JP2006229294A - Variable directional antenna system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reception system whereby a variable directional antenna system receives a plurality of desired radio waves arriving in various directions, and a composed signal is transmitted through one transmission line. <P>SOLUTION: Dipole antennas 4, 6, 8, 10 are arranged in a main body 2 so as to have directivity in different directions, directivity adjustment circuits 42, 44, 46, 48 provided in the main body 2 adjust and compose output signals of the antennas 4, 6, 8, 10 so that each composite signal is a signal principally corresponding to radio waves arrived respectively in desired directions. Frequency converters 60a to 60d provided in the main body 2 corresponding to the directivity adjustment circuits 42, 44, 46, 48 apply frequency conversion to the output signals from the directivity adjustment circuits 42, 44, 46, 48 into output signals with frequency bands assigned respectively to them and different from each other. A composite unit 64 provided in the main body 2 composes the output signals from the frequency converters 60a to 60d and outputs the composed output signals. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a variable directional antenna device capable of receiving radio waves coming from a desired direction and a receiving system using the same.

  Conventionally, as the variable directivity antenna device as described above, for example, there is one disclosed in Patent Document 1. In this antenna device, a main body and a lid that covers the opening of the main body are provided. Four sets of Yagi antennas are provided in the main body. Of the four sets, two sets of Yagi antennas are arranged on one virtual straight line passing through the main body so as to have directivity in opposite directions. The remaining two sets of Yagi antennas are arranged so as to have directivity in opposite directions on different virtual lines orthogonal to the virtual line. By adjusting and synthesizing the received signals of these four sets of Yagi antennas, a synthesized signal mainly corresponding to radio waves coming from a desired direction is output.

JP 2001-36327 A

  However, this variable directivity antenna device can output only an output signal mainly corresponding to radio waves from a specific direction selected from various directions. By the way, in a place where an antenna is installed, it may be desired to receive radio waves arriving from a plurality of different directions. In order to meet this demand with the variable directional antenna device, a plurality of the variable directional antenna devices must be installed.

  An object of the present invention is to enable reception of a plurality of desired radio waves from radio waves arriving from various directions by a single variable directivity antenna system.

  The variable directivity antenna system according to the present invention has a main body. A plurality of antennas are accommodated in the main body, and these antennas show directivity in different directions. As these antennas, for example, directional antennas such as a dipole antenna and a Yagi antenna can be used. A plurality of directivity adjusting means are provided in the main body. Each of the plurality of directivity adjusting means is supplied with an output signal of each antenna. Each directivity adjustment unit adjusts the supplied output signal of each antenna, adjusts the amplitude level and / or phase, for example, and synthesizes and outputs the result. This adjustment is performed so that the corresponding combined signal is a signal mainly corresponding to radio waves coming from a desired direction. The directivity adjusting means can be adjusted independently of each other. A plurality of frequency converting means are provided in the main body corresponding to each directivity adjusting means. These frequency conversion means frequency-convert the output signals from the corresponding directivity adjustment means into output signals in different frequency bands assigned to the respective frequency conversion means. A synthesizing means is provided in the main body. The synthesizing unit synthesizes and outputs the output signals from the frequency converting units.

  If comprised in this way, the signal mainly corresponding to the electromagnetic wave which arrives from a different direction from each direction will be output from each directivity adjustment means by adjusting each directivity adjustment means independently. These signals are frequency-converted by frequency conversion means into signals of different frequency bands and synthesized. Therefore, this synthesized signal is composed of signals that receive radio waves from different directions and do not overlap in frequency. Therefore, the output signal of the combining means can be transmitted through one transmission line.

  Each of the directivity adjusting means can adjust the synthesized signal so as to mainly correspond to a selected one of a plurality of radio waves arriving toward the main body from different directions. In this case, variable filters are respectively provided between the directivity adjusting means and the frequency converting means corresponding to each other. The variable filter is preferably a band pass filter that can change the pass band. The pass bands of these variable filters are adjusted so as to pass the selected radio wave signal.

