JP2010223749A - Method and apparatus for monitoring of ils device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an output of monitoring a signal closest to an ILS signal that an actual aircraft is receiving, and also to improve maintainability. <P>SOLUTION: A BPF 14a performs frequency selection of a frequency component of approximately 6 kHz to 8 kHz with 10.7 MHz as a center of an ILS signal (NF POSN) subjected to frequency conversion to an intermediate frequency of 10.7 MHz output from a mixer 13a for monitoring by a monitoring circuit 16a. A BPF 14b performs frequency selection of a frequency component of approximately 6 kHz to 8 kHz with 10.7 MHz as a center frequency of an ILS signal (INTG WD) subjected to frequency conversion to the intermediate frequency for monitoring by a monitoring circuit 16c. BPFs 15a, 15b monitor frequency components of ≥18 kHz with 10.7 MHz as a center frequency of ILS signals (INTG POSN, INTG CL) subjected to frequency conversion by mixers 13b, 13d by monitoring circuits 16b, 16d. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a monitoring method and a monitoring device for an ILS device, and more particularly to a monitoring method and a monitoring device for an ILS (Instrument Landing System) device using two carrier frequency radio waves.

  There is known an ILS device that guides landing of an aircraft by launching a radio wave to the aircraft from a forward direction of an aircraft entering the airfield and landing (Patent Document 1, Non-Patent Document). 1).

  In view of its importance, this ILS device is provided with a monitor device that constantly monitors whether the transmission radio wave satisfies prescribed values of various parameters determined by the system. The monitor device monitors the transmission radio wave transmitted by the ILS device, and determines that the transmission radio wave is abnormal when it detects that any one or more of the prescribed values of various parameters are not satisfied. For example, the standby ILS device Measures such as switching to transmission radio waves from are taken.

  FIG. 3 shows a configuration diagram of an example of a monitor device of an ILS device using two carrier frequency radio waves. The monitor device 20 includes a signal received by a monitor antenna device (not shown) installed in the vicinity of the transmission antenna device and a pickup element incorporated in the transmission antenna device. A part of the radiated radio wave is taken out and a signal obtained by artificially synthesizing the far field is detected by the monitor network, and the course characteristic or path characteristic of the ILS is detected in front (POSN), course width or path width direction (WD), clearance direction ( CL).

  The attenuator (ATT) 21a attenuates the front ILS signal (NF POSN) output from the monitor antenna device to an appropriate signal level. The attenuators 21b, 21c, and 21d respectively receive front direction ILS signal (INTG POSN), course width or path width direction ILS signal (INTG WD), and clearance direction ILS signal (INTG CL) output from the monitor network as appropriate signals. Decay to level.

  The band pass filters (BPF) 22a to 22d use the ILS signals output from the attenuators 21a to 21d in a predetermined frequency band (108 to 112 MHz for a localizer device, 328.6 to 335.4 MHz for a glide pass device). ) To limit the frequency. The mixers 23a to 23d mix the ILS signals from the BPFs 22a to 22d with the local signals (designated frequency minus 10.7 MHz) from the local oscillator 26, respectively, and convert the ILS signals to an intermediate frequency of 10.7 MHz ILS signals. To do.

  The band-pass filters (BPF) 24a to 24d have narrow band pass characteristics with a pass bandwidth of 10 kHz or more, and band-limit the intermediate frequency 10.7 MHz ILS signals output from the mixers 23a to 23d. The image frequency component and the adjacent channel component generated by the frequency conversion in the mixers 23a to 23d are removed. The monitor circuits 25a to 25d monitor the RF level, modulation degree difference (DDM), and modulation degree, which are characteristics of the ILS signal, based on the ILS signals output from the BPFs 24a to 24d.

Japanese Patent Laid-Open No. 01-127985

International Civil Aviation Organization, International Standards and Recommended Practices Annex 10 to the Convention on International Civil Aviation Volume I, Radio Navigation Aids, 3.1 Specification for ILS

  However, the monitor device of the ILS device using the above two carrier frequency radio waves has the following two problems.

