JP5809598B2 - Signal measuring apparatus, signal measuring method, program, and recording medium - Google Patents

Description

  The present invention relates to measurement of an electric field of a signal received by two antennas used for space diversity.

  Conventionally, it is known that the degradation of communication quality due to multipath is eliminated by space diversity using two antennas. Further, it is known that space diversity can be effectively performed by adjusting the interval and angle between two antennas used for space diversity (see, for example, Patent Document 1).

JP 2007-110384 A

  Here, it is preferable in terms of space diversity that the difference between the electric fields received by each of the two antennas is the smallest and the sum is the largest.

  Therefore, an object of the present invention is to derive the minimum value and the maximum value of the sum of the differences between the electric fields received by each of the two antennas used for space diversity.

  A signal measuring apparatus according to the present invention includes a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies, a single local signal source that provides a common local signal input to the plurality of mixers, An error measuring unit for measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers, and a signal under test input having a frequency common to the plurality of mixers. A difference / sum measurement unit that measures a minimum value of a difference between the electric fields output from the plurality of mixers and a maximum value of the sum of the electric fields, and the difference / sum based on a measurement result of the error measurement unit. An error correction unit that corrects a measurement result of the measurement unit, and the plurality of antennas receive signals while changing the angle and distance of another antenna with respect to one of the plurality of antennas. The signal, configured the to the measured signal input.

  According to the signal measuring apparatus configured as described above, the plurality of mixers output signals having a frequency equal to the difference between the frequencies of the two inputs. A single local signal source provides a common local signal input to the plurality of mixers. The error measuring unit measures a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers. The difference / sum measurement unit measures the minimum value of the difference between the electric fields output from the plurality of mixers and the maximum value of the sum of the electric fields when the signal under measurement having a common frequency is given to the plurality of mixers. . The error correction unit corrects the measurement result of the difference / sum measurement unit based on the measurement result of the error measurement unit. Signals received by the plurality of antennas while changing the angle and distance of another antenna with respect to one of the plurality of antennas are set as the signal under measurement input.

  In the signal measuring apparatus according to the present invention, the error measuring unit measures the level difference and the phase difference in association with the frequency of the local signal input, and the error correcting unit is configured to detect the local signal input. The measurement result of the difference / sum measurement unit may be corrected according to the frequency.

  In the signal measuring apparatus according to the present invention, the error correction unit corrects the measurement result of the difference / sum measurement unit based on the result of interpolation of the measurement result of the error measurement unit with respect to the frequency of the local signal input. You may do it.

  The signal measuring apparatus according to the present invention is supplied with the local signal input and the intermediate frequency signal input, and outputs a signal having a frequency equal to the sum of the frequencies of the local signal input and the intermediate frequency signal input as the correction signal. A correction signal mixer may be provided.

  A signal measuring apparatus according to the present invention includes a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies, a single local signal source that provides a common local signal input to the plurality of mixers, A difference / sum measuring unit for measuring a minimum value of a difference between electric fields output from the plurality of mixers and a maximum value of the sum of the electric fields when a plurality of mixers are input with a signal under measurement having a common frequency. When there is a common signal input to the plurality of mixers, there is no level difference and phase difference between the outputs of the plurality of mixers, and the angle of another antenna with respect to one antenna of the plurality of antennas The signals received by the plurality of antennas while changing the distance are used as the measured signal input.

  According to the signal measuring apparatus configured as described above, the plurality of mixers output signals having a frequency equal to the difference between the frequencies of the two inputs. A single local signal source provides a common local signal input to the plurality of mixers. The difference / sum measuring unit measures the minimum value of the difference between the electric fields output by the plurality of mixers and the maximum value of the sum of the electric fields when the signal under measurement having a common frequency is given to the plurality of mixers. There is no level difference or phase difference between the outputs of the plurality of mixers when a common signal input is given to the plurality of mixers. Signals received by the plurality of antennas while changing the angle and distance of another antenna with respect to one of the plurality of antennas are set as the signal under measurement input.