  In this way, by providing a variable filter between the directivity adjusting means and the frequency converting means and appropriately adjusting the passband, only the signal output from the directivity adjusting means can be supplied to the frequency converting means. it can. Moreover, since the variable filter can change the pass band, the directivity adjusting means outputs a signal mainly corresponding to the radio wave from a certain direction, and the radio wave of a different frequency from the other direction. Even if it is switched to the state of outputting the output signal corresponding mainly to the variable signal, only the output signal for the main can be passed to the radio wave from the other direction and supplied to the frequency conversion means.

  The plurality of antennas may include first to fourth antennas. In this case, the first and second antennas are arranged in parallel with a distance therebetween, and the third and fourth antennas are spaced from each other so as to intersect and orthogonally intersect with the first and second antennas. Are arranged in parallel. Thus, since the first and second antennas and the third and fourth antennas are crossed and accommodated in the main body, the main body can be reduced in size.

  Each of the first to fourth antennas can be a dipole antenna. In this case, each directivity adjusting means includes a phase adjusting means for adjusting the phase between the signals of the first and second antennas, and a phase adjusting means for adjusting the phase between the signals of the third and fourth antennas. And an amplitude adjusting means for adjusting the amplitude of the signals of the first to fourth antennas adjusted in phase.

  If comprised in this way, if the signal of both these antennas was synthesize | combined by adjusting the phase between the signals of the 1st and 2nd antenna, the virtual synthetic | combination signal will be the arrangement direction of the 1st and 2nd antennas The radio wave mainly corresponds to the radio wave in one direction selected from both sides. If the signals of both antennas were synthesized by adjusting the phase between the signals of the third and fourth antennas, the virtual synthesized signal was selected from both sides of the arrangement direction of the third and fourth antennas. The signal mainly corresponds to radio waves in one direction. These two virtual composite signals mainly correspond to radio waves from two orthogonal directions. Then, by adjusting the amplitudes of the first to fourth antennas that have been phase-adjusted so as to be equivalent to appropriately adjusting the amplitudes of these two virtual combined signals, the actual combined signal becomes the orthogonality thereof. The signal mainly corresponds to radio waves from a desired direction between the two directions.

  The receiving system according to the present invention includes the above-described variable directivity antenna device, and further, one transmission line transmits the output signal of the combining means of this antenna device. The output signal of the combining means transmitted through this transmission line is supplied to a plurality of receiving means. Each receiving means is configured to be able to receive the assigned one of the output signals of each frequency converting means.

  As described above, according to the present invention, a plurality of radio waves arriving from different directions can be received by one variable directivity antenna device, and signals corresponding to these radio waves can be transmitted by a single transmission line. It becomes possible.

  The variable directivity antenna apparatus according to one embodiment of the present invention has a main body 2 schematically shown in FIG. The main body 2 has an octagonal planar shape, and a plurality of, for example, four sets of directional antennas, for example, first to fourth dipole antennas 4, 6, 8, 10 are accommodated therein. The first to fourth dipole antennas 4, 6, 8, and 10 are for receiving television broadcasts in the UHF band, for example. The first to fourth dipole antennas 4, 6, 8, and 10 have antenna elements 4a, 4b, 6a, 6b, 8a, 8b, 10a, and 10b arranged in a straight line, respectively. The first dipole antenna 4 has feeding terminals 12a and 12b at the inner ends of the antenna elements 4a and 4b, and the second dipole antenna 6 has a feeding terminal 14a at the inner ends of the antenna elements 6a and 6b. 14b, the third dipole antenna 8 has feeding terminals 16a and 16b at the inner ends of the antenna elements 8a and 8b, and the fourth dipole antenna 10 is the inner part of the antenna elements 10a and 10b. Power supply terminals 18a and 18b are provided at one end.

  The first dipole antenna 4 is arranged in parallel with the virtual line 20 on one side of the virtual line 20 passing through the center of the main body 2. The second dipole antenna 6 is disposed on the other side of the virtual line 20 in parallel with the virtual line 20. In the first and second dipole antennas 4 and 6, feed terminals 12 a, 12 b, 14 a, and 14 b are located on both sides of a virtual line 22 orthogonal to the virtual line 20. The first and second dipole antennas 4 and 6 are both located at a predetermined first distance from the virtual line 20.

