JP4893988B2 - Radar spectrum measuring device - Google Patents

Description

  The present invention relates to a radar spectrum measuring apparatus that receives radio waves radiated from an antenna of a radar system and measures a spectrum in a wide frequency band including unwanted radiation.

  Conventionally, the spectrum of a radio wave emitted from a radar is used to measure the radiation level over a wide frequency band and analyze what frequency and its intensity are distributed, including unwanted radiation. A measurement system combining an analyzer is known. The ITU, which is an international telecommunications union, defines conditions and the like according to the frequency band for the regulation value of unnecessary radiation radiated from the radar and the method of measuring the radar spectrum including unnecessary radiation. In the ITU, which is the International Telecommunication Union, it is stipulated that the radar antenna measures in a normal operating state (mechanically rotated or electronically controlled by rotating the direction of radio wave radiation).

In the radio wave environment measuring apparatus described in Japanese Patent Laid-Open No. 6-21864, the propagation of radio waves between mobile phones and the like is directly propagated, the reflected wave reflected from the structure, and other external radio waves are propagated. Is to measure.
JP-A-6-21864

  When measuring a radar spectrum according to a measurement method recommended by the ITU, radio waves mainly emitted from an antenna of a radar system, various types of radar systems that rotate mechanically or electronically control the radiation direction of the radio waves. Under the condition that the emitted radio wave is asynchronous and the timing at which the radio wave arrives is unknown, a currently available measuring device requires a long measurement time. For example, when measuring unwanted radiation from a 9 GHz band pulse radar, assuming that the pulse width is 1 μsec or less and the radar antenna is rotating at 20 rpm, the total measurement required for one measurement in the frequency band from 30 MHz to 26 GHz The time is about 22 hours. The long-time measurement has a problem in reliability of measurement results due to environmental changes such as temperature and humidity. Further, the spectrum of the radar is measured by a spectrum analyzer including a frequency conversion unit, an A / D conversion unit, a DSP, and the like. However, since the spectrum analyzer is not supposed to measure a broadband frequency as in the present invention, the spectrum analyzer is divided into a plurality of times and measured over a long time.

  In order to solve the above-described problems, an object of the present invention is to provide a radar spectrum measuring apparatus that shortens a long measurement time and has high reliability with a simple configuration.

(First invention)
Radar spectrum measurement device of the first invention receives desired radio wave radiated from the antenna of Les chromatography Zehnder systems, emitted in all directions from the 30MHz, including unnecessary radiation from an antenna of the radar system in the frequency band of 26GHz spectrum Is measured at the same time as radiation of a desired radio wave, and an antenna that receives a radar radio wave including unwanted radiation in the frequency band, and unwanted radiation radiated in all directions of the frequency band received by the antenna. A plurality of frequency conversion means for converting the radar radio wave to different frequency bands, and detecting one frequency in the radar radio wave including unwanted radiation in the frequency band from one of the frequency conversion means, and using the frequency as a trigger signal Converted by the trigger signal creating means and the plurality of frequency converting means. A plurality of A / D conversion means for converting analog signals of different frequency bands into digital signals, and the respective digital signals converted by the plurality of A / D conversion means are converted into amplitudes for each frequency, and the trigger signal A plurality of programmable DSPs that are synchronized by a trigger signal created by the creating means, a synthesizing means that synthesizes the result converted into amplitude for each frequency by the plurality of programmable DSPs into all frequency bands, and the synthesizing means And radar spectrum storage means for storing the radar spectrum synthesized by the above.

(Second invention)
Radar spectrum measurement apparatus of the second invention receives desired radio wave radiated from the antenna of Les chromatography Zehnder systems, emitted in all directions from the 30MHz, including unnecessary radiation from an antenna of the radar system in the frequency band of 26GHz spectrum Is measured at the same time as radiation of a desired radio wave, and an antenna that receives a radar radio wave including unwanted radiation in the frequency band, and unwanted radiation radiated in all directions of the frequency band received by the antenna. A plurality of frequency conversion means for converting the radar radio wave to different frequency bands, and detecting one frequency in the radar radio wave including unwanted radiation in the frequency band from one of the frequency conversion means, and using the frequency as a trigger signal Trigger signal generating means and the respective bands of the plurality of frequency converting means Frequency band setting means for setting the frequency bands so as to overlap little by little; a plurality of A / D conversion means for converting analog signals of different frequency bands converted by the plurality of frequency conversion means into digital signals; A plurality of programmable DSPs that convert each digital signal converted by the A / D conversion means into an amplitude for each frequency and that are synchronized by the trigger signal created by the trigger signal creation means; A synthesizing unit that synthesizes the result converted into amplitude for each frequency by the programmable DSP into the entire frequency band; an output level adjusting unit that adjusts the output level of the overlapping portion of the synthesized frequencies to the same output;
It comprises at least radar spectrum storage means for storing the radar spectrum synthesized by the synthesis means.

