JP3160272B2 - Microwave detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave detector and, more specifically, to a microwave detector which is less susceptible to microwaves (jamming radio waves) other than a microwave to be detected and intended, and The present invention relates to a microwave detector capable of preventing a false alarm.

[0002]

2. Description of the Related Art There has been conventionally known a microwave detector configured to generate an alarm by an alarm device when detecting a microwave emitted from a radar type speed measuring device. Although a specific description of the internal circuit is omitted, the target detection is performed when microwaves having a certain electric field strength (level) or more in a predetermined frequency band are present in a radio wave received via an antenna. It is determined to be the target microwave, and an alarm is sounded to alert the driver. Since such a microwave detector needs to be detected with high sensitivity, a weak microwave is also detected.

[0003]

The automobile on which the microwave detector according to the present invention is mounted includes a radio,
Electronic devices and communication devices that generate electromagnetic waves, such as a television receiver, a navigation system, a mobile communication device, and a personal computer, are installed or brought into a vehicle interior or the like. And such various devices improve performance,
With an increase in the clock frequency or the like, there is a possibility that electromagnetic waves in the microwave frequency band detected by the microwave detector will be emitted. Further, in the case of a mobile communication device, a navigation system, or the like, radio waves in the predetermined frequency band are positively transmitted or received. As a result, a high-sensitivity microwave detector may erroneously recognize an electromagnetic wave or the like radiated from the various devices as a target microwave and output a false alarm. That is, the electromagnetic wave radiated from the device is a disturbance wave for the microwave detector. As a result, it becomes difficult to use the microwave detector and the various devices together.

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and has as its object to solve the above-described problems, and to respond to such interference even if there is any. It is an object of the present invention to provide a microwave detector capable of detecting a microwave having a frequency of:

[0005]

In order to achieve the above-mentioned object, a microwave detector according to the present invention detects microwaves in a predetermined band and outputs an alarm. Jamming wave detecting means for detecting jamming radio waves, storage means for storing jamming wave information detected by the jamming wave detecting means, and whether the received microwave is a jamming wave based on the jamming wave information stored in the storage means. It is assumed that the target radio wave is discriminated, and the alarm is not output when it is determined that the radio wave is a jamming radio wave.

[0006] As the jammer detection means, Ru can be used as a manual or automatic variety.

[0007]

[0008]

[0009]

In the present invention, based on the above-mentioned premise, the jamming radio wave detecting means can judge a microwave detected at power-on as a jamming radio wave.

That is, in general, jamming radio waves emitted from an on-vehicle device or the like always emit under a constant condition while the device is operating or under a constant condition. As an example, the local oscillator of a GPS receiver used in a navigation system oscillates while the GPS receiver is operating, and its harmonics are radiated at a constant level during that time. That is, in many cases, the frequency is constant and the signal strength is constant (both may vary within a certain range).

On the other hand, the source of the microwave to be detected is
Generally, the antenna is fixedly installed, and receives microwaves only when passing near the installation location. Therefore, the period during which a signal is received is relatively short. In addition, the signal strength is weak at the beginning of reception, increases as approaching the transmission source, and gradually weakens when passing through the installation location.

In the case of a navigation system or the like, since the operation is started from the start of the engine, it occurs when the power of the microwave detector is turned on or immediately thereafter. Microwaves can be determined as jammers.

In each of the above-mentioned inventions, "identical" when judging whether or not a jamming signal may be required to completely match, but usually there is a variation, so that a certain tolerance is required. It is preferable to perform processing so that those existing in the range are regarded as the same (frequency, signal strength).

Still another configuration of the jamming wave detecting means
A forced interference radio wave detection switch is provided, and when a user presses the forced interference radio wave detection switch during radio wave detection, a signal at the time of depression is stored in the storage means as an interference radio wave. You may. If the source of the jamming is known and used, the microwave generated and received at that time is forcibly recognized as the jamming. This can prevent unnecessary alarms from being output for a certain period of time.

