JPH05259727A - Antenna system - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain an antenna device provided with an excitation phase calculation means capable of calculating the phase setting amount of a phase shifter in a short calculation time. [Constitution] The conventional element electric field vector rotation method is applied only to selected element antennas, and at least for element phase shifters of element antennas other than the above, a predetermined direction and element calculated based on the values obtained by the above method Excitation phase calculating means for obtaining the phase shift amount of the phase shifter based on the relationship between the distance between the antennas and the phase difference and determining the phase setting amount of the phase shifter of all the element antennas required to direct the main beam in a predetermined direction. Equipped with.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device having an excitation phase calculating means capable of calculating the phase setting amount of a phase shifter for changing the phase of an element antenna in a short calculation time.

[0002]

2. Description of the Related Art FIG. 8 and FIG. 9 are principles for explaining a conventional excitation phase calculating means for obtaining the excitation amplitude phase of a phased array antenna, which is shown in the IEICE Transactions J65-B (May 1982). FIG. 10 is a configuration diagram of a phased array antenna necessary for explaining a conventional excitation phase calculation means. In the figure, A1 is the first element antenna, An is the nth element antenna, P1 is the first phase shifter, and Pn is the nth phase shifter.

Excitation phase calculation means for obtaining the excitation amplitude and phase in the conventional antenna device will be described below with reference to FIGS. 8, 9 and 10. E ₀ and Φ _{0 in} FIG. 8 are the amplitude and phase of the combined electric field obtained by combining the signal waves received by the element antennas A1, A2, ... AN by the power combiner 4, and E _n and Φ
_n is the amplitude and phase of the received electric field of the n-th element. Figure 9
Of Δ is the phase change of the nth phase shifter, Q ₁ is the combined power due to the phase change of the nth phase shifter, and k is n for E ₀ .
The relative amplitude of the nth element, Y, is a function of the relative phase of the nth element with respect to Φ ₀ .

Generally, the combined electric field vector of the phased array antenna can be represented by combining the electric field vectors of the respective elements as shown in FIG. Further, if the phase of each element is changed by the phase shifter that changes the phase of each element antenna, all the element electric field vectors can be combined into one long vector, and the gain becomes maximum under the given amplitude condition. .. First, the display expressions of the relative amplitude k and the relative phase X of the n-th element are given by the following expressions.

[0005]

[Equation 1]

Next, the complex composite electric field when the phase of the n-th element is changed by Δ is

[0007]

[Equation 2]

Therefore, the combined relative power can be expressed as follows.

[0009]

[Equation 3]

From this, it is understood that the change in the combined power Q ₁ with respect to the phase change Δ of the n-th element is a cosine change having an amplitude of 2 kY which is superimposed on the constant bias Y ² + k ² as shown in FIG. .. Here, if the maximum / minimum ratio of Q ₁ is set to r ² as follows,

[0011]

[Equation 4]

Further, -Δ ₀ is a phase value which gives the maximum value of Q ₁ . By measuring Q ₁ with respect to the phase change, r and Δ ₀ are related to each other, whereby the relative amplitude and relative phase of the n-th element are obtained.

When this method is used to direct the main beam direction of the radiation pattern of the antenna device to the direction of arrival of the signal wave arriving at the antenna device, the phase opposite to the relative phase obtained here is transferred as the excitation phase. The phaser control circuit 6 may be given to each phase shifter.

[0014]

In the conventional antenna device, especially when the main beam direction of the radiation pattern of the antenna device is directed in the direction of arrival of the signal wave arriving at the antenna device, the phase of all element antennas is changed and the excitation is performed. There is a problem that the calculation time becomes long because the phase is obtained.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain an antenna device having an excitation phase calculation means capable of calculating the phase setting amount of a phase shifter in a short calculation time. And

[0016]

An antenna device according to a first aspect of the present invention comprises M element antennas, a phase shifter for changing the phase of the element antennas, and an input / output signal to / from the phase shifter. A power combiner / distributor and at least a receiver for receiving the signal combined by the power combiner / distributor or a transmitter for transmitting a signal to the power combiner / distributor;
The phase shifter control means for controlling the phase shifter and the phase shifter of the M element antennas are initially set so that the main beam is directed in the reference direction, and N of the M element antennas are set. For each (2 ≦ N <M) element antenna, the phase shift amount of the phase shifter required to direct the main beam in a predetermined direction from a change in signal level by sequentially controlling the phase shifters of each element antenna. Then, the predetermined direction is calculated from the phase shift amount, and for at least the phase shifters of the element antennas other than N, based on the calculated predetermined direction and the relationship between the distance between the element antennas and the phase difference. To obtain the phase shift amount of the phase shifter and direct the main beam in the predetermined direction.
And an excitation phase calculation means for determining the phase setting amount of the phase shifter of each element antenna.

