission, low noise amplifier used for reception, transmission / reception selector switch, noise removal filter, frequency selection filter, detection circuit, mixer, etc. are included, each of which is a discrete element or part of it Or all are realized by an integrated circuit.

  The processing circuit 33 performs signal processing of the signal received by the high frequency circuit, performs signal regeneration, and further processes a signal for transmission. These are realized by an LSI or the like. That is, the received signal is detected, demodulated, and reproduced.

The demodulated data is subjected to error detection as necessary. For example, error detection is performed by a cyclic code check (hereinafter referred to as “CRC”), a parity code, or the like. Specifically, a match between the parity code attached on the transmission side and the even parity or odd parity of the actually demodulated data is detected. Alternatively, it is detected by dividing the demodulated data by the generator polynomial and confirming the remainder. When an error is detected, processing such as requesting retransmission of data is performed.

  Alternatively, error correction may be performed by Viterbi decoding or Reed-Solomon decoding. In this case, since the detected error can be corrected, a data retransmission request or the like becomes unnecessary, resulting in an increase in reception performance.

  The control circuit 34 includes a CPU for controlling the entire electronic device, and executes time control, synchronization control, processing procedure control for each circuit, and the like. For example, it is executed by a program executed by the CPU. A battery pack or the like is used as the power source 35, and power is supplied to an internal circuit and a display unit.

  Since portable terminals such as mobile phones and PDAs or notebook personal computers, which are examples of such electronic devices, are required to be extremely small and thin, the antenna module 31 is the first embodiment. As explained in 2, the miniaturization contributes to the miniaturization of the device. In the case of a mobile phone, it is necessary to process a plurality of resonance frequencies such as a 900 MHz GSM band, a 1.8 GHz DCS band, and a 1.9 GHz GSM1900 band with a single device. In addition, as the amount of data increases, a wider band is also required. For example, in 1.8 GHz and 1.9 GHz, both the 900 MHz band, 1.8 GHz, and 1.9 GHz bands can be obtained by the antenna module 31 including two antennas by enabling reception at one resonance band. Can be covered. For this reason, it is possible to cover these three frequency bands by connecting the antennas in series via the connection conductors, efficiently forming the capacitive conductors, and realizing a wide band.

  In addition, in a wireless LAN used in a notebook personal computer or the like, it is possible to support both 2.4 GHz and 5 GHz. In this case as well, the miniaturization can be promoted.

  Moreover, since the longitudinal direction can be shortened by using a helical antenna in the antenna module 31, it is possible to reduce the size of the device by connecting on a straight line, reducing the area in the width direction, and packing in the length direction. It is also suitable. Of course, the reverse is also possible.

  With such an electronic device, transmission / reception of necessary signals and modulation / demodulation / reproduction thereof are executed, and transmission / reception in a wide band with multiple resonances becomes possible, and downsizing of the electronic device is also realized.

(Embodiment 4)
FIG. 16 is a configuration diagram of a diversity apparatus according to Embodiment 4 of the present invention.

  Using two or more antenna modules, a signal having higher received power is selected from received signals to improve reception performance, or signals are combined to improve reception performance.

  Reference numeral 40 denotes a selection unit, 41 denotes a detection unit, 42 denotes a power calculation unit, 43 denotes a demodulation unit, and 44 and 45 denote antenna modules. There are two antenna modules.

The power detected by the detector 41 is calculated by the power calculator 42. The calculated power is compared with an arbitrary threshold value, and the result is notified to the selection unit 40. If it is lower than the arbitrary threshold value, the antenna modules 44 and 45 are switched to another antenna module that is currently used for reception and selected for reception. If it is higher than the arbitrary threshold value, the reception is continued with the currently received antenna module.

  Eventually, the signal received by the selected antenna module is demodulated by the demodulator 43, and the reception performance can be improved.

  It is also preferable to perform combining diversity for improving reception performance by combining signals instead of selection. In this case, a synthesis unit may be provided instead of the selection unit 40.

