JP4924586B2 - Antenna device - Google Patents

Description

  The present invention relates to an antenna apparatus having a plurality of antenna elements and performing beam formation with a Rotman lens.

Conventionally, an antenna device that realizes two-dimensional scanning by combining a Rotman lens for horizontal scanning (horizontal lens) and a Rotman lens for vertical scanning is known (for example, see Patent Document 1).
Special Table 2002-523951

  In this conventional antenna device, as many Rotman lenses for horizontal scanning as the number of beam directions that should be realized during vertical beam scanning are prepared, and Rotman lenses for vertical scanning are realized during horizontal beam scanning. It is necessary to prepare as many beam directions as possible.

  In other words, the conventional antenna apparatus needs to be configured using many Rotman lenses, so that the apparatus configuration becomes large, and when the number of beam directions is increased in order to improve the detectable azimuth resolution, the Rotman is simply Not only does the number of lenses increase, but the scale of individual Rotman lenses also increases, so that there is a problem that the scale of the apparatus increases rapidly as the azimuth resolution is improved.

  In order to solve the above problems, an object of the present invention is to provide a small antenna device that can change the beam direction two-dimensionally.

  In order to achieve the above object, an antenna device of the present invention includes an antenna unit including a plurality of antenna elements arranged two-dimensionally on an antenna surface through which radio waves are input and output, and each of the antenna elements A plurality of antenna ports connected to each other, and a plurality of beam ports each associated with a beam having a different directivity, and when one of the beam ports is used, it is associated with the beam port The input signal from the beam port or the antenna port is distributed and combined so that the formed beam is formed, and the input signal from the beam port is input to the antenna port or the input signal from the antenna port. A Rotman lens to be supplied to the beam port, and a power supply controller for controlling power supply to the beam port of the Rotman lens It is equipped with a.

Here, the wavelength of the radio wave transmitted and received through the antenna surface is λ, and the antenna element specified by the identifier k is A _k as shown in FIG. 7A, and the first reference axis set on the antenna surface The distance from the antenna element A _k to the antenna element A _k is V _k , the distance from the second reference axis set to be orthogonal to the first reference axis on the antenna surface to the antenna element A _k is H _k , and the first reference axis is The unit distance in the direction along the axis is H _F (where 0 <H _F <λ), and the unit distance in the direction along the second reference axis is V _F (where 0 <V _F <λ).

Further, as shown in FIG. 7B, θ _H (where −sin ⁻¹ (λ / 2H _F ) <θ _H <sin ⁻¹ (in the first reference axis direction with respect to the normal direction of the antenna surface). λ / 2H _F )) is received at two points on the antenna surface that are separated by the unit distance H _F along the first reference axis. Similarly, the phase difference α is inclined by θ _V (−sin ⁻¹ (λ / 2V _F ) <θ _V <sin ⁻¹ (λ / 2V _F )) in the second reference axis direction with respect to the normal direction of the antenna surface. A phase difference when radio waves arriving from different directions are received at two points on the antenna surface separated by the unit distance V _F along the second reference axis is defined as a second reference phase difference β.

The relationship between the unit distance H _F and the arrival angle θ _H and the radio wave path difference d _H and the first reference phase difference α, and the unit distance V _F and the arrival angle θ _V and the radio wave path difference d _V , The relationship with the 1 reference phase difference β is expressed by equations (1) and (2).

そして、本発明において、ロトマンレンズは、第１及び第２基準線が交差する基準点で観測される電波の位相φ₀ を基準（φ₀ ＝０）として、アンテナ素子Ａ_k で観測される電波の位相φ_k が、次式（（３）式）で表され、且つビームポートのいずれか一つを使用して給電した場合、位相φ_k から特定されるアンテナ素子間の位相関係が、どのビームポートを使用しても保持されると共に、使用するビームポート毎に第１及び第２基準位相差α，βの値のうち少なくとも一方が互いに異なるように構成されている。

Then, the radio wave in the present invention, Rotman lenses, the phase phi ₀ of the radio wave which the first and second reference lines are observed at the reference point of intersection as a reference (φ ₀ = _0), which is observed by the antenna elements A _k When the phase φ _k is expressed by the following equation (Equation (3)) and power is supplied using any one of the beam ports, the phase relationship between the antenna elements specified from the phase φ _k Even when the beam port is used, the beam port is maintained, and at least one of the first and second reference phase differences α and β is different for each beam port to be used.