  The first problem is that since the distance between the transmitting antenna device and the monitor antenna device is short, the monitor antenna device cannot obtain the same ILS signal as far away, and the ILS signal (NF POSN), which is a region where the radio wave is strong, It is greatly affected by radio waves from other transmitters. For this reason, there is a possibility that the monitor device detects a characteristic different from the ILS signal received by the actual aircraft.

  The ratio of the radio wave of the transmission signal having a frequency 4 kHz higher than the predetermined carrier frequency received by the aircraft and the radio wave of the transmission signal having a frequency 4 kHz lower than the predetermined carrier frequency is 10 dB or more in the international standard. When the antenna device and the monitor antenna device are close to each other, the ratio may be reduced to about 2 dB.

  The second problem is that, in the glide path device, the above monitor device is greatly affected by the radio wave of the transmission unit in the path width direction ILS signal (INTG WD) output from the monitor network. For this reason, the phase length of the transmission signal until the transmission signal output from the transmission unit is combined in the monitor network via the antenna device changes due to temperature change, so it is necessary to perform zero adjustment of the monitor every season, Requires regular maintenance.

  The present invention has been made in view of the above points, and it is possible to obtain a monitor output of a signal closer to an ILS signal received by an actual aircraft, and to improve maintainability, and a monitoring method and monitor for an ILS device An object is to provide an apparatus.

  In order to achieve the above object, a monitoring method for an ILS apparatus according to the present invention is a monitoring method for a two-frequency ILS apparatus that induces landing of an aircraft using radio waves of first and second transmission signals having different center frequencies. And a monitor antenna device installed in the vicinity of the transmission antenna device for receiving a radio wave of a transmission signal obtained by combining the first and second transmission signals from the transmission antenna device for monitoring in a front direction. The first ILS signal is acquired, and a signal generated by artificially combining the first and second transmission signals in the far field within the transmission antenna apparatus is detected and monitored in each of a plurality of directions. Acquisition step of acquiring each of the two ILS signals, and a frequency different from a value half the difference between the center frequencies of the first and second transmission signals with respect to an intermediate frequency with respect to a predetermined carrier frequency or a value in the vicinity thereof No A second transmission from the first ILS signal converted to the intermediate frequency in the conversion step, the conversion step of mixing the Cull signal and the first and second ILS signals, respectively, and converting the frequency into an intermediate frequency ILS signal From the first frequency selection step of removing only the frequency component of the first transmission signal by removing the frequency component of the signal and the second ILS signal converted to the intermediate frequency in the conversion step, the first and first A second frequency selection step for selecting the frequency components of the two transmission signals, and a monitoring step for monitoring the characteristics of the ILS signal independently of each other based on the signals obtained in the first and second frequency selection steps It is characterized by including.

  In order to achieve the above object, the monitor device of the ILS device of the present invention is a two-frequency ILS device that induces landing of an aircraft using radio waves of first and second transmission signals having different center frequencies. A first antenna for receiving a radio wave of a transmission signal obtained by combining the first and second transmission signals from the transmission antenna apparatus with a monitor antenna apparatus installed in the vicinity of the transmission antenna apparatus and monitoring in a front direction. And a second signal for detecting in a plurality of directions by detecting a signal generated by artificially combining the first and second transmission signals in the far field in the transmission antenna apparatus. Acquisition means for acquiring each ILS signal, and a value different from a half value of a difference between the center frequencies of the first and second transmission signals with respect to an intermediate frequency with respect to a predetermined carrier frequency or a value in the vicinity thereof Local signal A local oscillating means for generating, a mixing means for mixing the local signal and the first and second ILS signals, respectively, and converting the frequency to an intermediate frequency ILS signal, and a first ILS signal converted to an intermediate frequency by the mixing means From the first filter means for removing the frequency component of the second transmission signal and selecting only the frequency component of the first transmission signal, and the second ILS signal converted to the intermediate frequency by the mixing means, Based on the second filter means for selecting the frequency components of the first and second transmission signals, respectively, and the signals output from the first and second filter means, the characteristics of the ILS signals are independent of each other. And monitoring means for monitoring.

  According to the present invention, by removing the frequency component of the transmission signal of the second transmission unit from the first ILS signal output from the monitor antenna apparatus and monitoring the ILS signal received by the actual aircraft, A closer monitor output can be obtained. Further, according to the present invention, maintainability can be improved by improving the stability of the path width direction ILS signal (INTG WD).

