JP2008017384A - Antenna device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna device for acquiring a fixed gain regardless of a distance to a conductor. <P>SOLUTION: Radiation owing to currents directly flowing from an antennal element 105 which is strong in radio wave radiation, and affected by the size or shape of a ground board 101 to the ground board 101 is suppressed by a balance/unbalance conversion circuit 103, and when the antenna device approaches a conductor, the decrease of radiation from a loop antenna part 105c results in the increase of radiation from first and second linear antenna parts 105a and 105b, and the decrease of radiation from first and second linear antenna parts 105a and 105b results in the increase of radiation from a loop antenna 105c. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an antenna device including a loop antenna.

  In recent years, in order to ensure information security, wireless personal authentication technology has been developed. Specifically, a user possesses a wireless communication device, and an object such as a personal computer, a mobile phone, or a car is provided with the wireless communication device, and authentication is always performed wirelessly. When the object enters a certain range around the user, the object can be controlled. When the user is out of a certain range, the control of the object is disabled.

  In order to determine whether or not there is an object in a certain range around the user, it is necessary to measure the distance between the object and the user with a wireless communication device during wireless authentication communication.

  As the simplest distance measurement method, there is a measurement based on the received electric field strength. The distance can be measured using a wireless communication device for wireless authentication without requiring a special circuit for distance measurement.

  However, since the user possesses the wireless communication device, the gain of the mounted antenna is strongly influenced by a conductor such as a human body. Also, when used in a multipath environment, it is affected by fading.

  For the above reasons, the reception electric field strength suddenly decreases due to the surrounding environment, and the relationship between the distance and the reception electric field strength that the reception electric field strength decreases as the distance increases collapses, and the accuracy of distance measurement greatly deteriorates. To do.

Conventionally, as a method of avoiding the influence of the conductor on the antenna, a loop antenna having a structure in which the loop surface is perpendicular to the conductor is used in order to prevent the gain from rapidly decreasing even when the conductor approaches the antenna. There was a method to use (see Patent Document 1). Further, as a method for preventing the influence of fading, there is a method of radiating different polarization components (see Patent Document 1 and Patent Document 2).
JP 2000-244219 A JP 2005-105609 A

  However, in the conventional method, the gain of the antenna changes depending on whether the conductor is close to the antenna or away from the antenna. Therefore, a constant antenna gain cannot be obtained regardless of the distance from the antenna to the conductor. Therefore, even if the influence of fading can be avoided, a variation in antenna gain due to the distance to the conductor cannot be avoided.

 In view of the above-described conventional problems, an object of the present invention is to provide an antenna device capable of obtaining a constant gain regardless of the distance to a conductor.

In order to solve the above problems, an antenna device of the present invention is provided with a ground plate having a ground conductor, and is connected to an unbalanced feeding means provided on the ground plate and provided on the ground plate to balance unbalanced signals. An antenna device comprising a balance-unbalance conversion circuit for converting to a signal and an antenna element having a full length of one or less wavelengths of radio waves to be transmitted and received, wherein the antenna element protrudes from the ground plate and is connected to the ground plate. A first linear antenna unit that is provided in parallel with the ground plane, connected to one of the balanced terminals of the balanced-unbalanced conversion circuit, and made of a linear conductor having a predetermined length; and protrudes from the ground plate, And a linear conductor having a predetermined length provided in parallel with the ground plate, connected to the other balanced terminal of the balanced-unbalanced conversion circuit, and disposed substantially parallel to the first linear antenna unit. A second linear assembly consisting of A tenor portion and a loop surface that protrudes from the ground plate and is formed so as to be substantially perpendicular to the surface of the ground plate, one end is connected to the first linear antenna portion, and the other end Is connected to the second linear antenna portion, and is composed of a loop antenna portion made of a loop-shaped conductor, and the balance-unbalance conversion circuit strongly emits radio waves, and the size and shape of the ground plate When the radiation from the loop antenna portion decreases when the antenna device is close to a conductor while suppressing radiation due to current flowing directly from the antenna element influenced by the antenna element to the ground plate, the first and second lines When the radiation from the linear antenna section increases and the radiation from the first and second linear antenna sections decreases, the radiation from the loop antenna section operates to increase.

  As described above, the present invention suppresses the radiation caused by the current flowing directly from the antenna element to the ground plate, which is difficult to adjust and is greatly affected by the size and shape of the ground plate, by the balanced / unbalanced conversion circuit. The structure of the antenna element is a combination of a loop antenna and a linear antenna that change in gain when approaching the conductor, and by setting the dimensions of each part of the antenna element to a predetermined value, the antenna device and the conductor It is possible to realize an antenna device that obtains a constant gain of a combined polarization component regardless of the distance between the two.

  A first invention includes a ground plate having a ground conductor, and a balanced / unbalanced conversion circuit that is provided on the ground plate and is connected to unbalanced power feeding means provided on the ground plate and converts an unbalanced signal into a balanced signal. And an antenna element having a total length of one or less wavelengths of radio waves to be transmitted and received, wherein the antenna element protrudes from the ground plate and is provided in parallel with the ground plate, A first linear antenna unit made of a linear conductor having a predetermined length, connected to one of the balanced terminals of the unbalanced conversion circuit, protrudes from the ground plate, and is provided in parallel with the ground plate. The second linear antenna unit, which is connected to the other balanced terminal of the balanced / unbalanced conversion circuit and is made of a linear conductor having a predetermined length and arranged substantially parallel to the first linear antenna unit. And protruding from the ground plate, One loop surface is formed so as to be substantially perpendicular to the surface of the ground plate, one end is connected to the first linear antenna portion, and the other end is connected to the second linear antenna portion. A loop antenna portion made of a loop-shaped conductor, and the grounding plate from the antenna element that is strongly radiated by the balance-unbalance conversion circuit and is influenced by the size and shape of the grounding plate. When radiation from the loop antenna unit decreases when the antenna device is close to a conductor while suppressing radiation due to a current flowing directly to the conductor, radiation from the first and second linear antenna units increases, When the radiation from the first and second linear antenna units decreases, the antenna device operates such that the radiation from the loop antenna unit increases.

  With this configuration, a constant gain can be obtained regardless of the distance between the antenna device and the conductor.

  According to a second invention, in the antenna device of the first invention, the loop antenna portion is provided so that a loop surface of the loop antenna portion is substantially perpendicular to the first and second linear antenna portions, and the loop antenna portion And the first and second linear antenna portions radiate from each other in a substantially orthogonal relationship.

  With this configuration, the antenna element can obtain a polarization diversity effect.

  According to a third aspect of the present invention, in the antenna device according to any one of the first and second aspects, the balanced / unbalanced conversion circuit is connected to one of the unbalanced terminal and the balanced terminal, and the phase of the signal at the unbalanced terminal is approximately 90. A +90 degree phase shifter that is fed forward and supplied to one of the balanced terminals, and connected to the other of the unbalanced terminal and the balanced terminal, and the phase of the signal at the unbalanced terminal is delayed by approximately 90 degrees and supplied to the other of the balanced terminals. An antenna device comprising a -90 degree phase shifter.

  With this configuration, the balance-unbalance conversion circuit can be reduced in size.

