JP3252353B2 - Power distribution measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a technique for accurately measuring a power cumulative probability distribution of a signal.

[0002]

2. Description of the Related Art Among communication devices, for example, in a portable telephone, a conventional TDM is used in order to solve a shortage of communication channels.
A (Time Division Multiple)
Access) system instead of CDMA (Code D)
It has been proposed to shift to an multiplex multiple access (i.e., multiple access) method.

The CDMA system is a system in which data of each channel is multiplexed and a high-frequency signal is spread-modulated. The amplitude of the modulated signal changes greatly. , Causing interference to adjacent channels.

[0004] The degree of interference on adjacent channels and adjacent channels caused by the narrow dynamic range of a circuit largely depends not only on the maximum value of the signal amplitude but also on the frequency of occurrence.

For this reason, when evaluating an amplifier or the like used in a CDMA communication device, the distribution of the instantaneous amplitude (instantaneous power) of the signal input from the signal generator to the circuit to be evaluated is determined by the output of the circuit to be evaluated. It is necessary to accurately understand how the signal changes. For this purpose, conventionally, a crest factor of a signal, that is, a cumulative probability distribution of a ratio of an average power to an instantaneous power of a signal has been measured.

Conventionally, the crest factor is measured using an A / D converter 1, an arithmetic unit 2 and an output means 3, as shown in FIG. The signal is sampled for a predetermined period, converted into a digital value, and the sampled value is output to the arithmetic unit 2. The arithmetic unit 2 calculates the average value of each sampled value as the instantaneous power of the signal and calculates the average value of the signal under measurement for the predetermined period. As the average power of S, the cumulative probability distribution of the instantaneous power equal to or higher than the calculated average power among the instantaneous powers is calculated, and the calculation result is expressed on the horizontal axis based on the average power, for example, as shown in FIG. The relative power and the vertical axis are displayed on the rectangular coordinates of the cumulative probability.

When the frequency of the input signal is high,
The signal is converted to a low frequency by a frequency conversion circuit (not shown) and input to the A / D converter 1.

[0008]

However, as described above, the method of obtaining a power distribution using the sampling value of the A / D converter as the instantaneous power of the signal under test and the average thereof as the average power of the signal under test is described. However, the absolute power distribution of the signal under measurement cannot be accurately grasped.

That is, an A / D converter generally determines how many times a voltage sampled with respect to an input signal is equivalent to an internal reference voltage, and binarizes and outputs this. , The absolute error increases.

When an input signal having a high frequency is converted to a low frequency and input to the A / D converter, the A / D conversion is performed from the input terminal depending on the frequency characteristics of the frequency conversion circuit and fluctuations in the conversion gain. The signal transmission rate to the container fluctuates.

Therefore, as described above, the power distribution obtained by using the sampling value of the A / D converter as the instantaneous power of the signal to be measured and the average value as the average power of the signal to be measured is represented by the power distribution of the signal to be measured. It is not accurately represented, and the circuit cannot be evaluated accurately.

It is an object of the present invention to solve this problem and to provide a power distribution measuring device capable of accurately measuring the power distribution of a signal.

[0013]

According to a first aspect of the present invention, there is provided a power distribution measuring apparatus, comprising: an input terminal (24) for inputting a signal under test (S); A branch circuit (2) for branching the signal under test input to the terminal
5) an A / D converter (30) for sampling one branch output of the branch circuit and converting it to a digital value;
Storage means (31, 32) for storing the sampling value output from the A / D converter; average calculation means (33) for calculating an average value of the sampling values stored in the storage means for a predetermined period; A relative value calculating means (34) for calculating a relative value of each of the sampling values in the predetermined period with respect to the average value, and receiving the other branch output of the branch circuit and inputting to the input terminal in the predetermined period Average power measurement means (3) for measuring the average power of the measured signal under test.
5) and a value obtained by adding the average power measured by the average power measuring means to each relative value calculated by the relative value calculating means as each instantaneous power of the signal under measurement input in the predetermined period, Power distribution calculating means (40) for calculating a frequency distribution of each instantaneous power with respect to the average power
And output means (4) for outputting a calculation result of the power distribution calculation means together with absolute power information based on the average power.
3).

