JP2001230714A - Communication equipment for flying body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide communication equipment for a flying body capable of maintaining a communication function even under an environment accompanied by air pressure change such as the time of launching the flying body such as an earth satellite by providing a filter discharge prevention measure. SOLUTION: A first switch 11, a transmission line 14 and a second switch 15 are serially connected and added between a transmitter-receiver 1 and a first antenna 6. A filter 5 is bypassed at the time of launching the flying body by switching the first switch 11 by switch changeover signals 12 and a route passing through the filter 5 is returned by using the switch changeover signals 12 before operating transmission system communication equipment after getting in to the orbit. Thus, the discharge of the filter 5 in an air pressure area where a discharge withstand current rating lowers is prevented and the communication function is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device for mounting a flying object mounted on a flying object such as an artificial satellite or an aircraft, and particularly operating normally even in an environment with a change in air pressure observed when the flying object is launched. It is.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram showing a configuration of a conventional communication device for mounting a flying object. In the figure, 1 is a transceiver, 2 is a receiver, 3 is a first transmitter, 4 is a diplexer, 5 is a filter, 6 is a first antenna, 7 is a second transmitter, 8 is a low-pass filter, 9 Is the second antenna, 1
0 is a disturbance signal to the receiver.

First, the configuration of a conventional communication device for mounting a flying object will be described. As shown in FIG. 8, the communication device for mounting a flying object includes a control communication device having a function of transmitting telemetry data indicating the state of the flying object to the ground and receiving a command signal for sending a command from the ground station to the flying object, A transmission system communication device having a function of transmitting data to a ground station. The control communication device includes a transceiver 1, a filter 5, and a first antenna 6. The transmitting communication device is a second communication device.
, A low-pass filter 8 and a second antenna 9. The transceiver 1 comprises a receiver 2 and a first transmitter 3
And a diplexer 4 for separating transmission and reception signals.

Next, the operation of the conventional communication device for mounting a flying object will be described. RF of transceiver 1 (RADIO FREQUENC
Y) After passing through the filter 5, the output signal is transmitted to the ground station by the first antenna 6h to transmit the flying object telemetry signal. The command signal for the flying object transmitted from the ground station is input to the first antenna 6, passes through the filter 5, and is input to the transceiver 1. on the other hand,
The data signal output from the second transmitter 7 is input to the low-pass filter 8 to remove harmonics generated by the second transmitter 7 and then transmitted to the ground station by the second antenna 9. . The filter 5 is connected to the RF (R
ADIO FREQUENCY) A reception wave and a transmission wave, which are input / output signals, are set as pass bands, and a disturbance signal 10 which is a leak component from the second antenna 9 to the receiver 3 via the first antenna 6 is suppressed. .

FIG. 9 shows an example of the band attenuation characteristic of the filter 5. 9, the horizontal axis represents the frequency, and the vertical axis represents the attenuation of the filter 5. As shown in FIG.
And the output frequency f (TX1) of the first transmitter 2 as a pass band, and the output frequency f (TX2) of the second transmitter 7 which is a source of interference with the receiver 3 is centered. By having an attenuation band of a specific communication bandwidth, the disturbance signal 10 to the receiver 3 can be suppressed.

The operation of the conventional communication device for mounting a flying object will be described in detail. The device of the receiver 2 of the transceiver 1 is always on so as to be able to receive commands from the ground station before the launch of the flying object, and is in a receiving state. The first transmitter 3 of the transmitter / receiver 1 has been turned on and the monitor signal has been transmitted from before launching to monitor the ground for a telemetry signal indicating the state of the flying object or the mounted device. Therefore, the high power signal of the first transmitter 3 is input to the filter 5. The diplexer 4 is provided for the purpose of suppressing the transmission frequency so that the output of the first transmitter 3 does not go to the receiver 2 and separating the reception signal received by the first antenna 6 to the receiver 2. Second transmitter 7
Is off from before launch to orbit insertion to avoid transmitting unwanted waves to the ground. After orbital injection,
When the attitude of the flying object is stabilized and the second antenna 9 is directed to the ground station, the second transmitter 7 is controlled by a command from the ground.
Is turned on. This enables data transmission of communication signals and the like.