  A fourth invention is the antenna device according to any one of the first to third inventions, wherein the lengths and thicknesses of the first and second linear antenna units, the first and second linear antenna units, By setting the distance between them to a predetermined value, the polarization component radiated from the first and second linear antenna portions and the ground plate and the polarization orthogonal to the loop surface radiated from the loop antenna portion are set. The antenna device is characterized in that the polarization component obtained by combining the wave components and the polarization component parallel to the loop surface radiated from the loop antenna unit are set to the same level.

  With this configuration, a constant gain can be obtained regardless of the distance between the antenna device and the conductor.

  According to a fifth invention, in the antenna device according to any one of the first to fourth inventions, the loop antenna unit has a plurality of loop turns, and the distance between the loops of the loop antenna unit and the number of turns are set to a predetermined value. By combining the polarization component radiated from the first and second linear antenna units and the ground plate and the polarization component orthogonal to the loop plane radiated from the loop antenna unit. The antenna device is characterized in that the component and the polarization component parallel to the loop surface radiated from the loop antenna portion are set to the same level.

  With this configuration, a constant gain can be obtained regardless of the distance between the antenna device and the conductor.

  A sixth invention is the antenna device according to any one of the first to fifth inventions, wherein the distance between the loop antenna portion and the ground plate, the width direction of the ground plate, and the length in the longitudinal direction are set to predetermined values. A polarization component obtained by combining a polarization component radiated from the first and second linear antenna units and the ground plate and a polarization component orthogonal to the loop surface radiated from the loop antenna unit, The antenna device is characterized in that the polarization component parallel to the loop surface radiated from the loop antenna unit is set to the same level.

  With this configuration, a constant gain can be obtained regardless of the distance between the antenna device and the conductor.

According to a seventh aspect of the present invention, there are provided a ground plate having a ground conductor, two sets of balanced / unbalanced conversion circuits provided on the ground plate for converting unbalanced signals into balanced signals, and two sets of the balanced / unbalanced converted circuits. Two sets of antenna elements each connected to a balanced terminal and having a total length equal to or less than one wavelength of radio waves to be transmitted and received, an unbalanced feeding means provided on the ground plate, and two sets of the balanced Connected to the unbalanced terminal of the unbalanced conversion circuit, one of the two unbalanced terminals of the balanced / unbalanced conversion circuit is connected to the unbalanced power supply means, or the other is connected to the unbalanced power supply means. The antenna device includes a switch for selectively switching between the two antenna elements, the two antenna elements projecting from the ground plate and provided in parallel with the ground plate. Connect to one of the balanced terminals A first linear antenna unit made of a linear conductor having a predetermined length, and protruding from the ground plate and in parallel with the ground plate, the balanced terminal of the balance-unbalance conversion circuit A second linear antenna portion made of a linear conductor having a predetermined length, connected to the other and disposed substantially parallel to the first linear antenna portion, and protruding from the ground plate and formed A loop surface is provided so as to be substantially perpendicular to the surface of the ground plate, one end is connected to the first linear antenna portion, the other end is connected to the second linear antenna portion, A loop antenna portion made of a loop-shaped conductor, and the two sets of antenna elements are arranged so as to be substantially orthogonal to each other on the surface of the ground plate, and the two sets of the antenna elements are respectively The balance / unbalance conversion circuit Radiation from the loop antenna unit when the antenna device is close to a conductor while suppressing radiation caused by current flowing directly from the antenna element, which is influenced by the size and shape of the ground plate, to the ground plate. Decreases, the radiation from the first and second linear antenna sections increases, and when the radiation from the first and second linear antenna sections decreases, the radiation from the loop antenna section increases. The antenna device is characterized by operating as described above.

  With this configuration, a constant gain can be obtained regardless of the distance between the antenna device and the conductor. Further, even when the distance between the antenna device and the conductor is very short with respect to the wavelength or when it is a multiple of a quarter wavelength, the effect of polarization diversity can be obtained.

  According to an eighth aspect of the present invention, there are provided a ground plate having a ground conductor, two sets of balanced / unbalanced conversion circuits provided on the ground plate for converting unbalanced signals into balanced signals, and two sets of the balanced / unbalanced converted circuits. Two sets of antenna elements each connected to a balanced terminal and having a total length equal to or less than one wavelength of radio waves to be transmitted and received, an unbalanced feeding means provided on the ground plate, and two sets of the balanced 90 degree phase difference connected to the unbalanced terminal of the unbalanced conversion circuit, supplying power to both unbalanced terminals of the two sets of balanced and unbalanced conversion circuits, and supplying power so that the difference in power supply phase is approximately 90 degrees 2 sets of antenna elements each projecting from the ground plate and parallel to the ground plate, and connected to one of the balanced terminals of the balanced-unbalanced conversion circuit Linear with a predetermined length A first linear antenna portion made of a conductor, protruding from the ground plate and parallel to the ground plate, and connected to the other balanced terminal of the balanced-unbalanced conversion circuit; A second linear antenna portion made of a linear conductor having a predetermined length disposed substantially parallel to the antenna portion, and a loop surface protruding from the ground plate and formed with respect to the surface of the ground plate A loop antenna unit having one end connected to the first linear antenna unit, the other end connected to the second linear antenna unit, and a loop-shaped conductor; The two antenna elements are arranged so as to be substantially orthogonal to each other on the surface of the ground plate, and the two antenna elements are radiated by the balance-unbalance conversion circuit, respectively. Strong and support of the ground plate When the radiation from the loop antenna portion decreases when the antenna device is close to a conductor while suppressing radiation due to a current flowing directly from the antenna element, which depends on the shape and shape, to the ground plate, the first and first When the radiation from the second linear antenna portion increases and the radiation from the first and second linear antenna portions decreases, the radiation from the loop antenna portion increases. It is an antenna device.

  With this configuration, the effect of polarization diversity can be obtained regardless of the distance between the antenna device and the conductor, and the switching operation of the switch can be made unnecessary.

  According to a ninth invention, in the antenna device according to any one of the seventh to eighth inventions, two sets of the antenna elements each have a loop surface of the loop antenna unit with respect to the first and second linear antenna units. The antenna device is provided so as to be substantially vertical, and the polarization components radiated from the loop antenna portion and the first and second linear antenna portions are substantially orthogonal to each other.

With this configuration, each of the two sets of antenna elements can obtain a polarization diversity effect.

  A tenth aspect of the invention is the antenna device according to any one of the seventh to ninth aspects, wherein the two sets of balanced / unbalanced conversion circuits are connected to one of the unbalanced terminal and the balanced terminal, respectively, A +90 degree phase shifter that advances the phase by approximately 90 degrees and supplies it to one of the balanced terminals, is connected to the other of the unbalanced terminal and the balanced terminal, and delays the phase of the signal at the unbalanced terminal by approximately 90 degrees to An antenna device comprising a -90 degree phase shifter supplied to the other.

  With this configuration, the two sets of balance-unbalance conversion circuits can be reduced in size.

  An eleventh invention is the antenna device according to any one of the seventh to tenth inventions, wherein the two sets of antenna elements are the length and thickness of the first and second linear antenna portions, respectively, By setting the distance between the second linear antenna parts to a predetermined value, the polarized wave components radiated from the first and second linear antenna parts and the ground plate and the loop antenna part are radiated. An antenna device characterized in that a polarization component obtained by synthesizing a polarization component orthogonal to a loop surface and a polarization component parallel to the loop surface radiated from the loop antenna unit have the same degree. is there.

