JPH06130102A - Two-dimensional electromagnetic wave radiant intensity measuring device - Google Patents

Abstract

PURPOSE:To intuitively know the two-dimensional generation position of the electromagnetic wave on the plane having electronic machinery present thereon. CONSTITUTION:Measuring display elements 21 are arranged on a measuring surface in a matrix form and the clocks from a clock generator 45 are counted by a counter 46 and the count value is decoded by a decoder 47 and switches Sx1-Sxn are successively turned ON on the basis of the output of the decorder and, at each time when the switches Sx1-Sxn are once turned ON, switches Sy1-Syn are successively turned ON to successively connect one element 21 to a constant current supply. When an electromagnetic wave is received from the loop antenna 22 of the element 21 connected to the constant current supply, the frequency set by a spectrum selecting amplifier 33 or the sweep frequency based on the frequency sweeping of a frequency sweep local oscillator 51 is received. The output thereof is detected by a detection circuit 41 and the detection output is held by a peak hold circuit 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-dimensional electromagnetic wave radiation intensity measuring device used for measuring unnecessary electromagnetic waves emitted from various electronic devices.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, for example, a search coil 12 of an electric field intensity meter is manually or automatically scanned along an upper surface of an electronic device 11 in a planar or linear manner.
The output was analyzed by the spectrum analyzer 13 to detect from which part of the electronic device 11 the unnecessary radio wave was emitted.

[0003]

In the conventional measurement method,
It is necessary to memorize the reception state of whether the radio wave is received at each point on the scanning surface or how strong it is, and detect the location of the unnecessary radio wave from the stored contents. It was troublesome. Further, the distance between the electromagnetic wave source and the antenna 12 greatly affects the measured value, but it is difficult to always scan the antenna in the same state, and the reproducibility of data is poor. Furthermore, when the frequencies of the electromagnetic waves are diverse, it was necessary to repeat the scanning for each evaluation frequency, which took time. It was difficult to know the relationship between the two-dimensional position, frequency, and intensity obtained by measuring the electromagnetic waves.

[0004]

According to the present invention, a plurality of measuring and displaying elements are arranged in a matrix, and the measuring and displaying elements are capable of receiving an electromagnetic wave passing through a small surface, and the measuring and displaying element is adapted to a receiving intensity thereof. It consists of a series circuit with a light-emitting element that emits light as a result of the measurement display elements being selected one by one by a selection switch, and a current is supplied to the selected measurement display element from a constant current source. The voltage induced in the display element is commonly input to the spectrum selection amplifier, the amplified output is detected by the detection circuit, and the brightness of the light emitting element of the measurement display element selected according to the output of the detection circuit is controlled. It

[0005]

Embodiment FIG. 1A shows an embodiment of the present invention. A plurality of measurement display elements 21 are arranged in a matrix on the measurement plane. As shown in FIG. 1B, the measurement display element 21 is composed of an antenna capable of receiving an electromagnetic wave passing through a minute area on the measurement plane, for example, a loop antenna 22 and a light emitting element 23. Since the polarization of an electromagnetic wave passing through the measurement plane is unknown, it is preferable that the loop surface of the loop antenna 22 be inclined with respect to the measurement surface, for example, about 45 °. In this example, the light emitting element 23 is used as the light emitting diode 23.
A resistor 24 is connected in series to the light emitting diode 23, a capacitor 25 is connected in parallel with a series circuit of the light emitting diode 23 and the resistor 24, and a loop antenna 22 and a PIN diode 26 are connected in series with the parallel circuit.
And are connected.

The measurement display elements 21 as described above are sequentially arranged one by one.
A selection means for selecting next is provided. That is, the measurement display element 2
Column lines 27 along each column arrangement of 1₁Through 27_nBut
A row is provided along each row of measurement display elements.
Line 28₁Through 28_nIs provided. Of these row and column lines
At each intersection, for example, one end on each loop side is connected to the column line 27.
The other end of the pin diode side is connected to the row line.
Will be continued. Each line 27 ₁Through 27₈One end of switch S
_x1Through S_xnGrounded through each line 28₁Through 28_n
Is the switch S_Y1Through S_YnCommonly connected through
Connected to the constant current source 31 through the AC blocking coil 30
To be done. Switch S_x1Through S_xnOne and switch S_Y1No
To S_YnAnd one of the two turned on
Through the switch, and the two switches that were turned on.
Through the column and row lines connected to each
From the constant current source 31 through the measurement display element connected to
A current flows, and at this time, the light emitting element 23 emits light in a normal state.
The current value is set so that a certain amount of current will flow.
There is. No current flows through the other measurement display elements 21.
In this way the switch S_x1Through S_xnOne and switch
S_Y1Through S_YnMeasuring luminescence by selecting one of
One of the elements 21 can be selected.