このように構成された本発明のアンテナ装置では、単一のロトマンレンズによって、第１基準軸方向、及び第２基準軸方向のいずれにもビーム方向を変化させることができるため、装置規模を抑えつつ二次元走査を実現することができる。

In the antenna device of the present invention configured as described above, the beam direction can be changed in both the first reference axis direction and the second reference axis direction by a single Rotman lens, so that the device scale can be reduced. However, two-dimensional scanning can be realized.

By the way, as described in claim 2, the antenna elements are desirably arranged in a lattice shape along the first reference axis and the second reference axis.
In this case, as shown in FIG. 8A, the antenna element is represented by A _ij (i = 0, 1, 2,..., M−1, j = 0, 1, 2,..., N−1). distance H _i from the reference axis to the antenna elements a _ij, the distance from the second reference axis to the antenna elements a _ij as V _j, the radio wave of the phase as a reference to be observed at the reference point, observed by the antenna elements a _ij The phase φ _{ij of the} received radio wave is expressed by equation (4).

なお、図８（ｂ）は、図８（ａ）に示したアンテナ素子Ａ_ijの位置と、位相φ_ijとの対応関係を示した説明図である。

FIG. 8B is an explanatory diagram showing the correspondence between the position of the antenna element A _ij shown in FIG. 8A and the phase φ _ij .

In addition, it is desirable that the arrangement intervals of the antenna elements along the first and second reference axes are equal intervals as described in claim 3.
In this case, in particular, if the arrangement intervals on the first and second reference axes are unit distances H _F and V _F , respectively, and the antenna element A ₀₀ is arranged at the reference position, H _i / H _F = i, V _j Since / V _F = j, equation (4) is simplified to equation (5).

そして、図９は、（ａ）がα＝０とした場合、（ｂ）がβ＝０とした場合の各アンテナ素子Ａ_ijの位相φ_ij値を示すことによって、アンテナ素子Ａ_ij間の位相関係を示したものである。つまり、α＝０とした場合は、第１基準軸方向については正面方向に、第２基準軸方向については第２基準位相差βに対応する角度方向にビームが形成されることがわかる。また、β＝０とした場合は、第１基準軸方向については第１基準位相差αに対応する角度方向に、第２基準軸方向については正面方向にビームが形成されることがわかる。

9 shows the phase φ _ij value of each antenna element A _ij when (a) is α = 0, and (b) is β = 0, so that the phase between the antenna elements A _ij It shows the relationship. That is, when α = 0, it can be seen that the beam is formed in the front direction in the first reference axis direction and in the angular direction corresponding to the second reference phase difference β in the second reference axis direction. When β = 0, it can be seen that the beam is formed in the angular direction corresponding to the first reference phase difference α in the first reference axis direction and in the front direction in the second reference axis direction.

Next, in the antenna device according to claim 4, m × n (m and n are integers of 2 or more) beam ports are prepared, and n partial ports each configured by m beam ports. It consists of groups G _{1 to} G _n .

In the Rotman lens, the setting of the first reference phase difference α differs between the m beam ports constituting each partial port group, and the setting of the second reference phase difference β matches each other. The second reference phase difference β is set to be different from each other, and the first reference phase difference α is set to coincide with each other. That is, α ₁ , α ₂ , and α ₃ represent different first reference phase differences α, and β ₁ , β ₂ , and β ₃ represent different second reference phase differences β, as shown in FIG. Street matching is performed.

  Accordingly, the beam direction (azimuth angle) along the second reference axis is selected by selecting the partial port group, and the beam direction along the first reference axis is selected by selecting the beam port in the partial port group. (Azimuth angle) can be specified. That is, it is possible to suitably perform two-dimensional scanning in which the direction along the first reference axis is the main scanning direction and the direction along the second reference axis is the sub-scanning direction.

  In this case, the power supply control means is provided for each partial port group, for example, as described in claim 5, and signals are input / output via any one of the beam ports constituting the partial port group. It may be configured by n first changeover switches that are switched in this way and a second changeover switch that is switched so that a signal is input and output via any one of the first changeover switches.

Further, as described in claim 6, the power supply control means may be configured by a variable amplifier or a phase shifter provided in each of the beam ports and individually adjustable.
In this case, signals are simultaneously supplied to a plurality of antennas, and the amplification factor or phase shift amount at each beam port is individually adjusted, so that an intermediate beam direction corresponding to the case of using a single beam port can be obtained. The beam direction can be realized, and the azimuth resolution can be further improved.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a block diagram showing a configuration of a radar apparatus 1 to which the present invention is applied. It is a block diagram which shows the connection relation of each part to perform.

<Overall configuration>
As shown in FIG. 1, the radar apparatus 1 includes an antenna unit 2 including nine antenna elements, a power supply control unit 3 that controls a power supply state to each antenna element, and an antenna unit 2 via the power supply control unit 3. A transmission / reception circuit 4 for generating a transmission signal supplied to the antenna unit 2 and processing a reception signal supplied from the antenna unit 2 via the power feeding control unit 3, and a horizontal switching signal SH for controlling the beam directivity of the antenna unit 2. And a signal processing unit 5 that outputs the vertical switching signal SV to the power supply control unit 3 and generates information on the object that has reflected the radar wave based on the received signal acquired through the transmission / reception circuit 4. Yes.

Here, FIG. 2 is an external view of the antenna unit 2 and the power feeding control unit 3 corresponding to the antenna device of the present invention, where (a) is a plan view and (b) is a side view.
As shown in FIG. 2, the antenna unit 2 and the power feeding control unit 3 are both formed in a rectangular plate shape and have a structure in which both are integrally laminated.

<Antenna part>
The nine antenna elements constituting the antenna unit 2 are arranged in three equal intervals (unit distances H _F and V _F ) along the first reference axis and the second reference axis that are orthogonal to each other, that is, They are arranged in a 3 × 3 grid.

The antenna unit 2 is used with the first reference axis aligned in the horizontal direction and the second reference axis aligned in the vertical direction.
Hereinafter, the identifier for identifying the antenna elements arranged along the first reference axis is i, the identifier for identifying the antenna elements arranged along the second reference axis is j, and the antenna elements are A _ij (i , J = 0, 1, 2).

<Power supply control unit>
Returning to FIG. 1, the feed controller 3 includes a Rotman lens 31 having nine antenna ports each connected to the antenna element A _ij and nine beam ports each associated with a different beam direction. And a power supply selection unit 33 that selects and supplies power to any one of the beam ports of the Rotman lens 31.

<Rotman lens>
Among these, the Rotman lens 31 is configured to have the following characteristics.
That is, as a reference (phi ₀₀ = 0) the phase phi ₀₀ of the antenna element A _00, the phase phi _ij of the other antenna elements _{A ij (i ≠ 0, j} ≠ 0) is represented by the above equation (4), In addition, regardless of which beam port is used, the phase relationship represented by the equation is maintained.

Here, FIG. 3 (a), corresponding to the arrangement of the antenna elements A _ij in FIG. 2 shows the phase phi _ij at each antenna element A _ij. However, the reference phase differences α and β in the equation have different values depending on the beam port used.

The phase relationship of each antenna element A _ij is shown in FIG. 3B when α = 0, and is shown in FIG. 3C when β = 0. The phase relationship shown in FIG. 3B is an angle (hereinafter referred to as a vertical azimuth angle) in which the beam of the antenna unit 2 is defined from the reference phase difference β using the equation (6) obtained by modifying the above equation (2). ) Means that it is tilted in the vertical direction by θ _V , and similarly, the phase relationship shown in FIG. 3C is that the beam of the antenna unit 2 is modified from the above-mentioned formula (1) (7) It means that the angle is inclined in the horizontal direction by an angle (hereinafter referred to as a horizontal azimuth angle) θ _H defined from the reference phase difference α using the equation.

また、９個のビームポートは、３個ずつの３グループ（部分ポート群という）に分けられている。以下では、各部分ポート群をＧ_q （ｑ＝０，１，２）で表し、部分ポート群Ｇ_q に属する各ビームポートをＢ_1q，Ｂ_2q，Ｂ_3qで表すものとする。

The nine beam ports are divided into three groups of three (referred to as partial port groups). Hereinafter, each partial port group is represented by G _q (q = 0, 1, 2), and each beam port belonging to the partial port group G _q is represented by B _1q , B _2q , B _3q .

Then, as shown in FIG. 3 (d), the second reference phase difference value of beta for each partial port group _{G q (β 1, β 2} , β 3) different, and, in any portion port group G _q, Each of the beam ports B _0q , B _1q , and B _2q belonging _thereto is set to have one of three types of values (α ₁ , α ₂ , α ₃ ) of the first reference phase difference α.

That is, in the same portion port group G _q, which also a beam port select, vertical orientation angle theta _V of the beam is formed is the same, which portion port group G _q even three beam ports belonging thereto Thus, the same three types of horizontal azimuth angles θ _H can be switched. That is, nine types of beams having different directivities can be formed by combining three types of horizontal azimuth angles θ _H and three types of vertical azimuth angles θ _V.

For example, as shown in FIG. 3E, if it is configured such that α ₂ = β ₂ = 0, −α ₁ = α ₃ = A, and −β ₁ = β ₃ = B, The direction of the beam can be controlled in the vertical direction (front, top, bottom).

<Power supply selector>
Feeding selector 33 is provided for each partial group of ports G _q, in accordance with the horizontal switching signal SH, 3 pieces of beam ports B _1q belonging to the partial group of ports G _q, B _2q, any one of B _3q A horizontal changeover switch 331, 332, 333 for selecting and supplying power, and a vertical changeover switch for selecting and supplying one of the three horizontal changeover switches 331, 332, 333 in accordance with the vertical changeover signal SV 334.

<Transceiver circuit>
The transmission / reception circuit 4 is a well-known circuit composed of an oscillator for generating a transmission signal, a mixer for generating a beat signal from a reception signal, an amplifier for amplifying the signal, a filter for removing unnecessary signal components, and the like. , FMCW radar, CW radar, pulse radar, or the like corresponding to the type of radar wave to be transmitted / received is used.

<Signal processing unit>
The signal processing unit 5 generates a horizontal switching signal SH and a vertical switching signal SV, and performs scanning control processing for performing two-dimensional scanning with the horizontal direction as the main scanning direction and the vertical direction as the sub-scanning direction, and the scanning. Based on the obtained information, an object detection process for obtaining information related to the object reflecting the radar wave is executed. The object detection process executes a known process corresponding to the type of radar wave processed by the transmission / reception circuit 4.

<Effect>
As described above, according to the radar apparatus 1, the beam direction can be changed by the single Rotman lens 31 in both the horizontal (first reference axis) direction and the vertical (second reference axis) direction. Therefore, two-dimensional scanning can be realized while suppressing the apparatus scale.
[Second Embodiment]
Next, a second embodiment will be described.

<Overall configuration>
FIG. 4A is a block diagram illustrating a configuration of the radar apparatus 11 according to the present embodiment.
The radar apparatus 11 differs from the radar apparatus 1 of the first embodiment only in the configuration of the antenna unit 6 and the power supply control unit 7 and part of the processing in the signal processing unit 8. The same reference numerals are assigned and the description is omitted, and the differences will be mainly described.

<Antenna part>
The antenna unit 6 includes four antenna elements A _ij (i, j = 0, 1) arranged in a lattice pattern (arranged at locations corresponding to the apexes of the square).

<Power supply control unit>
The power feeding control unit 7 includes a Rotman lens 71 having four antenna ports each connected to the antenna element A _ij , and four beam ports each corresponding to a different beam direction, and a Rotman lens 31. And a change-over switch 73 for selecting and feeding one of the beam ports.

Of these, the Rotman lens 71 is configured to have the following characteristics.
That is, as a reference (phi ₀₀ = 0) the phase phi ₀₀ of the antenna element A _00, the phase phi _ij of the other antenna elements _{A ij (i ≠ 0, j} ≠ 0) is represented by the above equation (4), In addition, regardless of which beam port is used, the phase relationship represented by the equation is maintained.

The four beam ports are divided into two partial port groups G _q (q = 0, 1).
The values (β ₁ , β ₂ ) of the second reference phase difference β are different for each partial port group G _q , and each beam port B _0q , B _1q belonging to any partial port group G _q is Each is set to be one of two types of values (α ₁ , α ₂ ) of the first reference phase difference α.

That is, in the same portion port group G _q, which also a beam port select, vertical orientation angle theta _V of the beam is formed is the same, in any section port group G _q, 2 or beam ports belonging thereto Thus, the same two types of horizontal azimuth angles θ _H can be switched. That is, four types of beams having different directivities can be formed by a combination of two types of horizontal azimuth angles θ _H and two types of vertical azimuth angles θ _V.

<Signal processing unit>
In the signal processing unit 8, a single switching signal S _{HV is used} instead of the horizontal switching signal and the vertical switching signal because the power feeding control unit 7 is configured to switch the beam port by the single switching switch 73. Is configured to output.

<Effect>
According to the radar apparatus 11 configured as described above, the same effects as those of the radar apparatus 1 of the first embodiment can be obtained except that the scanable beam direction is reduced.

Moreover, according to the radar apparatus 11, since it is comprised so that switching of a beam port may be performed by the single changeover switch 73, an apparatus scale can be restrained small.
[Third Embodiment]
Next, a third embodiment will be described.