  With this configuration, a constant gain can be obtained regardless of the distance between the antenna device and the conductor.

  A twelfth aspect of the invention is the antenna device according to any one of the seventh to eleventh aspects, wherein each of the two sets of antenna elements has a plurality of loop turns of the loop antenna part, By setting the distance and the number of turns to predetermined values, the polarization components radiated from the first and second linear antenna units and the ground plate are orthogonal to the loop surface radiated from the loop antenna unit. The antenna device is characterized in that a polarization component obtained by combining polarization components and a polarization component parallel to the loop surface radiated from the loop antenna unit are set to the same level.

  With this configuration, a constant gain can be obtained regardless of the distance between the antenna device and the conductor.

  A thirteenth invention is the antenna device according to any one of the seventh to twelfth inventions, wherein the two sets of antenna elements are respectively a distance between the loop antenna portion and the ground plate, a width direction of the ground plate, and a longitudinal direction. By setting the length to a predetermined value, the polarization component radiated from the first and second linear antenna units and the ground plate and the polarization orthogonal to the loop plane radiated from the loop antenna unit The antenna device is characterized in that the polarization component obtained by combining the components and the polarization component parallel to the loop surface radiated from the loop antenna unit are set to the same level.

  With this configuration, a constant gain can be obtained regardless of the distance between the antenna device and the conductor.

  The best mode for carrying out the antenna of the present invention will be described below with reference to FIGS. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
Details of Embodiment 1 of the antenna device of the present invention will be described below.

FIG. 1 is a diagram illustrating a configuration of an antenna device. X, Y, and Z denote the respective coordinate axes. In FIG. 1, reference numeral 101 denotes a ground plate having a ground conductor.

  Reference numeral 102 denotes a transmission / reception circuit that is provided on the ground plate 101, generates and outputs a transmission signal, and processes an input reception signal. The transmission / reception signal input / output from the transmission / reception circuit 102 is an unbalanced signal.

  103 is provided on the ground plate 101, the unbalanced terminal is connected to the transmission / reception circuit 102, the balanced terminal is connected to a matching circuit 104 (to be described later), and an unbalanced signal from the transmission / reception circuit 102 is converted into a balanced signal to match the matching circuit. 104 is a balance-unbalance conversion circuit to be supplied to 104.

  Reference numeral 104 is provided on the ground plate 101, and is connected to an antenna element 105 described later and a balanced / unbalanced conversion circuit 103. In order to efficiently supply power to the antenna element 105 described later, an antenna element 105 described later and a balanced / unbalanced conversion circuit are provided. 103 is a matching circuit that performs impedance matching between 103.

  An antenna element 105 includes a first linear antenna unit 105a, a second linear antenna unit 105b, and a loop antenna unit 105c, which will be described later.

  105a is a first linear antenna that protrudes from the ground plate 101, is provided in parallel with the ground plate 101, is connected to one of the balanced terminals of the matching circuit 104, and is formed of a linear conductor having a predetermined length. Part.

  105b protrudes from the ground plate 101, is provided in parallel with the ground plate 101, is connected to the other balanced terminal of the matching circuit 104, and is disposed in a predetermined length that is substantially parallel to the first linear antenna portion 105a. It is the 2nd linear antenna part which consists of a linear conductor which has thickness.

  105c protrudes from the ground plate 101 and is formed so that a loop surface to be formed is substantially perpendicular to the surface of the ground plate 101, one end is connected to the first linear antenna portion 105a, and the other end is This is a loop antenna unit that is connected to the second linear antenna unit 105b and includes a rectangular loop-shaped conductor having a plurality of turns.

  The number of turns of the loop of the loop antenna unit 105c is set to a plurality of turns in order to increase the gain of the loop antenna unit 105c, but may be one. Further, the loop shape of the loop antenna unit 105c may not be rectangular.

  The antenna element 105 has a full length equal to or less than one wavelength of radio waves transmitted and received. The antenna element 105 is provided so as to protrude from the ground plate 101 in order to prevent the radiation from the antenna element 105 from being shielded by the ground plate 101.

  The antenna element 105 is provided so that the loop surfaces of the first and second linear antenna portions 105a and 105b and the loop antenna portion 105c are orthogonal to each other.

  FIG. 2 is a diagram illustrating a configuration of the balance-unbalance conversion circuit 103.

  The balance / unbalance conversion circuit 103 includes a +90 degree phase shifter 103a and a −90 degree phase shifter 103b, which will be described later.

  In FIG. 2, 103a is a +90 degree phase shifter that is connected to one of the unbalanced terminal and the balanced terminal and advances the phase of the signal at the unbalanced terminal by approximately 90 degrees and supplies it to one of the balanced terminals.

  The capacitor C1 is connected in series between the unbalanced terminal and the balanced terminal, and the inductor L1 is connected in parallel to the balanced terminal side.

  Reference numeral 103b denotes a -90 degree phase shifter that is connected to the other of the unbalanced terminal and the balanced terminal and delays the phase of the signal at the unbalanced terminal by approximately 90 degrees and supplies the delayed signal to the other balanced terminal.

  The inductor L2 is connected in series between the unbalanced terminal and the balanced terminal, and the capacitor C2 is connected in parallel to the balanced terminal side.

  Since the balance-unbalance conversion circuit 103 can be configured by an inductor or a capacitor that can use chip components, the circuit can be reduced in size as compared with a balance-unbalance conversion circuit using a general transformer.

  The operation of the antenna device configured as described above will be described.

  The transmission signal output from the transmission / reception circuit 102 is converted into a balanced signal by the balance / unbalance conversion circuit 103, impedance-converted by the matching circuit 104, and output to the antenna element 105. The radio wave received by the antenna element 105 is impedance-converted by the matching circuit 104, converted to an unbalanced signal by the balanced / unbalanced converting circuit 103, and input to the transmitting / receiving circuit 102 as a received signal.

  Next, radio wave radiation of the antenna device configured as described above will be described.

  FIG. 3A is a diagram showing the positional relationship between the conductor plate and the loop antenna. FIG. 3B is a diagram showing the relationship between the distance between the loop antenna and the conductor plate and the gain of the loop antenna in the direction opposite to the conductor plate.

  Generally, when the loop surface is perpendicular to the conductor surface, the loop antenna has a high gain when the distance between the loop antenna and the conductor plate is sufficiently short with respect to the wavelength.

  When the distance between the loop antenna and the conductor plate is an odd multiple of a quarter wavelength, the gain is significantly reduced. When the distance between the loop antenna and the conductor plate is an even multiple of a quarter wavelength, the gain is high.

  FIG. 4A is a diagram showing the positional relationship between the conductor plate and the linear antenna. FIG. 4B is a diagram showing the relationship between the distance between the linear antenna and the conductor plate and the gain of the linear antenna in the direction opposite to the conductor plate.

  In general, when the linear antenna is parallel to the conductor surface, the gain is greatly reduced when the distance between the linear antenna and the conductor plate is sufficiently short with respect to the wavelength.

  When the distance between the linear antenna and the conductor plate is an odd multiple of a quarter wavelength, the gain is high. When the distance between the linear antenna and the conductor plate is an even multiple of a quarter wavelength, the gain is greatly reduced.