An antenna device according to a second aspect of the present invention comprises M element antennas, a phase shifter for changing the phase of the element antennas,
A power combiner / distributor that distributes or combines input / output signals to and from the phase shifter, and a signal is transmitted to at least a receiver that receives the signal combined by the power combiner / distributor or the power combiner / distributor. A transmitter, a phase shifter control means for controlling the phase shifter, and an initial phase memory storing initial phase shift values of the M element antennas, and N of the M element antennas are included. For the element antennas of (2 ≦ N <M), the initial phase is set so that the main beam is directed to the phase shifters of the respective element antennas in the reference direction, and the phase shifters of the respective element antennas are sequentially controlled. The phase shift amount of the phase shifter required to direct the main beam in a predetermined direction from the change in the signal level, the predetermined direction is calculated from the phase shift amount, and the phase shift of at least the element antennas other than N For vessels, the above calculation Based on the relationship between the predetermined direction and the distance between the element antennas and the phase difference, the phase shift amount of the phase shifter is calculated. Excitation phase calculation means for determining a phase setting amount of the phase shifter of the M element antennas necessary for directing the main beam in the predetermined direction by correction by calculation using the initial phase value of the initial phase memory. Be prepared.

[0018]

In the antenna device of claim 1, the conventional element electric field vector rotation method is applied only to the selected element antenna,
At least for the phase shifter of the element antenna other than the above, the phase shift amount of the phase shifter based on the relationship between the predetermined direction calculated based on the value obtained by the above method and the distance between the element antennas and the phase difference. Since the excitation phase calculating means for determining and determining the phase setting amount of the phase shifter of all element antennas required to direct the main beam in the predetermined direction is provided, the phase setting amount of the phase shifter of all element antennas can be calculated in a short calculation time. Can be determined.

According to another aspect of the antenna device of the present invention, the initial phase memory stores the initial phase values of the element antennas, and the N element antennas (2 ≦ N <M) of the M element antennas are respectively stored. The initial phase setting is performed so that the main beam is directed to the phase shifter of the element antenna of (1) and the phase shift amount of the phase shifter of the M element antennas is obtained, and the phase shift of the element antennas other than the above N The amount is corrected by calculation using the initial phase value of the above initial phase memory of each element antenna, and the phase setting amount of the phase shifter of all element antennas required to direct the main beam in a predetermined direction is determined. Since the excitation phase calculating means is provided, it is possible to accurately determine the phase setting amounts of the phase shifters of all the element antennas in a short calculation time even if the initial phases of the element antennas vary.

[0020]

EXAMPLES Example 1. FIG. 1 is an explanatory view showing an antenna device having a phased array antenna on a moving body according to an embodiment of the present invention, showing a phase shifter for changing a phase of an element antenna of the phased array antenna for a signal wave from a satellite. It is a conceptual diagram of the system which tracks by controlling.
In the figure, 1 is a communication satellite, 2 is a moving body, and 3 is an antenna device having a phased array antenna. FIG. 2 is a configuration diagram showing an antenna device according to an embodiment of the present invention. In the figure, 4 is a power combiner / distributor for distributing or combining input / output signals to / from a phase shifter for changing the phase of an element antenna. A power combiner, 5 is a receiver for receiving the signal combined by the power combiner 4, 6 is a phase shifter control circuit, and 7 is an excitation phase calculation circuit which is an excitation phase calculation means. It should be noted that the present invention is described here by showing the receiving system, and the description of the transmitting system is omitted because it is reversible.

In the conventional antenna device, when the radiation pattern is directed in the main beam direction, the excitation phase is determined by obtaining the relative phases of all M element antennas and applying the opposite phases. In the antenna device of the present invention, in order to increase the calculation speed while maintaining accuracy, N (N ≦ M) element antennas are selected from among M element antennas, and this operation is performed, and the rest (MN). The individual element antennas are assumed to have linearity and are interpolated or extrapolated to determine the phase setting amount of the phase shifter by the excitation phase calculation circuit 7.