The information stored by each of the above-described methods may be deleted immediately when the corresponding jamming radio wave disappears, or may be stored and retained thereafter, and then the jamming electromagnetic wave is generated. At this time, an alarm may not be output from the beginning. As the erasing timing when the data is stored and held as described above, for example, the information stored in the storage unit may be canceled by at least one of turning off the power and pressing the reset switch. Furthermore, when the same state as the signal information stored in the storage means is not continuously detected for a certain period, the signal information stored in the storage means may be deleted.

[0017]

FIG. 1 shows the overall configuration of a preferred embodiment of a microwave detector according to the present invention.
As shown in the figure, the input of the horn antenna 1 and the output of the local oscillator 2 are frequency-mixed by the mixer 3. The intermediate frequency signal thus obtained is band-amplified through an intermediate frequency band amplifier (BPF + AMP) 4 at the next stage, and then input to a detector 5. Then, based on the detection signal output from the detector 5, the signal identification circuit 6 determines whether or not the target microwave exists. If the microwave exists, the detection signal is sent to the alarm circuit 7. Send to When receiving the detection signal, the alarm circuit 7 operates the alarm device 8 to notify the driver. The alarm 8 may be a sound such as a buzzer or an alarm, or a visual alarm such as a lamp.

The local oscillator 2 is controlled by a sawtooth wave or a triangular wave generated from the control voltage generator 9, and the frequency of the output of the local oscillator 2 that mixes the frequency with the received signal is periodically swept within the reception band. I do. Therefore, when the sweep control voltage changes as shown in FIG. 2A, the output of the detector 5 shows a large peak when a microwave of the corresponding frequency exists as shown in FIG. White noise appears in the region of. Therefore, for example, by using a comparator using a threshold value Th as a reference voltage that can be distinguished from white noise as the signal discriminating circuit 7, as shown in FIG. The pulse can be turned ON only when a microwave of an intensity or more is received. That is, when the pulse is turned on, it becomes the above-described detection signal. When the alarm circuit 7 receives the pulse (ON), the alarm circuit 7 operates the alarm device 8 for a certain time (at least one sweep time or more).

The above configuration is a commonly used superheterodyne type microwave detector. Here, in the present invention, the microcomputer 10 as the jamming wave detecting means is connected to the output of the signal identification circuit 6 so that a detection signal can be obtained. Then, the microcomputer 10 monitors the appearance state of the detection signal, and when it is determined that the detection signal is a jamming wave, stores information on the jamming wave in the memory 11.

Further, the microcomputer 10 invalidates the detection signal when the detection signal is a jamming radio wave, so that the alarm circuit 7 and / or the alarm device 8 do not operate depending on the jamming radio wave. That is, based on the information stored in the memory 11, it is determined whether the detection signal is a jamming radio wave,
If it is determined that jamming radio waves are present, no alarm is output.

Next, a specific configuration will be described. In the case of the microwave to be detected, the microwave is detected only for a certain period of time. However, the microwave disappears when the vehicle passes through the installation position of the radar type speed measuring device which is the source of the microwave. On the other hand, in the case of a jamming radio wave, if the electromagnetic wave is emitted from an electronic device or the like existing in the vehicle interior, the electromagnetic wave is always generated regardless of the movement of the vehicle while using the electronic device or the like. Therefore, when a signal of the same frequency is received continuously for a certain period of time or more, it is determined to be a jamming radio wave and the information is stored in the memory 11. As a result, the memory 1
When the same signal as the jamming radio wave stored in 1 is received, it is detected and the alarm circuit 7 is not operated.

* Jammer Detection Function In order for the microcomputer 10 to detect jammer, an A / D converter 12 is connected to the output of the control voltage generator 9 as shown in FIG.
The digital value of the sweep control voltage is input to the microcomputer 10. The microcomputer 10 monitors the output of the signal identification circuit 6 and, when detecting the detection signal (pulse ON), outputs the output value (digital data of the sweep control voltage) P of the A / D converter 12 at the time of the rise of the pulse. Acquire (see FIG. 4). Then, the obtained output value P is stored in the memory 1
1 is stored. Of course, when a plurality of pulses are detected, each output value is stored in the memory 11.