According to a second aspect of the present invention, there is provided a power distribution measuring device according to the first aspect, wherein the power distribution calculating means calculates a cumulative frequency distribution.

According to a third aspect of the present invention, there is provided a power distribution measuring apparatus according to the first aspect, wherein the power distribution calculating means calculates a cumulative probability distribution.

According to a fourth aspect of the present invention, in the power distribution measuring device according to the first or second or third aspect, the output means outputs the calculation result of the power distribution calculating means. , One axis is electric power, and the other axis is frequency or cumulative frequency or cumulative probability.

According to a fifth aspect of the present invention, there is provided the power distribution measuring device according to the first to fourth aspects, wherein the A / D converter and the respective units are housed in a common housing. It is characterized by:

The power distribution measuring device according to claim 6 of the present invention has a first input terminal (24a) and a second input terminal (24) for inputting the signals to be measured Sa and Sb, respectively.
b), a first branch circuit (25a) for branching the signal to be measured input to the first input terminal, and a second branch for branching the signal to be measured input to the second input terminal A circuit (25b) and a first A / D for sampling one branch output of the first branch circuit and converting it to a digital value
A converter (30a), a second A / D converter (30b) that samples one branch output of the second branch circuit and converts it into a digital value, and a first A / D converter. First storage means (31a, 32a) for storing the output sampling value and second storage means (3 for storing the sampling value output from the second A / D converter.
1b, 32b), first averaging means (33a) for calculating an average value of the sampling values stored in the first storage means during a predetermined period, and storage in the second storage means during the predetermined period. A second average calculating means (33b) for calculating an average value of the sampled values obtained, and a relative value of each of the sampling values in the predetermined period with respect to the average value calculated by the first average calculating means. First relative value calculating means (34a); and second relative value calculating means (34b) for calculating a relative value of each of the sampling values in the predetermined period with respect to the average value calculated by the second average calculating means. ), Receiving the other branch output signal of the first branch circuit, and measuring a first average power of the signal under test inputted to the first input terminal during the predetermined period. Receiving a second output signal of the other of the second branch circuit and the measuring means (35a), and measuring a second average power of the signal under test inputted to the second input terminal during the predetermined period; Average power measuring means of 2 (35b)
And a value obtained by adding the first average power to each relative value calculated by the first relative value calculating means, the value of the signal under test input to the first input terminal during the predetermined period. First power distribution calculating means (40a) for calculating a cumulative probability distribution of each instantaneous power with respect to the first average power; and each relative value calculated by the second relative value calculating means To the instantaneous power of the signal under test input to the second input terminal during the predetermined period, and a cumulative probability of the instantaneous power with respect to the second average power. Second to calculate distribution
Power distribution calculating means (40b), and output means (4) for outputting calculation results of the first and second power distribution calculating means together with absolute power information based on the first and second average powers.
3).

According to a seventh aspect of the present invention, there is provided the power distribution measuring device according to the sixth aspect, wherein the output means outputs a calculation result of the first and second power distribution calculating means. Is displayed on orthogonal coordinates where the axis of is the power and the other axis is the cumulative probability.

The power distribution measuring device according to claim 8 of the present invention is the power distribution measuring device according to claim 6, wherein
Subtraction means (51) for calculating a difference between the calculation result of the power distribution calculation means and the calculation result of the second power distribution calculation means, and the output means outputs the calculation result of the subtraction means to the first and second power distribution calculation means. 2 is output together with the absolute power information based on the average power.

According to a ninth aspect of the present invention, there is provided a power distribution measuring apparatus according to the sixth to eighth aspects, wherein the first and second A / D converters, the first and second branches are provided. The circuit and the respective means are housed in a common housing.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the appearance of a power distribution measuring device 20 of the embodiment, and FIG. 2 shows the internal configuration.

In FIG. 1, the power distribution measuring device 20
On the front side of the housing 21, a display unit 22 for displaying a measurement result as a graph and an operation unit 2 for specifying measurement conditions and the like are provided.
3 and an input terminal 24 for inputting the signal to be measured.

The input terminal 24 is connected to a branch circuit 25 as shown in FIG. The branch circuit 25 branches and outputs the signal under test S input to the input terminal 24 into two systems. It is assumed that the branch loss of the branch circuit 25 is both known.

One branch signal Sa of the branch circuit 25 is input to the switch 26. The switch 26 selectively inputs the branch signal U to either the frequency conversion circuit 27 or the switch 28.

The frequency conversion circuit 27 converts the frequency of the branch signal U input via the switch 26 by using a local oscillation signal, lowers the frequency to a frequency band that can be handled by an A / D converter 30 described later, and outputs the resultant signal to the switch 28.

The switch 28 switches in conjunction with the switch 26, and inputs the branch signal U from the switch 26 or the conversion signal U ′ from the frequency conversion circuit 27 to the A / D converter 30.

The states of the switches 26 and 28 and the frequency of the local signal of the frequency conversion circuit 27 are set by the measurement control means 29. The measurement control means 29 switches the switches 26, 2 in accordance with the measurement frequency specified by the operation unit 23.
The state of 8 and the frequency of the local signal of the frequency conversion circuit 27 are set, and the measurement start signal Ms and the measurement end signal Me are output at the measurement start timing and the measurement end timing specified by the operation unit 23, respectively.

The A / D converter 30 samples the branch signal U or the converted signal U 'input via the switch 27 at a predetermined sampling period, converts the sampled signal into a digital value having a predetermined number of bits, and stores it in the memory 31. Output. Note that A
The sampling cycle of the / D converter 30 is sufficiently shorter than the cycle of the input signal, and the sampling value is output as an absolute value.

The data writing means 32 constitutes a storage means together with the memory 31, and has a predetermined period from when the measurement start signal Ms is received to when the measurement end signal Me is received.
A write pulse synchronized with the sampling of the A / D converter 30 and an address signal sequentially updated at a sampling cycle are output to the memory 31, and the sampling value A ₁ output from the A / D converter 30 for a predetermined period is output. and stores the to a _N in the memory 31.

The averaging means 33 receives the measurement end signal Me and stores the sampling values A _{1 to} A stored in the memory 31.
_N is read out, its average value B is calculated, and output to the relative value calculation means 34.

The relative value calculating means 34 calculates each of the sampled values A _{1 to} A _N stored in the memory 31 and the average calculating means 32
Using the average value B calculated as follows, C ₁ = 20 · log (A ₁ / B) C ₂ = 20 · log (A ₂ / B) C _N = 20 · log (A _N / B), and each sampling value A _{1 to} A _{N with} respect to the average value B.
Are obtained by converting the relative values C _{1 to} C _N of dB into dB. It should be noted that a linear value can be obtained as a relative value. in this case,
It is the difference between the sampling values A _{1 to} A _N and the average value B.

The relative values C _{1 to} C _N accurately indicate the relative amount of each instantaneous power with respect to the average power of the signal under test S input during a predetermined period.

That is, as described above, the sampling values A _{1 to} A _N of the A / D converter 30 are affected by changes in various conditions including a temperature change, and an error occurs with respect to a true value. . Further, when the frequency of the input signal is converted by the frequency conversion circuit 27, an error due to a change in the frequency characteristic or conversion gain is added. Therefore, the sampling values A ₁ to
The average value B obtained by the average calculation of A _N also has an error with respect to the true average value, but by taking the relative value, the mutual error is canceled or compressed.

On the other hand, the other branch signal V of the branch circuit 25
Are input to the average power measuring device 35. The average power measuring device 35 intermittently operates, like an A / D converter, on the signal under test S input to the input terminal 24 during a predetermined period from receiving the measurement start signal Ms to receiving the measurement end signal Me. A signal is continuously input without performing a proper sampling, and the average power D is measured.

Here, the average power measuring device 35 is a thermocouple-type power meter that continuously absorbs power into a resistor and electrically detects a temperature rise. In principle, this type of power meter is hardly affected by the ambient temperature, and can match over a wide band. Therefore, the average power of the signal can be increased irrespective of conditions such as frequency, signal waveform, and ambient temperature change. Can be detected with high accuracy.

As shown in FIG. 3, for example, as shown in FIG.
) Resistors 36 a to 36 d and one of the resistors 36
a, and a thermocouple 37 that generates an electromotive force corresponding to heat generated by a current flowing through the resistor 36a, and a thermocouple for a predetermined period from receiving the measurement start signal Ms to receiving the measurement end signal Me. An average power detection circuit 38 for detecting the average power of the branch signal V based on the electromotive force generated by 37
A correction circuit that corrects the average power of the branch signal V detected by the average power detection circuit 38 with the branch loss of the branch circuit 25 and outputs the average power D of the signal under test S input to the input terminal 24 for a predetermined period. 39, and as described above,
The average power of the signal under measurement S can be detected with high accuracy irrespective of various conditions including the frequency, signal waveform, and ambient temperature change.

The average power measuring device 35 has a means for outputting the detected average power D in dBm and as a digital value. The input unit has a function.

The relative values C _{1 to} C _N calculated by the relative value calculator 34 and the average power D of the signal under test S measured by the average power meter 35 are input to the power distribution calculator 40.

The power distribution calculating means 40 calculates a power distribution with respect to the average value of the instantaneous power, for example, a frequency distribution, a cumulative frequency distribution,
Find the cumulative probability distribution, etc.

That is, first, the signal to be measured in a predetermined period is
Instantaneous power E for each sampling of S₁~ E_N To the next operation
Therefore, it is determined. E₁ = D + C₁  E_Two = D + C_Two  E_Three = D + C_Three  ...... E_N = D + C_N

These instantaneous powers are, as described above, the exact average power D of the signal under test S input during the predetermined period,
Accurate relative value C calculated by relative value calculating means 34
Since ₁ is obtained by adding -C _N, accurately represents the instantaneous power at each sampling timing of the measured signal S.

This instantaneous power E₁ ~ E_N The average power D of
The power required for the measurement
Is defined as Δd, and N instantaneous powers E₁ ~ E_N Horse
That is, the total number K in which the instantaneous power is equal to or larger than D and smaller than D + Δd.₀  The total number K in which the instantaneous power is greater than D + Δd and smaller than D + 2 · Δd₁  The total number K in which the instantaneous power is equal to or more than D + 2 · Δd and smaller than D + 3 · Δd._Two  ...... Total number K of instantaneous powers that are greater than or equal to D + L · Δd and smaller than D + (L + 1) · Δd_L  Ask for.

The total numbers K _{0 to} K _L obtained when this operation is performed for all instantaneous powers equal to or higher than the average power D are:
The frequency distribution of the instantaneous powers E _{1 to} E _N with respect to the average power D is shown.

This frequency distribution K₀ ~ K_L Output and display
However, here, the frequency distribution K₀ ~ K_L 
Then, the following calculation is performed. Total number M above average power D₀ = K₀ + K₁ + ... + K_L  Total power M equal to or more than average power D + Δd₁ = K₁ + K_Two + ... + K_L  Average power M + 2 · Δd or more total number M_Two = K_Two + K_Three + ... + K_L  Average power D + 3 · Δd or more total number M_Three = K_Three + K_Four + ... + K_L  ... Average power D + L · total number M equal to or more than Δd_L = K_L

The total number M _{0 to} M obtained by this operation
_L indicates the cumulative frequency distribution of the instantaneous power with respect to the average power.