The measurement display element 2 selected in this way
The voltage induced in the first antenna is commonly input to the spectrum selection amplifier 33. That is, the switches S _{Y1 to} S
The connection point between the common connection side of _Yn and the AC blocking coil 30 is connected to the input side of the spectrum selection amplifier 33 through the DC blocking capacitor 32. Spectrum selection amplifier 3
3 is provided with a wideband bandpass filter 34 that passes all the components of the frequency to be measured at its first stage, and the output thereof is amplified by an amplifier 35 and supplied to a frequency converter 36. The signal converted into the intermediate frequency signal by the frequency converter 36 passes through the intermediate frequency filter 37, is further amplified by the amplifier 38, and becomes the output of the spectrum selection amplifier 33.

The output of the spectrum selection amplifier 33 is amplified by the AGC amplifier 39, the amplified output is detected by the detection circuit 41, and the detected output is the peak hold circuit 4.
2 is supplied. The output of the detection circuit 41 is integrated by the low pass filter 43, the output is sampled and held by the sample and hold circuit 44, and the sample and hold value is supplied to the amplifier 39 as an AGC control signal.

The sequential selection of the measurement display elements 21 is automatically performed.
A clock generator 45 is provided to generate the clock.
The clock from the generator 45 is counted by the counter 46,
The count value of the counter 46 is decoded by the decoder 47,
The output of the decoder 47 of S is output when one clock is counted.
Itch S_X1Switch on and next time the clock is counted
Itch S_X2Is turned on, that is, counts n clocks
And switch S_X1Through S _XnAre all turned on once. This
Each time the n clocks of_X1Through
S_XnIs turned on once so that the
Switch S at the output of coder 47_x1Through S_xnIs controlled
It On the other hand, switch S_Y1Through S_YnCounts n clocks
Only one switch is on during the
The switch that turns on each time the lock is counted moves sequentially
It is controlled by the output of the decoder 47.
When counting n × n clocks, carry from the counter 46
Roughing occurs and the counter 46 is reset, that is, the cow
The counter 46 is configured as an n × n base counter. still
The decoder 47 counts and outputs the designated address from the counter 46.
Can be selected and output instead of
It is possible to specify and select one of the measurement display elements
come. In this way, the counter 46 counts clocks and
Decode the count output of the switch S_x1Through S_xn, S_Y1
Through S_YnBy controlling the measurement display element 21.
The selection is performed one by one.

When the measurement frequency is changed while the one measurement display element 21 is selected, the clock from the clock generator 45 is set to the sweep switch 4.
8 is supplied to the ramp wave generation circuit 49, and the ramp wave generation circuit 49 generates one triangular wave signal, a so-called ramp wave signal, every time the clock is applied, and the ramp wave signal is applied to the variable frequency oscillator 51, The oscillation frequency is swept. The output of the variable frequency oscillator 51 is supplied to the frequency converter 36 as a local oscillator signal. Therefore, while selecting one measurement display element 21,
The received signal frequency is swept from, for example, f ₁ to f.

When an electromagnetic wave is received by the antenna when one measurement display element 21 is selected,
The received output is supplied to the spectrum selection amplifier 33, and the amplified output is detected by the detection circuit 41, so that an output is generated in the detection circuit 41. The time constant of the low-pass filter 43 is made approximately equal to the time for scanning the measurement plane once, so that the gain of the amplifier 39 is controlled according to the average of the outputs obtained by scanning the measurement plane once. The gain of the amplifier 39 is kept substantially constant during one measurement scan of the plane. The brightness of the light emitting element is controlled according to the antenna output of the one measurement display element. That is, the peak hold circuit 42 is reset for each clock from the clock generator 45, so that the peak value of the output of the detection circuit 47 during the selection of one measurement display element 21 is the peak hold circuit. 42, the constant current value of the constant current source 31 is controlled by this output. For example, as the output V of the peak hold circuit 42 increases, the constant current i (V) of the constant current source 31 increases. 2A is controlled.

