JP2014157027A - Antenna measuring device and antenna measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antenna measuring device which measures wide band frequency characteristics of an antenna simultaneously and at low cost.SOLUTION: A high frequency signal in a frequency range desired to be measured is radiated from an antenna 110 and received by a measuring antenna part 120. After that, the high frequency signal distributed by a power distribution part 130 is band-limited by filters 141, 142, 143 which are different in passing frequency band. The high frequency signal having passed the filters 141, 142, 143 is frequency-converted by frequency conversion parts 151, 152, 153 and detected by a receiver 190 after synthesized by a power synthesizing part 180 so that an amplitude and a phase of the detected signal is detected by an amplitude phase detection part 200. By this configuration, the measurement can be performed using the receiver 190 which corresponds to a frequency range narrower than the frequency range desired to be measured, and wide band frequency characteristics of the antenna can be measured simultaneously and at low cost.

Description

  The present invention relates to an antenna measurement apparatus and an antenna measurement method that can measure the passing amplitude phase characteristics of an antenna over a wide frequency range.

In order to confirm whether or not the antenna satisfies a predetermined performance, it is required to measure the radiation characteristics (amplitude and phase) in a necessary frequency range in an anechoic chamber or the like.
In order to obtain desired radiation characteristics, an array antenna composed of a plurality of element antennas requires a calibration technique that measures the amplitude phase characteristics of each element antenna and corrects them to a predetermined value.
Thus, it is important to measure the amplitude phase characteristics of each antenna with high accuracy and at high speed.

When measuring over a wide frequency range, it is necessary to increase the bandwidth of the measuring device, but depending on the frequency bandwidth that can be handled including the analog / digital converter, the configuration of the measuring device becomes complicated and the cost is reduced. There is a problem to be raised.
This may be particularly problematic when a measurement function is mounted on a product body such as a wireless communication device.
Therefore, for example, as a technique related to a wideband receiver for a wireless communication system, in Patent Document 1 below, a configuration in which a plurality of filters having different pass frequency bands are combined and demultiplexed into a narrowband signal and then communication processing is performed. Is shown.

JP 2006-121161 A

The technique of Patent Document 1 is a narrow-band signal for processing after demultiplexing, but it is necessary to prepare receivers for the number of demultiplexes, and there is a problem of high cost because the apparatus scale becomes large.
Further, this is a technique related to a radio communication receiver, and there is no description on the point of simultaneously measuring the wideband frequency characteristics of the antenna.

  An object of the present invention is to provide an antenna measurement apparatus and an antenna measurement method that can simultaneously measure the wideband frequency characteristics of an antenna at low cost.

  An antenna measurement apparatus according to the present invention includes a high-frequency generator that generates a high-frequency signal, a first antenna that transmits a high-frequency signal, a second antenna that receives a high-frequency signal from the first antenna, A power distribution unit that distributes M high-frequency signals from the two antenna units to M, M filters that filter the high-frequency signals distributed by the power distribution unit, a frequency setting unit that sets M frequency values, and a frequency M reference signal sources that respectively generate local oscillation signals having frequencies set by the setting unit, and M that perform frequency conversion on the respective high-frequency signals that have passed through the filter by the respective local oscillation signals generated by the reference signal source. Frequency converters, a power combiner that combines the signals frequency-converted by the frequency converter, a receiver that detects the output signal of the power combiner, and a receiver Those having an amplitude phase detector for detecting the amplitude and phase of detected signals by the machine.

  According to the present invention, the high-frequency signal that has passed through the filter is frequency-converted by the frequency conversion unit, synthesized by the power combining unit, then detected by the receiver, and the amplitude and phase of the signal detected by the amplitude-phase detection unit are detected. Therefore, it is possible to perform measurement using a receiver corresponding to a frequency range narrower than the frequency range to be measured, and there is an effect that the wideband frequency characteristics of the antenna can be measured simultaneously and at low cost.

It is a block diagram which shows the antenna measuring apparatus by Embodiment 1 of this invention. It is a flowchart which shows the antenna measuring method by Embodiment 1 of this invention. It is a block diagram which shows the antenna measuring apparatus by Embodiment 2 of this invention. It is a flowchart which shows the antenna measuring method by Embodiment 2 of this invention. It is a frequency characteristic figure which shows the multicarrier signal produced | generated by the multicarrier signal production | generation part. It is a frequency characteristic figure which shows the subcarrier group output from each filter. It is a frequency characteristic figure which shows the subcarrier group output from each frequency conversion part. It is a frequency characteristic figure which shows the subcarrier group combined by the electric power combiner. It is a block diagram which shows the antenna measuring apparatus by Embodiment 3 of this invention. It is a frequency characteristic figure which shows the subcarrier allocated to each element antenna. It is a block diagram which shows the antenna measuring apparatus by Embodiment 4 of this invention.