<Configuration>
FIG. 4B is a block diagram illustrating a configuration of the radar apparatus 13 according to the present embodiment.
In the radar apparatus 13, the antenna unit 6 and the power supply control unit 7 in the second embodiment are used for both transmission and reception, whereas the transmission antenna unit 6 a and the power supply control unit 7 a (Rotman lens 71 a and changeover switch 73 a). And a receiving antenna section 6b and a power feeding control section 7b (Rotman lens 71b, changeover switch 73b). The antenna units 6a and 6b and the power supply control units 7a and 7b are configured in the same manner as the antenna unit 6 and the power supply control unit 7, respectively.

In place of the transmission / reception circuit 4, a transmission circuit 4a and a reception circuit 4b are provided.
<Effect>
The radar device 13 configured as described above can realize two-dimensional scanning with a small-scale configuration (particularly, the number of Rotman lenses) compared to the conventional device.

<Modification>
As a modification of the radar apparatus 13, the transmission-side power supply control section 7a is omitted and the transmission-side antenna section 6c is configured by a single antenna element, as in the radar apparatus 15 shown in FIG. At the same time, the transmission circuit 4c may be configured to directly supply a transmission signal to the antenna unit 6c so that beam control is performed only on the reception side.

Further, as in the radar device 17 shown in FIG. 5B, the power supply control unit 7b on the reception side is omitted, and the reception circuit 4d is configured to individually process the reception signal from each antenna element. The beam forming on the receiving side may be performed by processing in the signal processing unit 8, or the beam forming may be performed only on the transmitting side.
[Fourth Embodiment]
Next, a fourth embodiment will be described.

FIG. 6 is a block diagram showing the configuration of the radar apparatus 19 of the present embodiment.
The radar apparatus 19 differs from the radar apparatus 13 of the third embodiment only in the configuration of the power supply control units 9a and 9b and part of the processing in the signal processing unit 8, and therefore the same configuration is the same. The description will be omitted with reference numerals, and the description will focus on the differences.

<Power supply control unit>
The power supply control units 9a and 9b are provided with signal adjustment units 93a and 93b, respectively, instead of the changeover switches 73a and 73b.

  The signal adjustment unit 93a on the transmission side includes four variable amplifiers provided for each beam port. The signal supplied from the transmission circuit 4a is divided into four and supplied to the variable amplifiers. 8 is configured to supply a signal amplified by an amplification factor corresponding to the adjustment signal from 8 to the Rotman lens 71a.

  The signal adjustment unit 93b on the reception side includes four variable amplifiers provided for each beam port, and amplifies the signal supplied from the Rotman lens 71b with an amplification factor corresponding to the adjustment signal from the signal processing unit 8, respectively. The amplified signals are combined and supplied to the receiving circuit 4b.

<Effect>
In the radar device 19 configured as described above, not only the same effect as the radar device 13 is obtained, but also a single beam port is selected by individually adjusting the amplification factor of each variable amplifier by the adjustment signal. Arbitrary azimuth angles between the four types of beam directions obtained in this case can be set, and the azimuth resolution of two-dimensional scanning can be improved.

<Modification>
In the radar device 19, the signal adjustment units 93 a and 93 b may include a phase shifter instead of the variable amplifier or in addition to the variable amplifier, and may perform phase adjustment according to the adjustment signal.

In the radar device 19, the transmission side may be configured in the same manner as in FIG. 5A, and the reception side may be configured in the same manner as in FIG.
[Other Embodiments]
As mentioned above, although several embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it is possible to implement in various aspects. is there.

  For example, in the above-described embodiment, an example in which the radar apparatus is configured to perform two-dimensional scanning has been described. However, one of the horizontal direction and the vertical direction is used for scanning and the other is used for adjusting the beam axis, thereby enabling primary You may comprise as a radar apparatus which performs original scanning. Moreover, you may comprise as a non-scanning-type radar apparatus by using it for adjustment of a beam axis in both directions.

  In the above-described embodiment, the antenna elements are arranged in a grid pattern. However, the antenna elements are not necessarily arranged in a grid pattern. In that case, in each antenna element, the phase shown in the above equation (3) is used. A Rotman lens may be designed to satisfy the relationship.

1 is a block diagram showing an overall configuration of a radar apparatus according to a first embodiment. The external view of an antenna part and a feed control part. Explanatory drawing which shows the characteristic of a Rotman lens. The block diagram which shows the whole structure of the radar apparatus of 2nd Embodiment and 3rd Embodiment. The block diagram which shows the whole structure of the modification of the radar apparatus of 3rd Embodiment. The block diagram which shows the whole structure of the radar apparatus of 4th Embodiment. BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the structure used as the premise of this invention. BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the structure used as the premise of this invention. Explanatory drawing which shows the effect | action of the Rotman lens in this invention. Explanatory drawing which shows the example of the correspondence of the reference | standard phase difference which prescribes | regulates the azimuth | direction of the beam formed of a Rotman lens and the Rotman lens.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,11,13,15,17,19 ... Radar apparatus 2, 6, 6a-6c ... Antenna part 3, 7, 7a, 7b, 9a, 9b ... Feed control part 4 ... Transmission / reception circuit 4a, 4c ... Transmission circuit 4b , 4d ... receiving circuit 5, 8 ... signal processing unit 31, 71, 71a, 71b ... Rotman lens 33 ... feeding selection unit 73, 73a, 73b, 331-334 ... changeover switch 93a, 93b ... signal adjustment unit

Claims (6)

An antenna unit composed of a plurality of antenna elements arranged two-dimensionally on an antenna surface through which radio waves are input and output;
When there are a plurality of antenna ports each connected to one of the antenna elements, and a plurality of beam ports each associated with a beam having a different directivity, and one of the beam ports is used In addition, an input signal from the beam port or the antenna port is distributed and combined so that a beam associated with the beam port is formed, and the input signal from the beam port is input to the antenna port, or A Rotman lens for supplying an input signal from the antenna port to the beam port;
A power supply control unit that controls power supply to the beam port of the Rotman lens;
In an antenna device comprising:
The wavelength of the radio wave transmitted / received via the antenna surface is λ, the antenna element specified by the identifier k is A _k , and the distance from the first reference axis set on the antenna surface to the antenna element A _k is V _k, wherein the second distance from the reference axis to the antenna element a _k H _k which is set to be perpendicular to the first reference axis on the antenna surface, the direction of the unit distance along the first reference axis H _F (where 0 <H _F <λ), the unit distance in the direction along the second reference axis is V _F (where 0 <V _F <λ), and the normal direction of the antenna surface Radio waves arriving from a direction inclined by θ _H (where −sin ⁻¹ (λ / 2H _F ) <θ _H <sin ⁻¹ (λ / 2H _F )) in the first reference axis direction are The phase difference when received at two points on the antenna surface separated by the unit distance H _F along the first reference The phase difference α is inclined by θ _V (−sin ⁻¹ (λ / 2V _F ) <θ _V <sin ⁻¹ (λ / 2V _F )) in the second reference axis direction with respect to the normal direction of the antenna surface. The phase difference when the radio wave arriving from a certain direction is received at two points on the antenna surface separated by the unit distance V _F along the second reference axis is defined as a second reference phase difference β.
The Rotman lens is
With reference to the phase of the radio wave observed at the reference point where the first and second reference lines intersect, the phase φ _{k of the} radio wave observed at the antenna element A _k is expressed by the following equation, and When power is supplied using any one of them, the phase relationship between the antenna elements specified from the phase φ _k calculated by the following equation is maintained and used regardless of which of the beam ports is used. An antenna device characterized in that at least one of the first and second reference phase differences α and β is different for each beam port.

  The antenna device according to claim 1, wherein the antenna elements are arranged in a lattice shape along the first reference axis and the second reference axis.   The antenna apparatus according to claim 2, wherein the antenna elements are arranged at equal intervals along the first and second reference axes. The beam ports are prepared by m × n (m and n are integers of 2 or more), each consisting of n partial port groups each consisting of m beam ports,
In the Rotman lens, the setting of the first reference phase difference α is different between the m beam ports constituting the partial port group, and the setting of the second reference phase difference β is mutually matched, 2. The port group is configured such that the setting of the second reference phase difference β is different from each other, and the setting of the first reference phase difference α is the same. Item 4. The antenna device according to any one of Items 3 to 4. The power supply control means includes
N first changeover switches that are provided for each of the partial port groups and switch so that a signal is input / output via any one of the beam ports constituting the partial port group;
A second changeover switch for switching so that a signal is input / output via any one of the first changeover switches;
The antenna device according to claim 4, comprising:   The antenna apparatus according to any one of claims 1 to 4, wherein the power supply control means includes a variable amplifier or a phase shifter provided in each of the beam ports and individually adjustable.

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