JP3118632U - Distance measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distance measuring device provided with a standing wave detecting means which does not require additional parts and wiring and is not easily affected by external noise.
An electromagnetic wave output from a transmission source including an oscillation source is transmitted to a transmission / reception unit, transmitted from the transmission / reception unit toward a measurement target, reflected from the measurement target and incident from the transmission / reception unit, and transmission The standing wave detection circuit detects the amplitude of the standing wave formed between the transmission source and the measurement object by the electromagnetic wave output from the source, and the measurement object is determined from the standing wave amplitude and the frequency of the transmission source. A distance measuring device that calculates a distance to a transmission source, a transmission line that transmits electromagnetic waves from the transmission source to the transmission / reception means, and a detector circuit that includes a coupling circuit and a detector coupled to the transmission line The standing wave detection circuit is disposed on the dielectric substrate, and at least the transmission line, the coupling circuit, and the detector circuit are configured by strip lines.
[Selection] Figure 1

Description

  The present invention relates to a distance measuring apparatus, and more particularly, to an apparatus for measuring a distance to a measuring object using a standing wave formed between a transmission source and the measuring object.

  FIG. 4 shows a conventional distance measuring apparatus using a standing wave. In the distance measuring apparatus 1 shown in FIG. 4, electromagnetic waves output from a transmission source 23 including a frequency control unit 21 that controls an oscillation frequency and an oscillation source 22 are transmitted from the transmission unit 24 such as an antenna into the air (in the transmission medium). Released. The electromagnetic wave emitted from the transmission means 24 is reflected by the measurement object 2 and a reflected wave is formed in the direction of the distance measuring device. Here, when the electromagnetic wave is continuously output from the transmission unit 24, the traveling wave (electromagnetic wave output from the transmission source) and the reflected wave interfere with each other, and the standing wave 103 is generated between the transmission unit 24 and the measurement target 2. It is formed. The amplitude of the standing wave is detected by the standing wave detection means 25a, and is input to the signal processor 26 together with the oscillation frequency information of the frequency control unit 21 and is calculated, whereby the transmission means 24 of the distance measuring device 1 and the measurement object are measured. The distance between the two can be calculated.

  The standing wave detecting means 25a is a detector comprising a coupler for a spatial electromagnetic wave such as a probe arranged in the space between the transmitting means 24 and the measuring object 2, and an SBD that is connected to this coupler and detects the electromagnetic wave. (Patent Document 1).

  Another distance measuring device is shown in FIG. Unlike the distance measuring apparatus shown in FIG. 4, the electromagnetic wave reflected by the measuring object 2 passes through the transmission / reception means 24a and enters the transmission line connecting the transmission source 23 and the transmission / reception means 24a. As a result, the standing wave 103 is also formed on the transmission line. In the distance measuring apparatus shown in FIG. 5, the standing wave detection means 25b is installed on the transmission line between the transmission source 23 and the transmission / reception means 24a.

  In addition, as standing wave detection means, each comprises three couplers and detectors for transmission lines, calculates three signals from the standing wave detection means and frequency information from the frequency control unit, up to zero meters A distance measuring device that enables distance measurement has also been proposed. (Non-Patent Document 1, FIG. 6)

JP 2002-357656 A (page 13, FIG. 1) Tetsushi Kamibo, 2 people, "IEICE TRANSACTION ON COMMUNICATIONS" VOL.E88-B NO.6 JUNE 2005 (Page 2609, Figure 1 and Page 2612, Figure 6)

  In the conventional method as shown in FIG. 4, it is necessary to fix the standing wave detecting means 25 a between the transmitting means 24 and the measuring object 2. For example, at an experimental level where a distance measuring device and a measuring object can be installed on a plane, the standing wave detecting means 25a is installed on the plane between the distance measuring device 1 and the measuring object 2 and wired to the signal processor 26. It was also possible. However, in practice, there are cases where the distance measuring device 1 is installed on a moving body, or there is no means for fixing the standing wave detecting means 25a in the space between the transmitting means 1 and the measuring object 2. In such a case, it is necessary to attach an arm or the like to the distance measuring apparatus 1 main body to fix the standing wave detecting means 25a, and to install a wiring for transmitting a signal from the standing wave detecting means 25a to the signal processor 26. It was.

  However, it is preferable not to use an additional part such as an arm because it causes an increase in cost. Long wires can also cause external noise. Furthermore, since the frequency of the electromagnetic wave used in this type of distance measuring device is a high frequency such as a 24 GHz band, the presence of an arm or the like may cause a large variation in detection results.

  Therefore, a configuration in which the standing wave detection means 25b is installed on the transmission line between the transmission source 23 and the transmission / reception means 24a as shown in FIG. 5 is preferable. However, the specific structure of the standing wave detection means 25b has not been disclosed in Non-Patent Document 1.

  An object of the present invention is to provide a distance measuring device including a standing wave detecting means that does not require additional parts and wiring and is not easily affected by external noise.