(Third invention)
In the radar spectrum measuring apparatus of the third invention, the radar spectrum storage means of the first or second invention stores a measurement position of an antenna of a radar system and an antenna that receives the radar radio wave. .

  According to the present invention, it is possible not only to significantly reduce the radar spectrum in the radar system to be measured, but also to obtain a highly reliable measurement result. In the present invention, a plurality of spectrum analyzers comprising frequency conversion means, A / D conversion means, and DSP are provided in parallel, and the plurality of spectrum analyzers are synchronized by a trigger signal generated by one frequency in the received radar. By taking it, accurate measurement became possible.

  According to the present invention, since the measurement device is provided in parallel, the maximum radiated power and the other radiated power can be compared at the same time. Can be measured accurately.

  According to the present invention, when synthesizing signals in a frequency band that overlaps little by little at the boundary part of the frequency band, the output level in that part is adjusted so that the same output is obtained, so that the boundary part of the frequency band The accuracy of the strength of the amplitude is improved.

  According to the present invention, the measurement position of the antenna of the radar system and the antenna that receives the radar radio wave can be specified by the GPS, and can be correlated with the radar spectrum, thereby enabling more accurate analysis.

(First invention)
The radar spectrum measuring apparatus according to the first aspect of the invention receives radio waves radiated from the antenna of the radar system to be measured and is radiated in all directions from the antenna of the radar system in a frequency band of 30 MHz to 26 GHz including unnecessary radiation. The measured spectrum is measured at the same time as the desired radio wave emission . Measurement side antenna receives radar wave including unnecessary radiation emitted in all directions of the frequency band that is emitted from the radar system. The frequency conversion means down-converts the radio wave of a predetermined band received by the antenna into a plurality of different frequency bands. A plurality of the frequency conversion means are provided in parallel so as to cover a wide range of frequencies to be measured. The trigger signal creating means detects, for example, one frequency in the radar radio wave including the unnecessary radiation from one of the frequency conversion means, and uses the frequency as a trigger signal. The A / D conversion means converts the analog signal received by the antenna into a digital signal by a plurality of frequency conversion means covering each frequency band.

Each digital signal converted by the plurality of A / D conversion means is converted into an amplitude for each frequency of a digital signal within a predetermined band by a plurality of programmable DSPs (hereinafter simply referred to as DSPs). At the same time, the plurality of programmable DSPs are synchronized by the trigger signal. That is, the programmable DSP converts the converted digital signal into the strength for each frequency in each band, and is synchronized with each other. The amplitude of each frequency is synthesized by the plurality of programmable DSPs by a synthesizing unit such as a full-band programmable DSP. The radar spectrum synthesized by the synthesis means such as the full-band programmable DSP is stored by the radar spectrum storage means.

The radio wave radiated from the antenna of the radar system to be measured is measured in parallel by a plurality of frequency conversion means, A / D conversion means and programmable DSP, and synthesized by a synthesis means such as a full-band programmable DSP. Measurement time can be greatly reduced. The processing of the synthesizing means such as the frequency converting means, A / D converting means, programmable DSP, and all-band programmable DSP provided in parallel can be performed in real time because they are synchronized with each other by the trigger signal. it can. The frequency conversion means, A / D conversion means, and programmable DSP connected in parallel constitute a real-time spectrum analyzer.

  The real-time spectrum analyzer performs fast Fourier transform (FFT) on a digital signal. However, since the Fourier transform is in a free-running state, the result of FFT (First Fourier Transformer) conversion of pulse waves varies. Conventionally, when a large number of commercially available real-time spectrum analyzers are connected in parallel, the spectrum of the radar pulse wave cannot be analyzed. However, since the present invention performs all the FFT conversions synchronously, a correct analysis is possible.

  Moreover, since a commercially available real-time spectrum analyzer is relatively large, it is not suitable for many parallel processing. The real-time spectrum analyzer of the present invention can be a small-sized gate array that can change the analysis step by using a programmable DSP to change the data size of the FFT conversion. Furthermore, the present invention provides a trigger signal creating means for generating a trigger signal of the DSP in synchronization with a radar pulse or at a timing estimated from a radar pulse signal, and by synchronizing with the trigger signal, Rapid and accurate measurement is now possible.

(Second invention)
The radar spectrum measuring apparatus of the second invention differs from the first invention in that it comprises a frequency band setting means and an output level adjusting means. The frequency band setting means can set the frequency band so that the bands of the plurality of frequency conversion means overlap little by little. The output level adjusting means may have different amplitudes of digital signals in different frequency bands depending on different frequency converting means. When synthesizing a signal in a frequency band that overlaps little by little at the boundary part of the frequency band, the present invention adjusts the output level in that part so that the output is the same, The accuracy of amplitude strength is improved. The DSP and the full-band DSP in the first and second inventions can be programmable DSPs.