  The present invention relates to a signal measuring apparatus including a plurality of mixers that output a signal having a frequency equal to a difference between frequencies of two inputs, and a single local signal source that provides a common local signal input to the plurality of mixers. A signal measurement method for performing signal measurement processing, wherein when a common correction signal input is given to the plurality of mixers, an error measurement step of measuring a level difference and a phase difference between outputs of the plurality of mixers; A difference / sum measurement step of measuring a minimum value of a difference between electric fields output by the plurality of mixers and a maximum value of a sum of the electric fields when a signal input to be measured having a common frequency is provided to the plurality of mixers; An error correction step of correcting the measurement result of the difference / sum measurement step based on the measurement result of the error measurement step, and the other antenna with respect to one antenna of the plurality of antennas. Degrees and a signal received said plurality of antennas while changing the distance, the a signal measurement method according to the measured signal input.

  The present invention relates to a signal measuring apparatus including a plurality of mixers that output a signal having a frequency equal to a difference between frequencies of two inputs, and a single local signal source that provides a common local signal input to the plurality of mixers. A program for causing a computer to perform signal measurement processing, wherein the signal measurement processing provides level correction and phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers. And measuring the minimum difference in electric field output by the plurality of mixers and the maximum sum of the electric fields when a plurality of mixers are supplied with a signal under measurement having a common frequency. A difference / sum measurement step, and an error correction step for correcting the measurement result of the difference / sum measurement step based on the measurement result of the error measurement step. A certain one signal received said plurality of antennas while changing the angle and distance of the other antennas for antenna, wherein a program for a signal to be measured input.

  The present invention relates to a signal measuring apparatus including a plurality of mixers that output a signal having a frequency equal to a difference between frequencies of two inputs, and a single local signal source that provides a common local signal input to the plurality of mixers. A computer-readable recording medium storing a program for causing a computer to execute signal measurement processing, wherein the plurality of mixers when the signal measurement processing gives a common correction signal input to the plurality of mixers. An error measurement step for measuring a level difference and a phase difference between the outputs of the mixers, and a minimum value of a difference between the electric fields output by the plurality of mixers when a measured signal input having a common frequency is given to the plurality of mixers. And the difference / sum measurement step for measuring the maximum value of the sum of the electric fields and the measurement result of the difference / sum measurement step based on the measurement result of the error measurement step. An error correction step, and a signal received by the plurality of antennas while changing an angle and a distance of another antenna with respect to one of the plurality of antennas, and the signal under measurement input Recording medium.

It is a functional block diagram which shows the structure of the signal measuring apparatus 1 concerning embodiment of this invention. It is a functional block diagram which shows a structure when a correction signal is given to the signal measuring apparatus 1 concerning embodiment of this invention. It is a figure which shows an example of the measurement of the level difference between the outputs of the several mixers 14 and 24 when a common correction signal input is given to the several mixers 14 and 24. FIG. Output level differences ΔLv1 to _ΔLv3 interpolated with respect to the frequency f _Lo1 of the local signal input when a common correction signal input is given to the plurality of mixers 14 and 24 (see FIG. 4A) and output phase difference It is a figure which shows what interpolated ( _{DELTA) P1-} ( _{DELTA) P3} about local signal input frequency _fLo1 (refer _FIG.4 (b)). It is a functional block diagram which shows a structure when a to-be-measured signal is given to the signal measuring apparatus 1 concerning embodiment of this invention. It is a figure for demonstrating to-be-measured signal input.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a functional block diagram showing a configuration of a signal measuring apparatus 1 according to an embodiment of the present invention. The signal measuring device 1 includes a first terminal 11, a second terminal 21, an output terminal 31, a first local signal source 12, a first mixer 14, a first A / D converter 16, a first level / phase measuring unit 18, Second local signal source 22, second mixer 24, second A / D converter 26, second level / phase measurement unit 28, intermediate frequency signal source 32, correction signal mixer 34, switches 42 and 44, local frequency setting Unit 52, error measurement unit 54, error correction unit 56, and difference / sum measurement unit 60. The signal measuring device 1 is, for example, a spectrum analyzer.

  FIG. 2 is a functional block diagram showing a configuration when a correction signal is given to the signal measuring apparatus 1 according to the embodiment of the present invention. FIG. 5 is a functional block diagram showing a configuration when a signal under measurement is given to the signal measuring apparatus 1 according to the embodiment of the present invention.