The cumulative frequency distributions M _{0 to} M _L may be output and displayed. However, here, the following calculation F ₀ = 100 · M ₀ / NF ₁ = 100 · M ₁ / determined by the cumulative probability F ₀ to F _L for each power percentage (or not multiplied by a constant 100) by _{N F 2 = 100 · M 2} / N ...... F L = 100 · M L / N, the calculation result Is output to the display control means 41.

The display control means 41, together with the display 22, forms the output means 43 of this embodiment. As shown in FIG. There displays orthogonal coordinates of cumulative probability, the cumulative probability F ₀ to F _L for each power calculated by the power distribution calculating section 40 on the orthogonal coordinate, and displays the absolute power information based on the average power D.

For example, as shown in FIG. 4, a scale of the relative amount of the instantaneous power with respect to the average power and a scale of the absolute power based on the average power D (10 dBm in the figure) are displayed on the power axis.

When the frequency distributions K _{0 to} K _L are displayed, the vertical axis of the rectangular coordinates is the frequency. When the cumulative frequencies M _{0 to ML} are displayed, the vertical axis of the rectangular coordinates is the cumulative frequency. do it.

As described above, in the power distribution measuring device 20 according to the embodiment, the relative amount of each sampling value with respect to the average value of the sampling values of the A / D converter 30 is added to the measured signal of the measured signal obtained by the average power measuring device 35. Calculate the instantaneous power of the signal under measurement by adding the average power, calculate the frequency distribution, cumulative frequency distribution, or cumulative probability distribution for the average power of each instantaneous power, and display and output the calculation result together with the absolute power information based on the average power. ing.

Therefore, the power distribution of the signal under measurement can be accurately grasped regardless of the frequency characteristic of the frequency converter 27, the fluctuation of the conversion gain, or the error of the A / D converter 30.

The power distribution measuring device 20 of the above embodiment is
Although the power accumulation probability distribution of a single input signal was measured, for example, if the power distribution of the signal input to the amplifier and the power distribution of the signal output from the amplifier can be measured in parallel, the dynamic range of the amplifier can be grasped. Cheap. 5 and 6
Shows a power distribution measuring device 50 that realizes this.

As shown in FIG. 5, the power distribution measuring device 50 includes a display 22, an operation unit 23, and first and second input terminals 24a and 24b on the front surface of a housing 51.
An input terminal 2 of the power distribution measuring device 20 is provided inside the housing 51 so as to correspond to each of the input terminals 24a and 24b.
4 to power distribution calculation means 40 are provided for two channels.

That is, as shown in FIG. 6, on one channel side, the signal to be measured Sa input to the first input terminal 24a is branched by the first branch circuit 25a and the one branch output Ua Is input to the first frequency conversion circuit 27a via the switch 26a, and the branch output Ua or the conversion output Ua 'of the first frequency conversion circuit 27a is selected by the switch 28a to be supplied to the first A / D converter 30a. input.

Then, the sampling values Aa _{1 to} Aa _N of the signal input from the switch 28a in a predetermined period are stored in the first memory 31 by the first data writing means 32a.
The average value Ba of the sampled values Aa _{1 to} Aa _N is calculated by the first average calculation means 33a, and the first relative value calculation means 34 calculates the average value Ba of each sample value Aa _{1 to} Aa _N with respect to the average value Ba. Relative values Ca _{1 to} Ca _N are expressed in dB
Calculate by conversion.

In parallel with this, the first average power measuring device 35a outputs the first branch power Va from the other branch output Va for a predetermined period.
The first average power Da of the signal under measurement Sa input to the input terminal 24a of the
As a result, the instantaneous power E of the signal under measurement
Cumulative probabilities Fa _{0 to} Fa _L for a _{1 to} Ea _N of the first average power Da or more are obtained for each power in the same manner as in the above embodiment.