If the same output value P is continuously detected N times or more (a value corresponding to a certain time or more),
The microwave having a frequency corresponding to the output value P is used as a jamming radio wave, and the frequency is used as the frequency of the jamming radio wave in the memory 11.
(Specifically stored data may be an output value P corresponding to a frequency.) It should be noted that the same output value P may be the only one that completely matches, or
A certain margin may be set, and those existing within the range may be determined to be based on the same signal. Further, once the reception of the same output value P is interrupted, the number of continuous receptions integrated up to that point is reset. Instead of counting the number of receptions as described above, when a timer is started and a signal of the same frequency is continued for a certain period of time or longer, the signal of that frequency may be used as a jamming radio wave.

That is, since there is a correlation between the sweep control voltage and the frequency, the relative frequency is stored by storing the sweep control voltage in this way, and the same sweep control voltage is detected. Means that the same frequency signal is continuously detected.

* Alarm stop function at the time of detection of jamming radio waves Even if jamming radio waves are detected by any of the above determinations, there is a case where a microwave to be detected exists at the same time. Therefore, it is necessary not to completely output an alarm when the jamming radio wave is detected.

Therefore, when jamming radio waves are present, data on the frequency of the jamming radio waves is stored in the memory 11.
Is stored in the A / D.
The output of the converter 12 is monitored, and the output value is stored in the memory 1
It is determined whether or not the jamming control voltage value corresponding to the frequency at which the jamming radio wave stored in 1 is coincident. If so, the detection signal generated at that time can be regarded as being caused by the jamming radio wave. The pulse (ON) output from the signal identification circuit 6 is invalidated.

That is, the input signal to the alarm circuit 7 is kept low based on the control signal from the microcomputer 10. This corresponds to the output of the signal identification circuit 6 and the microcomputer 1
The control signal from 0 is supplied to a 2-input AND circuit, and the output of the AND circuit is supplied to the alarm circuit 7. The control signal from the microcomputer 10 is H when normal and L when the jamming radio frequency.
Output. As a result, the output of the AND circuit becomes L when jamming radio waves are generated, so that the alarm circuit 7 recognizes that there is no detection signal during the jamming radio wave generation period. On the other hand, when no jamming radio wave is generated, the input signal from the microcomputer 10 of the AND circuit becomes H, so that the output of the AND circuit is equivalent to the output from the signal identification circuit 6. Therefore, when the microwave to be detected does not exist, the output of the signal identification circuit 6 is Low.
Will remain. When a microwave to be detected is present together with the jamming radio wave, the detection signal is recognized as being present only when the frequency of the microwave is not the jamming radio wave.

As another method, since the presence or absence of jamming waves is monitored by the microcomputer 10, it is determined whether or not only jamming waves exist in one sweep. If it is determined that only the jamming radio wave is present, a stop command is sent to the alarm circuit 7. On the other hand, if there is no jamming radio wave, or if there is a signal other than the jamming radio wave, the stop command is not sent. The alarm circuit 7 may be configured not to output an alarm when receiving a stop command.

FIGS. 5 and 6 show a main part of a second embodiment of the microwave detector according to the present invention. In the present embodiment, a synchronous sawtooth wave oscillator that generates a sawtooth wave in synchronization with a timing pulse from the microcomputer 10 is used as the control voltage generator 9 that outputs the sweep control voltage. This oscillator outputs a one-time sweep voltage when a timing pulse is received from the microcomputer 10. Therefore, as shown in FIG. 7, when a timing pulse is output from the microcomputer 10 at regular intervals, a sawtooth sweep control voltage is output.

Here, in the present embodiment, the microcomputer 10 is supplied with the output of the signal discriminating circuit 6 in the same manner as in the first embodiment, and the memory 11 for storing the jamming radio wave information is connected. The elapsed time from the output of the timing pulse is measured by a timer built in the microcomputer 10, and the output of the signal identification circuit 6 is turned on (H).
Then, the elapsed time at which the time has become is acquired and stored in the memory 11. This elapsed time becomes information on the frequency of the received microwave.