It is a systematic diagram of one Embodiment of the monitor apparatus of the ILS apparatus of this invention. It is a figure which shows an example of the frequency spectrum etc. of the transmission signal of the ILS apparatus of this invention. It is a block diagram of an example of the monitor apparatus of the ILS apparatus which uses two carrier frequency electromagnetic waves.

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

  FIG. 1 is a system diagram of an embodiment of a monitor device for an ILS apparatus according to the present invention. In the figure, a transmission unit (DIR) 1 outputs transmission signals DIR CAR and DIR SB having a frequency 4 kHz higher than the carrier frequency f0 designated by the ILS device. The transmission unit (CL) 2 outputs transmission signals CLCAR and CLSB having a frequency 4 kHz lower than the carrier frequency f0 designated by the ILS device. That is, the first transmission signal from the transmission unit (DIR) 1 is an upper side band of the center frequency f0 + 4 kHz obtained by amplitude-modulating the carrier frequency f0 designated by the ILS device with predetermined audio information. The second transmission signal from the part (CL) 2 is a lower sideband of the center frequency f0-4 kHz obtained by amplitude-modulating the carrier frequency f0 with predetermined audio information. Since the frequency band of the audio information is limited to about 3 kHz, the frequency bandwidths of the first and second transmission signals are each about 6 kHz.

  The power distributor 3 distributes the first transmission signal from the transmission unit 1 and the second transmission signal from the transmission unit 2 to a predetermined power ratio and phase ratio. The transmission antenna device 5 radiates the first transmission signal from the transmission unit 1 and the second transmission signal from the transmission unit 2 distributed by the power distributor 3 to the space as radio waves. The monitor antenna device 6 is installed in the vicinity of the transmission antenna device 5 and receives a signal in the front (POSN) direction radiated from the transmission antenna device 5.

  The monitor network 4 has a function of synthesizing a part of the radiated radio wave extracted by the pickup element built in the transmission antenna device 5 with a phase difference, and is in the front (POSN), course width or path width direction (WD). ), And artificially synthesize the radiated radio waves in the clearance direction (CL). Front direction ILS signal (NF POSN) output from the monitor antenna device 6, front direction ILS signal (INTG POSN) output from the monitor network 4, course width or path width direction ILS signal (INTG WD), clearance direction ILS signal (INTG CL) is input to each independent monitor device 10.

  The above four types of ILS signals (NF POSN, INTG POSN, INTG WD, INTG CL) input to the monitor device 10 are formed by combining the radio waves of the first and second transmission signals. The four types of ILS signals all contain the frequency components of the first and second transmission signals. However, among the four types of ILS signals, three types of ILS signals (NF POSN, INTG POSN, INTG WD) have stronger frequency components of the first transmission signal from the transmission unit (DIR) 1, and the remaining One type of ILS signal (INTG CL) includes a stronger frequency component of the second transmission signal from the transmission unit (CL) 2.

  The monitor device 10 includes attenuators (ATT) 11a to 11d, band pass filters (BPF) 12a to 12d, mixers 13a to 13d, band pass filters (BPF) 14a and 14b, 15a and 15b, monitor circuits 16a to 16d, and It consists of a local oscillator (LO OSC) 17.

  The attenuator 11a attenuates the front ILS signal (NF POSN) output from the monitor antenna device 6 to an appropriate signal level. The attenuators 11b, 11c, and 11d appropriately output the front direction ILS signal (INTG POSN), the course width or path width direction ILS signal (INTG WD), and the clearance direction ILS signal (INTG CL) output from the monitor network 4, respectively. Attenuates to signal level.

  The BPFs 12a to 12d limit the frequency of the ILS signals output from the attenuators 11a to 11d to a predetermined frequency band (108 to 112 MHz for a localizer device and 328.6 to 335.4 MHz for a glide path device). The mixers 13a to 13d mix the ILS signals output from the BPFs 12a to 12d with local signals having predetermined local oscillation frequencies output from the local oscillator 17 and frequency-convert them to an intermediate frequency of 10.7 MHz. Output a signal.

