JP2006080772A - Antenna assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain the output of auxiliary HC capable of covering the side lobe of a main antenna if its gain or side lobe is high, thus performing SLC or SLB processing. <P>SOLUTION: Among N multi-beams by a main antenna 1 used in a no-jamming environment, a high side lobe angular area of the main antenna 1 is a jamming environment is covered by using M beam signals forming an antenna pattern of the main antenna 1, while a low side lobe wide angular area is covered by using subsidiary beams by L low-gain subsidiary antennas 2. In this case, for the high side lobe area of the main antenna 1, beams are formed to form high-gain subsidiary beams using the entire aperture of the main antenna 1 to cover the low side lobe area of the main antenna 1 with subsidiary beams of a small subsidiary antenna, thus forming subsidiary beam signals efficiently covering the side lobes of the main antenna 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antenna apparatus using an auxiliary channel (hereinafter referred to as CH) such as a sidelobe canceller (SLC) or a sidelobe blanker (SLB).

  In an antenna device that requires an auxiliary CH to implement conventional SLC and SLB, when the gain and side lobe of the main CH are high, a small auxiliary antenna is insufficient, and SLC (see, for example, Non-Patent Document 2) Suppression performance due to performance was degraded. In addition, regarding SLB (for example, see Non-Patent Document 3), there is a problem that the SLB does not operate when the level of the auxiliary CH is lower than the side lobe of the main CH.

As a conventional technique related to the present invention, the Gram Schmidt method is described in Patent Document 1. Non-patent document 1 describes the monopulse angle measurement, the SLC method, and the SLB method. The MSN method is described in Non-Patent Document 2. The direct solution method (SMI method or the like) is described in Non-Patent Document 3.
Patent registration number P1816548: Adaptive antenna device IEICE, “Revised Radar Technology”, pp.119-129: Antenna pattern, pp.134-137: Directivity synthesis, pp260-264: Monopulse angle measurement, pp295-296: SLC method, pp295-296: SLB method Alfonso Farina, “Antenna-Based Signal Processing Techniques for Radar Systems”, Artech House, pp. 170-176 (1992) Nobuyoshi Kikuma, “Adaptive signal processing by array antenna”, Science and Technology Publishing (1999), pp.67-86 Nobuyoshi Kikuma, "Adaptive signal processing by array antenna", Science and Technology Publishing (1999), pp. 35-37, 98-99

  As described above, in the conventional antenna device, when the gain or side lobe of the main antenna is high, the auxiliary antenna for covering the side lobe becomes large, and there are restrictions on dimensions, mass, etc. There was a problem that was difficult to realize.

  The present invention has been made in view of the above circumstances. Even when the gain and side lobe of the main antenna are high, the output of the auxiliary CH that can cover the side lobe is obtained, and the SLC process and the SLB process are performed. An object of the present invention is to provide an antenna device that can be used.

  In order to solve the above problem, an antenna device according to the present invention is configured as follows.

  (1) An antenna device including a main antenna capable of forming N (N is a natural number of 2 or more) multi-beams and L (L is a natural number of 2 or more) auxiliary antennas having a gain lower than that of the main antenna. Of the N multi-beams formed by the main antenna, the side lobe of the main antenna is a reference using M (M is a natural number satisfying M <N) beam signals obtained by shaping an antenna pattern. An angle region higher than the level is covered, and an angle region where the side lobe of the main antenna is lower than a reference level is covered with an auxiliary beam by the L auxiliary antennas.

  In the antenna device having the configuration of (1), the high side lobe region of the main antenna forms a beam using the entire aperture of the main antenna to form an auxiliary beam having a high gain, and the side lobe of the main antenna is low. By covering the region with an auxiliary beam by a small auxiliary antenna, an auxiliary beam signal that efficiently covers the side lobe of the main antenna can be formed.

  (2) An antenna device including a main antenna capable of forming N (N is a natural number of 2 or more) multi-beams and L (L is a natural number of 2 or more) auxiliary antennas having a gain lower than that of the main antenna. Of the N multi-beams used in an environment without interference, when only the Σ beam is used in the interference environment, the phase monopulse Δ beam corresponding to the Σ beam is used to An area higher than the reference level of the side lobe of the beam is covered, and an angle area where the side lobe is lower than the reference level is covered with an auxiliary beam by the L auxiliary antennas.