Similarly, on the other channel side, the signal under test Sb inputted to the second input terminal 24b is branched by the second branch circuit 25b, and one branch output Ub is passed through the switch 26b to the second branch circuit 25b. To the second frequency conversion circuit 27b, and selects the branch output Ub or the conversion output Ub 'of the second frequency conversion circuit 27b with the switch 28b to output the second A / A
The signal is input to the D converter 30b.

The sampling values Ab _{1 to} Ab _N of the signal input from the switch 28b during a predetermined period are stored in the second memory 31 by the second data writing means 32b.
stored in b, the second average calculation unit 33b calculates the average value Bb sampled value Ab ₁ ~Ab _N, of each sampling value Ab ₁ to ab _N with respect to the average value Bb by second relative value calculating unit 34b Relative values Cb ₁ -Cb _N
Calculate in B conversion.

At the same time, the second average power measuring device 35b outputs the second average power from the other branch output Vb for a predetermined period.
The second average power Db of the signal under test Sb input to the input terminal 24b is measured, and the second power distribution calculating means 40b
As a result, the instantaneous power E of the signal under measurement Sb during a predetermined period
b ₁ as in the embodiment the cumulative probability Fb ₀ ~Fb _L for the second average power Db or more ones of the ～Eb _N determined for each power.

The first power distribution calculating means 40a calculates
Cumulative probability distribution Fa₀ ~ Fa _L And the second power
Cumulative probability distribution F calculated by distribution calculation means 40b
b₀~ Fb_L Are subtraction means 51 and display control means 4
1 '.

The subtraction means 51 calculates the following operation G₀ = Fa₀ -Fb₀  G₁ = Fa₁ -Fb₁  G_Two = Fa_Two -Fb_Two  ...... G_L = Fa_L -Fb_L  And the operation result G₁ ~ G_L Display control means 41 '
To enter.

The display control means 41 ′ is, for example,
Operation from the measurement control means 29 to the 2-channel display mode
Is designated, as shown in FIG.
In the display screen, the horizontal axis is the power and the vertical axis is the rectangular coordinates of the cumulative probability
The first power distribution calculating means 40a is displayed on the coordinates.
Cumulative probability distribution Fa calculated by₀ ~ Fa_L and
Cumulative value calculated by the second power distribution calculating means 40b
Probability distribution Fb₀ ~ Fb _L Are displayed so that they can be distinguished from each other
And the first average power Da and the second average power
The absolute power information based on the force Db is displayed.

When the difference display mode is designated, the display control means 41 'displays the power on the horizontal axis and the rectangular coordinates on the vertical axis on the display screen of the display 22, as shown in FIG. Then, on this coordinate, the subtraction result G
_{In addition} to displaying _{0 to GL} , the average power Da and the average power Db are displayed.

The power distribution measuring device 5 thus configured
At 0, the crest factor of the signals under test Sa and Sb input to the first and second input terminals 24a and 24b in the same period can be accurately grasped on the absolute power, and for example, evaluation of a circuit such as an amplifier , The change in the crest factor of the output signal of the circuit with respect to the change of the crest factor of the input signal to the circuit can be simultaneously observed, and the evaluation of the circuit can be performed accurately and easily.

Also, the subtraction results G ₀ -G _{L of} the subtraction means 51
Can be displayed, the difference between the crest factors of the two input signals can be easily grasped, and the variation of the modulation signal of the signal generator and the distortion characteristics of the circuit such as the amplifier can be easily recognized.

The power distribution measuring devices 20, 5
In the case of 0, since the input terminal to the output means are housed in one common housing, maintenance is easy and it is possible to easily cope with a change of the installation location and the like.