In the above operation, the large power signal transmitted from the second transmitter 7 is spatially radiated by the second antenna 9 toward the ground station. A part of the electromagnetic wave radiated in space is coupled by the first antenna 6, and the leakage component is input to the receiver 2 as a disturbance signal 10. When the disturbance signal 10 passes through the diplexer 4 and is input to the receiver 2, the receiver 2 becomes inoperable or breaks due to excessive input. The filter 5 protects the receiver 2 by suppressing and removing the disturbance signal 10 using the transmission wave of the second transmitter 7 as a signal source.

[0008]

In an environment where atmospheric pressure changes from normal pressure to vacuum, such as in a launch environment of a flying object, the high-frequency discharge withstand capability drops sharply at low pressures compared to normal pressure and vacuum. For example, the Institute of Electrical Engineers of Japan 1
"Discharge Handbook" published on February 15, 974 (p.23)
6) etc. FIG. 10 is a diagram showing how high-frequency discharge is likely to occur in low pressure when a high-frequency voltage is applied between arbitrary electrodes. The horizontal axis represents the atmospheric pressure, and the vertical axis represents the discharge breakdown electric field strength. In the drawing, Vb is the electric field intensity generated between the electrodes inside the resonator type filter. At normal pressure and vacuum, the discharge breakdown electric field strength is sufficiently larger than Vb, so that high-frequency discharge does not occur inside the filter. However, in the low pressure region, Vb exceeds the discharge breakdown electric field strength. A discharge phenomenon called high-frequency discharge or corona discharge occurs between them.

The filter 5 for removing a disturbance signal is realized by a resonator type filter such as a band rejection filter (BAND REJECTION FILTER) or a pass band filter (BAND PASS FILTER). The edge of the passband and the edge of the suppression band approach,
In order to realize a filter requiring a large amount of suppression attenuation, it is necessary to increase the characteristic impedance and the Q value inside the filter, which are design parameters. In addition, the distance d between the electrodes forming the capacitance of the resonator of the filter also becomes smaller. Under the above conditions, the electric field intensity generated inside the filter locally increases, so that Vb shown in FIG. 10 increases, and in a low pressure region, the electric field exceeds the discharge breakdown electric field intensity curve.
The discharge withstand capacity is reduced. When a discharge occurs inside the filter, a short circuit occurs between the electrodes, so that large signal power input from the transmitter cannot be transmitted, and ground monitoring of the telemetry signal cannot be performed. In addition, if the large signal power is totally reflected due to the short circuit and the passing loss of the filter increases rapidly, abnormal heat generation occurs, and the inside of the filter, the input connector or the dielectric of the coaxial transmission line is burned, and the communication function cannot be recovered. Occur.

[0010] As a measure for increasing the discharge withstand capacity, a number of design techniques for increasing the withstand power of the filter itself have been considered as disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 7-235803. When the attenuation bands are adjacent to each other and a certain amount of attenuation is required in the attenuation band, the discharge countermeasure is not sufficient only by designing the filter alone.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is possible to satisfy the requirements of the filter attenuation characteristics and to ensure that even in an atmospheric pressure region where discharge withstand capacity becomes severe under an environment accompanied by atmospheric pressure changes. This is a communication device for mounting a flying object, which can maintain a communication function by preventing discharge.

[0012]

According to a first aspect of the present invention, there is provided a communication device for mounting a flying object, comprising a transceiver having a receiver and a first transmitter, and a first device for suppressing disturbance to the receiver. , A first antenna connected to the first filter for transmission with the ground station, and a first antenna connecting the first antenna, the first filter, and the transceiver.
A second transmitter for transmitting to the ground station; a second filter connected to the second transmitter for removing a harmonic output of the second transmitter; A communication device for mounting on a flying object comprising a transmission system communication device having a second antenna for transmitting an output of the second filter to a ground station, wherein the communication device is provided between the transceiver and the first antenna; A second path that is provided in parallel with the first path and connects the transceiver and the first antenna; and a switching unit that switches the first path and the second path. is there.

A communication device for mounting a flying object according to a second aspect of the present invention includes, as the switching means, a switch connected to the transceiver and switching between a first path and a second path by a switching signal.