Therefore, similarly to the first embodiment, the elapsed time is the same (including a variation within a certain range).
Is received N times continuously, it is determined to be a jamming radio wave, and the elapsed time is recorded in the memory 11 as the jamming radio wave information. Thereafter, a detection signal of a microwave generated at the same time as the elapsed time is regarded as a jamming radio wave, so that no alarm is output. The function of stopping the alarm can be the same as that of the first embodiment.

FIG. 7 shows a main part of a third embodiment of the microwave detector according to the present invention. As shown in the figure, in the present embodiment, a control voltage generator 9 that outputs a sweep control voltage is applied to a control voltage generator 9 using a D / A converter. That is, the microcomputer 10 supplies digital data that gradually steps up to a predetermined sawtooth wave to the D / A converter, converts the digital data into an analog value (voltage) corresponding to the digital data, and supplies the analog data to the local oscillator 2. It is provided as a sweep control voltage.

With this configuration, since the microcomputer 10 directly controls the voltage value of the sweep control voltage, the sweep voltage when the detection signal (H) is output from the signal identification circuit 6 is:
Since the microcomputer 10 knows the corresponding digital data, the data is stored in the memory 11. Then, it is determined whether the data is due to jamming radio waves,
The alarm stop processing after the determination of the jamming radio wave is performed by the first
This can be realized by the same algorithm as that of the embodiment.

In each of the above embodiments, when the output of the signal identification circuit 6 becomes H (microwave detection), the sweep may be temporarily stopped as shown in FIG. . In this way, even if the processing speed of the microcomputer 10 is low, processing can be performed without lowering the detection accuracy.

** Judgment of jamming radio waves based on the number of signals detected in one scan-Fourth Embodiment-In the description of each of the above-described embodiments, when the same frequency is continuously detected, the jamming radio waves are determined. It is about the method of recognition. In the present invention, the algorithm for detecting jamming radio waves is not limited to the method based on whether or not the frequencies are the same.

That is, although not specifically shown, the output of the signal discriminating circuit 6 is taken into the microcomputer 10 as in the above-described embodiments. Then, the microcomputer 10 counts and stores the number of detected signals (the output of the identification circuit 6 is H) (the number of received microwaves) generated in one sweep. Then, when the state where the counted number of receptions is the same is continuously continued for a predetermined time or more (for example, N times),
It is determined that only the jamming radio wave is detected, and the alarm output is stopped.

The number of receptions is counted continuously even after the recognition as the interference wave, and is compared with the reception number of the interference wave stored in the memory 11. If they match, it is recognized that only the jamming radio wave is still being received, and no alarm is output. On the other hand, when the number of receptions changes, the alarm stop state is released, and the number of receptions stored in the memory 11 is also reset. Therefore, even if the number of receptions changes, if there is one or more receptions, an alarm is output because there is a possibility that the number of receptions may be a target microwave (alarm stop state is already released). .
When the number of receptions is 0, no alarm is output since the jamming radio wave has just disappeared.

In the present embodiment, the determination as to whether or not a jamming radio wave can be made based only on the output signal of the signal discriminating circuit 6 (the frequency information is not looked at as in the above embodiments). Processing can be performed by a simple algorithm with a simple structure, and the load required for determination can be reduced.

** Judgment of jamming radio wave by signal level-Fifth Embodiment-In each of the above-described embodiments, it is determined whether or not jamming radio waves are based on at least the output signal of the signal identification circuit. I have. This embodiment is different from them,
As shown in FIG. 9, the signal strength output of the intermediate frequency amplifier 4 is A
After being converted into digital data by the / D converter 14, the digital data is input to the microcomputer 10.

The microcomputer 10 stores the given signal strength. If the signal strength does not change for a certain period of time (it is allowed to fluctuate within a certain range), it is determined that the signal is caused by jamming radio waves. That is, in the case of a microwave to be detected, the signal strength generally increases gradually as the vehicle moves closer to the source of the microwave as it moves. Therefore, the fact that the signal strength does not change for a certain period of time or more means that the transmission source can be regarded as having a high possibility of interfering radio waves existing in the vehicle interior.

The processing after the detection of the jamming radio wave is the same as in the above-described embodiments. That is, the microcomputer 1
A value of 0 issues an alarm stop command to the alarm circuit 7, and thereafter monitors the signal strength output, and releases the alarm stop command when the signal strength changes.