(Third invention)
In the radar spectrum storage means of the third invention, the measurement positions from the antenna of the radar system of the first invention or the second invention and the antenna that receives the radar radio wave are stored, for example, by GPS. Since the radar spectrum measurement apparatus stores the radiation and reception position of radar as data, the accuracy in analyzing a spectrum in a wide frequency band including unnecessary radiation could be improved.

  FIG. 1 is a diagram for explaining a radar spectrum measuring apparatus for measuring radio waves radiated from a radar system according to a first embodiment of the present invention. Note that the symbols * in FIG. 1 are connected by lines. The radar spectrum measurement apparatus according to the first embodiment includes a radar system 11 to be measured, a measurement antenna 12 that receives radio waves including unwanted radiation radiated from the radar system 11, at least one high-frequency down converter 131, and the high-frequency signal. An A / D conversion unit 141 that converts the frequency of the down converter 131 into a digital signal and a programmable DSP 151 that converts the frequency of the A / D conversion unit 141 into an amplitude (Fourier transform) are provided.

  The radar spectrum measurement apparatus includes a plurality of spectrum analyzers 181, 182, and 18 n including the high-frequency down converter, A / D conversion means, and programmable DSP. The trigger signal creating means 13 detects a certain frequency of the high frequency down converter 131, for example, a center frequency, and uses this frequency as a trigger signal. The programmable DSPs 151, 152, and 15n start conversions in synchronization with the trigger signal, and perform frequency analysis. The trigger signal creating means 13 can be controlled from the radar system 11 by radio or wire. Further, the trigger signal creating means 13 can be controlled by the high frequency down converter 131 and / or the radar system 11.

  The amplitudes of the digital signals obtained in the programmable DSPs 151, 152, and 15n are synthesized by the all-band programmable DSP 16 as the intensity of the amplitude over the entire band. The intensity of the amplitude over the entire band is stored in the radar spectrum storage means 17, and the propagation state of radio waves including unnecessary radiation of the radar system can be analyzed. Since the data stored in the radar spectrum storage means 17 is synchronized with the trigger signal, accurate analysis is possible even if the signals obtained by the plurality of spectrum analyzers 181, 182 and 18n are combined. .

  FIG. 2 is a diagram for explaining a state in which the radio wave radiated from the radar system is measured in almost all directions in the embodiment of the present invention. In FIG. 2, the radar system 11 has radar spectrum measuring devices arranged at, for example, eight locations, and can measure the radar spectrum of the entire band including unnecessary radiation. Since the radar spectrum measuring apparatus can measure in all bands in a relatively short time, even when measuring in all directions, the radar spectrum measuring apparatus can measure without a large time shift.

  FIG. 3 is a diagram for explaining a radar spectrum measuring apparatus for measuring radio waves radiated from a radar system according to a second embodiment of the present invention. As in FIG. 1, the symbols * are connected by lines. The radar spectrum measuring apparatus according to the second embodiment is provided with frequency setting means 1311, 1312, 13n1 in each of the high-frequency down converters 131, 132, 13n, and the frequency overlap portion output adjusting means 161 is provided in the all-band programmable DSP 16. This is different from the first embodiment in that it is provided and that the position when measured by the position setting means 171 is set in the radar spectrum storage means 17.

  The frequency setting means 1311, 1321, 13n1 can arbitrarily set the frequency band in the high frequency down converters 131, 132, 13n. The high-frequency down converters 131, 132, and 13n can be set so that the same frequency overlaps the upper and lower ends of the set frequency. Further, when the programmable DSPs 151, 152, and 15n are combined, the full-band programmable DSP 16 puts the overlapping portions of the frequencies into an overlapping state. The frequency overlap portion output adjusting means 161 adjusts the output of the overlap portion to the same level in the all-band programmable DSP 16. The output adjustment can eliminate respective errors in the high-frequency down converter, the A / D conversion means, the programmable DSP, etc., and an accurate measurement result can be obtained.

  The radar spectrum is measured in all directions, but there may be places where measurement is not always possible due to obstacles. When the place is avoided, the measurement position is stored in the radar spectrum storage means 17 together with the radar spectrum. The position setting means 171 can use, for example, a GPS (Global Positioning System) used for a car navigator. The programmable DSP and the full-band programmable DSP can be a DSP. Further, the all-band programmable DSP may be a combining unit that combines the programmable DSPs. Further, the synthesizing means can be an ordinary personal computer.