  FIG. 5 is a diagram showing a positional relationship between the antenna device and a conductor plate 106 described later when a conductor plate 106 described later approaches the antenna device of the present embodiment. Reference numeral 106 denotes a conductor plate made of a plate-like conductor.

Radio waves from the antenna device are emitted from the first and second linear antenna portions 105a and 105b.
Radiation from the ground plate 101, radiation from the ground plate 101, radiation from the loop antenna portion 105c.

  Furthermore, the radiation from the loop antenna unit 105c is composed of a polarization component orthogonal to the loop surface radiated from between the loops and a polarization component parallel to the loop surface radiated from the loop itself. Become.

  The polarization components orthogonal to the first and second linear antenna portions 105a and 105b, the ground plate 101, and the loop surface radiated from the loop antenna portion 105c are all vertically polarized (in the Z-axis direction). This refers to polarization, and so on.

  The polarization component parallel to the loop surface radiated from the loop antenna unit 105c is horizontal polarization (referred to as polarization in the X-axis direction, and so on).

  When the conductor plate 106 is close to the antenna device as shown in FIG. 5, the first and second linear antenna portions 105a and 105b and the ground plate 101 are parallel to the conductor plate 106, and the loop antenna portion 105c is The loop surface is perpendicular to the conductor plate 106.

  Since the portion that radiates the vertically polarized component is parallel to the conductor plate 106, the relationship between the distance between the antenna device and the conductor plate and the gain of the vertically polarized component of the antenna device in the direction opposite to the conductor plate is This is the same as FIG.

  That is, when the distance between the antenna device and the conductor plate is sufficiently short with respect to the wavelength, the gain of the vertically polarized component is greatly reduced.

  When the distance between the antenna device and the conductor plate is an odd multiple of the quarter wavelength, the gain of the vertical polarization component is increased. When the distance between the antenna device and the conductor plate is an even multiple of a quarter wavelength, the gain of the vertically polarized component is greatly reduced.

  Further, since the loop surface of the loop antenna unit 105c that radiates the horizontally polarized component is perpendicular to the conductor plate 106, the distance between the antenna device and the conductor plate and the horizontal deviation of the antenna device in the direction opposite to the conductor plate are obtained. The relationship with the gain of the wave component is the same as in FIG.

  That is, when the distance between the antenna device and the conductor plate is sufficiently short with respect to the wavelength, the gain of the horizontal polarization component becomes high.

  When the distance between the antenna device and the conductor plate is an odd multiple of the quarter wavelength, the gain of the horizontal polarization component is greatly reduced. When the distance between the antenna device and the conductor plate is an even multiple of a quarter wavelength, the gain of the horizontal polarization component is increased.

  Therefore, when the antenna device is close to the conductor plate, when the gain of the horizontal polarization component decreases, the gain of the vertical polarization component increases, and when the gain of the vertical polarization component decreases, the gain of the horizontal polarization component increases. Works to increase.

  FIG. 6A shows the distance between the antenna device of this embodiment and the conductor plate 106 when the gain of the vertical polarization component is higher than the gain of the horizontal polarization component, and the antenna device in the direction opposite to the conductor plate 106. It is a figure which shows the relationship of a gain.

FIG. 6B shows the distance between the antenna device of this embodiment and the conductor plate 106 when the gain of the vertical polarization component is lower than the gain of the horizontal polarization component, and the antenna device in the direction opposite to the conductor plate 106. It is a figure which shows the relationship of a gain.

  FIG. 6C shows the distance between the antenna device of the present embodiment and the conductor plate 106 when the gain of the vertical polarization component is the same as the gain of the horizontal polarization component, and the antenna device in the direction opposite to the conductor plate 106. It is a figure which shows the relationship of a gain.

  The combined polarization component radiated by the antenna device is a combination of the vertical polarization component and the horizontal polarization component.

  As shown in FIG. 6A, when the gain of the vertical polarization component is higher than the gain of the horizontal polarization component, when the distance between the antenna device and the conductor plate is an odd multiple of a quarter wavelength, The gain of the wave component is high.

  As shown in FIG. 6 (b), when the gain of the vertical polarization component is lower than the gain of the horizontal polarization component, when the distance between the antenna device and the conductor plate is an odd multiple of a quarter wavelength, The gain of the wave component is low.

  As shown in FIG. 6C, when the gain of the vertical polarization component is the same as the gain of the horizontal polarization component, the gain of the combined polarization component is constant regardless of the distance between the antenna device and the conductor plate.

  By making the gains of the vertical polarization component and the horizontal polarization component about the same, the combined polarization component becomes constant regardless of the distance between the antenna device and the conductor plate 106.

  Since the antenna element 105 is balancedly fed by the balance-unbalance conversion circuit 103, the radiation due to the current flowing directly from the antenna element 105 to the ground plate 101 is very small. Radiation from the ground plate 101 is mainly due to current induced in the ground plate 101 by radiation from the antenna element 105. Therefore, the radiation from the ground plate 101 is smaller than the radiation from the antenna element 105. Radio waves from the entire antenna device are mainly emitted by the antenna element 105.

  Therefore, by setting the dimension of each part of the antenna element 105 to a predetermined value, the gains of the vertical polarization component and the horizontal polarization component can be made comparable.

  FIG. 7 is a diagram showing the relationship between the length A of the linear antenna units 105a and 105b and the average gain of the XY plane of the antenna device.

  The frequency is 426 MHz, the distance B between the linear antenna parts 105a and 105b is 5 mm, the thickness W of the linear antenna parts 105a and 105b is 1 mm, the number of turns of the loop antenna part 105c is 2, the size is 20 mm × 2 mm, and between the loops The calculated distance P is 0.5 mm, the size of the ground plate 101 is 22 mm (T) × 23 mm (L), and the distance C between the loop antenna portion 105 c and the ground plate 101 is a calculated value when it is 12.5 mm.

  FIG. 8 is a diagram showing the relationship between the thickness W of the linear antenna units 105a and 105b and the average gain of the XY plane of the antenna device.

  The frequency is 426 MHz, the length A of the linear antenna parts 105a and 105b is 5 mm, the distance B between the linear antenna parts 105a and 105b is 5 mm, the number of turns of the loop antenna part 105c is 2, the size is 20 mm × 2 mm, and between the loops The calculated distance P is 0.5 mm, the size of the ground plate 101 is 22 mm (T) × 23 mm (L), and the distance C between the loop antenna portion 105 c and the ground plate 101 is a calculated value when it is 12.5 mm.

  FIG. 9 is a diagram illustrating the relationship between the distance B between the linear antenna units 105a and 105b and the average gain of the XY plane of the antenna device.

  The frequency is 426 MHz, the length A of the linear antenna parts 105a and 105b is 5 mm, the thickness W is 1 mm, the number of turns of the loop antenna part 105c is 2, the size is 20 mm × 2 mm, and the distance P between the loops is 0.5 mm. The size of the ground plate 101 is a calculated value when the size is 22 mm (T) × 23 mm (L), and the distance C between the loop antenna portion 105 c and the ground plate 101 is 12.5 mm.

  When the length A and thickness W of the linear antenna portions 105a and 105b and the distance B between the linear antenna portions 105a and 105b increase, radiation from the linear antenna portions 105a and 105b increases, so that the horizontal polarization The component is almost constant, but the vertical polarization component increases. That is, by setting the length A and thickness W of the linear antenna units 105a and 105b and the distance B between the linear antenna units 105a and 105b to predetermined values, the vertical polarization component and the horizontal polarization The component gain can be made comparable.