** Judgment of jamming radio wave based on same frequency + same level -Sixth Embodiment- In this embodiment, when the same frequency is continuous as in the above-described first to third embodiments, jamming is performed. Combining a method of determining a radio wave with a method of determining an interfering radio wave when the same signal strength continues as in the fifth embodiment,
This is to make a more accurate judgment.

Specifically, it can be realized by adopting the configuration as shown in FIG. What is shown is the first embodiment and the fifth embodiment. That is, the detection signal is given to the microcomputer 10 from the signal identification circuit 6,
The sweep voltage (corresponding to the frequency) at that time is supplied via the A / D converter 12. Further, the signal strength is also given through the A / D converter 14.

The microcomputer 10 that has obtained the three pieces of information as described above combines the frequency information (the voltage value of the sweep control voltage) obtained when the detection signal issued from the signal identification circuit 6 is obtained with the signal strength of the memory 11 To be stored. Of course, when a plurality of detection signals are acquired by one sweep, two pieces of information are stored in pairs for each.

When a signal having the same frequency and the same signal strength (variation within a predetermined range is allowed) is continuously received for a certain period of time or more, it is regarded as a jamming wave. to decide. As a result, the microcomputer 10 recognizes that the frequency and the signal strength related to the memory are caused by the jamming radio waves, and stores them in the memory 11 as the jamming radio wave information in association with them.

In the subsequent search, if a signal having the same frequency and the same signal strength as that of the stored signal is received, it is recognized as a jamming radio wave, so that no alarm is output. More specifically, for example, since the jamming radio wave is detected by the microcomputer 10 thereafter, an alarm stop command is output when all the detection signals output from the signal identification circuit 6 are jamming radio waves, and even one of the jamming waves is interrupted. When it is not a radio wave, the control can be performed by not outputting the alarm stop command. In this way, even if the frequency of the microwave to be detected happens to be once the frequency of the jamming radio wave and is the same as the frequency stored in the memory 11, for example, the intensity of the microwave to be detected is higher. If it is larger, the condition of the same frequency and the same signal strength is not satisfied, so that it is possible to recognize that there is a microwave to be detected instead of a jamming radio wave and output an alarm. Also, even if the signal strength of the microwave to be detected is smaller, if no jamming radio waves are generated at that time, the signal strengths do not match and the conditions for jamming radio waves are not satisfied, and detection should be performed. Can be.

In the illustrated example, the combination of the first embodiment and the fifth embodiment is shown. However, the second or third embodiment is combined with the fifth embodiment. Of course you can.

** Judgment of jamming radio wave based on the same number of signals + same level -Seventh Embodiment- This embodiment is a combination of the fourth embodiment and the fifth embodiment. That is, as shown in FIG. 11, a detection signal is given to the microcomputer 10 from the signal identification circuit 6, and a signal strength is also given via the A / D converter 14.

Then, each time one sweep is performed, the number of received detection signals is counted, and the signal intensities of the detection signals are stored in the memory 11 in pairs. When there are a plurality of detection signals, the order of reception and the signal strength are stored in association with each other.

If the number of detected signals matches and the signal strengths of all the signals (variations within a predetermined range are allowed) all match continuously for a certain period of time or longer, Is determined to be jamming. This allows
The microcomputer 10 recognizes that the frequency and the signal strength related to the memory are due to the jamming radio waves, and stores them in the memory 11 as the jamming radio wave information in association with them (the number of received signals and the signal strength of each signal). Note that the fact that the signal strength of each detection signal is the same does not mean that the signal strengths of the detection signals detected in one sweep are the same, but that the signal strength of the nth detection signal is detected during the previous and subsequent sweeps. Means that the signal strength is the same as the signal strength of the n-th detection signal.

In the subsequent search, if a signal having the same number of received signals as the stored signal and the same signal strength of each detection signal received in each sweep is received, it is regarded as a jammer. Recognize, and do not output an alarm. If the number of received signals changes or the signal intensity changes even in one wave, the alarm stop command is released, and if a microwave is present, an alarm is output.