According to a third aspect of the present invention, there is provided a communication device for mounting a flying object, wherein the first antenna is combined with a signal output from the first transmitter and transmitted via the first and second paths. And a coupler for outputting to

A communication device for mounting a flying object according to a fourth invention is provided with a switch connected to the first antenna and for switching between the first and second paths.

The communication device for mounting a flying object according to a fifth aspect of the present invention uses a transfer switch as the switching means.

The communication device for mounting a flying object according to a sixth invention uses a circulator as the switching means.

A communication device for mounting a flying object according to a seventh aspect of the present invention includes a pull-out connector between the circulator and the second path so that the output of the first transmitter passes through the first filter during operation. It is.

The communication device for mounting a flying object according to an eighth aspect of the present invention further includes a computer for controlling an on / off switching signal and a switch switching signal of the second transmitter based on a signal detected by a barometric pressure sensor. Things.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a diagram showing a first embodiment of the present invention. In the figure, 1 to 10
Is equivalent to FIG. 11 is a first switch, 12 is a switch switching signal, 13 is a coupler, and 14 is a transmission line.

Next, the operation of the first embodiment of the present invention will be described. The basic operation is the same as the conventional one. The coupler 13 functions as a multiplexer for multiplexing (coupling) the output of the transmission line 14 and the output of the filter 5 during detour, and is connected to the first antenna 6. Since the air pressure is reduced from normal pressure to vacuum during the period before launch of the flying object and before the orbit is injected, the discharge resistance of the filter 5 decreases and increases again according to the characteristics shown in FIG. Due to the design of the filter, the first switch 11 is connected to the side of the transmission line 14 bypassing the filter 5 when passing through a pressure range below the lower limit (threshold) of electric power safe for discharge. After the flying object enters the pressure range safe for the discharge of the filter, the first switch 11 is switched to the path passing through the filter 5 by the switch signal 12 to pass through the pressure range where the risk of discharge is high. The discharge of the filter at the time can be avoided. The switch switching signal 12 may be transmitted from the ground, or may generate a switch switching signal by detecting passage through the air pressure region inside the flying object.

Also, in FIG. 1, the first switch 11 and the coupler 13 can operate in the same manner even if they are interchanged.

Embodiment 2 FIG. FIG. 2 shows a second embodiment of the present invention. In the figure, 1 to 12 are equivalent to FIG. Reference numeral 15 denotes a second switch.

Next, the operation of the second embodiment of the present invention will be described. The basic operation is the same as the operation described in the first embodiment of the present invention. However, since the coupler 13 is replaced by the second switch 15 to improve the loss, the path switching operation switches the first switch 11 and the second switch 15 simultaneously by the switch switching signal 12.

Embodiment 3 FIG. 3 shows a third embodiment of the present invention. In the figure, 1 to 12 are equivalent to FIG. Reference numeral 16 denotes a transfer switch.

Next, the operation of the third embodiment of the present invention will be described. The basic operation is the same as that of the second embodiment shown in FIG. In the pressure range where discharge is likely to occur, the filter 5
The position of the transfer switch 16 is selected in advance so that the input and output form a loop. When the operation shifts to the atmospheric pressure region safe for discharge, the switch switching signal 12
By changing the position of the transfer switch 16 using, the large power signal output of the transceiver 1 is output to the first antenna 6 via the filter 5, so that the discharge of the filter in low pressure can be prevented. .

Embodiment 4 FIG. 4 shows a fourth embodiment of the present invention. In the figure, 1 to 14 are equivalent to FIG. 17 is a first circulator.

Next, the operation of the fourth embodiment of the present invention will be described. The basic operation is the same as that of the second embodiment shown in FIG. However, since the second switch 15 is replaced with the first circulator 17, the number of switch operation locations for path switching is reduced by half.

The same operation can be performed even if the positions of the second switch 15 and the first circulator 17 are interchanged.

Embodiment 5 FIG. 5 shows a fifth embodiment of the present invention. In the figure, 1 to 17 are equivalent to FIG. 18 is a second circulator.