In this example, the width of the clock pulse of the clock generator 45 is controlled by the output V of the peak hold circuit 42. For example, as the output V of the peak hold circuit 42 increases as shown in FIG. 2B, the pulse width increases. PW becomes large. However, the clock cycle of the clock generator is kept constant. Therefore, when the electromagnetic wave is received by the antenna 22 of the selected measurement display element 21, the higher the reception level is, the brighter the brightness of the light emitting diode 23 of the selected measurement display element is, and the intensity of the received electromagnetic wave is low. The light amount of the light emitting diode 23 is small and looks dark, and the light amount of the light emitting diode 23 is large when the intensity of the received electromagnetic wave is high. While selected, the capacitor 25 of the measurement display element 21 is charged, and the charged electric charge is discharged through the light emitting diode 23 and the resistor 24 to emit light, so that the scanning speed of the measurement display element is high, That is, even if the selection switching speed of the measurement display element is high, when the light emitting diode 23 emits light, there is no fear that the light emission will be emitted for a certain length of time and the emission will not be noticed.

To measure whether electromagnetic waves can be obtained from the measurement plane only for a certain frequency, the sweep switch 4
8 may be turned off and the control voltage for the variable frequency oscillator 51 may be set corresponding to the frequency to be measured. The sample command to the sample hold circuit 44 may be given by the carry output of the counter 46. The light emission amount of the light emitting element controlled by the output of the peak hold circuit 42 may be controlled by only one of the control of the current value of the constant current source 31 and the control of the width of the clock of the clock generator. Is preferable. This control is also shown in Fig. 2.
As shown in A, in addition to the control that gradually increases with respect to the output V of the peak hold circuit, step-like control, that is, ON / OFF control may be performed. That is, the light emitting element may be caused to emit light only when the intensity of the received electromagnetic wave is above a certain level.

Switch S _Y1 on the side for taking in the antenna output
It is required that S _Yn be a switch having a small input capacitance. Therefore, in order to install a large number of switches in parallel, it is difficult to reduce the input capacitance.
From this point, as shown in FIG. 2C, the switches S _{Y1 to} S _{Yn are}
Each group may be selected as four groups. That to switch S _Y1 example connecting one end of the S _Y4 in parallel, connecting the one end and the switch S _Y1-4 in series, the switch S _Y1-4 switch S _Y1 to S _Y4
Is controlled to be on while any of them is on. The peak hold circuit 42 is used to obtain the maximum peak value, that is, the strongest output of the spectrum during the time when one measurement display element is selected. However, when measuring the average value, the peak hold circuit 42 is used instead. An average value circuit may be used.

[0015]

As described above, according to the present invention, the measurement display elements 21 are arranged on the measurement surface with a uniform distribution, and the respective measurement display elements are automatically and sequentially selected and selected. When the electromagnetic wave at that position is received during the operation, the brightness of the light emitting element is controlled according to its intensity. Therefore, when observing on the array surface of the measurement display element, the emission point of the electromagnetic wave can be found immediately and intuitively from the emission state, and the measurement can be performed only for the desired frequency.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and B is a connection diagram showing an example of a measurement display element 21 thereof.

FIG. 2A is a diagram showing an example of a relation of a constant current value with respect to a detection level, B is a diagram showing an example of a relation of a clock width with respect to a detection output, and C is for making the input capacitances of the switches S _{Y1 to} S _Yn small. It is a figure which shows a connection structure.

FIG. 3 is a diagram showing a conventional two-dimensional electromagnetic wave intensity measuring device.

Claims (1)

[Claims] 1. A measurement element in which a plurality of measurement display elements, each of which is composed of an antenna for receiving the intensity of electromagnetic waves passing through a minute surface and a series circuit of light emitting elements for emitting light according to the intensity of the received output, are arranged in a matrix. A group, a selection switch for sequentially selecting the measurement display elements one by one, a common current source for supplying a current to the measurement display element selected by the selection switch, and an antenna of the selected measurement display element. A spectrum selection amplifier to which the induced voltage is commonly input, a detection circuit that detects the output of the spectrum selection amplifier, and the brightness of the light emission of the light emitting element of the measurement display element selected above according to the output of the detection circuit. A two-dimensional electromagnetic wave radiation intensity measuring device comprising: