JPH03295303A - Array antenna system - Google Patents

Abstract

PURPOSE:To make complicated amplitude control unnecessary by providing an exciter to excite each element connected to each elements of an antenna element by constant excitation weighting. CONSTITUTION:The function of two beame is made capable of being controlled according to ON/OFF of the excitation of a phase shifter and the antenna elements 11 to 1n by sampling excitation amplitude by the binary code of '1', '-1' or the ternary code of '1', '0', '-1'. In this case, the excitation weight Wn is Wn=EnAntheta<jphin>. However, in the case of ¦an¦=0, either An=0 or An=-1, in the case of an>0, An=1, and in the case of an<0, An=-1, where an=cosx/lambda[(sintheta1.cosphi1-sintheta2.cosphi2)xn+(sintheta1-sinp hi1.sintheta2.sinphi2)yn], phin=-pi/lambda [(costheta1.cosphi1+sintheta2.cosphi2)xn+(sintheta1.sinphi1+sintheta2. sinphi2)yn], (theta1,phi1) and (theta2,phi2) are the desired directions of two beams of the antenna, (xn,yn) is each position of N-pieces of the antenna elements, En is the low side lobed weight of two desired beams of the antenna, and lambda is the wavelength of an electromagnetic wave. Thus, the complicated excitation amplitude control becomes unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This array antenna device relates to an antenna used for communication, broadcasting, and guidance of moving objects.

[Conventional technology]

Figure 2 is a diagram showing the coordinate system of the array antenna device.
In the figure, (11) to (1N) are N arranged on a plane.
FIG. 3 is a diagram showing a part of the configuration of the array antenna device, where (11) to (1N) are N
antenna elements, (2; is the above N antenna elements (
11) ~ (IN) K-connected exciter.

FIG. 4 is a diagram showing an example of excitation weights of a conventional array antenna device. In the figure, (a) shows an antenna element (11
) to (120) and the final excitation amplitude phase shift, and φ) indicates the radiation pattern in that case.

Next, the operation will be explained. - To form a beam in two directions at the same time when fishing on a boat, use the coordinate system shown in Figure 2, and let those directions be (θ1.φ1) and (θ2.φ2) to form a beam in each direction. It is given by vector addition of the excitation distribution. That is, to form a beam in the (θ1.φ1) direction, the weight given to the nth antenna element (11) to (1N) is... (1) Here, ("n + 7n) is n The coordinate En of the th element is ra
To form a beam in the complex weight order K (θ2.φ2) direction that gives a beam shape such as y1or distribution, the weight given to the nth antenna element (11) to (IN) is... (2) Therefore, To simultaneously form beams in the (θ1.φ1) and (θ2.φ2) directions, use the formula fil, +21 = W ”(θ't('hMθ2pφ2)+n(θ1.φ1),
n” (92+$2), n-En(e-row [(-θ1-1
9 jo-1sin9h )7B]+6-,lli[(th
02 residence φ2 ) xn + (sin θ1 torture φt) 7n'l)
It is separated into a portion Ar1 and a portion Φi that provides a phase shift and is expressed in the following form.

Here an=cas÷CCmθ-φ1--2cas'162)
XQ + (opposition θ1 sporse φ1 -θ2 opposition φz) YN] - = t
s+π 4c, T [(mθ1μsφ1 bit θ2casf62)
X B+(1θ1sknφ1−bloodθ2 tortureφ2)yn)
−=・ (3) Therefore, W(θ4.φ,)+(θ2.φ
2), giving an amplitude of n #'i, thus in a conventional array antenna device.

As the function of the exciter (2) in FIG. 3 requires control of amplitude and phase shift, a phase shifter and an amplitude controller are required each time to switch between two arbitrary directions.

Figure 4 shows an example of this.(θ1.φ1)=(
3Q・, so') (θ2.φ2)=(60°, 9
In the case of G'), the number of antenna elements is 20. Q on the Y axis, 5
This is a case where the wavelengths are arranged at equal intervals. Fan =
It is j.

It can be seen that fine-grained amplitude control is required.

[Problem to be solved by the invention]

Since the conventional array antenna device is configured as described above, the configuration becomes complicated, requiring a variable phase shifter and a variable attenuator. Furthermore, although it can be used as a receiving antenna if the above considerations are taken into consideration, it is difficult to use it as a transmitting antenna, especially when combined with an active phased array, because of restrictions on amplitude control.

This invention was made in order to solve the above-mentioned problems, and is a play antenna that forms beams in two directions simultaneously by controlling the phase shift and stopping the excitation of the antenna elements (11) to (1N). The purpose is to obtain equipment.

[Means for Solving the Problems] The array antenna device according to the present invention has an excitation amplitude of the formula (
As can be seen from 5), focusing on the fact that it is a function of 0, we can sample the excitation amplitude ftl with two values of −1 or 1. O
By sampling at 3@ of , -1, it is possible to control the two-beam shape only by turning on and off the excitation of the phase shifter and the antenna elements (11) to (IN).