** Judging the Microwave Detected When Power is Turned On as Jamming Radio Wave Eighth Embodiment In each of the above embodiments, the same state is maintained for a certain period of time while the vehicle is running. Is determined to be a jamming radio wave, and if the same state occurs thereafter, no alarm is output.

This embodiment is different from the first embodiment in that microwaves received within a certain period of time after the power of the microwave detector is turned on are regarded as jamming waves. That is, generally, a microwave detector, a vehicle-mounted electronic device such as a navigation system, and the like are powered on at an accessory position of an engine key. Therefore, the electromagnetic waves emitted from electronic devices that become jamming radio waves,
It exists when the power of the microwave detector is turned on or immediately thereafter. On the other hand, in the case of the microwave to be detected, it is unlikely that the microwave exists from the start of the engine (power-on of the microwave detector). Therefore, the microcomputer 10 measures the time by a timer after the power is turned on, and if a microwave is detected within a predetermined time, it is determined that the microwave is a jamming radio wave, and information on the jamming is stored in the memory 11.

The information to be stored may be any of the information described in the above embodiments. That is,
The present invention can be applied to various things such as a frequency, a received signal, a signal strength, and a combination thereof (of course, a circuit corresponding to information to be stored is formed). This embodiment may be implemented independently, or may be implemented in combination with the above-described embodiments.

** Judgment of jamming radio waves by forced input -Ninth Embodiment- In each of the above-described embodiments, the microcomputer 10 automatically recognizes jamming radio waves and stores information related thereto in the memory 1.
1 to control whether or not to stop the alarm thereafter. In the present embodiment, these are different from those in FIG.
As shown in FIG. 9 and FIG. 9, when the forced interference radio wave detection switch 15 is attached to the microcomputer 10 and the user presses the forced interference radio wave detection switch during radio wave detection,
The signal received when the button is pressed is determined to be jamming radio waves, and information on the jamming radio waves is stored in the memory 11. Thereafter, when a signal under the same condition as that stored in the memory 11 is received, the signal is determined to be a jamming radio wave, and accordingly, no alarm is output.

That is, for example, a mobile phone may be used after the start of driving, or an electronic device such as a personal computer or a radio may be used. If it is known that the interfering radio wave is output from the electronic device, the power of the communication device or the electronic device is turned on and the switch 1 is turned on.
Press 5. Thereby, the microwave detector can instantaneously recognize the received microwave as the jamming radio wave, and can stop the alarm without waiting for a certain period of time required before making a determination in each of the above embodiments. It is possible to suppress as much as possible discomfort due to unnecessary alarm output.

In some cases, a warning can be prevented from being output by pressing a mute switch of a microwave detector in advance when using a cellular phone or the like. Pressing the button will not output any alarm until it is released, and the monitoring process itself will be stopped.However, in this embodiment, an alarm is output only when a signal that can be regarded as the same as the jamming radio wave is received Only when no microwave is received, an alarm is output when other microwaves are received, so that the microwave to be detected can be detected while using the electronic device or the like. That is, it is possible to use a micro detector together with a communication device, an electronic device, and the like.

As in the case of the eighth embodiment, the information to be stored may be any of those described in the above embodiments. That is, it can be applied to various things such as frequency, received signal, signal strength, and a combination thereof (of course,
A circuit corresponding to the information to be stored is formed). This embodiment may be implemented independently, or may be implemented in combination with the above-described embodiments.

** Releasing Method Information stored in the memory 11 determined as jamming in each of the above embodiments may be deleted at the same time as the jamming disappears, or may be retained for a certain period of time. Next, when a jamming radio wave appears, it may be recognized as a jamming radio wave from the beginning to suppress unnecessary alarm output. The timing of erasing (releasing) the jamming radio wave information in the case where the method of retaining the radio wave information for a fixed period is used may be the following various types.

As an example, the information can be erased when the power of the microwave detector is turned off. For example, by using a volatile memory such as a RAM as the memory 11, the data can be automatically erased when the power is turned off without performing the erasing process.