  FIG. 4 is a block diagram illustrating a DSP according to an embodiment of the present invention. In FIG. 4, the DSP is an FFT (First Fourier Transformer), a control means 411 for controlling in synchronization with the trigger created by the trigger signal creating means 13, a RAM 412 storing a calculation program, It comprises at least calculation means 414 for calculating according to the program of the RAM 412. A ROM or RAM 413 is provided in place of the RAM 412 in the DSP 151, 152, 15 n. The DSP may be a programmable DSP. Each of the programmable DSPs is provided with a DSP control means (not shown) for rewriting a program, for example.

  As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example. Various design changes can be made without departing from the scope of the present invention. The blocks shown in FIG. 1 and FIG. 3 are constructed by a known or publicly known technique.

It is a figure for demonstrating the radar spectrum measuring device which measures the electromagnetic wave radiated | emitted from a radar system in 1st Example of this invention. Example 1 In the Example of this invention, it is a figure for demonstrating the state which measures the electromagnetic wave radiated | emitted from a radar system in almost all directions. It is a figure for demonstrating the radar spectrum measuring device which measures the electromagnetic wave radiated | emitted from a radar system in 2nd Example of this invention. (Example 2) In the Example of this invention, it is a block block diagram for demonstrating DSP.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Radar system 12 ... Measurement antenna 13 ... Trigger signal preparation means 131, 132, 13n ... High frequency down converter 1311, 1321, 13n1 ... Frequency setting means 141, 142, 14n ... A / D conversion means 151, 152, 15n... Programmable DSP
16 ... All-band programmable DSP
161 ... Frequency overlapping portion output adjusting means 17 ... Radar spectrum storage means 171 ... Position setting means 181, 182, 18n, 311, 312, 31n ... Spectrum analyzer 411 ... Control means 412 ...・ RAM
413 ... ROM or RAM
414 ... Calculation means

Claims (3)

Receiving a desired radio wave radiated from the antenna of Les chromatography Zehnder systems, the spectrum emitted in all directions from the 30MHz, including unnecessary radiation from an antenna of the radar system in the frequency band of 26GHz to a desired radio wave radiation at the same time In the radar spectrum measurement device to measure,
An antenna for receiving radar radio waves including unwanted radiation in the frequency band;
A plurality of frequency conversion means for converting radar radio waves including unnecessary radiation radiated in all directions of the frequency band received by the antenna into different frequency bands;
Trigger signal creating means for detecting one frequency in a radar radio wave including unwanted radiation in the frequency band from one of the frequency conversion means, and using the frequency as a trigger signal;
A plurality of A / D conversion means for converting analog signals of different frequency bands converted by the plurality of frequency conversion means into digital signals;
A plurality of programmable DSPs that convert each digital signal converted by the plurality of A / D conversion means into an amplitude for each frequency and that are synchronized by the trigger signal created by the trigger signal creation means,
A synthesizing unit that synthesizes the result converted into the amplitude for each frequency by the plurality of programmable DSPs into the entire frequency band;
Radar spectrum storage means for storing the radar spectrum synthesized by the synthesis means;
A radar spectrum measuring device comprising at least the following. Receiving a desired radio wave radiated from the antenna of Les chromatography Zehnder systems, the spectrum emitted in all directions from the 30MHz, including unnecessary radiation from an antenna of the radar system in the frequency band of 26GHz to a desired radio wave radiation at the same time In the radar spectrum measurement device to measure,
An antenna for receiving radar radio waves including unwanted radiation in the frequency band;
A plurality of frequency conversion means for converting radar radio waves including unnecessary radiation radiated in all directions of the frequency band received by the antenna into different frequency bands;
A trigger signal generating means for said detecting a single frequency within the radar wave including from one frequency converting means unnecessary radiation of the frequency band to the frequency trigger signal,
A frequency band setting means for setting the frequency band so that the respective bands of the plurality of frequency converting means are slightly overlapped;
A plurality of A / D conversion means for converting analog signals of different frequency bands converted by the plurality of frequency conversion means into digital signals;
A plurality of programmable DSPs that convert each digital signal converted by the plurality of A / D conversion means into an amplitude for each frequency and that are synchronized by the trigger signal created by the trigger signal creation means,
A synthesizing unit that synthesizes the result converted into the amplitude for each frequency by the plurality of programmable DSPs into the entire frequency band;
Output level adjusting means for adjusting the output level of the overlapping portion of the synthesized frequencies to the same output;
Radar spectrum storage means for storing the radar spectrum synthesized by the synthesis means;
A radar spectrum measuring device comprising at least the following.   The radar spectrum measuring apparatus according to claim 1 or 2, wherein the radar spectrum storage means stores a measurement position of an antenna of a radar system and an antenna that receives the radar radio wave.

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