FIG. 3 is a flowchart showing the operation of the excitation phase calculating means of the antenna device according to the first embodiment.
First, in steps 1 and 2, the initial phase is set to 0 ° for all elements, and the initial phase of each element antenna is obtained using the conventional element electric field vector rotation method. Using this value, the beam is directed toward the broadside direction of the antenna. Set the phase shifter to. Next, reception is performed from one direction θ which is step 3, and in step 4, any N (2 ≦ N <
M) element antennas are selected, the phase shifters of the respective element antennas are sequentially controlled, and the phase shift amount of the phase shifter required to direct the main beam in a predetermined direction from the change in the signal level is obtained. In step 5, the receiving direction θ is calculated by performing interpolation or extrapolation from the phase shift amount of the N element antennas obtained in step 4 using, for example, the least square method. The above calculation result is θ ′
Then, θ ′ is expressed by the equation (5).

[0023]

[Equation 5]

Further, from the above equation (5), equation (6) is obtained,

[0025]

[Equation 6]

In steps 6 and 7, the phase setting amount Ψ n from the element antenna selected as the reference for the M element antennas is determined from the equation (6), and the phase shifter control circuit is arranged to direct the main beam in the receiving direction θ. 6 controls a phase shifter that changes the phase of the M element antennas.

Example 2. Next, an example will be described in which the arbitrary number N of element antennas selected in the antenna device of the above-described example 1 is set to two. Two element antennas are selected from all the M element antennas, and the element antennas selected as the reference for the M element antennas are selected in the same manner as in the case of selecting the N element antennas in the first embodiment. Determine the phase setting amount.

In FIG. 4, the receiving direction in the second embodiment is 8
It is the radiation pattern of the beam when the phase is excited as °. Further, for comparison, the radiation pattern of the beam when the phase of all the elements is changed by the signal wave arrival direction detector to determine the excitation phase is shown in FIG. From the comparison between FIG. 4 and FIG. 5, also in the second embodiment in which the first embodiment is further simplified,
It is proved that the phase setting amount of the phase shifter can be calculated in a short calculation time, and an antenna device having a radiation pattern with the same accuracy as in the past can be obtained.

Example 3. FIG. 6 is a configuration diagram showing an antenna device according to another embodiment of the present invention. In the figure, reference numeral 8 is an initial phase memory which constitutes excitation phase calculation means and stores initial phase data of the element antenna. Are the same as those shown in FIG. It should be noted that the present invention is described here by showing the receiving system as in FIG. 2, and the description of the transmitting system is omitted because it is reversible.

FIG. 7 is a flowchart showing the operation of the excitation phase calculating means of the antenna device according to the third embodiment.
First, in step 1, the initial setting phase is set to 0 ° for all elements, the initial phase of each element antenna is obtained using the conventional electric field vector rotation method, and this value is stored in the initial phase memory 8. Next, in step 2, arbitrary N (2 ≦ N <M) element antennas are selected from all M element antennas, and the phase shifter is set so that the beam is directed in the broadside direction of the antenna. In order to direct the main beam in a predetermined direction from the change in the signal level, the phase shifters of the N element antennas selected in step 2 are controlled in order by receiving in one direction θ which is step 3. The required phase shift amount of the phase shifter is calculated, and the reception direction θ is calculated by performing interpolation or extrapolation using the least square method or the like from the phase shift amount of the N element antennas calculated in step 4 in step 5. .. Assuming that the above calculation result is θ ′, θ ′ is expressed by the above equation (5). Further, the above equation (6) is obtained from the equation (5), and in step 6, the phase shift setting amount Ψ _n from the element antennas is determined by selecting the M element antennas from the equation (6) as a reference, and the step With respect to the phase setting amount Ψ _n obtained in step 6 in steps 7 and 8, the initial phases Ψ _n0 of element antennas other than the N element antennas selected in step 2 are retrieved from the initial phase memory 8 and the following (7)
And the initial phase correction of [psi _n of N elements element antennas other than the antenna selected by the expression 'seek, [psi _n or [psi _n' [psi _n phase shift to direct the main beam to the receiving direction θ on the basis of the The controller control circuit 6 controls the phase shifter that changes the phases of the M element antennas.