Next, the operation of the fifth embodiment of the present invention will be described. The basic operation is the same as that of the fourth embodiment shown in FIG. By replacing the first switch 11 with the second circulator 18, no switch switching operation is required. Further, the output of the first transmitter 3 is output to the transmission line 14 by the pass selectivity of the second circulator 18, so that the large power signal of the first transmitter 3 is not input to the filter 5. Thereby, discharge of the filter 5 can be prevented. In addition, by disposing the second transmitter 7 in the transmission state after the orbit, the disturbance signal 10 generated by the second transmitter 7 is input to the first circulator 17 via the first antenna 6. Is done. The first circulator 17
, The disturbance signal 10 is input to the filter 5. The disturbance signal 10 is removed as an unnecessary wave according to the out-of-band attenuation characteristic of the filter 5. The received signal that has passed through the filter 5 passes through the second circulator 18 and is input to the receiver 2 via the diplexer 4.

Embodiment 6 FIG. FIG. 6 is a diagram showing a sixth embodiment of the present invention. In the figure, 1 to 18 are equivalent to FIG. 19 is a first pull-out connector, 20 is a second pull-out connector.
This is a pull-out connector.

Next, the operation of the sixth embodiment of the present invention will be described. The basic operation is the same as that of the fifth embodiment shown in FIG. For example, an artificial satellite mounted on a rocket will be described. The satellite is stored in the fairing at the rocket tip from before launch until the satellite is separated.
During this time, the output of the first transmitter 3 can bypass the filter 5 because it passes through the transmission line 14 due to the pass selectivity of the first circulator 17 and the second circulator 18. The signal received from the ground station is transmitted to the first antenna 6
Through the first circulator 17 and the second circulator 17
Of the filter 5 due to the pass selectivity of the circulator 18
Pass through. By attaching the first extraction connector 19 and the second extraction connector 20 to both ends of the transmission line 14, the fairing of the rocket is opened, and at the same time, the transmission line 14 is connected to the first and second circulators 17,
18 can be disconnected. After the satellite is disconnected, both the reception signal input to the receiver 2 and the high power signal output of the first transmitter 3 are output due to the passage and reflection selectivity of the first circulator 17 and the second circulator 18. Pass through the filter 5. Since the separation of the artificial satellite is performed after the altitude has reached a sufficient level, the atmospheric pressure has also reached a vacuum, so that it is possible to prevent the discharge of the filter 5 until the artificial satellite is separated.

Embodiment 7 FIG. 7 shows a seventh embodiment of the present invention. In the figure, 1 to 17 are equivalent to FIG. 21 is an atmospheric pressure sensor, 22 is a computer, and 23 is an on / off switching signal.

Next, the operation of the sixth embodiment of the present invention will be described. The basic operation is the same as that of the fifth embodiment shown in FIG. However, in the state where the flight of the flying object is stable and the second transmitter 7 is operating, a function corresponding to a case where the altitude of the flying object suddenly drops is added. The pressure sensor 21 installed near the filter 5 continuously monitors the pressure, and inputs pressure information to the computer 22. The data of the pressure range in which the filter 5 is likely to discharge is input to the computer 22 in advance, and a comparison operation is performed with the pressure information of the pressure sensor 21. When the flight altitude of the flying object drops rapidly and the air pressure approaches a preset dangerous area, the computer 22 turns off the second transmitter 7 by an on / off switching signal 23 of the second transmitter 7. To Next, a switch switching signal 12 is output to operate to select a detour.

After detecting that the altitude of the flying object has returned and the air pressure has returned to a safe area, the computer 22 first outputs the switch switching signal 12 to switch to the path of the filter 5. Thereafter, the second transmitter 7 is turned on by the on / off switching signal 23, thereby returning to the normal operation. As a result, even when an altitude change accompanied by a sudden pressure change occurs, the device can function as a device for preventing discharge of the filter.

[0037]

According to the first, second, and third aspects of the present invention, by providing a bypass transmission line, the filter is temporarily bypassed, and the use of the filter in a discharge region that becomes critical due to a change in atmospheric pressure is reduced. Since it can be avoided, it is possible to prevent discharge from occurring.

According to the fourth aspect, since a coupler does not need to be used, a transmission path loss between the transceiver and the antenna can be reduced. As a result, the uplink between the ground station and the receiver,
And the quality of the downlink between the first transmitter and the ground station is improved.

