JP2014082794A - Active array antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active array antenna device that implements a high sensitivity reception system by reducing internal noise of low noise amplifiers.SOLUTION: The active array antenna device includes: M low noise amplifiers 8 for amplifying M reception signals of M reception filters 7 for passing a predetermined band of reception signals received by M antenna elements; M dividers 9 for dividing M respective amplification signals into N division signals; N phase shifters 10 disposed for each divider to shift phases of the N division signals; N attenuators 11 for attenuating N phase shift signals; N beam combination circuits 12 disposed in correspondence with the N attenuators to additively beam-combine attenuator outputs of the corresponding attenuators past the M dividers; heat insulating containers 6 housing the low noise amplifiers and the reception filters made of a superconductive material; a cooling section 69 for cooling the reception filters and the low noise amplifiers to bring the reception filters in a superconducting state; and a cooling plate. Part of the M reception filters and the M low noise amplifiers are dividedly housed in a plurality of heat insulating containers.

Description

  Embodiments described herein relate generally to an active array antenna device used as a receiving antenna for a radar, a communication system, a microwave radiometer, a radio wave receiving system, and the like.

  Radar performance is represented by a radar equation. In order to improve radar performance, (a) increase in transmission peak power, increase in pulse width, (b) increase in antenna gain, (c) use of a long wavelength, ( d) Reduction of system noise temperature, (e) Reduction of system loss, etc.

  There are many restrictions on the increase in the transmission peak power and the increase in the size of the antenna, which leads to an increase in the system scale. Therefore, there are certain limitations in implementation. In addition, it is difficult to use a long wavelength due to a recent shortage of radio wave resources.

  In addition, a target that intentionally reduces radio wave reflection, such as stealth, appears, and there is a strong demand for improving radar performance. In order to cope with this, high-sensitivity reception performance is required, and reduction of system loss and reduction of system noise temperature are required.

  There are various items in the system loss, but a typical item is a transmission power loss from the transmitter to the antenna. In order to reduce transmission power supply loss, an active array antenna using a number of modules called transmission / reception modules in which a transmission amplification function, a transmission / reception switching function and a reception function are integrated is used, and an active phased array system is mainly used.

  The active phased array system incorporates a transmission / reception switching function between each antenna element and phase shifter, and both a transmission amplifier in the transmission system and a low-noise amplifier ((LNA)) for reception in the reception system. This is an antenna system in which modules called transceiver modules incorporating (or one) are arranged.

  When a transmission amplifier is incorporated in a transmission / reception module, the module is placed close to the antenna element, so power loss due to the waveguide does not occur, and loss due to components that minimize transmission power loss (such as circulators) Can only be suppressed.

In addition, when a reception LNA is incorporated in the transmission / reception module, loss during reception can be reduced and a multi-beam can be formed. In other words, since the reception signal amplified by the LNA can be distributed to a plurality of signals without degrading the S / N, a plurality of independent reception beams can be formed by the distributed reception signals.
An active phased array antenna has a plurality of reception beams, so that it can simultaneously cope with different targets and can realize various functions simultaneously and independently. It can be seen that an active array in which at least a receiving LNA is provided for each antenna element is suitable for multi-functionalization requiring a multi-beam.

  In order to realize a plurality of reception beams (reception multi-beams), after distributing the reception signals for each antenna element amplified by the LNA by the required number of reception beams, amplitude weights and beam pointing for sidelobe suppression are performed. There is a problem that the number of received beams is required to synthesize a signal after passing through an attenuator, a phase shifter, and the like that apply phase weights for direction control, and the system scale increases.

JP 2000-236206 A

  However, even with an active phased array antenna, the power loss from the antenna to the low-noise amplifier has been reduced to zero, and the internal noise of the low-noise amplifier has been reduced, making it impossible to achieve high sensitivity in the receiving system. .

  The problem to be solved by the present invention is that an active array antenna apparatus which can reduce the internal noise of the low noise amplifier and increase the sensitivity of the receiving system while reducing the power supply loss from the antenna to the low noise amplifier to zero. Is to provide.

  According to the active array antenna apparatus according to the embodiment, M reception filters that pass a predetermined band with respect to reception signals received by M (M ≧ 2) antenna elements or antenna subarrays, and the M reception filters. For each of the M low-noise amplifiers that amplify the M reception signals from the reception filters and the M amplification signals amplified by the M low-noise amplifiers, N amplification signals ( N ≧ 2) distributed to the distribution signals of N ≧ 2), and N sets of M number of units that are provided for each of the distributors and phase-shift the phases of the N distribution signals distributed by the distributor. A phase shifter, N sets of M phase attenuators for attenuating N sets of M phase shift signals from the N sets of M phase shifters, and N sets of M attenuators; By adding the attenuator outputs for the M distributors for each attenuator, A heat insulating container for storing the N beam combining circuits for combining the system, the reception filter composed of the low noise amplifier and the superconducting material, the reception filter stored in the heat insulating container, and the low A cooling means for cooling the noise amplifier and bringing the reception filter into a superconducting state; and a cooling plate that is housed in the heat insulating container and on which the reception filter and the low noise amplifier are mounted and that is cooled by the cooling unit. The M reception filters and a part of the M low noise amplifiers are divided and accommodated in the plurality of heat insulating containers.

1 is a configuration block diagram of an active array antenna device according to a first embodiment. It is sectional drawing of the vacuum vessel with which the receiving filter and low noise amplifier of the active array antenna apparatus which concern on 1st Embodiment were enclosed. It is a block diagram of the configuration of the active array antenna device according to the second embodiment. It is a block diagram of the configuration of the active array antenna device according to the third embodiment. It is a block diagram of the configuration of the active array antenna device according to the fourth embodiment. It is a block diagram of the configuration of the active array antenna device according to the fifth embodiment. It is a block diagram of the configuration of the active array antenna device according to the sixth embodiment. It is a block diagram of the configuration of the active array antenna device according to the seventh embodiment. It is a structure block diagram of the active array antenna apparatus which concerns on 8th Embodiment. It is a block diagram of the configuration of the active array antenna device according to the ninth embodiment.

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

First embodiment

  The active array antenna apparatus according to the first embodiment employs an active phased array system incorporating at least a reception LNA, adopts a DBF (Digital Beam Forming) system that forms a plurality of independent reception beams (multi-beams), and Realize multiple functions. Note that the embodiment is not limited to the DBF method. In this active array antenna device, the feed loss from the antenna to the low-noise amplifier is made close to zero, and the internal noise of the low-noise amplifier is reduced to increase the sensitivity of the receiving system.

  First, the system noise temperature in the receiving antenna will be described. The system noise temperature is a numerical value that determines the noise level in the receiving system, and the multiplication output obtained by multiplying the product of the system noise temperature and the receiving system bandwidth by a constant (Boltzmann constant) is the noise power in the receiving system. . For this reason, if the system noise temperature is reduced, the S / N of the received signal can be directly improved, and the sensitivity of the receiving system can be increased.

  In general, the system noise temperature is represented by the system noise temperature Ts at the antenna output end, and the noise (Ta) incident from the outside of the antenna output to the antenna output (reception) end and the feed system from the antenna to the LNA. It is composed of noise (Tr) due to loss, LNA internal noise (Te) added by the LNA, and noise added by the receiving system after the LNA.

  The influence of the noise added in the receiving system after the LNA can be ignored by taking design considerations such as sufficiently increasing the gain of the LNA. Then, the calculation formula of the system noise temperature is as follows.

Ts = Ta + Tr + Lr * Te
Under general conditions, it is expressed as
Ta = (0.876 * Tsky + 36) / La + Tta * (1-1 / La)
Tr = Ttr * (Lr-1)
Te = To * (Fn-1)
Here, Tsky: Sky noise temperature, La: Antenna ohmic loss, Tta: Antenna temperature Ttr: Feed system temperature, Lr: Feed system loss, To: Equipment (LNA part) temperature, Fn: LNA noise index. In a normal design, Tta = Ttr = To = 290K is used as the standard temperature of each part of the equipment.