As shown in FIGS. 1 and 9, a reset switch 16 is provided, and when the reset switch 16 is depressed, the microcomputer 10 detects this and erases the information related to the jamming radio wave stored in the memory 11. You may make it. Especially in this method, for example, the cause of the jamming is known to be a mobile phone or a personal computer.
After that, when the equipment that causes the jamming radio wave is not used, the information of the jamming radio wave is positively deleted, and the malfunctioning that the coincidence of the jamming radio wave and the microwave signal to be detected does not output the alarm is possible. As much as possible.

Further, when the same state as the signal information stored in the memory 11 is not continuously detected for a predetermined period, the signal information stored in the memory 11 may be deleted. As a result, when there is more than one jamming wave information, unnecessary jamming wave information can be erased, and the possibility that the microwave to be detected is erroneously recognized as jamming wave and the alarm is not output as much as possible can be reduced. Can be reduced.

[0063]

As described above, in the microwave detector according to the present invention, the storage unit stores the jamming radio wave information,
Using the stored jamming wave information, if there is a subsequently received microwave, if it is a jamming wave, it does not react and detects the microwave of the frequency to be detected (target), and correctly alarms Can be output.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a microwave detector according to the present invention.

FIG. 2 is a diagram illustrating a general operation of microwave detection.

FIG. 3 is a diagram showing a main part of the first embodiment.

FIG. 4 is a diagram illustrating the operation.

FIG. 5 is a diagram showing a main part of a microwave detector according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating the operation.

FIG. 7 is a diagram showing a main part of a third embodiment of the microwave detector according to the present invention.

FIG. 8 is a diagram showing a modification.

FIG. 9 is a block diagram showing a fifth embodiment of the microwave detector according to the present invention.

FIG. 10 is a diagram illustrating a main part of a microwave detector according to a sixth embodiment of the present invention.

FIG. 11 is a diagram showing a main part of a microwave detector according to a seventh embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antenna 2 Local oscillator 3 Mixer 4 Intermediate frequency band amplifier 5 Detector 6 Signal discriminating circuit 7 Alarm circuit 8 Alarm 9 Control voltage generator 10 Microcomputer (disturbance wave detecting means) 11 Memory (storage means) 12 A / D converter 14 A / D converter 15 Forced jammer detection switch 16 Reset switch

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-4983 (JP, A) JP-A-5-297111 (JP, A) JP-A-5-249156 (JP, A) JP-A-Heisei 4- 92524 (JP, A) JP-A-63-103991 (JP, A) JP-A-63-1285 (JP, A) JP-A-61-165475 (JP, U) (58) Fields investigated (Int. G01S ^7/ 00-7/42 G01S 13/00-13/95 G01R 29/08

Claims (4)

(57) [Claims] 1. A microwave detector for detecting a microwave in a predetermined band and outputting an alarm, a jammer detecting means for detecting jamming waves other than a detection target, and jamming wave information detected by the jammer detecting means. And a storage unit for storing, based on the jammer information stored in the storage unit, discriminates whether the received microwave is a jammer or a microwave to be detected, and does not output the alarm when it is determined that the jammer is a jammer. The microwave detector is characterized in that the jamming radio wave detecting means judges a microwave detected at power-on as a jamming radio wave. 2. A microwave detector for detecting microwaves in a predetermined band and outputting an alarm, a jammer detecting means for detecting jamming waves other than a detection target, and jamming wave information detected by the jammer detecting means. And a storage unit for storing, based on the jammer information stored in the storage unit, discriminates whether the received microwave is a jammer or a microwave to be detected, and does not output the alarm when it is determined that the jammer is a jammer. In this way, a forced jamming radio wave detection switch is provided, and if the user presses the forced jamming radio wave detection switch during radio wave detection, the signal at the time of depression is stored in the storage means as jamming radio wave. A microwave detector, comprising: 3. The microwave detector according to claim 1, wherein the information stored in the storage unit is canceled by at least one of turning off a power supply and pressing a reset switch. . 4. The apparatus according to claim 1, wherein when the same state as the signal information stored in said storage means is not detected continuously for a predetermined period, the signal information stored in said storage means is deleted. The microwave detector according to any one of claims 1 to 3.