  Referring to FIG. 2, distributor 4 provides a correction signal to first terminal 11 and second terminal 21. The distributor 4 may be built in the signal measuring device 1. Referring to FIG. 5, the first terminal 11 and the second terminal 21 are supplied with measured signal inputs from antennas ANT1 and ANT2, respectively.

  FIG. 6 is a diagram for explaining the signal under measurement input. The multiple antennas ANT1 and ANT2 are antennas that receive multipath (P1, P2, P3) signals. The antennas ANT1 and ANT2 are used for space diversity.

  Signals received by the plurality of antennas ANT1 and ANT2 while changing the angle θ and the distance Δ of another antenna ANT2 with respect to one antenna ANT1 of the plurality of antennas ANT1 and ANT2, are used as the signal under measurement. . For example, a signal received by a plurality of antennas ANT1 and ANT2 is changed as a signal under measurement input while changing the distance Δ with the angle θ fixed, and then changing the angle θ with the distance Δ fixed. . It should be noted that the measured signal inputs from the multiple antennas ANT1 and ANT2 have the same frequency.

  The first terminal (CH1: channel 1) 11 supplies a signal under measurement (see FIG. 5) given from the antenna ANT1 or a correction signal (see FIG. 2) given from the distributor 4 to the first mixer 14. The second terminal (CH2: channel 2) 21 supplies the signal to be measured (see FIG. 5) given from the antenna ANT2 or the correction signal (see FIG. 2) given from the distributor 4 to the second mixer 24.

  The output terminal 31 outputs a correction signal. The output terminal 31 is connected to the distributor 4 (see FIG. 2).

  The first mixer 14 outputs a signal having a frequency equal to the difference between the frequencies of two inputs (R input and L input) (I output). However, the R input is supplied from the first terminal 11 and the L input is supplied from the first local signal source 12. R input, L input, and I output mean Radio Frequency input, Local input, and Intermediate Frequency output, respectively.

  The second mixer 24 outputs a signal having a frequency equal to the difference between the frequencies of the two inputs (R input and L input) (I output). However, the R input is supplied from the second terminal 21 and the L input is supplied from the first local signal source 12. The meanings of the R input, the L input, and the I output are the same as those of the first mixer 14.

The first local signal source 12 is a single local signal source that provides a common local signal input to the L inputs of the plurality of mixers 14 and 24 (see FIGS. 2 and 5). Note that the frequency f _{Lo1 of the} local signal is variable, that is, can be swept.

  The first A / D converter 16 receives the I output (analog signal) of the first mixer 14 and converts it into a digital signal. The second A / D converter 26 receives the I output (analog signal) of the second mixer 24 and converts it into a digital signal.

  The first level / phase measurement unit 18 provides the first mixer when a plurality of mixers 14 and 24 are supplied with a signal under measurement (see FIG. 5) having a common frequency or a common correction signal input (see FIG. 2). Measure the level and phase of the 14 outputs. The measurement result of the first mixer 14 is given to the error measuring unit 54 (see FIG. 2) or given to the difference / sum measuring unit 60 (see FIG. 5).

  The second level / phase measurement unit 28 provides the second mixer when the measured signal input (see FIG. 5) or the common correction signal input (see FIG. 2) having the same frequency is given to the plurality of mixers 14 and 24. Measure the level and phase of the 24 outputs. The measurement result of the second mixer 24 is given to the error measuring unit 54 (see FIG. 2) or given to the difference / sum measuring unit 60 (see FIG. 5).

  The first level / phase measurement unit 18 and the second level / phase measurement unit 28 are implemented by, for example, a DSP (Digital Signal Processor).

  The second local signal source 22 is a signal source that can be swept (variable in frequency).

  The intermediate frequency signal source 32 provides an intermediate frequency signal input to the correction signal mixer 34. The intermediate frequency signal may be a signal similar to the signal under measurement, or may be a pulse, a continuous wave (frequency may be swept), a modulated signal, or noise.

  The correction signal mixer 34 is supplied with a local signal input (L input) and an intermediate frequency signal input (I input). Further, the correction signal mixer 34 outputs a signal having a frequency equal to the sum of the frequencies of the local signal input and the intermediate frequency signal input as a correction signal (R output). The local signal input (L input) is supplied from the first local signal source 12 via the switch 42. The intermediate frequency signal input (I input) is supplied from the intermediate frequency signal source 32. The correction signal is given to the output terminal 31.

