JPS5994903A - Phased array antenna - Google Patents

Abstract

PURPOSE:To simplify the constitution and to reduce the total weight by shifting the vertical direction of the array plane of a primary radiator comprising plural arrays. CONSTITUTION:The vertical direction of the array plane of array feeding circuits 10, 10' is made different. The array feeding circuits 10, 10' are placed at a position apart from a sub-reflection mirror 2', further from the position of the real image of a main reflection mirror 1' fromed by the subreflection mirror 2'. The array feeding circuts 10, 10' use the main reflection mirror 1' in common and form two beams. A signal inputted to a terminal 4'' is divided by a power divider 5'' and irradiated from a radiator 9' after being phase-shifted by a prescribed amount at a phase shifter 6''. No multiplexer (or power synthesizer) is required. Since a power amplifier 8' only amplifies a single signal, it is operated at a nonlinear region.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microwave antenna device, and more particularly to a phased array antenna that has a simple structure, is highly efficient, and forms a plurality of antenna beams whose directions can be changed.

FIG. 1 is a diagram explaining a conventional 7-aided array antenna, in which 1 is a main reflector, 2 is a sub-reflector, and main reflector 1
The sub-reflector 2 is formed of a part of a paraboloid of revolution which makes the focal point F and the axis S equal. 3 is an array power supply circuit.

Although this antenna also operates as a receiving antenna, it will be described here as a transmitting antenna.

The array power supply circuit 3 includes an array composed of a plurality of radiating elements arranged so that their apertures are located on the same plane, and includes a focal length f1 of the main reflecting mirror 1 and a focal length f3 of the sub-reflecting mirror 2. It is installed at a point away from the sub-reflector by a distance d that satisfies fl''h d f*.The point is the position of the geometrical optical real image of the main reflector formed by the sub-reflector. The antenna beams in each direction are radiated from the same array feeding circuit, and for example, the antenna beams are formed in the directions shown by solid lines and broken lines in FIG. FIG. 2 is a block diagram showing a configuration example, and shows a case where two beams are formed.

In Figure 2, 4.4' is an input terminal, 5.5' is a power divider, 6.6' is a phase shifter, 7 is a multiplexer (or power combiner), 8 is a power amplifier, and 9 is a power amplifier. It is a radiating element.

2 corresponding to each beam input from input terminal 4.4'
The signals are power divided by a power divider 5.5', respectively;
A phase amount corresponding to a predetermined beam direction is set in a phase shifter 6, 6', two signals are combined (or power combined) in a multiplexer (or power combiner) 7, and a common amplification is performed in a power amplifier 8. After that, it is radiated from the radiating element 9. In such a configuration, a multiplexer (t or power combiner) 7 is required,
Furthermore, since wiring that takes phase changes into consideration is required, there is a drawback that the circuit scale becomes large.

Furthermore, since the power amplifier 8 commonly amplifies two signals, it has the disadvantage that it must be operated in a linear region with low power efficiency to avoid cross-modulation. Another example is a method of multiplexing (or power combining) on the output side of the power amplifier 8, but in this case too, there is a lot of power loss, and the space between the power amplifier 8 and the radiating element 90 is generally narrow. The drawback was that wiring was difficult.

In order to eliminate these drawbacks, the present invention provides a different array for each antenna beam, and will be described in detail below with reference to the drawings.

FIG. 3 is a diagram illustrating an embodiment of the present invention, 1'
is a main reflecting mirror, 2' is a sub-reflecting mirror, and the main reflecting mirror 1' and the sub-reflecting mirror 2' are part of a paraboloid of revolution that makes the focal point F and axis S equal, and the paraboloid of the concave part is have. 10.1
0' is an array power supply circuit, and the directions shown by solid lines and broken lines are perpendicular to one plane of the array. By installing the array power supply circuit 10.10' at a position further away from the sub-reflector 2' than the position of the real image of the main reflector 1' formed by the sub-reflector 2', the main reflector 1 ', and form two beams.