The power distribution measuring devices 20 and 5
At 0, the calculation results of the power distribution calculation means 40, 40a, and 40b and the absolute power information are displayed on the display 22, but the power distribution measurement device 2 shown in FIGS.
0 'and 50', the print control means 4
5 and a printer 46, and a power distribution calculating means 40,
The calculation results of 40a and 40b and the absolute power information may be input to the print control unit 45, and the printout or the bitmap data may be output from the printer 46 by operating the operation unit 23.

Further, as shown in FIG. 9, an information output means 47 may be provided in the output means 43 to output a measurement result from an output terminal 48 to an external computer or the like. The output unit 47 may be provided in the output unit 43 of FIG. 10 so that the measurement results of two channels can be output to an external computer or the like.

[0070]

As described above, according to the power distribution measuring apparatus of the present invention, the relative amount of each sampling value with respect to the average value of the sampling values of the A / D converter is equal to the signal under test obtained by the average power measuring device. Calculate the instantaneous power of the signal under measurement by adding the average power of the measured power, calculate the frequency distribution, cumulative frequency distribution, or cumulative probability distribution for the average power of the instantaneous power, and output the calculation result and the absolute power information based on the average power. Therefore, the power distribution of the signal under measurement can be accurately grasped on the absolute power.

Further, for each of the signals under test input to the first and second input terminals, the relative amount of each sampling value with respect to the average value of the sampling values of the A / D converter is determined by an average power measuring device. The average power of the signal under test is added to obtain the instantaneous power of the signal under test, a cumulative probability distribution with respect to the average power of the instantaneous power is calculated, and the calculation result is output together with absolute power information based on the average power. According to the power distribution measuring apparatus of the present invention, the cumulative power probability distribution of the signal under test input to each input terminal can be accurately grasped on the absolute power, and the two can be easily and accurately compared.

In the power distribution measuring device of the present invention in which the input terminal to the output means are housed in one common housing,
Maintenance is easy, and it is possible to easily cope with a change in the installation location.

[Brief description of the drawings]

FIG. 1 is an external view of an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of the embodiment.

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

FIG. 4 is a diagram showing measurement results of the embodiment.

FIG. 5 is an external view of a two-channel embodiment.

FIG. 6 is a block diagram showing the internal configuration of a two-channel embodiment.

FIG. 7 is a diagram showing a measurement result of an embodiment in which two channels are provided.

FIG. 8 is a diagram showing a measurement result of the embodiment in which two channels are provided.

FIG. 9 is a block diagram showing an internal configuration of an embodiment capable of printing and outputting data.

FIG. 10 is a block diagram showing an internal configuration of an embodiment capable of printing output.

FIG. 11 is a configuration diagram of a conventional apparatus.

FIG. 12 is a diagram showing a measurement result by a conventional apparatus.

[Explanation of symbols]

 20, 50 Power distribution measurement device 21, 51 Housing 22 Display 23 Operation unit 24, 24a, 24b Input terminal 25, 25a, 25b Branch circuit 26, 26a, 26b Switch 27, 27a, 27b Frequency conversion circuit 28, 28a, 28b switch 29, 29a, 29b measurement control means 30, 30a, 30b A / D converter 31, 31a, 31b memory 32, 32a, 32b data writing means 33, 33a, 33b average calculation means 34, 34a, 34b Relative value Calculation means 35, 35a, 35b Average power measuring device 40, 40a, 40b Power distribution calculation means 41, 41 'Display control means 43 Output means 45 Printing control means 46 Printer 47 Information output means 51 Subtraction means

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01R 21/00-22/00 130 G01R 11/00-11/66 G01R 29/08 H04B 17/00

Claims (9)