  In order to achieve the above object, an electromagnetic wave output from a transmission source including an oscillation source is transmitted to a transmission / reception unit, transmitted from the transmission / reception unit toward a measurement target, reflected from the measurement target, and incident from the transmission / reception unit. The standing wave detection circuit detects the amplitude of the standing wave formed between the transmission source and the measurement object by the reflected wave and the electromagnetic wave output from the transmission source, and the amplitude of the standing wave And a distance measuring device that calculates a distance from the transmission source frequency to the measurement target, the transmission source, a transmission line that transmits the electromagnetic wave from the transmission source to the transmission / reception means, and a coupling to the transmission line A standing wave detection circuit comprising a coupling circuit and a detector circuit including a detector are disposed on a dielectric substrate, and at least the transmission line, the coupling circuit, and the detector circuit are configured by strip lines. To do It is an feature.

  The standing wave detection means of the present invention comprises a transmission source, a transmission line for transmitting electromagnetic waves from the transmission source to the transmission / reception means, a coupling circuit coupled to the transmission line, and a detector, and a standing wave detection circuit. Since it is arranged on a substrate and at least a transmission line and a coupling circuit are formed by strip lines, it can be formed in a very small size and with high productivity.

  Further, the distance measuring device of the present invention does not require additional parts and wiring for fixing the standing wave detecting means, and is not easily affected by external noise. In addition, since the standing wave detecting means can be very miniaturized, it can be easily arranged at a position where the detection result does not vary, so that it is possible to provide a distance measuring device with little characteristic variation.

  The distance measuring device of the present invention is basically the same as the configuration shown in FIG. That is, the distance measuring apparatus 1 transmits electromagnetic waves output from a transmission source 23 including a frequency control unit 21 and an oscillation source 22 for controlling an oscillation frequency to a transmission / reception means 24a such as an antenna, and in the air (in a transmission medium). discharge. The electromagnetic wave emitted from the transmission / reception means 24 a is reflected by the measurement object 2. Here, when the electromagnetic wave is continuously output from the transmission / reception means 24a, the traveling wave and the reflected wave interfere to form a standing wave between the transmission source 23 and the measurement object 2. The standing wave detection means 25b detects the amplitude of the standing wave formed on the transmission line between the transmission source 23 and the transmission means 24b, and the signal processor 26 calculates from the oscillation frequency information of the frequency control unit 21. Thus, the distance between the transmission source 23 of the distance measuring device 1 and the measuring object 2 is calculated. Here, in the present invention, a transmission source 23, a transmission line for transmitting electromagnetic waves from the transmission source 23 to the transmission / reception means 24a, and a standing wave detection circuit 25b including a coupling circuit and a detector coupled to the transmission line, Formed on a dielectric substrate, the transmission line and the coupling circuit are formed by strip lines. The specific structure will be described below.

  FIG. 1 is a stripline pattern diagram centering on a standing wave detection circuit according to a first embodiment of the present invention. 6 shows a transmission line between the transmission source 23 and the transmission / reception means 24a shown in FIG. 5 and a portion corresponding to the standing wave detection means 26b formed on the dielectric substrate on which the transmission line is formed. In FIG. 1, 11 is an antenna coupling unit, 12 is an amplifier, 13 is a T branch circuit, 14 is a detector circuit, 15 is an SBD, and 17 is a transmission line.

  The amplifier 12 is connected to the transmission source 23 and functions as a buffer that amplifies the electromagnetic wave output from the oscillation source to a necessary level and reduces the influence of the load of the transmission / reception means 22 connected to the transmission source 23. ing. The amplifier 12 has a normal configuration including a signal input unit, an amplifying element such as an FET, a signal output unit, and an amplifying element bias unit. The amplifier 12 constitutes a part of the transmission source 21.

  The electromagnetic wave amplified by the amplifier 12 is transmitted through the transmission line 17 through the DC blocking circuit. A T-branch circuit 13 (coupling circuit) is connected to the transmission line 17. The T branch circuit 13 is connected to a detector circuit 14 having a detector for detecting a standing wave. The detector is composed of an SBD 15, and the detector circuit 14 is formed with a resistor for biasing the SBD 15, a capacitor for removing noise, a high frequency choke, a terminal for taking out an SBD output signal, and the like. The detector circuit 14 has a known circuit configuration.

  The antenna coupling unit 11 is a converter from a stripline (transmission line 17) to a waveguide. A rectangular waveguide (not shown) that forms a short-circuited surface on the surface of the dielectric substrate on which the transmission line 17 is formed, and a rectangular waveguide that is connected to the back surface of the dielectric substrate by transmission / reception means such as a horn antenna (see FIG. (Not shown) are connected to each other to form a stripline-rectangular waveguide converter in which a stripline antenna (tip portion of the transmission line 17) protrudes into the rectangular waveguide. The electromagnetic wave transmitted through the transmission line 17 by this converter is converted in transmission mode from the strip line to the rectangular waveguide, transmitted to a transmitting / receiving means such as a horn antenna, and radiated into the air.