The local oscillation frequency of the local oscillator 17 is such that the difference frequency from the carrier frequency f0 designated by the ILS device is the center frequency f0 + 4 kHz of the first transmission signal and the center of the second transmission signal with respect to the intermediate frequency 10.7 MHz. It is set to a frequency (10.7 MHz + 4 kHz) that is higher by 4 kHz, which is a half of the frequency difference from the frequency f0-4 kHz. That is, the local oscillation frequency of the local oscillator 17 is higher than the local oscillation frequency of the local oscillator 26. f0− (10.7 MHz + 4 kHz) = f0−10.7 MHz−4 kHz
As shown in FIG. 4, the frequency is set to 4 kHz lower.

  The BPFs 14a and 14b are narrow bandpass filters for selecting the frequency of the frequency converted ILS signals (NF POSN and INTG WD) output from the mixers 13a and 13c. The passband width is set to about 6 kHz to 8 kHz. Yes. As a result, the BPFs 14a and 14b can convert the frequency components of the second transmission signal from the transmission unit (CL) 2 from the ILS signals (NF POSN and INTG WD) after the frequency conversion output from the mixers 13a and 13c, and the image frequency. Remove components and adjacent channel components.

  The BPFs 15a and 15b are bandpass filters for selecting the frequency of the ILS signals (INTG POSN and INTG CL) after the frequency conversion output from the mixers 13b and 13d, and the passband width is set to 18 kHz or more. Thereby, the BPFs 15a and 15b remove the image frequency component and the adjacent channel component from the frequency-converted ILS signals (INTG POSN and INTG CL) output from the mixers 13b and 13d.

  Here, the allowable deviation of the center frequency of both transmission signals from the transmission unit (DIR) 1 and the transmission unit (CL) 2 is 20 ppm, which is about 2 kHz, and about 4 kHz when shifted in the reverse direction. The design center frequency difference between the two transmission signals is 8 kHz, and the modulation frequency (ID 1020 Hz) is about 2 kHz for both transmission signals. Therefore, the minimum pass frequency bandwidth required for frequency selection of both transmission signals is about 16 kHz, which is the sum of the above frequencies, but the BPF pass bandwidth is between 3 dB lower frequencies. In order to obtain a more flat characteristic, in this embodiment, the pass bandwidths of the BPFs 15a and 15b are set to 18 kHz or more.

  The monitor circuits 25a, 25b, 25c, and 25d receive the signals output from the BPFs 24a, 24b, 24c, and 24d as input signals, and monitor the RF level, modulation degree difference (DDM), and modulation degree that are the characteristics of the ILS signal, respectively. To do.

  Next, the operation of the monitor device 10 of this embodiment will be described.

  The front direction ILS signal (NF POSN) output from the monitor antenna device 6 is attenuated to an appropriate signal level by the attenuator 11a, frequency-limited to a predetermined frequency band by the BPF 12a, and then supplied to the mixer 13a. Thus, the signal is mixed with a local signal having a local oscillation frequency (f0-10.7 MHz-4 kHz) from the local oscillator 17 and is converted into an intermediate frequency signal having an intermediate frequency of 10.7 MHz. The BPF 14a selects a frequency component of about 6 kHz to 8 kHz centering on 10.7 MHz of the front direction ILS signal (NF POSN) frequency-converted to the intermediate frequency 10.7 MHz, and transmits the frequency of the transmission unit (CL) 2 The frequency component, image frequency component, and adjacent channel component of the transmission signal are removed.

  On the other hand, the front direction ILS signal (INTG POSN), the course width or path width direction ILS signal (INTG WD), and the clearance direction ILS signal (INTG CL) output from the monitor network 4 are respectively transmitted by the attenuators 11b, 11c, and 11d. After being attenuated to an appropriate signal level and frequency-limited to a predetermined frequency band by the BPF 12b, 12c, 12d, the signal is supplied to the mixers 13b, 13c, 13d, where the local oscillation frequency (f0-10.f) from the local oscillator 17 is supplied. 7MHz-4kHz) is mixed with a local signal and converted to an intermediate frequency signal having an intermediate frequency of 10.7MHz.