According to the fifth aspect, the transmission path loss between the transceiver and the antenna can be reduced. Also, the number of switches can be reduced to one. Therefore, a decrease in reliability due to a contact failure of the switch can be halved. In addition, since the number of devices mounted on the flying object is reduced, the overall mass can be reduced.

According to the sixth aspect, it is possible to suppress a decrease in reliability due to a contact failure of the switch.

According to the sixth aspect of the present invention, there is no need to use a switch at all, and there is no reduction in reliability due to a contact failure of the switch. In addition, there is no need for a route switching operation.
Since the high power signal of the first transmitter is not input to the filter, discharge of the filter can be permanently prevented even if a pressure change occurs due to a change in altitude of the flying object or the like.

According to the seventh aspect of the present invention, the connector can be mechanically pulled out at the timing of the opening of the fairing of the rocket, for example, which is an alternative to the switching method using an electric signal.

According to the eighth aspect, the path can be automatically switched according to the change in the atmospheric pressure by the on-board atmospheric pressure sensor and the computer. For this reason, even if the air pressure environment of the flying object changes suddenly, the discharge of the filter can be prevented without relying on commands from the ground.

[Brief description of the drawings]

FIG. 1 is a diagram showing Embodiment 1 of a flying object mounting communication device according to the present invention.

FIG. 2 is a diagram showing Embodiment 2 of a flying object mounting communication device according to the present invention.

FIG. 3 is a diagram showing Embodiment 3 of a flying object mounting communication device according to the present invention.

FIG. 4 is a diagram showing Embodiment 4 of a flying object mounting communication device according to the present invention.

FIG. 5 is a diagram showing Embodiment 5 of a communication device for mounting a flying object according to the present invention.

FIG. 6 is a diagram showing Embodiment 6 of a flying object mounting communication device according to the present invention.

FIG. 7 is a view showing Embodiment 7 of a flying object mounting communication device according to the present invention.

FIG. 8 is a diagram showing a conventional flying object mounting communication device.

FIG. 9 is a diagram illustrating a band attenuation characteristic of a filter.

FIG. 10 is a diagram showing discharge characteristics of a filter in a low pressure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transceiver, 2 receiver, 3 1st transmitter, 4 diplexer, 5 filter, 6 1st antenna, 7 2nd transmitter, 8 low-pass filter, 9 2nd antenna, 1
1 first switch, 13 coupler, 14 transmission line, 1
5 second switch, 16 transfer switch, 1
7 1st circulator, 18 2nd circulator, 19 1st withdrawal connector, 20 2nd withdrawal connector, 21 barometric pressure sensor, 22 calculator.

Claims (8)

[Claims] 1. A transceiver having a receiver and a first transmitter, a first filter for suppressing disturbance to the receiver, and a first filter for performing transmission with a ground station. A first antenna connected to a filter, and a first antenna connecting the first antenna, the first filter, and the transceiver.
A second transmitter for transmitting to the ground station; a second filter connected to the second transmitter for removing a harmonic output of the second transmitter; A communication device for mounting on a flying object comprising a transmission system communication device having a second antenna for transmitting an output of the second filter to a ground station, wherein the communication device is provided between the transceiver and the first antenna; A second path that is provided in parallel with the first path and connects the transceiver and the first antenna; and a switching unit that switches the first path and the second path. Characteristic communication device for mounting a flying object. 2. The flying object mounting communication according to claim 1, wherein said switching means includes a switch connected to said transceiver and switching between a first path and a second path by a switching signal. apparatus. 3. A coupler for combining a signal output from the first transmitter and transmitted through the first and second paths and outputting the combined signal to the first antenna. The communication device for mounting a flying object according to claim 2. 4. The communication device for mounting a flying object according to claim 2, further comprising a switch connected to the first antenna and switching the first and second paths. 5. The communication device according to claim 1, wherein the switching unit is a transfer switch. 6. The flying object mounting communication device according to claim 1, wherein said switching means is a circulator. 7. A flying object according to claim 6, further comprising a pull-out connector between said circulator and said second path so that an output of said first transmitter passes through said first filter during operation. Communication device for mounting. 8. A computer according to claim 2, further comprising a computer for controlling an on / off switching signal of said second transmitter and a switch switching signal based on a signal detected by a barometric pressure sensor. The communication device for mounting a flying object according to the above.