[Effect]

In this invention, two beams can be formed during transmission by simply controlling the phase shifter and turning on and off the excitation of the antenna elements (11) to (1N), so complex amplitude control is not required. It can now be applied to Active 7 aided arrays as well.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, (a) d antenna elements (11) to (I
N) position, which indicates the final excitation amplitude phase shift.

(b) shows the radiation pattern in that case.

Next, how to apply excitation phase shift will be explained. (Note that in the beginning, the excitation amplitude is a function of !a, 1≦1.

aI) If =O then An=1 or An=-1an
>00, An= f If an<O, An=-1 jπ, it is replaced by -' ``eT 1 '' ejo, so that everything except EΩ can be directly controlled by phase shift at +47. Furthermore, since En can be set using a fixed weight, in order to shape two beams in any direction,
It turns out that only the phase shift needs to be controlled by sound.

The first page shows an embodiment of the present invention.

(θ1.φ1) = (30', 900) (θ2
．． In the case of φ2)=(600900), the antenna nest ridge is 20. This is a case where they are arranged at equal intervals on the Y axis (at L5 revision intervals).

BHn==1. As can be seen from the figure, although the side loaf is slightly raised, it can be seen that the beam is formed in the desired direction.

The above is an explanation of the first claim of the method for determining μΩ, but next, the second item will be explained.

The following method is used to calculate An
i decide.

If an=:Q, An=9 an>QC) if riAn=1 a n (in case of Q, An=-1 Then, two beams can be formed in any direction.

It can be seen that control is possible only by phase shift control and turning the exciter output on and off.

In addition, in the above embodiment, the antenna elements (11) to
Although the case where (1N) is linear has been described, the case is not limited to this, and the application is also applicable to any arbitrary arrangement on a plane. Further, in the above embodiments, an example of an active phased array has been described, but it goes without saying that the present invention is also effective for other cases such as a passive phased array.

〔Effect of the invention〕

As described above, according to the present invention, beam formation in any two directions can be realized by phase shift control only or by phase shift control and turning on and off of active elements. In addition to eliminating the need for a distributor, control wiring, memory, etc. can also be omitted. In addition, although the amount is approximately twice as much as in conventional beam scanning phase shift calculations, phase shift calculations can be performed using the same calculation algorithm, and no special algorithm is required; all that is needed is a phase shifter. This can be easily achieved by making simple modifications to existing phased arrays, and the effects can be expected to be great.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the position, final excitation amplitude phase shift, and radiation pattern of an antenna element according to an embodiment of the present invention, and FIG. 2 is a diagram showing the coordinate system of the antenna device. FIG. 3 is a diagram showing a part of the configuration of the array antenna device, and FIG. 4 is a diagram showing the antenna elements (11
) to (IN), the final excitation amplitude phase shift, and the radiation pattern are shown. (11) to (IN)II'i antenna elements; (2) is an exciter. In addition, in FIG. 9, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) N antenna elements (N is a plurality of 3 or more) and each element connected to each element of the N antenna elements are excitation weight Wn Wn=EnAn■＾＾φ＾n [However | If a_n|=0, An=1 or An=
-1 If a_n>0, An=1 If a_n<0, An=-1 a_n=cosx/λ・[(sinθ1cosφ1-s
inθ2cosφ2)x_n+(sinθ1sinφ1
-sinθ2sinφ2)y_n]φ_n=-x/λ[
(sinθ1cosφ1+sinθ2cosφ2)x_
n+(sinθ1sinφ1+sinθ2sinφ2)
y_n] (φ1, φ1), (θ2, φ2) are the desired two beam directions of the antenna (x_n, y_n) are the positions of each of the N antenna elements En are the desired two beam directions of the antenna Side rope weight λ is the wavelength of radio waves] An array antenna device comprising an exciter excited by: (2) N antenna elements (N is a plurality of 3 or more) and each element connected to each element of the N antenna elements are excitation weights Wn Wn=EnAn■＾＾φ＾n [However, |a_n An=1 if |>0 An=−1 if |a_n|<0 A_n=0 if a_n=0 a_n=cosx/λ・[(sinθ1cosφ1−s
inθ2cosφ2)x_n+(sinθ1sinφ1
-sinθ2sinφ2)y_n]φ_n=-x/λ[
(sinθ1cosφ1+sinθ2cosφ2)x_
n+(sinθ1sinφ1+sinθ2sinφ2)
y_n] (θ1, φ1), (θ2, φ2) are the directions of the desired two beams of the antenna (x_n, y_n) are the positions of each of the N antenna elements E_n are the low side lobes of the desired two beams of the antenna [0016] An array antenna device comprising: an exciter excited by a wavelength of a radio wave].