  The BPF 14b frequency-selects a frequency component of about 6 kHz to 8 kHz having a center frequency of 10.7 MHz of the course width or path width direction ILS signal (INTG WD) frequency-converted to an intermediate frequency of 10.7 MHz, and a transmission unit ( CL) The frequency component, image frequency component, and adjacent channel component of the transmission signal of 2 are removed. On the other hand, the BPFs 15a and 15b have a frequency component of 18 kHz or more with a center frequency of 10.7 MHz of the front direction ILS signal (INTG POSN) and the clearance direction ILS signal (INTG CL) converted to an intermediate frequency of 10.7 MHz. Each frequency is selected, and the image frequency component and the adjacent channel component are removed.

  Here, the frequency spectrum of the transmission radio wave of the 2-frequency ILS device will be described. FIG. 2 shows the frequency spectrum of the transmission radio wave of the two-frequency ILS device. In FIG. 1, when the monitor antenna device 6 is installed at a position sufficiently far from the transmission antenna device 5, as shown in FIG. 2 (A), the radio wave of the transmission signal of the transmission unit (DIR) 1 is transmitted. The frequency spectrum is indicated by II, the frequency spectrum of the radio wave of the transmission signal of the transmission unit (CL) 2 is indicated by I, and the level ratio of the radio wave of both transmission signals is the radio wave of the transmission signal of the transmission unit (DIR) 1 10 dB or more is secured in comparison with the radio wave of the transmission signal of the transmission unit (CL) 2. Therefore, with respect to the ILS signal (NF POSN) output from the monitor antenna device 6, it is possible to monitor the characteristics of the ILS signal based on the frequency component of the transmission signal of the transmission unit (DIR) 1.

  However, when the distance between the transmission antenna device 5 and the monitor antenna device 6 is short, the monitor antenna device 6 cannot obtain the same ILS signal (NF POSN) as far away, and the transmission signal of the transmission unit (CL) 2 Since the ILS signal (NF POSN) output from the monitor antenna device 6 is strongly influenced by radio waves, the frequency spectrum IV of the frequency component of the transmission signal of the transmission unit (DIR) 1 as shown in FIG. However, it becomes substantially the same level as the frequency spectrum III of the frequency component of the transmission signal of the transmission unit (CL) 2.

  In the monitoring method shown in FIG. 3, the local oscillation frequency of the local oscillator 26 is set to a value obtained by subtracting 10.7 MHz from the designated carrier frequency f0 in accordance with the intermediate frequency of 10.7 MHz. The center frequency of the output signal spectrum of 23d is an intermediate frequency between the center frequencies of the transmission signal from the transmission unit (DIR) and the transmission signal from the transmission unit (CL).

  For this reason, in the monitoring method shown in FIG. 3 using the BPF 24a having a pass bandwidth of 10 kHz or more shown by BW0 in FIG. 2, when the distance between the transmitting antenna device 5 and the monitoring antenna device 6 is short, FIG. As shown in the frequency spectrum, the radio wave level of the transmission signal of the transmission unit (DIR) 1 is higher than the radio wave level of the transmission signal of the transmission unit (CL) 2 according to the international standard as shown in FIG. Since a level difference equal to or greater than a predetermined value cannot be obtained, monitoring of the characteristics of the ILS signal (NF POSN) performed based on the frequency component of the transmission signal of the transmission unit (DIR) 1 from the output signal of the mixer 23a is actually performed. There is a possibility of monitoring with characteristics different from the ILS signal received by the other aircraft.

  On the other hand, in the monitoring apparatus 10 of the present embodiment, the local oscillation frequency of the local oscillator 17 is set to a frequency (f0-10.7 MHz-4 kHz) that is lower by 4 kHz than that of the local oscillator 26 of FIG. Therefore, the center frequencies of the ILS signals frequency-converted to the intermediate frequencies output from the mixers 13a to 13d are 10.7 MHz + 8 kHz (= f0 + 4 kHz− (f0−10.7 MHz−4 kHz)) and 10.7 MHz (= f0-4 kHz- (f0-10.7 MHz-4 kHz)). The signals output from the mixers 13a to 13d include image frequency components in addition to these signals.

