JPH0466891A - Beam scanning of antenna - Google Patents

Abstract

PURPOSE:To obtain a transmitting beam which has a wide range beam and high effective emitting power by scanning spirally a comparatively narrow width transmitting beam so as to cover wide range beam width, and then by emitting the beam. CONSTITUTION:RF signals distributed by a power distributor 11 are fed to phase shifters 12a,12b ..., and phases thereof are sequentially shifted there by a predetermined amount, by control signal from a beam controller 13. The iso phase surface, that is to say, are changed and emitted from elements 1a,1b ...through amplifiers 14a,14b .... In this case, the phase shifting is controlled by the beam controller 13 so that the beam scanning may be conducted spirally from a point P to a center and may scan almost the same range as that of an ordinary beam width W', on the whole. In this way, even by using an emitting beam B of narrower beam width than the ordinary beam width W', almost the same extent of widening as an ordinary one, can be attained, on the whole.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a scanning method for a transmission beam radiated from a transmitting antenna. TECHNICAL FIELD The present invention relates to a method for scanning a transmission beam radiated from a transmission antenna.

A phased array antenna, which can instantly switch the transmission beam direction, is sometimes used as a transmitting antenna for radio wave application equipment.

In addition to such phased array antennas, transmitting antennas are designed to widen the transmitting beam area in order to compensate for errors in transmitting beam setting accuracy and receiving direction detection accuracy. In this case, in order to widely apply it to radio wave application equipment, it is necessary to widen the transmission beam and increase the effective radiated power (hereinafter referred to as ERP).

[Conventional technology]

For the reasons mentioned above, the conventional phased array antenna has widened the transmission beam B' as shown by diagonal lines in FIGS. 2(A) to 2(C). Note that the transmitting antenna 1 has a plurality of elements Ia, lb... arranged in parallel in an array, and the transmitting beam B'' shown in Fig. 2 is radiated from the plurality of elements la, lb..., respectively. This shows the overall shape of the transmitted beams. In this case, the beam width of the transmitted beam B- is W' and is radiated toward the target 2. As described above, since the phased array antenna can instantly switch the transmission beam direction, the transmission beam is sequentially switched and radiated in a direction other than the target 2.

[Problem to be solved by the invention]

However, in general, the ERP of an antenna is inversely proportional to the beam width, and if the beam width of the transmitting beam is set wide as in the conventional example, the ERP decreases, and a high-performance amplifier is used to compensate for this decrease in ERP. If the number of elements in the transmitting antenna is increased to compensate for the drop in effective radiated power, the size of the transmitting antenna will become larger and the cost will also increase.

SUMMARY OF THE INVENTION An object of the present invention is to provide an antenna beam scanning method that can obtain an ERP and a wide-area transmission beam with a compact and low-cost configuration.

[Means to solve the problem]

FIG. 1 shows a diagram of the principle of the present invention. Same figure (A).

In (B), B is a transmission beam in the present invention having a relatively narrow beam width W, and is scanned in an overwinding manner so as to cover the wide beam width W' as in the conventional example.

[Effect]

In the present invention, since the beam width W of the transmitting beam B is set to a relatively narrow beam width W, a high ERP can be obtained.On the other hand, since the transmitting beam B is scanned in an overwinding manner, a wide area can be obtained. I can cover it.

In this case, since a transmission beam with a narrow beam width W is used, there is no need to use a particularly high-performance antenna with a large number of amplifier elements in order to obtain high ERP over a wide area, and the structure can be made compact and low-cost.

〔Example〕

As shown in FIGS. 2(A) and 2(B), a transmission beam B having a beam width W narrower than the beam width W' of the conventional transmission beam B' is radiated while being scanned at high speed in an overwinding manner, As a whole, the beam width W' between the paths is obtained as compared to the conventional example. Such beam scanning is performed by an apparatus shown in the block diagram of FIG. The configuration shown in FIG. 3 is the same as a general phased array antenna.

In FIG. 3, reference numeral 10 denotes a transmission source which outputs an RF multiplied signal. 11
is a power divider, which distributes RF multiplied signals by the number of elements la, lb, . . . . 12a, 12b, . . . are phase shifters that shift the phase of the RF multiplied signal distributed by the power divider 11 by a phase amount controlled by the beam controller 13. 14a, llb... are amplifiers, phase shifters 12a, 1
It amplifies each output of 2b... and has general performance.

Here, the RF multiplied signal distributed by the power divider 11 is supplied to the phase shifters 12a, 12b, . Equiphase plane can be changed, amplifier], 4a
, 14b... from the elements la, lb... In this case, the phase shift described above is shown in FIG. 2(C).
As shown in FIG. 2, the beam controller 13 is controlled so that the beam scan is performed in an overwinding manner from point P toward the center, that is, the beam convergence B' and the beam width range in the conventional example are scanned as a whole. A painting is being done. in this way,
Although the present invention uses a transmitting beam B having a beam width W narrower than the beam width W' in the conventional example, it is different from the conventional example as a whole and can achieve a wider area. High E without using or increasing the number of elements
RP can be obtained, and the structure can be made small and at low cost.

By the way, there are cases where a beam emitted from a certain target is interfered with, for example at a defense facility, etc., and such a case will be described below. Figure 4 (C
), there is a target 2 at a certain position within the range of the transmitting beam that is scanned in a supercircular manner, and a beam is emitted from this target 2, for example, as shown in FIG. Suppose we have obtained a waveform. Assuming that the scanning speed of the transmission beam B according to the present invention is constant, the transmission beam from the tarp/nod 2 can be interfered with three times in the case shown in FIG. On the other hand, if the pulse width of the received waveform due to the beam emitted from the target 2 is relatively small as shown in FIG. 2(B), interference can be caused only once.

〔Effect of the invention〕

As explained above, according to the present invention, since the transmission beam with a narrow beam width is scanned in an overwound manner, a particularly high-performance amplifier and an antenna with a large number of elements are used in order to obtain high ERP over a wide area. It is not necessary and can be configured to be small and low cost.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the principle of the present invention, Fig. 2 is a diagram illustrating an embodiment of the present invention, Fig. 3 is a block diagram of a configuration for implementing the invention, and Fig. 4 is a diagram of received waveforms in the present invention. It is a figure explaining the relationship with the number of disturbances. In the figure, I is a transmitting antenna, la, lb, ... are elements, 2 is a target, 0 is an RF signal oscillation source, 1 is a power divider, 2a, ! 2b is a phase shifter, 3 is a beam controller, 4a, 14b, ... are amplifiers, B is a transmission beam in the present invention, B' is a transmission beam in the conventional example, W is the beam width in the present invention, W' is the conventional example This example shows Pi in the example. Width case 2

Claims (1)

[Claims] An antenna beam scanning method characterized in that a transmission beam (B) with a relatively narrow beam width (W) is scanned and radiated in a supercircular manner so as to cover a wide beam width (W').