  In the antenna apparatus having the configuration of (2), when all the Σ beams are used among the plurality of beams, a region having a high side lobe of the main antenna is obtained by using a Δ beam formed in a pair with the Σ beam. An area of the main antenna having a low side lobe is covered with an auxiliary beam of a small auxiliary antenna, so that an auxiliary beam signal that efficiently covers the side lobe of the main antenna can be formed.

  ADVANTAGE OF THE INVENTION According to this invention, even when the side lobe of a main antenna is high, it can provide the antenna apparatus which can implement the process of SLC and SLB, without providing a large sized auxiliary antenna.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a configuration of an antenna apparatus according to the first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a phased array main antenna. A received signal of the main antenna 1 is combined by a power feeding circuit 12 via a transmission / reception module 11 and converted into a digital signal by a receiver 3. Specifically, as shown in FIG. 2, the transceiver module 11 includes a circulator 112 connected to the antenna element 111, and an amplifier 113 and a phase shifter 114 on the transmission side and the reception side (N systems), respectively. Is connected.

  On the other hand, the controller 7 selectively executes the SLC or SLB process according to the disturbance information (presence / absence of disturbance). When executing the processing, the beam switch 4 selects the signals (ba1 to baM) used for the auxiliary beam, and the main beam signals (bm1 to bm (NM)) are sent to the SLC or SLB processor 5 from the auxiliary antenna 2. Input together with received signals (a1 to aL). The basic configuration of the SLC processor is shown in FIG. 3, its processing example is shown in FIG. 4, the basic configuration of the SLB processor is shown in FIG. 5, and its processing example is shown in FIG.

  The SLC processor shown in FIG. 3 includes a delay circuit A1, amplifiers A2 and A3, a narrowband filter including an adder A4, and a weighting circuit including multipliers A5 and A6 and a subtractor A7. As illustrated in FIG. In each of the input signal bands, the interference signal input from the side lobe direction of the main antenna 1 can be canceled by the interference signal input to the auxiliary antenna 2, and thereby the interference signal can be suppressed by an angular filter.

  The SLB processor shown in FIG. 5 includes a comparator B1 that compares the auxiliary CH signal and the main CH signal, and a switch (SW) B2 that selectively derives the main CH signal based on the comparison result. As shown in FIG. 6, the main CH output at the time of occurrence of short pulse interference can be cut off by setting ON when main CH ≧ auxiliary CH and OFF when main CH <auxiliary CH.

  Here, the auxiliary beam signal is shaped so as to cover an angle region where the side lobe of the main beam signal is high by the arithmetic processing of the auxiliary beam arithmetic processor 6 for the main antenna 1. As a forming method, for example, as described below, there is a method by inverse Fourier transform.

First, when the element position vector and the wave vector are defined as shown in FIG.

Next, assuming that the amplitude and phase response of the angular range in which the side lobe of the main antenna 1 is to be reduced is bm, the complex weight (amplitude and phase weight) of the auxiliary beam that approximates the response is the inverse Fourier transform of bm, It is expressed by the following formula.

The auxiliary beam response ba at this time is expressed by the following equation.

  The amplitude and phase may be determined by the auxiliary beam arithmetic processor 6 so that the antenna pattern of the auxiliary CH covers the side lobe of the main CH, as shown in FIG. The calculated amplitude and phase are set in the gain and phase shifter 114 of the amplifier 113 of the transmission / reception module 11 shown in FIG. In the case of controlling only the phase shifter 114, as a simple method, only the phase of Wa is extracted and set in the phase shifter 114 of the transmission / reception module 11. If the main lobe side lobe cannot be covered by control using only the phase, the desired beam pattern used for the inverse Fourier transform is modified and the phase weight is calculated and set in the same manner. .

  In this case, if each of the AZ plane and the EL plane cannot be covered with one beam, it may be set so as to be covered with a plurality of beams (ba1 to baM). FIG. 9 shows the configuration of an SLC processor that realizes multiple beam SLC processing. In this case, the outputs of the SLC systems C11, C12,..., C1m of the auxiliary CH are added by the adder C2, and subtracted from the main CH signal by the subtractor C3, thereby forming nulls corresponding to the number of disturbances. Can do.

  Although FIG. 9 shows the case of a multi-loop MSN system (see Non-Patent Document 2), the Gram Schmitt system (see Patent Document 1), a direct solution system (see Non-Patent Document 3), etc. that are connected in cascade. Needless to say, other methods may be used.

  However, in the case of using a plurality of circuits, the input of SLC and SLB circuits increases, which increases the circuit scale. The region where the side lobe of the main beam is low may be covered using auxiliary antenna signals (a1 to aL).