  Therefore, in the monitor device 10 of this embodiment, even when the distance between the transmission antenna device 5 and the monitor antenna device 6 is short, as shown by BW1 in FIG. 2, the transmission signal from the transmission unit (DIR) 1 Is selected from the frequency-converted ILS signal output from the mixer 13a by the BPF 14a having a center frequency of about 6 kHz to 8 kHz and the frequency component of the transmission signal from the transmission unit (DIR) 1. And the frequency component of the transmission signal from the transmission unit (CL) 2 can be removed. At this time, adjacent channel frequency components and image frequency components can also be removed.

  Thereby, a ratio larger than the ratio of the radio wave of the transmission signal of the transmission unit (DIR) 1 received by the actual aircraft and the radio wave of the transmission signal of the transmission unit (CL) 2 is ensured. Therefore, the monitor circuit 16a shown in FIG. 1 is based on the frequency component of the transmission signal from the transmission unit (DIR) 1 separated by the BPF 14a, and the difference in RF level and modulation degree that are the characteristics of the ILS signal (NF POSN). (DDM), which can monitor the degree of modulation. This monitoring result corresponds to the ILS signal (NF POSN) received by the actual aircraft almost accurately.

  Further, the monitor device 10 transmits from the transmission unit (DIR) 1 from the ILS signal frequency-converted to the intermediate frequency output from the mixer 13c by the BPF 14b whose passband width indicated by BW1 in FIG. Only the frequency component of the signal is frequency-selected, and the frequency component of the transmission signal from the transmission unit (CL) 2, the adjacent channel frequency component, and the image frequency component are also removed. Thereby, the monitor circuit 16c, based on the frequency component of the transmission signal from the transmission unit (DIR) 1 separated by the BPF 14b, the RF level, the modulation difference (DDM), which are the characteristics of the ILS signal (INTG WD), A monitor can be used to monitor the modulation degree.

  Thus, according to the monitoring apparatus 10 of the present embodiment, in the path width direction ILS signal (INTG WD) output from the monitor network 4, the frequency component of the transmission signal of the transmission unit (DIR) 1 passes by the BPF 14b. However, the frequency component of the transmission signal of the transmission unit (CL) 2 is removed. As a result, the frequency component of the transmission signal of the transmission unit (CL) 2 disappears in the signal monitored by the monitor circuit 16c, and the stability of the path width direction ILS signal (INTG WD) is improved. Thereby, according to the monitoring apparatus 10 of this embodiment, the radio wave of the transmission unit (CL) 2 interferes with the radio wave of the transmission unit (DIR) 1, the beat output affects the monitor, and the phenomenon varies seasonally. Can be improved, the need for regular monitor adjustment can be reduced, and maintainability can be improved.

  On the other hand, as shown by BW2 in FIG. 2, the BPFs 15a and 15b have the center frequency of the transmission signal from the transmission unit (DIR) 1 as the center frequency and the pass bandwidth is set to 18 kHz or more. The frequency components of both the transmission signal from the transmission unit (DIR) 1 and the transmission signal from the transmission unit (CL) 2 are frequency-selected from the ILS signal after frequency conversion to the intermediate frequency output from 13b and 13d, and adjacent Channel frequency components and image frequency components can be removed.

  As a result, the monitor circuits 16b and 16d allow the ILS signal (INTG POSN) and ILS based on the frequency components of both transmission signals from the transmission unit (DIR) 1 and the transmission unit (CL) 2 separated by the BPFs 15a and 15b. It is possible to monitor the RF level, the modulation difference (DDM), and the modulation degree which are characteristics of the signal (INTG CL).

  The present invention is not limited to the above-described embodiment. For example, the frequency (f0-10) obtained by subtracting (10.7 MHz-4 kHz) from the frequency f0 designated by the ILS device as the local oscillation frequency of the local oscillator. (7 MHz + 4 kHz), only the frequency component of the transmission signal of the transmission unit (CL) 2 may be passed and the frequency component of the transmission signal of the transmission unit (DIR) 1 may be blocked. The local oscillation frequency is (f0-10.7 MHz), which is half the frequency of the difference between the center frequencies of the transmission signal of the transmission unit (DIR) 1 and the transmission signal of the transmission unit (CL) 2. It is also possible to set it higher or lower by a frequency close to a certain 4 kHz.