  However, R output, L input, and I input mean Radio Frequency output, Local (local) input, and Intermediate Frequency input (intermediate frequency), respectively.

  The switch 42 is a switch for switching whether the first local signal source 12 is connected to the correction signal mixer 34 (see FIG. 2) or not (see FIG. 5).

  The switch 44 is a switch that connects the second mixer 24 to the single local signal source 12 (see FIGS. 2 and 5) or the second local signal source 22.

The local frequency setting unit 52 sets f _Lo1 that is the frequency of the first local signal source 12.

  The error measurement unit 54 outputs the level and phase of the output of the first mixer 14 from the first level / phase measurement unit 18 when a common correction signal input is given to the plurality of mixers 14 and 24 (see FIG. 2). Then, the level and phase of the output of the second mixer 24 are received from the second level / phase measurement unit 28.

  Further, the error measurement unit 54 is configured to provide a common correction signal input to the plurality of mixers 14 and 24 based on the measurement results received from the first level / phase measurement unit 18 and the second level / phase measurement unit 28. (See FIG. 2), the level difference and phase difference between the outputs of the plurality of mixers 14, 24 are measured.

The error measuring unit 54 calculates the level difference and phase difference between the outputs of the plurality of mixers 14 and 24 when the common correction signal input is given to the plurality of mixers 14 and 24 (see FIG. 2). _Measured in association with frequency f _Lo1 .

  FIG. 3 is a diagram showing an example of the measurement of the level difference and the phase difference between the outputs of the plurality of mixers 14 and 24 when a common correction signal input is given to the plurality of mixers 14 and 24.

The error measurement unit 54 receives from the first level / phase measurement unit 18 the output level of the first mixer 14 (CH1) when the frequency f _Lo1 of the local signal input is f ₁ . In addition, the error measurement unit 54 receives the output level of the second mixer 24 (CH2) from the second level / phase measurement unit 28 when the frequency f _Lo1 of the local signal input is f ₁ . Further, the error measuring unit 54 calculates (ΔLv1) and records the difference (CH2−CH1) between the two output levels. The error measurement unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₁ . The error measurement unit 54 records ΔLv1 in association with f ₁ .

Similarly, the error measurement section 54 calculates the difference between the output levels of both when the frequency f _Lo1 of the local signal input is _{f 2 (CH2-CH1) (} ΔLv2), is recorded. The error measuring unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₂ . Error measuring section 54 records the ΔLv2 in association with f _2.

Further, the error measurement section 54 calculates the difference between the output levels of both when the frequency f _Lo1 of the local signal input is _{f 3 (CH2-CH1) (} ΔLv3), is recorded. The error measuring unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₃ . Error measuring section 54 records the ΔLv3 in association with f _3.

For example, f ₃ −f ₂ = f ₂ −f ₁ and f ₃ > f ₂ > f ₁ .

The error measurement unit 54 receives from the first level / phase measurement unit 18 the output phase of the first mixer 14 (CH1) when the frequency f _Lo1 of the local signal input is f ₁ . Moreover, the error measurement unit 54 receives the output phase of the second mixer 24 (CH2) from the second level / phase measurement unit 28 when the local signal input frequency f _Lo1 is f ₁ . Further, the error measurement unit 54 obtains (ΔP1) and records the difference (CH2−CH1) between the two output phases. The error measurement unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₁ . The error measurement unit 54 records ΔP1 in association with f ₁ .

Similarly, the error measurement section 54 calculates the difference between the output phase when the frequency f _Lo1 of the local signal input is _{f 2 (CH2-CH1) (} ΔP2), is recorded. The error measuring unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₂ . Error measuring section 54 records the ΔP2 in association with f _2.

Further, the error measurement section 54 calculates the difference between the output phase when the frequency f _Lo1 of the local signal input is _{f 3 (CH2-CH1) (} ΔP3), is recorded. The error measuring unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₃ . Error measuring section 54 records the ΔP3 in association with f _3.

  The difference / sum measuring unit 60 (see FIG. 5) receives the measured signal input having a common frequency to the plurality of mixers 14 and 24, and the minimum value of the difference between the electric fields output from the plurality of mixers 14 and 24. Measure the maximum sum of electric fields.