  From the above formula, the system noise temperature can be reduced by reducing each loss and reducing the noise figure of the LNA (sky noise, which is noise coming from outside, is not subject to environmental noise). Further, the system noise temperature can be reduced by lowering the temperature by cooling.

Here, a calculation example of the system noise temperature in the virtual reception system configuration is shown. In the calculation example, the representative value is approximately 50K (equivalent to an elevation angle of 2 degrees) in a microwave band of 1 GHz to 10 GHz where sky noise temperature is frequently used by radar.
Tsky = 50K; Sky noise temperature
Tta = Ttr = To = 290K; Standard equipment temperature La = 0.2 dB; Antenna ohmic loss Lr = 5 dB; Feed system loss Fn = 3 dB; LNA noise figure Ta = 89 K, Tr = 627 K, Te = 289 K → Ts = 1629 K It is.
Here, if other conditions are not changed and Lr = 0 dB and Fn = 1 dB,
Ta = 89K, Tr = 0K, Te = 75K → Ts = 164K
It becomes. When the system noise temperature becomes 1/10, the S / N can be improved by 10 dB. That is, the power loss from the antenna to the LNA is brought close to zero, and at the same time, the internal noise added by the LNA is reduced as much as possible. That is, the sensitivity of the receiving system can be increased by reducing the LNA noise figure (Fn) as much as possible.

  Thus, by applying an active phased array in which a large number of antenna elements are arranged, multi-beam formation and high reception sensitivity can be realized simultaneously. In order to make effective use of the characteristics of the active antenna, this embodiment uses a superconducting transmission line from the antenna to the LNA to make the loss close to zero and reduce the internal noise added by the LNA by cooling the LNA. To reduce.

  Further, by cooling the LNA, the noise figure is lowered and the noise temperature can be lowered by lowering the equipment temperature. A large noise reduction effect can be obtained by combining both. Here, each noise reduction effect is as follows.

・ Parabolic antennas (before improvement)
Lr = 5 dB; power supply system loss, Fn = 3 dB; LNA noise figure Ta = 89K, Tr = 627K, Te = 289K → Ts = 1629K
In the case of an active antenna, Lr = 2 dB; feed loss, Fn = 3 dB; LNA noise figure Ta = 89K, Tr = 170K, Te = 289K → Ts = 716K
(3.6 dB improvement)
・ When superconducting technology is applied to the feeding system, change to Lr = 0.5 dB, Ttr = 80K Ta = 89K, Tr = 10K, Te = 289K → Ts = 423K
(5,9 dB improvement)
・ When applying cooling of LNA in addition to (3) To = 100K, change to Fn = 1dB Ta = 89K, Tr = 10K, Te = 26K → Ts = 128K
(11.0 dB improvement)
Thus, by using the superconducting line and cooling the LNA, the system noise temperature can be greatly reduced.

  Next, a specific configuration of the first embodiment will be described. FIG. 1 is a configuration block diagram of an active array antenna device according to the first embodiment. The active array antenna device includes a distributor 1, phase shifters 2-1 to 2-n, transmission amplifiers 3-1 to 3-n, transmission filters 4-1 to 4-n, circulators 5-1 to 5-n, Vacuum containers 6-1 to 6-n, reception filters 7-1 to 7-n, LNA (low noise amplifier) 8-1 to 8-n, distributors 9-1 to 9-n, phase shifter 10a-1 10a-n, 10b-1 to 10b-n, attenuators 11a-1 to 11a-n, 11b-1 to 11b-n, and combining circuits 12-1 and 12-2. There are n antenna elements corresponding to the transmission filters 4-1 to 4-n.