  Furthermore, in the above-described embodiment, narrow band BPF having a passband width of about 6 kHz to 8 kHz is used for two types of ILS signals (NF POSN, INTG WD). However, the present invention is applied to other ILS signals. It is also possible to use it or use it for one kind of ILS signal. Further, it is possible to use a frequency other than 10.7 MHz as the intermediate frequency.

  According to the monitoring system of the present invention, it can be easily realized by changing the local oscillation frequency of the existing monitoring system and replacing the narrowband bandpass filter. Removing only the frequency component of the transmission signal of the transmission unit (CL) without using the present invention is expensive because it is necessary to design a special bandpass filter. However, in the present invention, since the local signal is generated by the synthesizer oscillator, the local signal is selected from the many narrow-band bandpass filters having different frequencies currently in circulation, so that the transmitter (CL) Selection and replacement of a narrow band pass filter that can remove only the frequency component of the transmission signal can be facilitated.

1 Transmitter (DIR)
2 Transmitter (CL)
3 Power Divider 4 Monitor Network 5 Transmitting Antenna Device 6 Monitor Antenna Device 10 Monitor Devices 11a to 11d Attenuator (ATT)
12a to 12d Band pass filter (BPF)
13a to 13d Mixers 14a and 14b Narrowband bandpass filters (BPF)
15a, 15b Bandpass filters 16a to 16d Monitor circuit 17 Local oscillator

Claims (6)