  The difference / sum measuring unit 60 outputs the measurement result of the output (electric field) of the first mixer 14 (CH1) when the signal under measurement having a common frequency is given to the plurality of mixers 14 and 24 (see FIG. 5). The first level / phase measurement unit 18 receives the measurement result of the output (electric field) of the second mixer 24 (CH 2) from the second level / phase measurement unit 28.

  Further, the difference / sum measuring unit 60 measures the sum and difference between the output (electric field) of the first mixer 14 (CH1) and the output (electric field) of the second mixer 24 (CH2). Then, the maximum value of the sum of the two and the minimum value of the difference between the two are measured and output.

Based on the measurement result of the error measurement unit 54, the error correction unit 56 corrects the measurement result of the difference / sum measurement unit 60 according to the frequency f _Lo1 of the local signal input (see FIG. 5).

For example, the error correction unit 56 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₁ . Further, the error correction unit 56 reads out the output level difference ΔLv 1 and the output phase difference ΔP ₁ associated with f ₁ from the error measurement unit 54. The error correction unit 56 corrects the measurement result of the difference / sum measurement unit 60 by providing ΔLv1 and ΔP1 to the difference / sum measurement unit 60. For example, when the difference / sum measuring unit 60 measures the sum and difference between the output (electric field) of the first mixer 14 (CH 1) and the output (electric field) of the second mixer 24 (CH 2), the second mixer 24 The level [dBm] and the phase [rad] of the output (electric field) of (CH2) are reduced by ΔLv1 and ΔP1.

Similar correction is performed when the frequency f _Lo1 of the local signal input is f ₂ or f ₃ .

However, when the frequency f _Lo1 of the local signal input is not any of f ₁ , f ₂ and f ₃ , the measurement result of the difference / sum measuring unit 60 cannot be corrected by the above method. In such a case, the error correction unit 56 corrects the measurement result of the difference / sum measurement unit 60 based on the measurement result of the error measurement unit 54 interpolated with respect to the frequency f _Lo1 of the local signal input.

FIG. 4 shows an output level difference ΔLv1 to _ΔLv3 interpolated with respect to the frequency f _Lo1 of the local signal input when a common correction signal input is given to the plurality of mixers 14 and 24 (see FIG. 4A) and It is a figure which shows what interpolated the difference (DELTA) P1-ΔP3 of output phase about the frequency fLo1 of local signal input (refer _FIG.4 (b)).

  In FIG. 4, the output level and the output phase are interpolated by a linear function as an example. The result obtained by interpolating the output level and the output phase is recorded in the error measurement unit 54.

The error correction unit 56 _acquires the value of the frequency f _Lo1 of the local signal input from the local frequency setting unit 52. The error correction unit 56 acquires the difference between the output level and the output phase corresponding to this value from the interpolation result (see FIG. 4A and FIG. 4B), and sends it to the difference / sum measurement unit 60. By giving, the measurement result of the difference / sum measuring unit 60 is corrected.

  Next, the operation of the embodiment of the present invention will be described.

(1) Input of correction signal (see Fig. 2)
First, referring to FIG. 2, a correction signal is given to the signal measuring apparatus 1.

A switch 42 connects the first local signal source 12 to the L input of the correction signal mixer 34. Here, the local frequency setting unit 52 sets the frequency f _Lo1 of the first local signal source 12. Then, the local signal input (L input) is supplied from the first local signal source 12 to the correction signal mixer 34. In addition, an intermediate frequency signal input (I input) is supplied from the intermediate frequency signal source 32 to the correction signal mixer 34.

  Then, a signal having a frequency equal to the sum of the frequencies of the local signal input and the intermediate frequency signal input is output from the correction signal mixer 34 as a correction signal (R output). The correction signal is output from the output terminal 31 and given to the distributor 4. The distributor 4 gives a correction signal to the first terminal 11 and the second terminal 21.

  Here, the switch 44 connects the second mixer 24 to the single local signal source 12.

  The correction signal given to the first terminal (CH1) 11 is given to the R input of the first mixer 14. A local signal input from the local signal source 12 is given to the L input of the first mixer 14. Then, a signal having a frequency equal to the difference between the frequencies of the two inputs (R input and L input) is output from the first mixer 14 (I output). The frequency of the I output is the frequency of the intermediate frequency signal output from the intermediate frequency signal source 32.