  FIG. 10 is a diagram showing the relationship between the distance P between loops of the loop antenna unit 105c and the average gain of the XY plane of the antenna device.

  The frequency is 426 MHz, the length A of the linear antenna portions 105a and 105b is 1.5 mm, the thickness W is 1 mm, the distance B between the linear antenna portions 105a and 105b is 1 mm, the number of turns of the loop antenna portion 105c is 2, The size is a calculated value when the size is 20 mm × 2 mm, the size of the ground plate 101 is 22 mm (T) × 23 mm (L), and the distance C between the loop antenna portion 105 c and the ground plate 101 is 3.5 mm.

  FIG. 11 is a diagram showing the relationship between the number of turns of the loop antenna unit 105c and the average gain of the XY plane of the antenna device.

  The frequency is 426 MHz, the length A of the linear antenna portions 105a and 105b is 1.5 mm, the thickness W is 1 mm, the distance B between the linear antenna portions 105a and 105b is 1 mm, and the size of the loop antenna portion 105c is 20 mm × 2 mm. The distance P between the loops is 0.5 mm, the size of the ground plate 101 is 22 mm (T) × 23 mm (L), and the distance C between the loop antenna portion 105 c and the ground plate 101 is 3.5 mm. It is.

  When the distance P between the loops of the loop antenna unit 105c increases, the vertical polarization component radiated from between the loops increases, so the horizontal polarization component is substantially constant, but the vertical polarization component increases.

  When the number of turns of the loop antenna unit 105c increases, both the vertical and horizontal polarization components increase, but the vertical polarization component has a larger degree of increase than the horizontal polarization component.

  By setting the distance P between the loops of the loop antenna unit 105c and the value of the number of turns to predetermined values, the gains of the vertical polarization component and the horizontal polarization component can be made comparable.

  FIG. 12 is a diagram showing the relationship between the distance C between the loop antenna unit 105c and the ground plate 101 and the average gain of the XY plane of the antenna device.

The frequency is 426 MHz, the length A of the linear antenna portions 105a and 105b is 1.5 mm, the thickness W is 1 mm, the distance B between the linear antenna portions 105a and 105b is 1 mm, the number of turns of the loop antenna portion 105c is 2, This is a calculated value when the size is 20 mm × 2 mm, the distance P between the loops is 0.5 mm, and the size of the ground plate 101 is 22 mm (T) × 23 mm (L).

  FIG. 13 is a diagram showing the relationship between the length T of the ground plate 101 and the average gain of the XY plane of the antenna device.

  The frequency is 426 MHz, the length A of the linear antenna portions 105a and 105b is 1.5 mm, the thickness W is 1 mm, the distance B between the linear antenna portions 105a and 105b is 1 mm, the number of turns of the loop antenna portion 105c is 2, The size is 20 mm × 2 mm, the distance P between the loops is 0.5 mm, the length L of the ground plate 101 is 23 mm, and the distance C between the loop antenna portion 105 c and the ground plate 101 is a calculated value when it is 3.5 mm. is there.

  When the distance C between the loop antenna portion 105c and the ground plate 101 increases, the radiation due to the current induced in the ground plate 101 decreases, so the horizontal polarization component is substantially constant, but the vertical polarization component decreases.

  When the length T of the ground plate 101 is changed, the area of the ground plate 101 changes, and the magnitude of radiation caused by the current induced in the ground plate 101 changes. Therefore, the horizontal polarization component is almost constant, but the vertical The polarization component changes.

  By setting the distance C between the loop antenna unit 105c and the ground plate 101, the width direction of the ground plate 101, and the length in the longitudinal direction to predetermined values, the gains of the vertical polarization component and the horizontal polarization component are made approximately the same. can do.

  As described above, the balance-unbalance conversion circuit 103 suppresses the radiation due to the current flowing directly from the antenna element 105 to the ground plate 101, which is strongly radiated, difficult to adjust, and greatly influenced by the size and shape of the ground plate 101. The structure of the element 105 is a structure in which a loop antenna that changes in gain when approaching a conductor and a linear antenna are combined, and the dimensions of each part of the antenna element 105 are set to predetermined values, whereby the antenna device and the conductor It is possible to realize an antenna device that obtains a constant gain of a combined polarization component regardless of the distance between the two.

  In addition, when the polarization components of the linear antenna units 105a and 105b and the loop antenna unit 105c are orthogonal to each other, both vertical and horizontal polarization components are included, so that the effect of polarization diversity can be obtained.

  Even when the linear antenna units 105a and 105b and the loop antenna unit 105c radiate the same polarization component, the gains of the linear antenna units 105a and 105b and the loop antenna unit 105c with respect to the distance between the antenna device and the conductor plate 106 are obtained. Therefore, an antenna device that obtains a constant combined polarization component gain can be realized regardless of the distance between the antenna device and the conductor.

  In addition, regardless of the distance between the antenna device and the conductor, the length A and the thickness W of the linear antenna portions 105a and 105b and the distance B between the linear antenna portions 105a and 105b are set to predetermined values. An antenna device that obtains a constant gain of a combined polarization component can be realized.

  It should be noted that the antenna device that obtains a constant gain of the combined polarization component regardless of the distance between the antenna device and the conductor by setting the distance P between the loops of the loop antenna unit 105c and the number of turns to a predetermined value. Can be realized.

Note that the distance C between the loop antenna unit 105c and the ground plate 101, the width direction of the ground plate 101,
By setting the length in the longitudinal direction to a predetermined value, it is possible to realize an antenna device that obtains a constant gain of the combined polarization component regardless of the distance between the antenna device and the conductor.

(Embodiment 2)
Details of the second embodiment of the antenna device of the present invention will be described below.

  FIG. 14 is a diagram illustrating a configuration of the antenna device. X, Y, and Z denote the respective coordinate axes. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and differences will be mainly described.

  The difference from the first embodiment is that a balance / unbalance conversion circuit 203, a matching circuit 204, and an antenna element 205, which will be described later, are provided, a balance / unbalance conversion circuit 103, a balance / unbalance conversion circuit 203 and a transmission / reception circuit 102, which will be described later, A switch 206 described later is provided between the two. Further, a control signal for controlling a switch 206 described later is output from the transmission / reception circuit 102.

  In FIG. 14, 203 has the same configuration as the balanced / unbalanced conversion circuit 103, provided on the ground plate 101, an unbalanced terminal is connected to a switch 206 described later, and a balanced terminal is connected to a matching circuit 204 described later. This is a balanced / unbalanced conversion circuit that converts an unbalanced signal from a switch 206 (to be described later) into a balanced signal and supplies it to the matching circuit 204.

  204 is provided on the ground plate 101 and is connected to an antenna element 205 and a balanced / unbalanced conversion circuit 203 (to be described later). In order to efficiently supply power to the antenna element 205 (to be described later), an antenna element 205 and a balanced / unbalanced conversion circuit (to be described later). 203 is a matching circuit that performs impedance matching with the terminal 203.

  Reference numeral 205 denotes an antenna element having the same configuration as that of the antenna element 105, and includes a first linear antenna unit 205a, a second linear antenna unit 205b, and a loop antenna unit 205c, which will be described later.