A method of monitoring a two-frequency ILS device that induces landing of an aircraft using radio waves of first and second transmission signals having different center frequencies,
A first antenna for receiving a radio wave of a transmission signal obtained by synthesizing the first and second transmission signals from a transmission antenna apparatus by a monitor antenna apparatus installed in the vicinity of the transmission antenna apparatus and monitoring the front direction. A signal for acquiring an ILS signal and detecting a signal generated by artificially combining the first and second transmission signals in the far field in the transmission antenna apparatus and monitoring them in a plurality of directions. An acquisition step of acquiring each of the two ILS signals;
A local signal having a frequency different from a value half the difference between the center frequencies of the first and second transmission signals with respect to an intermediate frequency or a value in the vicinity thereof with respect to a predetermined carrier frequency, and the first and second Each of the ILS signals is mixed and converted to the intermediate frequency ILS signal,
A first frequency for selecting only the frequency component of the first transmission signal by removing the frequency component of the second transmission signal from the first ILS signal converted to the intermediate frequency in the conversion step. A selection step;
A second frequency selection step of selecting a frequency component of each of the first and second transmission signals from the second ILS signal converted to the intermediate frequency in the conversion step;
And a monitoring step of monitoring the characteristics of the ILS signal independently of each other based on the signals obtained in the first and second frequency selection steps. A method of monitoring a two-frequency ILS device that induces landing of an aircraft using radio waves of first and second transmission signals having different center frequencies,
A first antenna for receiving a radio wave of a transmission signal obtained by synthesizing the first and second transmission signals from a transmission antenna apparatus by a monitor antenna apparatus installed in the vicinity of the transmission antenna apparatus and monitoring the front direction. While acquiring the ILS signal, the signal generated by artificially synthesizing the first and second transmission signals in the far field in the transmission antenna apparatus is detected and the course characteristic or path characteristic of the ILS is monitored in front. Obtaining a second ILS signal, a third ILS signal monitored in the course width or path width direction, and a fourth ILS signal monitored in the clearance direction,
A local signal having a frequency different from a value half the difference between the center frequencies of the first and second transmission signals with respect to a predetermined intermediate frequency with respect to a predetermined carrier frequency, A conversion step of mixing each of the fourth ILS signals and converting the frequency into the intermediate frequency ILS signal;
The frequency components of the second transmission signal are removed from the first and third ILS signals converted to the intermediate frequency in the conversion step, respectively, and only the frequency components of the first transmission signal are selected. A first frequency selection step;
A second frequency selection step of selecting a frequency component of the first and second transmission signals from the second and fourth ILS signals converted to the intermediate frequency in the conversion step, respectively;
And a monitoring step of monitoring the characteristics of the ILS signal independently of each other based on the signals obtained in the first and second frequency selection steps. The first transmission signal is an upper sideband of the first center frequency obtained by amplitude-modulating the carrier frequency f0 designated by the ILS device with predetermined information, and the second transmission signal is the second transmission signal. Is the lower sideband of the center frequency of
The frequency of the local signal is lower than the value obtained by subtracting the intermediate frequency from the carrier frequency f0, or a value that is half of the difference between the center frequencies of the first and second transmission signals or a value in the vicinity thereof. 3. The method for monitoring an ILS apparatus according to claim 1, wherein the frequency is a frequency. A two-frequency ILS device that induces landing of an aircraft using radio waves of first and second transmission signals having different center frequencies,
A first antenna for receiving a radio wave of a transmission signal obtained by synthesizing the first and second transmission signals from a transmission antenna apparatus by a monitor antenna apparatus installed in the vicinity of the transmission antenna apparatus and monitoring the front direction. A signal for acquiring an ILS signal and detecting a signal generated by artificially combining the first and second transmission signals in the far field in the transmission antenna apparatus and monitoring them in a plurality of directions. Acquisition means for respectively acquiring two ILS signals;
A local oscillating means for generating a local signal having a frequency different from a value half the difference between the center frequencies of the first and second transmission signals with respect to an intermediate frequency with respect to a predetermined carrier frequency or a value in the vicinity thereof;
Mixing means for mixing the local signal and the first and second ILS signals, respectively, and converting the frequency into the intermediate frequency ILS signal;
A first filter that removes a frequency component of the second transmission signal from the first ILS signal converted to the intermediate frequency by the mixing unit and frequency-selects only the frequency component of the first transmission signal. Means,
Second filter means for frequency-selecting frequency components of the first and second transmission signals, respectively, from the second ILS signal converted to the intermediate frequency by the mixing means;
A monitor device for an ILS apparatus, comprising: monitor means for independently monitoring the characteristics of the ILS signal based on signals output from the first and second filter means. A monitoring device for a two-frequency ILS device that induces landing of an aircraft using radio waves of first and second transmission signals having different center frequencies,
A first antenna for receiving a radio wave of a transmission signal obtained by synthesizing the first and second transmission signals from a transmission antenna apparatus by a monitor antenna apparatus installed in the vicinity of the transmission antenna apparatus and monitoring the front direction. While acquiring the ILS signal, the signal generated by artificially synthesizing the first and second transmission signals in the far field in the transmission antenna apparatus is detected and the course characteristic or path characteristic of the ILS is monitored in front. Acquisition means for acquiring a second ILS signal, a third ILS signal to be monitored in the course width or path width direction, and a fourth ILS signal to be monitored in the clearance direction;
A local oscillating means for generating a local signal having a frequency different from a value half the difference between the center frequencies of the first and second transmission signals with respect to an intermediate frequency with respect to a predetermined carrier frequency or a value in the vicinity thereof;
Mixing means for mixing the local signal and the first to fourth ILS signals, respectively, and converting the frequency into the intermediate frequency ILS signal;
Only the frequency component of the first transmission signal is selected by removing the frequency component of the second transmission signal from the first and third ILS signals converted to the intermediate frequency by the mixing unit. First and second filter means;
Third and fourth filter means for selecting the frequency components of the first and second transmission signals from the second and fourth ILS signals converted to the intermediate frequency by the mixing means, respectively;
A monitoring device for an ILS apparatus, comprising: monitoring means for independently monitoring characteristics of the ILS signal based on signals output from the first to fourth filter means. The first transmission signal is an upper sideband of the first center frequency obtained by amplitude-modulating the carrier frequency f0 designated by the ILS device with predetermined information, and the second transmission signal is the second transmission signal. Is the lower sideband of the center frequency of
The frequency of the local signal is lower than the value obtained by subtracting the intermediate frequency from the carrier frequency f0, or a value that is half of the difference between the center frequencies of the first and second transmission signals or a value in the vicinity thereof. 6. The monitor apparatus for an ILS apparatus according to claim 4, wherein the monitor apparatus is a frequency.

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