  The distributor 1 distributes the transmission signal to the phase shifters 2-1 to 2-n. The phase shifters 2-1 to 2-n shift the phase of the transmission signal from the distributor 1 by a predetermined phase for each antenna element and output it to the transmission amplifiers 3-1 to 3-n. The transmission amplifiers 3-1 to 3-n amplify the transmission signals from the phase shifters 2-1 to 2-n and output the amplified signals to the transmission filters 4-1 to 4-n.

  The transmission filters 4-1 to 4-n perform filtering on the transmission signals from the transmission amplifiers 3-1 to 3-n, and output the filtered signals to the corresponding antenna elements. Circulators 5-1 to 5-n output reception signals from corresponding antenna elements to reception filters 7-1 to 7-n.

  The vacuum vessels 6-1 to 6-n include reception filters 7-1 to 7-n and LNAs (low noise amplifiers) 8-1 to 8-n. Details of the vacuum vessels 6-1 to 6-n, the reception filters 7-1 to 7-n, and the LNAs 8-1 to 8-n will be described later. The reception filters 7-1 to 7-n pass a predetermined band with respect to the reception signals from the circulators 5-1 to 5-n, and output the passed signals to the LNAs 8-1 to 8-n. The LNAs 8-1 to 8-n amplify the signals from the reception filters 7-1 to 7-n with low noise and output the amplified signals to the distributors 9-1 to 9-n.

  The distributors 9-1 to 9-n distribute the signals from the reception filters 7-1 to 7-n to the phase shifters 10a-1 to 10a-n and the phase shifters 10b-1 to 10b-n. The phase shifters 10a-1 to 10a-n and 10b-1 to 10b-n shift the signals from the distributors 9-1 to 9-n by a predetermined phase amount for each phase shifter, It outputs to the attenuators 11a-1 to 11a-n and 11b-1 to 11b-n.

  The attenuators 11a-1 to 11a-n and 11b-1 to 11b-n are attenuated by a predetermined attenuation amount for each attenuator to be combined circuits 12-1 and 12-2 (corresponding to beam combining circuits). Output. The synthesizing circuit 12-1 beam-synthesizes a plurality of signals from the attenuators 11a-1 to 11a-n to obtain a beam output 1. The combining circuit 12-2 combines the plurality of signals from the attenuators 11b-1 to 11b-n to generate a beam output 2.

  In addition, although the beam output in FIG. 1 is described as 2 outputs, it is not limited to this, A required number of multiple beam outputs can be formed.

  FIG. 2 is a cross-sectional view of a vacuum vessel in which a reception filter and a low-noise amplifier of the active array antenna device according to the first embodiment are enclosed. The superconducting state can be realized at an extremely low temperature, and a vacuum vessel 6 (corresponding to a heat insulating vessel for heat insulation) is used for heat insulation from the surroundings.

  An airtight connector 61a connected to the antenna element via a circulator is attached to the input side of the vacuum vessel 6. The remaining terminal of the circulator is connected to a transmission amplification system including the transmission amplifier 3. An airtight connector 61 b is attached to the output side of the vacuum vessel 6. The airtight connector 61 a and the superconductive substrate 62 are connected by a coaxial cable 66, and the airtight connector 61 b and the superconductive substrate 62 are connected by a coaxial cable 67.

  A cooling plate 68 is installed in the vacuum vessel 6, a superconducting substrate 62 made of a superconducting element is disposed on the cooling plate 68, and a superconducting circuit such as a receiving filter 63 to be cooled composed of a substrate pattern is super It is installed on the conductive substrate 62. In addition to the reception filter 63, the antenna element, the circulator, and the connection line can be further cooled by cooling the cooling plate 68. However, it is not necessary to cool all of them. The cooling target is mainly the reception filter 63 and its input / output portion. A chip-mounted LNA 64 is disposed on the superconducting circuit board 62.

  A matching circuit required for the LNA can be configured in the LNA chip, but can also be configured on the superconducting substrate 62.