  Reference numeral 205a denotes a first linear antenna that protrudes from the ground plate 101 and is provided in parallel with the ground plate 101, is connected to one of the balanced terminals of the matching circuit 204, and includes a linear conductor having a predetermined length. Part.

  205b protrudes from the ground plate 101 and is provided in parallel with the ground plate 101, is connected to the other balanced terminal of the matching circuit 204, and is disposed in a predetermined length that is substantially parallel to the first linear antenna portion 205a. It is the 2nd linear antenna part which consists of a linear conductor which has thickness.

  205c protrudes from the ground plate 101 and is formed so that the loop surface to be formed is substantially perpendicular to the surface of the ground plate 101. One end is connected to the first linear antenna portion 205a and the other end is This is a loop antenna unit that is connected to the second linear antenna unit 205b and includes a rectangular loop-shaped conductor having a plurality of turns.

  The number of windings of the loop of the loop antenna unit 205c is a plurality of windings in order to increase the gain of the loop antenna unit 205c, but may be one. Further, the loop shape of the loop antenna unit 205c may not be rectangular.

  The antenna element 205 has a full length equal to or shorter than one wavelength of radio waves transmitted and received. In order to prevent radiation from the antenna element 205 from being shielded by the ground plate 101, the antenna element 205 is provided so as to protrude from the ground plate 101.

  The antenna element 205 is provided so that the loop surfaces of the first and second linear antenna portions 205a and 205b and the loop antenna portion 205c are orthogonal to each other.

  The antenna element 205 is provided in a direction orthogonal to the antenna element 105 on the XZ plane.

  206 is provided on the ground plate 101 and is connected to the unbalanced terminals of the transmission / reception circuit 102 and the balance / unbalance conversion circuits 103 and 203, and based on the control signal output from the transmission / reception circuit 102, the balance / unbalance conversion circuit 103, This switch selectively switches whether one of the 203 unbalanced terminals supplies the transmission / reception signal from the transmission / reception circuit 102 or the other supplies the transmission / reception signal from the transmission / reception circuit 102.

  The operation of the antenna device configured as described above will be described.

  The transmission signal output from the transmission / reception circuit 102 is output to one of the balance-unbalance conversion circuits 103 and 203 based on the control signal input to the switch 206.

  The signal is converted into a balanced signal by the balanced / unbalanced conversion circuit 103 or 203, impedance-converted by the matching circuit 104 or 204, and output to the antenna element 105 or 205.

  The radio wave received by the antenna element 105 or 205 is impedance-converted by the matching circuit 104 or 204, converted to an unbalanced signal by the balanced / unbalanced conversion circuit 103 or 203, and based on the control signal input to the switch 206. Any one of the balance-unbalance conversion circuits 103 and 203 is input to the transmission / reception circuit 102 as a reception signal.

  Antenna diversity is performed by switching power supply to the antenna element 105 and the antenna element 205 with the switch 206.

  Next, radio wave radiation of the antenna device configured as described above will be described.

  FIG. 15 is a diagram showing a positional relationship between the antenna device of this embodiment and the conductor plate 106.

  The emission of radio waves when power is supplied to the antenna element 105 is as in the first embodiment.

  Since the antenna element 205 is provided in a direction orthogonal to the antenna element 105 on the XZ plane, the radiation of radio waves when feeding power to the antenna element 205 is performed. The polarization components orthogonal to the radiation from the ground plate 101 and the loop surface radiated from the loop antenna unit 205c are all horizontally polarized.

  The polarization component parallel to the loop surface radiated from the loop antenna unit 205c is vertical polarization.

  FIG. 16A is a diagram showing the relationship between the distance between the antenna device of the present embodiment and the conductor plate 106 when power is supplied to the antenna element 105 and the gain of the antenna device in the direction opposite to the conductor plate 106.

FIG. 16B is a diagram showing the relationship between the distance between the antenna device of the present embodiment and the conductor plate 106 when power is supplied to the antenna element 205 and the gain of the antenna device in the direction opposite to the conductor plate 106.

  As in the first embodiment, when the dimensions of each part of the antenna element 105 are set to predetermined values and the gains of the vertical polarization component and the horizontal polarization component are set to the same level, as shown in FIG. In addition, when feeding power to the antenna element 105, a constant gain of the combined polarization component is obtained regardless of the distance between the antenna device and the conductor plate 106.

  Similarly, when the dimension of each part of the antenna element 205 is set to a predetermined value and the gains of the vertical polarization component and the horizontal polarization component are set to the same level, as shown in FIG. When power is supplied to the antenna, a constant gain of the combined polarization component is obtained regardless of the distance between the antenna device and the conductor plate 106.

  In addition, regardless of the distance between the antenna device and the conductor plate 106, the polarization component radiated from the antenna device when feeding to the antenna element 105 and the polarization component radiated from the antenna device when feeding to the antenna element 205 are: In an orthogonal relationship.

  As described above, a constant gain of the combined polarization component can be obtained regardless of the distance between the antenna device and the conductor, and the antenna element 205 similar to the antenna element 105 can be connected to the antenna element 105 in the XZ plane. If the distance between the antenna device and the conductor is sufficiently short with respect to the wavelength or a multiple of a quarter wavelength, one of the vertical and horizontal polarized waves is greatly attenuated. Even in this case, since the planes of polarization of the antenna element 105 and the antenna element 205 are orthogonal to each other, the effect of polarization diversity can be obtained.

(Embodiment 3)
Details of Embodiment 3 of the antenna device of the present invention will be described below.

  FIG. 17 is a diagram illustrating a configuration of the antenna device. X, Y, and Z denote the respective coordinate axes. In the present embodiment, the same configurations as those of the second embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and differences will be mainly described.

  The difference from the second embodiment is that a 90-degree phase difference distributor 301 described later is provided instead of the switch 206.

  301 is provided on the ground plate 101 and is connected to the unbalanced terminals of the transmission / reception circuit 102 and the balance / unbalance conversion circuits 103 and 203, and the transmission / reception signal from the transmission / reception circuit 102 is sent to the unbalanced terminals of the balance / unbalance conversion circuits 103 and 203. This is a 90-degree phase difference distributor that supplies power to both of them and supplies power so that the difference in power supply phase is approximately 90 degrees.

  The operation of the antenna device configured as described above will be described.

  The transmission signal output from the transmission / reception circuit 102 is output to the balance / unbalance conversion circuits 103 and 203 by the 90-degree phase difference distributor 301.

  The signal is converted into a balanced signal by balanced / unbalanced conversion circuits 103 and 203, impedance-converted by matching circuits 104 and 204, and output to antenna elements 105 and 205.

The radio waves received by the antenna elements 105 and 205 are impedance-converted by the matching circuits 104 and 204, converted into unbalanced signals by the balance-unbalance conversion circuits 103 and 203, and these signals are converted into a 90-degree phase difference distributor 301. The transmission / reception circuit 102
As a received signal.

  Next, radio wave radiation of the antenna device configured as described above will be described.

  The antenna elements 105 and 205 are fed with a phase difference of 90 degrees by a phase difference distributor 301 of 90 degrees. Further, the polarization planes of the antenna element 105 and the antenna element 205 are orthogonal to each other, and both vertical and horizontal polarized waves are generated even if the distance between the antenna elements 105 and 205 and the conductor is changed as shown in FIG. Therefore, the antenna device radiates a constant circular polarization regardless of the distance from the conductor.