  The electromagnetic wave radiated into the air is reflected by the measuring object 2 and a reflected wave is formed in the direction of the distance measuring device 1 (see FIG. 5). The reflected wave incident from the transmission / reception means 22 reaches the amplifier 12 through the antenna coupling unit 11 and the transmission line 17. As described above, since the amplifier 12 functions as a buffer, the influence of the reflected wave on the operation of the oscillation source, such as frequency fluctuation and output power fluctuation, is small.

  A standing wave is formed between the amplifier 12 and the measurement object 2 by the electromagnetic wave and the reflected wave continuously emitted from the transmission source 23. In the present invention, the amplitude of the standing wave formed on the transmission line 17 is detected by the T branch circuit 13, the detector circuit 14, and the SBD 15 connected to the transmission line 17. In this embodiment, the degree of coupling between the transmission line 17 and the SBD 15 is −6 dB to −8 dB so that the electromagnetic wave output from the transmission / reception means 24a is not lowered and sufficient detection output of the standing wave is obtained. The T branch circuit 13 and the detector circuit 14 are formed so that

  A standing wave signal (amplitude of the standing wave) detected by the standing wave detecting means 25b is sent from the SBD output signal extraction terminal to the signal processor 26, and is sent from the frequency control unit 24 that controls the frequency of the oscillation source. The signal processing is performed together with the above information, and the distance to the measurement object 2 is calculated. The distance calculation method is a well-known method.

  As described above, in the present invention, a standing wave detection circuit including a transmission source, a transmission line for transmitting electromagnetic waves from the transmission source to the transmission / reception means, a coupling circuit coupled to the transmission line, and a detector is provided on the dielectric substrate. The transmission line and the coupling circuit are formed by strip lines, so that it is very small and can be formed with high productivity. The distance measuring device having the standing wave detecting means having such a structure does not require additional parts and wiring for fixing the standing wave detecting means, and is not easily affected by external noise. In addition, since the standing wave detecting means can be arranged at a position that is not affected by the positional relationship between the surrounding objects, it is possible to provide a distance measuring device with little characteristic variation.

  FIG. 2 is a stripline pattern diagram centering on the standing wave detection circuit according to the second embodiment of the present invention. In FIG. 2, reference numeral 16 denotes a spatial coupling circuit, which realizes coupling between the SBD 15 and the transmission line 17 by spatial coupling. Other parts common to those in FIG. 1 are given the same numbers, and the functions and configurations of the respective parts are the same as those in FIG.

  In this embodiment, the degree of coupling between the transmission line 17 and the detector SBD 15 is about −15 dB so that the electromagnetic wave output from the transmission / reception means 24a is not lowered and sufficient standing wave detection output is obtained. A spatial coupling circuit 16 is formed so as to increase the detection sensitivity by supplying a bias current to the SBD 15 from the outside.

  FIG. 3 is a stripline pattern diagram centering on the standing wave detection circuit according to the third embodiment of the present invention. The structure is provided with three coupling portions with the transmission line 17 of the standing wave detecting means described in FIG. Portions common to FIGS. 1 and 2 are given the same numbers.

  The interval between the three T-branch circuits 13 is desirably an integral multiple of one-fourth of the wavelength λg of the used frequency band (center frequency) (N × λg / 4, where N is an integer). In the present embodiment, the SBD 15 and the transmission line 17 are coupled by the T-branch circuit 13. However, as a matter of course, the SBD 15 and the transmission line 17 may be coupled by using the spatial coupling circuit 16.

  The three standing wave signals output from the SBD 15 are sent to the signal processor 26 and processed together with the frequency control signal, and the distance to the measurement object 2 is calculated. By processing a detection signal having a phase difference in this way, distance measurement in the vicinity of the pole can be performed. The distance measurement method in this case is also a well-known method.

It is explanatory drawing of the 1st Example which concerns on this invention. It is explanatory drawing of the 2nd Example which concerns on this invention. It is explanatory drawing of the 3rd Example which concerns on this invention. It is a conventional distance measuring device. It is another conventional distance measuring device.

Explanation of symbols

1: distance measuring device, 2: measurement object, 11: antenna coupling unit, 12: amplifier,
13: T branch circuit, 14: detector circuit, 15: SBD, 16: spatial coupling circuit,
17: transmission line, 21: frequency control unit, 22: oscillation source, 23: transmission source,
24, 24a: transmission means, 25a, 25b: standing wave detection means, 26: signal processor,
103: standing wave

Claims (1)

An electromagnetic wave output from a transmission source including an oscillation source is transmitted to a transmission / reception unit, transmitted from the transmission / reception unit toward a measurement target, reflected from the measurement target and incident from the transmission / reception unit, and the transmission The standing wave detection circuit detects the amplitude of the standing wave formed between the transmission source and the measurement object by the electromagnetic wave output from the source, and determines from the amplitude of the standing wave and the frequency of the transmission source. In the distance measuring device for calculating the distance to the measurement object,
A standing wave detection circuit comprising the transmission source, a transmission line for transmitting the electromagnetic wave from the transmission source to the transmission / reception means, and a detector circuit including a coupling circuit and a detector coupled to the transmission line, A distance measuring device arranged on a dielectric substrate, wherein at least the transmission line, the coupling circuit, and the detector circuit are configured by strip lines.

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