  For example, by combining and demodulating the maximum ratio according to the power ratio calculated by the power calculation unit 42, the C / N ratio (carrier-to-noise ratio) that causes reception performance is increased, and reception performance is increased. be able to.

  In addition, since noise is uncorrelated, a characteristic improvement of at least about 3 dB can be realized even with simple synthesis.

  As described above, it is possible to improve reception performance by performing selection diversity and synthesis diversity using multiple antenna modules. Even in this case, multi-resonance and broadband are realized, and the antenna module is small. Thus, there is an advantage that there is little obstruction of downsizing of the electronic device when storing a plurality of antenna modules.

  The present invention is provided on one of a number of antennas, a connection conductor provided between antennas connecting a plurality of antennas in series, and a terminal portion not connected to the connection conductors in a plurality of antennas connected in series. A power supply section, an additional conductor provided on the other side of the terminal section not connected to the connection conductor, and a capacitive conductor connected to the additional conductor, the connection conductor connecting a plurality of antennas in a substantially straight line. The additional conductor is an open end, and the capacitive conductor extends from the additional conductor to a mounting surface facing the at least one antenna among the plurality of antennas, so that the connection conductor is connected at the connection portion connecting the plurality of antennas. By using the connection conductor, the connection conductor has a capacitance component, and the Q component of the antenna module is lowered by the capacitance component of the connection conductor, and it is necessary to realize a wide band. It can also be applied to the Applications.

DESCRIPTION OF SYMBOLS 1 Antenna module 2, 3, 14 Helical antenna 4, 5, 6, 7, 15, 16 Terminal part 8, 8a, 8b Connection conductor 9 Additional conductor 10 Feed part 11, 12 Spiral groove 13 Feed point 20 Capacitance conductor 30 Housing 31 Antenna module 32 High frequency circuit 33 Processing circuit 34 Control circuit 35 Power supply 40 Selection unit 41 Detection unit 42 Power calculation unit 43 Demodulation unit 44, 45 Antenna module 100 Antenna module 101 Meander antenna 102 Feed unit 103 Additional conductor

Claims (7)

Multiple antennas,
A connection conductor provided between the antennas connecting the plurality of antennas in series;
A power feeding portion provided on one of the terminal portions not connected to the connection conductor in the plurality of antennas connected in series;
An additional conductor provided on the other side of the terminal portion not connected to the connection conductor;
A capacitive conductor conducted to the additional conductor;
The connecting conductor connects the plurality of antennas in a substantially straight line,
The additional conductor is an open end;
The antenna module, wherein the capacitive conductor extends from the additional conductor to a mounting surface facing at least one of the plurality of antennas. 2. The antenna module according to claim 1, wherein the additional conductor and the connection conductor have a width greater than a width of the antenna connected thereto. The first antenna,
A second antenna,
A connection conductor connecting the first antenna and the second antenna in series;
A feeding portion provided at a terminal portion facing the terminal portion to which the connection conductor is connected in the first antenna;
An additional conductor provided in a terminal portion facing the terminal portion to which the connection conductor is connected in the second antenna;
A capacitive conductor conducted to the additional conductor;
The connecting conductor connects the plurality of antennas in a substantially straight line,
The additional conductor is an open end;
The antenna module, wherein the capacitive conductor extends from the additional conductor to a mounting surface facing at least one of the first antenna and the second antenna. 4. The antenna according to claim 3, wherein a width of the additional conductor is larger than a width of the second antenna, and a width of the connection conductor is larger than widths of the first antenna and the second antenna. module. The antenna module according to claim 3, wherein the first antenna and the second antenna have different resonance frequencies. The antenna module according to claim 5, wherein a resonance frequency of the first antenna is higher than a resonance frequency of the second antenna. The antenna module according to claim 1, wherein the capacitive conductor is integral with the additional conductor.

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