  The I output (analog signal) of the first mixer 14 is converted into a digital signal by the first A / D converter 16 and supplied to the first level / phase measurement unit 18. The first level / phase measurement unit 18 measures the level and phase of the output of the first mixer 14, and provides them to the error measurement unit 54.

  The correction signal given to the second terminal (CH2) 21 is given to the R input of the second mixer 24. A local signal input from the local signal source 12 is given to the L input of the second mixer 24. Then, a signal having a frequency equal to the difference between the frequencies of the two inputs (R input and L input) is output from the second mixer 24 (I output). The frequency of the I output is the frequency of the intermediate frequency signal output from the intermediate frequency signal source 32.

  The I output (analog signal) of the second mixer 24 is converted into a digital signal by the second A / D converter 26 and supplied to the second level / phase measurement unit 28. The second level / phase measurement unit 28 measures the level and phase of the output of the second mixer 24, and provides them to the error measurement unit 54.

The local frequency setting unit 52 gives the error measurement unit 54 the value of the local signal input frequency f _Lo1 .

  Since the same correction signal is given to both the first mixer 14 and the second mixer 24, the output level and output phase, which are the measurement results of the first level / phase measurement unit 18, and the second level / phase measurement unit 28. Ideally, the output level and the output phase, which are measurement results, are equal.

  However, in reality, the same correction signal is given to both the first mixer 14 and the second mixer 24, but the output level and output phase, which are the measurement results of the first level / phase measurement unit 18, The output level and the output phase which are the measurement results of the second level / phase measurement unit 28 are different. Actually, there is a difference between the electrical length and attenuation of the electrical circuit from the local signal source 12 to the first mixer 14 and the electrical length and attenuation of the electrical circuit from the local signal source 12 to the second mixer 24. It is.

The error measurement unit 54 provides level differences ΔLv1 to ΔLv3 and phase differences ΔP1 to ΔP3 between outputs of the plurality of mixers 14 and 24 when a common correction signal input is given to the plurality of mixers 14 and 24 (see FIG. 2). _Is measured in association with the frequency f _Lo1 of the local signal input (see FIG. 3).

  The level difference between the outputs of the plurality of mixers 14 and 24 is the difference between the output level that is the measurement result of the first level / phase measurement unit 18 and the output level that is the measurement result of the second level / phase measurement unit 28. It is a difference.

  Further, the phase difference between the outputs of the plurality of mixers 14 and 24 is the difference between the output phase that is the measurement result of the first level / phase measurement unit 18 and the output phase that is the measurement result of the second level / phase measurement unit 28. It is a difference.

The error measuring unit 54 interpolates the output level differences ΔLv1 to ΔLv3 with respect to the local signal input frequency f _Lo1 (see FIG. 4A) and the output phase differences ΔP1 to ΔP3 with respect to the local signal input frequency f _Lo1 . The interpolated one (see FIG. 4B) is obtained and recorded.

(2) Input signal under measurement (see Fig. 5)
Next, referring to FIG. 5, a signal under measurement is given to the signal measuring device 1.

  First, the antenna ANT1 is connected to the first terminal 11 and the antenna ANT2 is connected to the second terminal 21. The antennas ANT1 and ANT2 receive multipath (P1, P2, P3) signals. These received signals are signals under measurement having a common frequency. A signal under measurement is supplied to the first terminal 11 and the second terminal 21.

  Here, the switch 44 connects the second mixer 24 to the single local signal source 12.

  The signal under measurement given to the first terminal (CH 1) 11 is given to the R input of the first mixer 14. A local signal input from the local signal source 12 is given to the L input of the first mixer 14. Then, a signal having a frequency equal to the difference between the frequencies of the two inputs (R input and L input) is output from the first mixer 14 (I output).

  The I output (analog signal) of the first mixer 14 is converted into a digital signal by the first A / D converter 16 and supplied to the first level / phase measurement unit 18. The first level / phase measurement unit 18 measures the level and phase of the output of the first mixer 14 and outputs the result to the difference / sum measurement unit 60.