Using this auxiliary CH signal, SLC processing or SLB processing is performed. In the SLC process, as shown in FIG. 4, the weight W is controlled by performing an operation represented by the following expression on the interference signal included in the main CH signal (Σ, ΔAZ, ΔEL) using the control CH signal. Then, the control CH is subtracted from the main CH to suppress the interference signal. The recurrence formula (n: number of iterations) of the weight W is as follows.

  The above shows the case of the MSN method (Non-Patent Document 2), but it goes without saying that other methods such as the Gram Schmitt method (Patent Document 1) and the direct solution method (Non-Patent Document 3) may be used.

Further, as shown in FIG. 6, the SLB process is a circuit that compares the levels of the main CH and the auxiliary CH and determines whether the main CH signal is ON / OFF by the following equation.

This is effective for pulse jamming in order to avoid false detection by turning off the receiver during the jamming pulse time.

  In the above, the SLC process and the SLB process have been described separately, but it goes without saying that both the SLC process and the SLB process may be applied.

  Further, the case of Σ, ΔAZ, and ΔEL has been described as the monopulse output (Non-Patent Document 1), but it goes without saying that the present invention can be applied only to Σ and ΔAZ (or ΔEL).

  Although the inverse Fourier transform method of the desired pattern has been described as the auxiliary beam shaping method, it goes without saying that other methods may be used as long as the beam forming method covers the side lobe of the main beam.

(Other embodiments)
Another embodiment is a method of selecting a Δ beam as an auxiliary beam when the main beam signal needs to use all of the Σ beam in an interference environment. This is shown in FIG. Also in this case, the low angle region of the side lobe of the main beam is covered with the auxiliary antenna. If this Δ beam and the signal of the auxiliary antenna are input to the SLC or SLB processor, it can be realized by the same processing as in the first embodiment.

  The above embodiment has been described in the case of a planar antenna, but it goes without saying that it is effective even in the case of a one-dimensional antenna.

  Further, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

1 is a block diagram showing a configuration of an antenna device according to a first embodiment of the present invention. The block diagram which shows the specific structure of the transmission / reception module of the radar apparatus shown in FIG. The block diagram which shows the basic composition of the SLC processor used for the radar apparatus shown in FIG. The figure for demonstrating the processing operation of the SLC processor shown in FIG. The block diagram which shows the basic composition of the SLB processor used for the radar apparatus shown in FIG. The figure for demonstrating the processing operation of the SLB processor shown in FIG. The figure which shows the example of a definition of an element position vector and a wave vector in the case of employ | adopting the inverse Fourier transform method of a desired pattern as an auxiliary beam forming method of the radar apparatus shown in FIG. The figure which shows a mode that the antenna pattern of auxiliary CH formed the pattern so that the side lobe of main CH might be covered in the radar apparatus shown in FIG. The block diagram which shows the structure of the SLC processor which implement | achieves SLC process of multiple beams. As another embodiment, a waveform diagram illustrating a method of selecting a Δ beam as an auxiliary beam when the main beam signal needs to use all of the Σ beam in an interference environment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Main antenna, 11 ... Transmission / reception module, 111 ... Antenna element, 112 ... Circulator, 113 ... Amplifier, 114 ... Phase shifter, 12 ... Feeder circuit, 2 ... Receiver, 3 ... Receiver, 4 ... Beam switch, 5 ... SLC or SLB processor, 6 ... Auxiliary beam arithmetic processor, 7 ... Controller.

Claims (2)

An antenna apparatus including a main antenna capable of forming N (N is a natural number of 2 or more) multi-beams and L (L is a natural number of 2 or more) auxiliary antennas having a gain lower than that of the main antenna. ,
Of the N multi-beams formed by the main antenna, an angle at which the side lobe of the main antenna is higher than a reference level using M beam signals (M is a natural number satisfying M <N) formed with an antenna pattern. An antenna device that covers a region and covers an angle region in which a side lobe of the main antenna is lower than a reference level with an auxiliary beam by the L auxiliary antennas. An antenna apparatus including a main antenna capable of forming N (N is a natural number of 2 or more) multi-beams and L (L is a natural number of 2 or more) auxiliary antennas having a gain lower than that of the main antenna. ,
Among the N multi-beams used in an environment without interference, when only the Σ beam is used in the interference environment, the side lobe of the Σ beam is obtained by using the phase monopulse Δ beam corresponding to the Σ beam. An antenna device characterized in that an area higher than the reference level is covered and an angle area whose side lobe is lower than the reference level is covered with an auxiliary beam by the L auxiliary antennas.

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