Figure 4 is a block diagram showing the configuration of each array power supply circuit in Figure 3, where 4' is an input terminal, 5' is a power divider, 6' is a phase shifter, 8' is a power amplifier, and 9' is a radiation It is element. The signal input from the input terminal 4' is divided by the power divider 5', a phase amount corresponding to a predetermined beam direction is set in the phase shifter 6', and after being amplified by the power amplifier 8', the signal is sent to the radiating element. It is radiated from 9'. As is clear from Figure 4,
According to this configuration, a multiplexer (or power combiner) is not required. Furthermore, since the power amplifier 8' amplifies a single signal, it can be operated in a nonlinear region with high power efficiency.

Note that although Figure 3 shows the case where the entire main reflecting mirror is shared,
It is also possible to share only a part of the arrays depending on the maximum gain direction of each array. Further, the configuration shown in FIG. 3 can be expanded to three beams or more, and can also be operated as a receiving antenna based on the antenna reversibility theorem.

FIG. 5 is a diagram illustrating another embodiment.

In Figure 5, 1' is the main reflector, 2' is the sub-reflector,
The main reflector I'' and the sub-reflector 2' have a focal point F and an axis S.
is a part of a paraboloid of revolution that equalizes . Reference numerals 11 and 11' designate array power supply circuits in which the directions indicated by solid lines and broken lines are perpendicular to the plane of the array, respectively. Therefore, as shown by the broken line in FIG. 5, the wave radiated from the array power supply circuit 11' uses a part of the main reflecting mirror.

Since the irradiation area of an antenna using a reflector is inversely proportional to the area of the reflector aperture, the area of the area irradiated by the array power supply circuit 11' is much larger than the area of the area irradiated by the array power supply circuit 11.

As explained above, the phased array antenna according to the present invention does not require a multiplexer (or power combiner) and wiring to connect them, so it can be used for multiple antennas using a simple array power supply circuit. Since it is possible to form a beam and only a single signal needs to pass through each array feed circuit, the power amplifier can be used in the nonlinear region with high power efficiency, and the requirements for frequency characteristics are relaxed. It has the advantage of being able to

Therefore, the phased array antenna according to the present invention has the advantage that it has large restrictions on weight and power consumption, and is suitable for communication satellites that transmit broadband signals.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating a conventional phased array antenna, FIG. 2 is a block diagram illustrating a configuration example of the array power supply circuit in FIG. 1, and FIG. 3 is a diagram illustrating an embodiment of the present invention. , FIG. 4 is a block diagram showing the configuration of each array power supply circuit shown in FIG. 3, and FIG. 5 is a diagram illustrating another embodiment. 1.1', 1'... Main reflecting mirror, 2.2'
, 2'...... Sub-reflector, 3...
...Array power supply circuit, 4°4', 4'...
...Input terminal, 5.5', 5'... Power divider, 6.6', 6'... Phase shifter, 7
...... Multiplexer (or power combiner), 8.
8'-... Power amplifier, 9.9'...
...Radiating element, 10.10'...Par array power supply circuit, 11.11'...Array power supply circuit, F... Focus, S...
...Axis agent Patent attorney Takashi Honma 15
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Claims (2)

[Claims] (1) One of the two parabolic mirrors with the same focal point and axis is used as the main reflector, and the other is the sub-reflector, and an array consisting of a plurality of radiating elements arranged facing the sub-reflector is used as the primary reflector. In a 7-aided array antenna used as a radiator, a plurality of arrays are arranged at positions further away from the sub-reflector from the position of the real image of the main reflector formed by the sub-reflector, and the vertical direction of the array plane is different from each other. A phased array antenna is characterized in that a plurality of antenna beams are formed by arranging primary radiators consisting of: (2) A seven-aided array antenna according to claim 1, in which a plurality of antenna beams with different irradiation areas are formed by a plurality of arrays having one plane of arrays with different areas.