  The signal under measurement given to the second terminal (CH 2) 21 is given to the R input of the second mixer 24. A local signal input from the local signal source 12 is given to the L input of the second mixer 24. Then, a signal having a frequency equal to the difference between the frequencies of the two inputs (R input and L input) is output from the second mixer 24 (I output).

  The I output (analog signal) of the second mixer 24 is converted into a digital signal by the second A / D converter 26 and supplied to the second level / phase measurement unit 28. The second level / phase measurement unit 28 measures the level and phase of the output of the second mixer 24 and outputs the result to the difference / sum measurement unit 60.

Further, the error correction unit 56 _acquires the value of the frequency f _Lo1 of the local signal input from the local frequency setting unit 52. Further, the error correction unit 56 reads out from the error measurement unit 54 the difference in output level and the difference in output phase corresponding to the value of the frequency f _Lo1 of the local signal input.

If the value of the frequency f _Lo1 of the local signal input is any one of f ₁ , f _2, and f ₃ , the error correction unit 56 is one of the actual measurement values ΔLv1 to ΔLv3 of the error measurement unit 54 and ΔP1 to ΔP3. Any one (see FIG. 3) may be read.

When the frequency f _Lo1 of the local signal input is not any of f ₁ , f ₂ and f ₃ , the error correction unit 56 calculates the difference in output level and output phase corresponding to the frequency f _Lo1 of the local signal input. From the interpolation result recorded in the error measurement unit 54 (see FIGS. 4A and 4B).

  The error correction unit 56 gives the read output level difference and output phase difference to the difference / sum measurement unit 60. Then, the difference / sum measurement unit 60 corrects the measurement result of the difference / sum measurement unit 60 according to the value given from the error correction unit 56.

  Thereby, there is a difference between the electrical length and attenuation of the electrical circuit from the local signal source 12 to the first mixer 14 and the electrical length and attenuation of the electrical circuit from the local signal source 12 to the second mixer 24. An error between the measurement results of the first level / phase measurement unit 18 and the second level / phase measurement unit 28 can be corrected.

  However, if there is no level difference or phase difference between the outputs of the first mixer 14 and the second mixer 24 when a common signal input is given to both the first mixer 14 and the second mixer 24, error correction is performed. Correction by the unit 56 is unnecessary.

  According to the embodiment of the present invention, it is possible to derive the minimum value and the maximum value of the sum of the electric field differences received by each of the two antennas ANT1 and ANT2 used for space diversity.

  In addition, the output of a single local signal source 12 is used as a local signal in the signal measuring apparatus 1 having a plurality of channels (CH1, CH2). For this reason, since the phase fluctuation of the local signal in each channel is common, the phase mismatch of the local signal can be reduced.

Furthermore, there is a difference between the electrical length and attenuation of the electrical circuit from the local signal source 12 to the first mixer 14 and the electrical length and attenuation of the electrical circuit from the local signal source 12 to the second mixer 24. The error between the measurement results of the first level / phase measurement unit 18 and the second level / phase measurement unit 28 is recorded in the error measurement unit 54 in association with the value of the frequency f _Lo1 of the local signal input. Since the error correction unit 56 reads the data and gives it to the difference / sum measurement unit 60 to correct the measurement result, the error can be corrected.

  According to the embodiment of the present invention, in this way, it is possible to deal with a mismatch in the level and phase of the local signal of each channel in the signal measuring apparatus 1 having a plurality of channels. Therefore, the minimum value of the difference between the electric fields received by each of the two antennas ANT1 and ANT2 used for space diversity and the maximum value of the sum can be obtained more accurately.

  Moreover, said embodiment is realizable as follows. A computer equipped with a CPU, a hard disk, and a medium (floppy (registered trademark) disk, CD-ROM, etc.) reader is added to each of the above-described parts, for example, the first level / phase measurement unit 18, the second level / phase measurement unit 28, The medium on which the program for realizing the error measuring unit 54, the error correcting unit 56, and the difference / sum measuring unit 60 is recorded is read and installed on the hard disk. Such a method can also realize the above functions.