  The LNA 64 is connected to the superconducting circuit board 62 by a bonding wire 65. The output of the LNA 64 is connected to an airtight connector 61 b on the output side of the vacuum vessel 6 via a line on the superconducting substrate 62 and a coaxial cable 67. Here, the power supply and control connection to the LNA 64 is also made by wiring penetrating the vacuum vessel 6.

  By cooling the cooling plate 68 from the outside of the vacuum vessel 6 by the cooling means 69, the superconducting circuit is brought into a superconducting state via the cooling plate 68, and at the same time, the LNA 64 is cooled. Since the vacuum vessel 6 is used, a certain restriction can be imposed on the size of the cooling object.

  The first embodiment can be applied to a reception system in an active antenna in which an LNA 64 is incorporated in the antenna, a reception system of a transmission / reception module, and the like.

  In the first embodiment, in addition to a reception system housed in a vacuum vessel 6, a transmission amplification system including a transmission amplifier 3, a circulator 5 and the like are configured as transmission / reception modules, and antenna elements and transmission / reception modules are arranged in an array. Thus, an active array antenna device is configured. Here, a sub-array may be used instead of the antenna element. Also, a switch or the like can be used instead of the circulator.

  The function of the attenuator 11 can also be given to the synthesis circuit 12. Further, the order of the phase shifter 10 and the attenuator 11 can be reversed.

  Furthermore, the DBF method is used in which the processing after the distributor 9 is digitally processed by either the reception signal obtained by AD conversion of the output of the LNA 6 or the reception signal obtained by performing frequency conversion and AD conversion using the IF signal. You can also

  If the transmission function is unnecessary, the distributor 1, the phase shifter 2, the transmission amplifier 3, the transmission filter 4, the circulator 5 and the like related to transmission may be deleted.

  As described above, according to the active antenna array device of the first embodiment, the superconducting circuit having the reception filter 63 is brought into the superconducting state by forming a multi-beam using the active phased array system and cooling the cooling plate 68. At the same time, since the LNA 64 is cooled at the same time, the power loss from the antenna to the low-noise amplifier can be made close to zero, and the internal noise of the LNA can be reduced to increase the sensitivity of the receiving system.

Second embodiment

  FIG. 3 is a block diagram showing the configuration of the active array antenna device according to the second embodiment. In the second embodiment of FIG. 3, all of the plurality of reception filters 7-1 to 7-n and LNAs 8-1 to 8-n of the first embodiment of FIG. It is divided into m <n). In the example shown in FIG. 3, two reception filters and two LNAs are provided in one vacuum vessel. In this way, fewer vacuum containers are required.

  In this case, a plurality of airtight connectors are arranged in a row on one side of each of the vacuum vessels 6a to 6m, and each is connected to the antenna element via the circulator. Note that the remaining terminals of the circulator are each connected to a transmission filter.

  In each vacuum vessel 6a-6m, there is one common cooling plate, and a superconducting substrate is disposed thereon. A plurality of reception filters are configured as a substrate pattern on the superconducting substrate, and one input / output of each reception filter is connected to an airtight connector and the other is connected to an LNA input.

  The same number of LNAs as the receiving filter are chip-amounted on the superconducting substrate, and their outputs are connected to output-side airtight connectors arranged in a line on the opposite surface of the vacuum vessel via lines on the superconducting substrate. In order to reduce the number of output side airtight connectors, a necessary beam combining circuit can be accommodated in the vacuum vessel at the same time. Connections such as power supply and control to the LNA are also made by wiring penetrating the vacuum vessel.

  In addition to the reception system housed in the vacuum vessel, a transmission amplification system, a circulator, and the like are integrally configured, and an active array antenna can be configured by arranging the antenna elements in an array. The array antennas may be arranged in a line (one-dimensionally), or may be arranged two-dimensionally.

  Moreover, you may comprise by the array antenna which used the antenna subarray instead of the antenna element. The receiving system is simply illustrated as a receiving filter and an LNA, but includes structurally necessary parts such as an airtight connector for connecting the inside and outside of the vacuum vessel.