  As described above, regardless of the distance between the antenna device and the conductor, the effect of polarization diversity can be obtained, and the switching operation of the switch by the control signal from the transmission / reception circuit 102 can be made unnecessary.

  The antenna device of the present invention can obtain a constant gain regardless of the distance from the conductor. Therefore, the antenna device of the present invention can be applied as an antenna device mounted on a wireless communication device built in a device that needs to ensure security by distance.

The block diagram which shows the antenna apparatus in Embodiment 1 of this invention The block diagram which shows the balance-unbalance conversion circuit 103 in Embodiment 1 of this invention (A) The figure which shows the positional relationship of the conductor plate and loop antenna in Embodiment 1 of this invention (b) The distance of the loop antenna and conductor plate in Embodiment 1 of this invention, and the loop of a direction opposite to a conductor plate Diagram showing antenna gain relationship (A) The figure which shows the positional relationship of the conductor plate and linear antenna in Embodiment 1 of this invention (b) The distance of the linear antenna and conductor plate in Embodiment 1 of this invention, and a direction opposite to a conductor plate Of gain relationship of linear antennas The figure which shows the positional relationship of the antenna apparatus and the conductor board 106 when the conductor board 106 in Embodiment 1 of this invention adjoins an antenna apparatus. (A) The distance between the antenna device of the present invention and the conductor plate 106 when the gain of the vertical polarization component in the first embodiment of the present invention is higher than the gain of the horizontal polarization component, and the antenna in the direction opposite to the conductor plate 106 FIG. 5B is a diagram illustrating the relationship between the gains of the device. The distance between the antenna device of the present invention and the conductor plate 106 when the gain of the vertical polarization component in the first embodiment of the present invention is lower than the gain of the horizontal polarization component; FIG. 8C is a diagram showing the gain relationship of the antenna device in the direction opposite to the conductor plate 106. FIG. 10C shows the antenna device of the present invention when the gain of the vertical polarization component in Embodiment 1 of the present invention is the same as the gain of the horizontal polarization component. The figure which shows the relationship between the distance with the conductor board 106, and the gain of the antenna apparatus of a direction opposite to the conductor board 106 The figure which shows the relationship between the length A of the linear antenna parts 105a and 105b in Embodiment 1 of this invention, and the average gain of the XY plane of an antenna apparatus. The figure which shows the relationship between the thickness W of the linear antenna parts 105a and 105b in Embodiment 1 of this invention, and the average gain of the XY plane of an antenna apparatus. The figure which shows the relationship between the distance B between the linear antenna parts 105a and 105b in Embodiment 1 of this invention, and the average gain of the XY plane of an antenna apparatus. The figure which shows the relationship between the distance P between the loops of the loop antenna part 105c in Embodiment 1 of this invention, and the average gain of the XY plane of an antenna apparatus. The figure which shows the relationship between the winding number of the loop antenna part 105c in Embodiment 1 of this invention, and the average gain of the XY plane of an antenna apparatus. The figure which shows the relationship between the distance C of the loop antenna part 105c and the ground plate 101 in Embodiment 1 of this invention, and the average gain of the XY plane of an antenna apparatus. The figure which shows the relationship between the length T of the ground plate 101 in Embodiment 1 of this invention, and the average gain of the XY plane of an antenna apparatus. The block diagram which shows the antenna apparatus in Embodiment 2 of this invention The figure which shows the positional relationship of the antenna device and the conductor board 106 in Embodiment 2 of this invention. (A) The figure which shows the relationship between the distance of the antenna apparatus and the conductor board 106 at the time of electric power feeding to the antenna element 105 in Embodiment 2 of this invention, and the gain of the antenna apparatus of the opposite direction to the conductor board 106 (b) this invention The figure which shows the relationship between the distance of the antenna apparatus and the conductor board 106 at the time of electric power feeding to the antenna element 205 in Embodiment 2, and the gain of the antenna apparatus of the opposite direction to the conductor board 106 The block diagram which shows the antenna apparatus in Embodiment 3 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Ground plate 102 Transmission / reception circuit 103 Balance / unbalance conversion circuit 103a +90 degree phase shifter 103b -90 degree phase shifter 104 Matching circuit 105 Antenna element 105a 1st linear antenna part 105b 2nd linear antenna part 105c Loop antenna Part 106 Conductor plate 203 Balance / unbalance conversion circuit 204 Matching circuit 205 Antenna element 205a First linear antenna part 205b Second linear antenna part 205c Loop antenna part 206 Switch 301 90 degree phase difference distributor

Claims (13)

A ground plate having a ground conductor;
A balanced-unbalanced conversion circuit that is provided on the ground plate, connected to unbalanced power supply means provided on the ground plate, and converts an unbalanced signal into a balanced signal;
An antenna element whose overall length is one wavelength or less of radio waves transmitted and received,
An antenna device comprising:
The antenna element is
A first linear antenna that protrudes from the ground plate and is provided in parallel with the ground plate, is connected to one of balanced terminals of the balanced-unbalanced conversion circuit, and includes a linear conductor having a predetermined length. And
A predetermined length protruding from the ground plate and provided in parallel with the ground plate, connected to the other balanced terminal of the balanced-unbalanced conversion circuit, and disposed substantially parallel to the first linear antenna unit. A second linear antenna portion made of a linear conductor having a thickness;
A loop surface that protrudes from the ground plate and is formed so as to be substantially perpendicular to the surface of the ground plate, one end is connected to the first linear antenna portion, and the other end is the second A loop antenna portion connected to the linear antenna portion and made of a loop-shaped conductor;
Consisting of
By the balance-unbalance conversion circuit, the radiation of radio waves is strong, and the radiation due to the current flowing directly from the antenna element, which is influenced by the size and shape of the ground plate, is suppressed,
When radiation from the loop antenna unit decreases when the antenna device is close to a conductor, radiation from the first and second linear antenna units increases, and the first and second linear antenna units When the radiation from the antenna decreases, the antenna device operates so that the radiation from the loop antenna portion increases. A loop surface of the loop antenna portion is provided so as to be substantially perpendicular to the first and second linear antenna portions;
2. The antenna device according to claim 1, wherein the polarization components radiated from the loop antenna unit and the first and second linear antenna units are substantially orthogonal to each other. The balance-unbalance conversion circuit is
A +90 degree phase shifter that is connected to one of the unbalanced terminal and the balanced terminal, advances the phase of the signal of the unbalanced terminal by approximately 90 degrees, and supplies the signal to one of the balanced terminals;
A -90 degree phase shifter connected to the other of the unbalanced terminal and the balanced terminal, the phase of the signal of the unbalanced terminal being delayed by approximately 90 degrees and supplied to the other of the balanced terminals;
The antenna device according to claim 1, wherein the antenna device is configured as follows. By setting the length and thickness of the first and second linear antenna portions and the distance between the first and second linear antenna portions to predetermined values,
A polarization component obtained by synthesizing a polarization component radiated from the first and second linear antenna portions and the ground plate and a polarization component orthogonal to the loop surface radiated from the loop antenna portion;
A polarization component parallel to the loop surface radiating from the loop antenna portion,
The antenna device according to any one of claims 1, 2, and 3, wherein the antenna device has the same degree. The loop antenna unit has a plurality of loop turns,
By setting the distance between the loops of the loop antenna unit and the number of turns to a predetermined value, the polarization components radiated from the first and second linear antenna units and the ground plate and the loop antenna unit A polarization component obtained by combining polarization components orthogonal to the radiating loop surface;
A polarization component parallel to the loop surface radiating from the loop antenna portion,
The antenna device according to any one of claims 1, 2, 3, and 4, wherein the antenna device has the same degree. By setting the distance between the loop antenna part and the ground plate, the width direction of the ground plate, and the length in the longitudinal direction to a predetermined value,
A polarization component obtained by synthesizing a polarization component radiated from the first and second linear antenna portions and the ground plate and a polarization component orthogonal to the loop surface radiated from the loop antenna portion;
A polarization component parallel to the loop surface radiating from the loop antenna portion,
The antenna device according to any one of claims 1, 2, 3, 4, and 5, characterized in that the antenna devices have the same degree. A ground plate having a ground conductor;
Two sets of balanced-unbalanced conversion circuits that are provided on the ground plate and convert unbalanced signals to balanced signals, and are connected to balanced terminals of the two sets of balanced-unbalanced conversion circuits, respectively, and the total length of radio waves transmitted and received Two sets of antenna elements having one wavelength or less;
Provided on the ground plate, connected to the unbalanced power supply means provided on the ground plate and unbalanced terminals of the two sets of balanced / unbalanced conversion circuits, and connected to unbalanced terminals of the two sets of balanced / unbalanced conversion circuits. A switch for selectively switching between connecting one of the unbalanced power supply means and the other to the unbalanced power supply means,
An antenna device provided with two sets of the antenna elements,
A first linear antenna that protrudes from the ground plate and is provided in parallel with the ground plate, is connected to one of balanced terminals of the balanced-unbalanced conversion circuit, and includes a linear conductor having a predetermined length. And
A predetermined length protruding from the ground plate and provided in parallel with the ground plate, connected to the other balanced terminal of the balanced-unbalanced conversion circuit, and disposed substantially parallel to the first linear antenna unit. A second linear antenna portion made of a linear conductor having a thickness;
A loop surface that protrudes from the ground plate and is formed so as to be substantially perpendicular to the surface of the ground plate, one end is connected to the first linear antenna portion, and the other end is the second A loop antenna portion connected to the linear antenna portion and made of a loop-shaped conductor;
Consisting of
Two sets of the antenna elements are arranged so as to be substantially orthogonal to each other on the surface of the ground plate,
Each of the two sets of antenna elements suppresses radiation due to current flowing directly from the antenna element to the ground plate, which is strongly radiated by the balance-unbalance conversion circuit and is influenced by the size and shape of the ground plate. ,
When radiation from the loop antenna unit decreases when the antenna device is close to a conductor, radiation from the first and second linear antenna units increases, and the first and second linear antenna units When the radiation from the antenna decreases, the antenna device operates so that the radiation from the loop antenna portion increases. A ground plate having a ground conductor;
Two sets of balanced / unbalanced conversion circuits which are provided on the ground plate and convert unbalanced signals to balanced signals, and are connected to balanced terminals of the two sets of balanced / unbalanced converted circuits, respectively, and the total length of radio waves transmitted and received Two sets of antenna elements having one wavelength or less;
Provided on the ground plate, connected to unbalanced power supply means provided on the ground plate and unbalanced terminals of the two sets of balanced-unbalanced conversion circuits,
A 90-degree phase difference distributor that feeds power to both unbalanced terminals of the two sets of balanced-unbalanced conversion circuits and feeds so that the difference in feeding phase is approximately 90 degrees;
An antenna device provided with two sets of the antenna elements,
A first linear antenna that protrudes from the ground plate and is provided in parallel with the ground plate, is connected to one of balanced terminals of the balanced-unbalanced conversion circuit, and includes a linear conductor having a predetermined length. And
A predetermined length protruding from the ground plate and provided in parallel with the ground plate, connected to the other balanced terminal of the balanced-unbalanced conversion circuit, and disposed substantially parallel to the first linear antenna unit. A second linear antenna portion made of a linear conductor having a thickness;
A loop surface that protrudes from the ground plate and is formed so as to be substantially perpendicular to the surface of the ground plate, one end is connected to the first linear antenna portion, and the other end is the second A loop antenna portion connected to the linear antenna portion and made of a loop-shaped conductor;
Consisting of
Two sets of the antenna elements are arranged so as to be substantially orthogonal to each other on the surface of the ground plate,
Each of the two sets of antenna elements suppresses radiation due to current flowing directly from the antenna element to the ground plate, which is strongly radiated by the balance-unbalance conversion circuit and is influenced by the size and shape of the ground plate. ,
When radiation from the loop antenna unit decreases when the antenna device is close to a conductor, radiation from the first and second linear antenna units increases, and the first and second linear antenna units The antenna apparatus operates so that radiation from the loop antenna portion increases when radiation from the antenna decreases. Each of the two sets of antenna elements is provided such that the loop surface of the loop antenna portion is substantially perpendicular to the first and second linear antenna portions,
9. The antenna device according to claim 7, wherein the polarization components radiated from the loop antenna unit and the first and second linear antenna units are substantially orthogonal to each other. Each of the two sets of balance-unbalance conversion circuits is
A +90 degree phase shifter that is connected to one of the unbalanced terminal and the balanced terminal, advances the phase of the signal of the unbalanced terminal by approximately 90 degrees, and supplies the signal to one of the balanced terminals;
A -90 degree phase shifter connected to the other of the unbalanced terminal and the balanced terminal, the phase of the signal of the unbalanced terminal being delayed by approximately 90 degrees and supplied to the other of the balanced terminals;
The antenna device according to any one of claims 7, 8, and 9, characterized by comprising: By setting the length and thickness of the first and second linear antenna portions and the distance between the first and second linear antenna portions to predetermined values, respectively, ,
A polarization component obtained by synthesizing a polarization component radiated from the first and second linear antenna portions and the ground plate and a polarization component orthogonal to the loop surface radiated from the loop antenna portion;
A polarization component parallel to the loop surface radiating from the loop antenna portion,
The antenna device according to any one of claims 7, 8, 9, and 10, characterized by having the same degree. Each of the two sets of antenna elements has a plurality of loop turns of the loop antenna unit,
By setting the distance between the loops of the loop antenna unit and the number of turns to a predetermined value, the polarization components radiated from the first and second linear antenna units and the ground plate and the loop antenna unit A polarization component obtained by combining polarization components orthogonal to the radiating loop surface;
A polarization component parallel to the loop surface radiating from the loop antenna portion,
The antenna device according to any one of claims 7, 8, 9, 10, and 11, wherein the antenna device has the same degree. By setting the distance between the loop antenna part and the grounding plate, the width direction of the grounding plate, and the length in the longitudinal direction to a predetermined value for each of the two sets of the antenna elements,
A polarization component obtained by synthesizing a polarization component radiated from the first and second linear antenna portions and the ground plate and a polarization component orthogonal to the loop surface radiated from the loop antenna portion;
A polarization component parallel to the loop surface radiating from the loop antenna portion,
The antenna device according to any one of claims 7, 8, 9, 10, 11, and 12, wherein the antenna device has the same degree.

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