DESCRIPTION OF SYMBOLS 1 Signal measuring device 4 Divider 11 1st terminal 21 2nd terminal 31 Output terminal 12 (Single) 1st local signal source 14 1st mixer 16 1st A / D converter 18 1st level and phase measurement part 22 Second local signal source 24 Second mixer 26 Second A / D converter 28 Second level / phase measurement unit 32 Intermediate frequency signal source 34 Correction signal mixer 42, 44 Switch 52 Local frequency setting unit 54 Error measurement unit 56 Error Correction unit 60 Difference / sum measurement unit
f _Lo1 local signal input frequency ΔLv1 to ΔLv3 Level difference between the outputs of the plurality of mixers 14 and 24 ΔP1 to ΔP3 Phase difference between the outputs of the plurality of mixers 14 and 24

Claims (6)

A plurality of mixers that output a signal having a frequency equal to the difference between the frequencies of the two inputs;
A single local signal source providing a common local signal input to the plurality of mixers;
An error measuring unit for measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
A difference / sum measuring unit for measuring a minimum value of a difference between electric fields output from the plurality of mixers and a maximum value of a sum of the electric fields when a plurality of mixers are provided with signals to be measured having a common frequency;
Based on the measurement result of the error measurement unit, an error correction unit that corrects the measurement result of the difference / sum measurement unit;
A correction signal mixer that is provided with the local signal input and the intermediate frequency signal input, and that outputs a signal having a frequency equal to the sum of the frequencies of the local signal input and the intermediate frequency signal input as the correction signal;
With
A signal received by the plurality of antennas while changing an angle and distance of another antenna with respect to one antenna of the plurality of antennas is used as the signal under measurement input.
Signal measuring device. The signal measuring device according to claim 1,
The error measurement unit measures the level difference and the phase difference in association with the frequency of the local signal input;
The error correction unit corrects the measurement result of the difference / sum measurement unit according to the frequency of the local signal input;
Signal measuring device. The signal measuring device according to claim 2,
The error correction unit corrects the measurement result of the difference / sum measurement unit based on the measurement result of the error measurement unit interpolated with respect to the frequency of the local signal input.
Signal measuring device. A signal measurement process in a signal measurement apparatus comprising: a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies; and a single local signal source that provides a common local signal input to the plurality of mixers. A signal measurement method to perform,
An error measuring step of measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
A difference / sum measurement step of measuring a minimum value of a difference between electric fields output from the plurality of mixers and a maximum value of the sum of the electric fields when a plurality of mixers are provided with signals to be measured having a common frequency; and
Based on the measurement result of the error measurement step, an error correction step of correcting the measurement result of the difference / sum measurement step,
With
A signal having a frequency equal to the sum of frequencies of the local signal input and the intermediate frequency signal input is used as the correction signal.
A signal received by the plurality of antennas while changing an angle and distance of another antenna with respect to one antenna of the plurality of antennas is used as the signal under measurement input.
Signal measurement method. A signal measurement process in a signal measurement apparatus comprising: a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies; and a single local signal source that provides a common local signal input to the plurality of mixers. A program for causing a computer to execute,
The signal measurement process
An error measuring step of measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
A difference / sum measurement step of measuring a minimum value of a difference between electric fields output from the plurality of mixers and a maximum value of the sum of the electric fields when a plurality of mixers are provided with signals to be measured having a common frequency; and
Based on the measurement result of the error measurement step, an error correction step of correcting the measurement result of the difference / sum measurement step,
With
A signal having a frequency equal to the sum of frequencies of the local signal input and the intermediate frequency signal input is used as the correction signal.
A signal received by the plurality of antennas while changing an angle and distance of another antenna with respect to one antenna of the plurality of antennas is used as the signal under measurement input.
program. A signal measurement process in a signal measurement apparatus comprising: a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies; and a single local signal source that provides a common local signal input to the plurality of mixers. A computer-readable recording medium storing a program to be executed by a computer,
The signal measurement process
An error measuring step of measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
A difference / sum measurement step of measuring a minimum value of a difference between electric fields output from the plurality of mixers and a maximum value of the sum of the electric fields when a plurality of mixers are provided with signals to be measured having a common frequency; and
Based on the measurement result of the error measurement step, an error correction step of correcting the measurement result of the difference / sum measurement step,
With
A signal having a frequency equal to the sum of frequencies of the local signal input and the intermediate frequency signal input is used as the correction signal.
A signal received by the plurality of antennas while changing an angle and distance of another antenna with respect to one antenna of the plurality of antennas is used as the signal under measurement input.
recoding media.

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