(57) [Claims] 1. An input terminal (24) for inputting a signal under test (S), a branch circuit (25) for branching a signal under test input to the input terminal, and one branch of the branch circuit An A / D converter (30) for sampling an output and converting it to a digital value; storage means (31, 32) for storing a sampled value output from the A / D converter; Average calculating means (33) for calculating an average value of the sampling values stored in the memory; and relative value calculating means (34) for calculating a relative value of each of the sampling values in the predetermined period with respect to the average value.
Average power measuring means (35) for receiving the other branch output of the branch circuit and measuring the average power of the signal under test inputted to the input terminal during the predetermined period, and calculated by the relative value calculating means A value obtained by adding the average power measured by the average power measuring means to each of the obtained relative values is defined as each instantaneous power of the signal under test input during the predetermined period, and the frequency distribution of each instantaneous power with respect to the average power is calculated. A power distribution measuring device comprising: a power distribution calculating means (40) for calculating the power distribution calculating means; 2. The power distribution measuring device according to claim 1, wherein said power distribution calculating means calculates a cumulative frequency distribution. 3. The power distribution measuring device according to claim 1, wherein said power distribution calculating means calculates a cumulative probability distribution. 4. The output means displays the calculation result of the power distribution calculation means on rectangular coordinates in which one axis is power and the other axis is frequency or cumulative frequency or cumulative probability. Claim 1 or Claim 2 or Claim 3
The power distribution measuring device as described in the above. 5. The power distribution measurement according to claim 1, wherein said A / D converter and each of said means are housed in a common housing. apparatus. 6. A first input terminal (24a) and a second input terminal (24b) for inputting signals under test Sa and Sb, respectively, and a signal under test input to the first input terminal. A first branch circuit (25a) for branching, a second branch circuit (25b) for branching the signal under test inputted to the second input terminal, and one branch output of the first branch circuit. A first A / D converter (30) for sampling and converting to a digital value
a) a second A / D converter (30) that samples one branch output of the second branch circuit and converts it into a digital value;
b), first storage means (31a, 32a) for storing a sampling value output from the first A / D converter, and a sampling value output from the second A / D converter. Second storage means (31b, 32b) for storing, and first averaging means (33a) for calculating an average value of the sampling values stored in the first storage means for a predetermined period.
And a second average calculating means (33) for calculating an average value of the sampling values stored in the second storage means during the predetermined period.
b) first relative value calculating means (34a) for calculating a relative value of each of the sampling values in the predetermined period with respect to the average value calculated by the first average calculating means, and the second average A second relative value calculating means (34b) for calculating a relative value of each of the sampling values for the predetermined period with respect to the average value calculated by the calculating means; and a second branch output signal of the first branch circuit. A first average power measuring means (35a) for measuring a first average power of the signal under test input to the first input terminal during the predetermined period; and a second branch of the second branch circuit. A second average power measuring means (35b) for receiving an output signal and measuring a second average power of the signal under test inputted to the second input terminal during the predetermined period; and the first relative value. Calculation means A value obtained by adding each of the calculated relative values to the first average power average power is defined as each instantaneous power of the signal under measurement input to the first input terminal during the predetermined period, and First power distribution calculating means (40a) for calculating a cumulative probability distribution with respect to the first average power; and the second average power is added to each relative value calculated by the second relative value calculating means. A second power distribution calculating means for calculating a value as each instantaneous power of the signal under measurement inputted to the second input terminal during the predetermined period, and calculating a cumulative probability distribution of each instantaneous power with respect to the second average power; (4
0b), and an output means (43) for outputting the calculation results of the first and second power distribution calculation means together with absolute power information based on the first and second average powers. . 7. The output means displays the calculation results of the first and second power distribution calculation means on rectangular coordinates where one axis is power and the other axis is cumulative probability. The power distribution measuring device according to claim 6. 8. A subtraction means (51) for calculating a difference between a calculation result of said first power distribution calculation means and a calculation result of said second power distribution calculation means, wherein said output means includes: The calculation result is the first,
7. The power distribution measuring device according to claim 6, wherein the power distribution measuring device outputs the absolute power information based on the second average power. 9. The apparatus according to claim 6, wherein said first and second A / D converters, said first and second branch circuits, and said means are housed in a common housing. The power distribution measuring device according to claim 7 or 8.