  The third dipole antenna 8 passes through the center of the main body 2 and intersects the virtual line 20, for example, is disposed in parallel with the virtual line 22 on one side of the orthogonal virtual line 22. The fourth dipole antenna 10 is disposed on the other side of the virtual line 22 in parallel with the virtual line 22. In the third and fourth dipole antennas 8 and 10, feed terminals 16 a, 16 b, 18 a, and 20 b are located on both sides of the virtual line 20. The third and fourth dipole antennas 8 and 10 are both located at a first distance from the virtual line 22.

  The first and second dipole antennas 4 and 6 show a figure eight directivity in the direction along the imaginary line 22, and the third and fourth dipole antennas 8 and 10 have eight directions in the direction along the imaginary line 20. Shows character directivity.

  Signals received by the first to fourth dipole antennas 4, 6, 8, and 10 are supplied to the circuit board 24 through the power supply terminals 12a, 12b, 14a, 14b, 16a, 16b, 18a, and 18b. . The circuit board 24 is arranged in the center of the main body 2 in a non-contact state with the first to fourth dipole antennas 4, 6, 8, 10.

  As shown in FIG. 1, amplifiers 26, 28, 30, and 32 that amplify signals received by the first to fourth dipole antennas 4, 6, 8, and 10 are provided on the circuit board 24. . The output signals of these amplifiers 26, 28, 30, and 32 are supplied to distributing means, for example, four distributors 34, 36, 38, and 40, and are distributed into a plurality. For example, 4 distributions are made.

  Distribution outputs of the distributors 34, 36, 38, and 40 are supplied to a plurality of, for example, four directivity adjusting means, for example, directivity adjusting circuits 42, 44, 46, and 48. Since these directivity adjustment circuits 42, 44, 46, and 48 have the same configuration, only the directivity adjustment circuit 42 will be described in detail.

  The directivity adjustment circuit 42 includes a phase shifter 50a to which the distribution output a1 of the first dipole antenna 4 is supplied from the distributor 34. Similarly, the directivity adjustment circuit 42 includes phase shifters 50b, 50c, and 50d to which the distributed outputs a2, a3, and a4 of the second, third, and fourth dipole antennas 6, 8, and 10 are supplied. Yes.

  The phase relationship between the received signals of the first and second dipole antennas 4 and 6 is adjusted by the phase shifters 50a and 50b. The adjustment is performed as follows. As shown in FIG. 3A, the first and second dipole antennas 4 and 6 have an 8-shaped directivity in a direction along the virtual line 22 (a direction orthogonal to the virtual line 20). Consider a case in which radio waves arrive from the direction indicated by the arrow A (the direction from the second dipole antenna 6 toward the first dipole antenna 4) toward the dipole antennas 4 and 6. When both received signals are combined with the phase of the received signal of the first dipole antenna 4 in reverse phase with respect to the received signal of the second dipole antenna 6 by this radio wave, the two cancel each other. That is, the combined antenna of the first and second dipole antennas 4 and 6 has no directivity in the direction A, and conversely, in the direction of the arrow B (from the first dipole antenna 4 to the second dipole antenna 6). Direction). When both signals are synthesized with the phase of the received signal of the second dipole antenna 6 opposite to that of the received signal of the first dipole antenna 4 by the radio wave from the direction A, they cancel each other and the first And the synthetic | combination antenna of the 2nd dipole antenna 4 and 6 does not have directivity in the direction B, but has directivity in the arrow A direction.

  By adjusting the phase shifters 50a and 50b so as to be either of the above two cases, the direction of directivity of the combined antenna of the first and second dipole antennas 4 and 6 is set to the direction A or B. be able to.

  Since it can be inferred from the above description, the detailed description is omitted, but the phase relationship between the received signals of the third and fourth dipole antennas 8 and 10 is adjusted by the phase shifters 50c and 50d. ), The directionality of the combined antenna of the third and fourth dipole antennas 8 and 10 is set to a direction C (direction from the third dipole antenna 8 to the fourth dipole antenna 10) or a direction D (fourth). In the direction from the dipole antenna 10 to the third dipole antenna 8).

The received signals of the first to fourth dipole antennas 4, 6, 8, and 10 that have undergone phase adjustment by the phase shifters 50a, 50b, 50c, and 50d as described above are amplitude adjusters 52a, 52b, 52c, The amplitude is adjusted by 52d. This amplitude adjustment is performed as follows. For example, the phase adjustment is performed, and the combined reception signal of the first and second dipole antennas 4 and 6 whose directivity is directed in the direction B is, for example, a combined signal b as illustrated in FIG. A combined received signal of the third and fourth dipole antennas 8 and 10 whose characteristics are directed in the direction D is defined as a combined signal d. The amplitudes of these synthesized signals b and d are multiplied by k1 to the amplitude of the synthesized signal b and the amplitude of the synthesized signal d is multiplied by k2 (however, the values of k1 and k2 so that the square root of k1 ² + k2 ² is 1). When the two are combined, the combined directivity of the first to fourth dipole antennas 4, 6, 8, and 10 can be directed to any direction between the direction B and the direction D. For example, when the combined signals b and d are respectively multiplied by 2 to ^1/2 , the combined signal mainly corresponds to radio waves arriving from the direction E of 45 degrees between the directions B and D with respect to both. It becomes. That is, the combined directivity of the first and fourth dipole antennas 4, 6, 8, 10 is directed in the direction E.

  Similarly, in the state where the combined directivity of the first and second dipole antennas 4 and 6 is directed in the direction B and the combined directivity of the third and fourth dipole antennas 8 and 10 is provided in the direction D, The direction of the combined directivity of the first and second dipole antennas is B, the direction of the combined directivity of the third and fourth dipole antennas is C, and the direction of the combined directivity of the first and second dipole antennas , A, the direction of the combined directivity of the third and fourth dipole antennas as D, the direction of the combined directivity of the first and second dipole antennas as A, the combination of the third and fourth dipole antennas With the direction of directivity set to C, the combined signal of the first and second dipole antennas 4 and 6 is multiplied by k1, and the combined signal of the third and fourth dipole antennas 8 and 10 is multiplied by k2. First The combined directivity of the optimum fourth dipole antenna 4, 6, 8, 10 may be oriented in any direction as shown in FIG.

  Therefore, the amplitude adjusters 52a and 52b multiply the amplitude of the output signals of the phase shifters 50a and 50b by k1, and the amplitude adjusters 52c and 52d multiply the amplitude of the output signals of the phase shifters 50c and 50d by k2. The output signals of these amplitude adjusters 52a, 52b, 52c, and 52d are synthesized by the synthesizer 54.

  The phase shifters 50a to 50d and the amplitude adjusters 52a to 52d described above are controlled in association with each other by the control unit 56a. In the other directivity adjusting circuits 44, 46 and 48, the directivity is controlled by the control units 56b to 56d. Accordingly, although only the first to fourth dipoles 4, 6, 8, and 10 are used, the directivity adjustment circuits 42, 44, 46, and 48 are adjusted by appropriately adjusting the control units 56a to 56d. Thus, signals corresponding mainly to radio waves arriving from different directions are output.

  The output signals from these directivity adjusting circuits 42, 44, 46, 48 are sent through corresponding variable filters 58a, 58b, 58c, 58d to corresponding frequency conversion means, for example, frequency converters 60a, 60b, 60c, 60d.

  The variable filters 58a, 58b, 58c, and 58d can change their passbands based on control signals from the corresponding control units 56a, 56b, 56c, and 56d. The pass bands of the variable filters 58a, 58b, 58c, and 58d are adjusted by the controllers 56a to 56d so that the output signals from the corresponding directivity adjustment circuits 42, 44, 46, and 48 are passed. Therefore, even if the directivity is adjusted by each directivity adjustment circuit 42, 44, 46, 48, and output signals corresponding to radio waves of different frequencies are output from each directivity adjustment circuit 42, 44, 46, 48, Only these output signals can be supplied to the corresponding frequency converters 60a, 60b, 60c, 60d.

  Each frequency converter 60a, 60b, 60c, 60d converts the output signal of the corresponding variable filter 58a, 58b, 58c, 50d into a signal of a different frequency assigned to each frequency converter 60a, 60b, 60c, 60d. Convert frequency. For example, the frequency converter 60a frequency-converts the input output signal of the variable filter 58a into a signal of a predetermined channel α, and the frequency converter 60b determines the input signal of the variable filter 58b that has been determined in advance. The frequency converter 60c converts the frequency of the input variable filter 58c into a predetermined channel γ signal, and the frequency converter 60d receives the input variable filter 58d. Is frequency-converted into a predetermined channel θ signal.

  As described above, since the frequency of the output signal of the variable filters 58a, 58b, 58c, 58d supplied to the frequency converters 60a, 60b, 60c, 60d may change, the frequency converters 60a, 60b, It is necessary to change the oscillation frequency of the local oscillator included in 60c and 60d. This change is performed by the corresponding control units 56a, 56b, 56c, and 56d.

  The output signals of the respective frequency converters 60a, 60b, 60c, 60d are supplied to the synthesizing means, for example, the synthesizer 64, through the corresponding fixed filters 62a, 62b, 62c, 62d, and synthesized. The fixed filter 62a selects the channel α signal, the fixed filter 62b selects the channel β signal, the fixed filter 62c selects the channel γ signal, and the fixed filter 62d selects the channel θ signal mainly. Has been. As a result, unnecessary signal components can be removed.

  The combined output signal of the combiner 64 is supplied to distribution means for distributing the combined output signal into a plurality of, for example, four distributors 68 via one transmission line, for example, the coaxial cable 66. From the four distributors 68, distribution outputs are supplied to receiving means, for example, the respective receivers 70a, 70b, 70c, and 70d. The receivers 70a, 70b, 70c, and 70d are provided in the same number as the frequency converters 60a, 60b, 60c, and 60d. The receiver 70a is configured to receive channel α, the receiver 70b is configured to receive channel β, the receiver 70c is configured to receive channel γ, and the receiver 70d is capable of receiving channel θ. It is configured. Therefore, the receiver 70a can receive a signal corresponding to a radio wave coming from the direction of directivity adjusted by the directivity adjustment circuit 42. The receiver 70b can receive a signal corresponding to the radio wave from the directionality adjusted by the directivity adjustment circuit 44. The receiver 70c can receive a signal corresponding to the radio wave from the directivity direction adjusted by the directivity adjustment circuit 46. The receiver 70d can receive a signal corresponding to the radio wave from the directivity direction adjusted by the directivity adjustment circuit 48. The same is true regardless of which directivity adjustment circuit 42, 44, 46, 48 changes the directivity. Thus, the variable directivity antenna apparatus, the coaxial cable 66, the distributor 68, and the receivers 70a, 70b, 70c, and 70d constitute a reception system.

  In this variable directivity antenna apparatus, only the first to fourth dipole antennas 4, 6, 8, and 10 are provided, but the received signals of these dipole antennas 4, 6, 8, and 10 are plural, for example, four. Distributed and supplied to a plurality of, for example, four variable directivity adjustment circuits 42, 44, 46, and 48, and mainly corresponds to radio waves from directions selected by these directivity adjustment circuits 42, 44, 46, and 48, respectively. Output signals are generated, and these output signals are frequency-converted into signals of different channels. Therefore, although a single directional antenna device can receive a plurality of radio waves arriving from different directions and transmit them to each of the receivers 70a to 70d through one coaxial cable 68, for example, jointly It is suitable as an antenna device used in a receiving system.