  A part of the plurality of reception filters 7-1 to 7-n and LNAs 8-1 to 8-n may be divided into a plurality of vacuum containers.

Third embodiment

  FIG. 4 is a block diagram showing the configuration of the active array antenna device according to the third embodiment. In the third embodiment of FIG. 4, the reception filters 7-1 to 7-n, LNAs 8-1 to 8-n, distributors 9-1 to 9-n, phase shifters 10a-1 to 10a-n, Phasers 10b-1 to 10b-n, attenuators 11a-1 to 11a-n, attenuators 11b-1 to 11b-n, and synthesis circuits 12-1 and 12-2 are provided in the same vacuum vessel 6A. It is characterized by.

  According to such a configuration, since the portion for combining the beams after amplifying and distributing the received signal is provided in the same vacuum vessel 6A, it is possible to more easily realize high sensitivity of reception.

Fourth embodiment

  FIG. 5 is a block diagram showing the configuration of an active array antenna device according to the fourth embodiment. In the fourth embodiment shown in FIG. 5, the antenna element 15 or the antenna subarray (not shown) is provided in the vacuum vessel 6B with respect to the configuration of the first embodiment shown in FIG. A material having a property of transmitting received radio waves into the vacuum vessel 6B, for example, a radome material 14 is provided in part. A signal received by the antenna element 15 via the radome material 14 is input to the reception filter 7 via the circulator 5.

  According to such a configuration, since the antenna element 15 and the circulator 5 are provided in the vacuum vessel 6B, it is possible to further improve the sensitivity of reception. Further, the number of airtight connectors can be reduced.

  The circulator can also be provided outside the vacuum container together with the transmission side circuit. Further, when the antenna element is used exclusively for reception (for example, when the antenna element for transmission and reception is different), the circulator may be deleted.

Fifth embodiment

FIG. 6 is a block diagram showing the configuration of the active array antenna device according to the fifth embodiment. In the fifth embodiment shown in FIG. 6, compared to the first embodiment shown in FIG. 1, IF converters 21-1 to 21-n and AD converter 22-1 are provided on the output side of the LNAs 8-1 to 8-n. ˜22-n is provided.

  The IF converters 21-1 to 21-n frequency-convert the signals from the LNAs 8-1 to 8-n to obtain IF signals. The AD converters 22-1 to 22-n A / D convert the IF signal. That is, beam synthesis can be performed by DBF (digital beam forming) processing.

  Further, in the beam synthesis processing after the received signal distributors 9-1 to 9-n, a DBF method in which digital processing is performed by an IF converter and an AD converter may be used.

Sixth embodiment

  FIG. 7 is a configuration block diagram of an active array antenna device according to the sixth embodiment. In the sixth embodiment of FIG. 7, compared with the first embodiment of FIG. 1, vertical synthesis circuits 12-1 and 12-2 that synthesize a plurality of vertical beams (one-dimensional) by RF signals are synthesized. An IF converter 21 for IF-converting the vertical beam (one-dimensional), an A / D converter 22 for converting the IF signal of the IF converter 21 into a digital signal, and a horizontal synthesis circuit 13 for synthesizing a plurality of horizontal beams based on the digital signal -1, 13-2.

  That is, when the scale of the beam synthesis circuit is increased in the case of performing DBF processing, the beam synthesis circuit 13-1 is provided in a casing separated from the antenna opening in which the reception system (or transmission / reception module) including the antenna element and the vacuum vessel is arranged. , 13-2.

  In this case, a plurality of vertical beams are synthesized by the RF signal, the synthesized beam is IF-converted, and then A / D conversion is performed to perform a DBF process for synthesizing the plurality of horizontal beams by the digital signal. It can be carried out in multiple stages.

  In addition, when performing beam synthesis in multiple stages, a part of the beam synthesis circuit can be accommodated in the same vacuum container as long as it can be accommodated in an appropriately sized vacuum container.

  In FIG. 7, the RF signal is divided into a plurality by the distributor 9 and different beam outputs are obtained by the vertical synthesis circuits 12-1 and 12-2, respectively. It is also possible to obtain a plurality of different beam outputs at the output of the horizontal synthesis circuit. Furthermore, it is also possible to use a combination of both.

Seventh embodiment

  FIG. 8 is a block diagram showing the configuration of the active array antenna device according to the seventh embodiment. The seventh embodiment of FIG. 8 is characterized in that a limiter 23 is provided between the circulator 5 and the reception filter 7 so that the transmission and reception center frequencies are the same.

  According to such a configuration, since the received signal is limited to a predetermined level by using the limiter 23, the receiving system such as the receiving filter 7 and the LNA 8 can be protected.

Eighth embodiment

  FIG. 9 is a block diagram showing the configuration of the active array antenna device according to the eighth embodiment. The eighth embodiment of FIG. 9 uses the antenna element of the active array antenna device 33 as a receiving antenna, the radio wave transmitted from the transmission antenna 31 is reflected from the target, and the reflected radio wave is reflected on the active array antenna device 33. The antenna element receives the signal. Thereby, a target can be detected from the received signal received by the antenna element of the active array antenna device 33.

Ninth embodiment

  FIG. 10 is a configuration block diagram of an active array antenna device according to the ninth embodiment. The ninth embodiment of FIG. 10 uses the antenna element of the active array antenna device 33 as a reception antenna, and a reception-dedicated antenna 34 for receiving a transmission signal directly (separate from the reception antenna that receives the target reflection). By directly receiving the radio wave emitted from the transmission antenna 31 by the reception antenna), the time when the radio wave was emitted can be analyzed.

  When the active array antenna device 33 is used as a receiving antenna, the active array antenna device 33 is not a radar device, but a microwave radiometer that measures the microwave radiation of the object, or a radio wave to be transmitted. It can also be used as an antenna for a high-sensitivity receiving system that receives directly. In addition, it can be applied to various applications that require high sensitivity.

  As described above, according to the active array antenna apparatus of the present embodiment, a reception filter is provided between the antenna element and the LNA to form an active antenna in which a plurality of antenna elements and LNAs are arranged, and a signal amplified by the LNA is distributed The receiving filter and the LNA are stored in the same vacuum container, and the receiving filter and the LNA are cooled in a superconducting state, so that the power loss from the antenna to the low-noise amplifier is reduced. While approaching zero, it is possible to reduce the internal noise of the LNA and increase the sensitivity of the receiving system.

  The present invention is not limited to the active array antenna device according to the first to ninth embodiments. For example, a transmission / reception switching function such as a circulator can be accommodated in the same vacuum vessel. In this case, the reception filter can be used for both transmission and reception by inserting it between the antenna element and the transmission / reception switching function.

  Further, higher sensitivity can be realized by cooling the circulator.

  In addition, by configuring the antenna element with a superconducting circuit, it is possible to avoid the ohmic loss of the antenna element and further reduce the noise temperature.

  Also, for example, in the radar antenna, a part of the opening can be used for both transmission and reception, and the other part can be used for reception. In addition, it is possible to divide the aperture itself for transmission and reception, such as providing a separate transmission-dedicated opening and configuring another opening portion for reception, or to combine the transmission / reception portion.

  In addition, a transmission-dedicated antenna element and a reception-dedicated antenna element can be combined.

  Moreover, it can be used not only for radar applications but also for other purposes such as communication antennas as antennas for transmitting and receiving radio waves. When the transmission / reception frequencies are different, a diplexer or the like can be used as a transmission / reception switching function.