[0031]

[Equation 7]

As described above, according to the third embodiment, even if the initial phase of the element antenna varies, the initial phase correction is simply performed to determine the set amount of the phase shifter, so that the accuracy can be reduced in a short calculation time. There is an effect that the set amount of the phase shifter is well determined and an antenna device having a desired radiation pattern can be obtained.

[0033]

According to the invention of claim 1, there is an effect that the determination can be made in a short calculation time.

According to the second aspect of the invention, there is an effect that the set amount of the phase shifter can be accurately determined in a short calculation time even when there is an initial phase variation of the element antenna.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a system for tracking a signal wave from a satellite by controlling a phase shifter that changes the phase of an element antenna of a phased array antenna according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing the antenna device according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing the operation of the excitation phase calculation means of the antenna device according to the first embodiment of the present invention.

FIG. 4 is a beam radiation pattern diagram when an antenna device according to a second embodiment of the present invention obtains a receiving direction of 8 °.

FIG. 5 is a radiation pattern diagram of a beam in a receiving direction of 8 ° obtained by a conventional antenna device.

FIG. 6 is a configuration diagram showing an antenna device according to a third embodiment of the present invention.

FIG. 7 is a flowchart showing the operation of the excitation phase calculation means of the antenna device according to the third embodiment of the present invention.

FIG. 8 is a conceptual diagram of an array element electric field vector rotation method for explaining a conventional excitation phase calculation means.

FIG. 9 is an explanatory diagram showing a change in combined power in an array element electric field vector rotation method for explaining a conventional excitation phase calculation means.

FIG. 10 is a configuration diagram of a conventional antenna device.

[Explanation of symbols]

 1 Communication Satellite 2 Mobile 3 Antenna Device Having Phased Array Antenna 4 Power Combiner 5 Receiver 6 Phase Shifter Control Circuit 7 Excitation Phase Calculation Circuit 8 Initial Phase Memory

[Procedure amendment]

[Submission date] September 2, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

[Figure 7]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Kataki 5-1-1 Ofuna, Kamakura-shi Electronic Systems Research Center, Mitsubishi Electric Corporation

Claims (2)

[Claims] 1. M element antennas, a phase shifter for changing the phase of the element antennas, a power combiner / divider for distributing or combining input / output signals to / from the phase shifter, and at least the power combiner / combiner. A receiver for receiving the signal combined by the distributor or a transmitter for transmitting the signal to the power combiner / distributor, a phase shifter control means for controlling the phase shifter, and a shift of the M element antennas. The initial phase is set so that the main beam is directed to the phase shifter in the reference direction, and for the N (2 ≦ N <M) element antennas of the M element antennas, the phase shifter of each element antenna is set. The phase shift amount of the phase shifter required to direct the main beam in a predetermined direction is obtained by controlling the signal levels in sequence, and the predetermined direction is calculated from the phase shift amount. Regarding the element antenna phase shifter , The phase shift amount of the phase shifter is calculated based on the calculated predetermined direction and the relationship between the distance between the element antennas and the phase difference, and the M element antennas required to direct the main beam in the predetermined direction are moved. An antenna device comprising: an excitation phase calculation means for determining a phase setting amount of a phaser. 2. M element antennas, a phase shifter that changes the phase of the element antennas, a power combiner / divider that distributes or combines input / output signals to and from the phase shifter, and at least the power combiner / combiner. A receiver for receiving the signal combined by the distributor or a transmitter for transmitting the signal to the power combiner / distributor, a phase shifter control means for controlling the phase shifter, and an initial stage of the M element antennas. It has an initial phase memory for storing phase values, and N (2
For the element antennas of ≦ N <M), the initial phase is set so that the main beam is directed to the phase shifters of the respective element antennas in the reference direction, and the phase shifters of the respective element antennas are sequentially controlled to output signals. The phase shift amount of the phase shifter required to direct the main beam in a predetermined direction from the level change is calculated, the predetermined direction is calculated from the phase shift amount, and at least the phase shifters of the element antennas other than N are described. Is the phase shift amount of the phase shifter based on the calculated predetermined direction and the relationship between the distance between the element antennas and the phase difference. For the phase shift amounts of the element antennas other than N, respectively, Excitation phase for determining the phase setting amount of the phase shifter of the M element antennas necessary for directing the main beam in the predetermined direction by correcting the initial phase value of the initial phase memory of the element antenna of Computing means Antenna apparatus characterized by having a.