  In the above embodiment, the first to fourth dipole antennas 4, 6, 8, and 10 for the UHF band are used as antennas, but instead, dipole antennas for the VHF band can be used. . Alternatively, in addition to the first to fourth dipole antennas 4, 6, 8, and 10, a dipole antenna for the VHF band is also provided, and a directivity adjustment circuit and a frequency converter for the dipole antenna for the VHF band are also provided. In the VHF band in addition to the UHF band, a plurality of radio waves from different directions can be received by one variable directional antenna device, converted into signals of different frequencies, and transmitted by a single coaxial cable. In the above-described embodiment, four directivity adjusting circuits and four frequency converters can be obtained. However, the number of these can be arbitrarily changed as long as the number is two or more. In the above embodiment, the first to fourth dipole antennas are used as the directional antennas. However, the present invention is not limited to this, and other directivities such as a folded dipole antenna and a Yagi antenna are used as the antennas. Can also be used. In the above embodiment, the number of frequency converters 60a, 60b, 60c, and 60d is equal to the number of receivers 70a, 70b, 70c, and 70d, but the number of frequency converters may be different. The number can be made larger than the number of frequency converters. In this case, there are a plurality of receivers that can receive the same channel. In the above embodiment, the distributor 68 is used, but instead of this, the signal of the channel to be supplied to each receiver 70a, 70b, 70c, 70d is generated at the output terminal corresponding to each receiver. A waver can also be used.

It is a block diagram of the receiving system using the variable directivity antenna apparatus of one Embodiment of this invention. It is a schematic plan view of the variable directivity antenna device of FIG. It is explanatory drawing of the synthetic directivity of the 1st and 2nd dipole used with the variable directivity antenna apparatus of FIG. 1, and explanatory drawing of the synthetic directivity of the 3rd and 4th dipole antenna. It is explanatory drawing of adjustment of the directivity in the variable directivity antenna apparatus of FIG. It is a figure which shows the change state of the directivity in the variable directivity antenna apparatus of FIG.

Explanation of symbols

2 Body 4, 6, 8, 10 Dipole antenna (directional antenna)
42 44 46 48 Directivity adjustment circuit (directivity adjustment means)
58a to 58d Variable filter 60a to 60d Frequency converter (frequency conversion means)
64 Synthesizer (synthesizer)

Claims (5)

The body,
A plurality of antennas housed in this body and having directivity in different directions;
Provided in the main body, the output signals of the antennas are supplied to the antennas, and the supplied output signals of the antennas are adjusted and synthesized. A plurality of directivity adjusting means that can be adjusted independently of each other to provide corresponding signals;
A plurality of frequency conversions provided in the main body corresponding to the directivity adjusting means, and converting the output signals from the corresponding directivity adjusting means into output signals of different frequency bands assigned to the respective directivity adjusting means. Means,
Synthesizing means provided in the main body and synthesizing and outputting the output signals from the respective frequency converting means;
A variable directional antenna device provided.   2. The variable directivity antenna device according to claim 1, wherein each of the directivity adjustment means mainly corresponds to the selected signal among a plurality of radio waves arriving from the different directions toward the main body. Variable directional antenna apparatus in which variable filters provided between the directivity adjusting means and the frequency converting means corresponding to each other adjust the pass band so as to pass the selected radio wave signal. .   2. The variable directivity antenna apparatus according to claim 1, wherein the plurality of antennas include first to fourth antennas, and the first and second antennas are arranged in parallel with an interval therebetween, and the third and second antennas are arranged. 4 is a variable directivity antenna apparatus which is arranged in parallel with a distance from each other so that the antenna 4 intersects and is orthogonal to the first and second antennas.   4. The variable directivity antenna according to claim 3, wherein each of the first to fourth antennas is a dipole antenna, and each directivity adjusting unit adjusts a phase between signals of the first and second antennas. Phase adjustment means, phase adjustment means for adjusting the phase between the signals of the third and fourth antennas, and amplitude adjustment means for adjusting the amplitudes of the signals of the first to fourth antennas adjusted in phase, A variable directional antenna device provided. One transmission line for transmitting the output signal of the combining means of the variable directivity antenna device according to claim 1;
A plurality of receiving means to which output signals of the combining means transmitted through the transmission line are respectively supplied;
Each receiving means is configured to receive an assigned signal among the output signals of each frequency converting means.

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