  As mentioned above, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1,9-1 to 9-n distributor
2-1 to 2-n, 10a-1 to 10a-n, 10b-1 to 10b-n Phase shifters 3-1 to 3-n Transmission amplifiers 4-1 to 4-n Transmission filters 5-1 to 5- n Circulator 6, 6-1 to 6-n Vacuum vessel 7-1 to 7-n, 63 Reception filter 8-1 to 8-n, 64 LNA
11a-1 to 11a-n, 11b-1 to 11b-n Attenuator 12-1 to 12-2 Combining circuit 23 Limiter 61a, 61b Airtight connector 62 Superconducting substrate 65 Bonding wire 66, 67 Coaxial cable 68 Cooling plate 69 Cooling means

Claims (10)

M reception filters that pass a predetermined band with respect to reception signals received by M (M ≧ 2) antenna elements or antenna subarrays;
M low noise amplifiers that amplify M received signals from the M receive filters;
For each amplified signal of the M amplified signals amplified by the M low noise amplifiers, M distributors that distribute the amplified signal to N (N ≧ 2) distributed signals;
N sets of M phase shifters that are provided for each of the distributors and that shift the phase of N distribution signals distributed by the distributors;
N sets of M attenuators for attenuating N sets of M phase shift signals from the N sets of M phase shifters;
N beam combining circuits which are provided corresponding to N sets of M attenuators, and combine the beams by adding the attenuator outputs of the M distributors for each attenuator;
A heat insulating container for heat insulation that houses the low noise amplifier and the reception filter composed of a superconducting material;
Cooling means for cooling the reception filter and the low-noise amplifier housed in a heat insulation container for heat insulation to bring the reception filter into a superconducting state;
A cooling plate which is housed in the heat insulation container for heat insulation and on which the receiving filter and the low noise amplifier are mounted and which is cooled by the cooling unit;
With
An active array antenna apparatus, wherein the M reception filters and a part of the M low noise amplifiers are divided and stored in the plurality of heat insulating containers.   2. The active array antenna device according to claim 1, wherein the heat insulation container for heat insulation further accommodates at least a part of the N beam combining circuits.   The heat insulation container for heat insulation further stores a part of the M antenna elements or a part of the antenna subarray, and transmits the received radio wave into the heat insulation container and inputs the antenna element or the subarray. The active array antenna device according to claim 1, further comprising a material.   The M received signals amplified corresponding to the M low noise amplifiers and amplified by the low noise amplifiers are RF signals or A / D converted by IF signals subjected to frequency conversion to perform the M conversion. A digital beam forming system that has M A / D converters that output to one distributor and performs N beam synthesis using a digital signal that has been A / D converted by the A / D converter; The active array antenna device according to any one of claims 1 to 3, wherein the active array antenna device is characterized. A first beam combining circuit that performs beam combining with an RF signal that is a received signal for a part of the M antenna elements or antenna subarrays, and a frequency conversion that converts the frequency of the RF signal that is the combined output of the first beam combining circuit An A / D converter for A / D-converting the frequency-converted signal, and a second beam combining circuit for further combining a plurality of beams with the A / D-converted digital signal,
5. The active array antenna device according to claim 1, wherein the second beam combining circuit is disposed separately from the heat insulating container for heat insulation. 6.   6. The active array antenna device according to claim 1, wherein the heat insulating container for heat insulation is a vacuum heat insulating container in which at least a part is in a vacuum state. A transmission / reception switching unit that switches transmission and reception of signals to and from the antenna element;
A limiter provided between the transmission / reception switching unit and the low-noise amplifier, for limiting a signal level of a reception signal from the transmission / reception switching unit;
The active array antenna apparatus according to claim 1, further comprising:   The M antenna elements or the antenna subarrays receive radio waves transmitted from a transmitting antenna and reflected by a target, and use the received signals for target detection of a radar apparatus. 8. The active array antenna device according to any one of 7 above.   9. The M antenna element or the antenna subarray receives radio waves radiated from an object, and uses a received signal for measurement of radio wave radiation intensity of the object. The active array antenna apparatus of any one of Claims.   The M antenna elements or the antenna subarrays receive radio waves transmitted from a transmitting antenna different from the present apparatus, and analyze at least the time when the radio waves are transmitted. Item 10. The active array antenna device according to any one of Items 9.

Images