Embodiment 1 FIG.
An antenna measurement apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an antenna measurement apparatus according to Embodiment 1 of the present invention, and shows a measurement example when an antenna to be measured is installed on the transmission side.
Only the portions necessary for the present invention are described.

  In FIG. 1, reference numeral 100 denotes a high-frequency signal generation unit that generates a high-frequency signal used for measurement, 110 denotes a measurement target, an antenna that transmits a high-frequency signal, and 120 denotes a measurement antenna unit that receives a high-frequency signal from the antenna 110. The measurement antenna unit 120 is disposed at a predetermined position with respect to the antenna 110.

  130 is a power distribution unit that distributes the received high-frequency signal to a predetermined number (M: M is an arbitrary natural number), 141, 142, and 143 are M filters having predetermined pass frequency bands, 151, 152, 153 is an M number of frequency converters that convert a high-frequency signal into a predetermined low frequency band, 161, 162, and 163 are M reference signal sources that provide sine waves of local oscillation frequencies to the frequency converters 151, 152, and 153, Reference numeral 170 denotes a frequency setting unit that sets the local oscillation frequency of each of the reference signal sources 161, 162, and 163.

  180 is a power combiner that combines the output signals of the frequency converters 151, 152, and 153, 190 is a receiver that detects the combined signal, and 200 is an amplitude that detects the amplitude and phase information using the detected signal. It is a phase detector.

Next, the operation will be described.
FIG. 2 is a flowchart showing an antenna measurement method according to Embodiment 1 of the present invention.
First, a frequency range to be measured is set (step ST101: frequency setting step).
The high frequency signal generation unit 100 generates a high frequency signal for measuring the amplitude phase characteristic in the set frequency range (step ST102: measurement signal generation step).
The high-frequency signal is radiated from the antenna 110 to be measured and received by the measurement antenna unit 120 (steps ST103 and ST104: measurement signal transmission process, measurement signal reception process).
The measurement antenna unit 120 means not only a single reception antenna but also an antenna unit including a function of adjusting a high-frequency signal to an appropriate power level, such as an amplifier and an attenuator.

Thereafter, the power distribution unit 130 distributes a predetermined number (M) of received signals.
The distributed high-frequency signals are band-limited by filters 141, 142, and 143 having different pass frequency bands, respectively (step ST105: demultiplexing process step).
For example, when the pass bandwidths of the filters 141, 142, and 143 are equal, the output signal has a frequency band of 1 / M times.
The output signals of the filters 141, 142, and 143 are converted into signals in a low frequency band (IF band) by the frequency converters 151, 152, and 153 so that they can be easily converted into digital signals later.
Reference signal sources 161, 162, and 163 generate a sine wave having a local oscillation frequency for converting a high-frequency signal into an IF band.
The oscillation frequency is controlled by the frequency setting unit 170.
The frequency setting unit 170 sets an oscillation frequency so that the frequency components of the output signals of the frequency conversion units 151, 152, and 153 do not overlap each other and are in the same frequency band (step ST106: frequency conversion processing step).

Next, the signal converted into the low frequency band is combined in the power combining unit 180 (step ST107: combining processing step).
The combined signal is detected by receiver 190 (step ST108: detection processing step).
The amplitude phase detection unit 200 detects the amplitude and phase information (step ST109: amplitude phase detection step).
The frequency converters 151, 152, and 153 perform frequency conversion into signals in the same frequency band, and a signal in a band narrower than the frequency band of the original high-frequency signal is obtained.
Therefore, the receiver 190 may have a frequency band that is narrower than the measured frequency bandwidth.

  As described above, according to the first embodiment, the high-frequency signals that have passed through the filters 141, 142, and 143 are frequency-converted by the frequency converters 151, 152, and 153, combined by the power combiner 180, and then received by the receiver 190. Is detected, and the amplitude and phase of the signal detected by the amplitude / phase detector 200 are detected. Therefore, measurement can be performed using the receiver 190 corresponding to a frequency range narrower than the frequency range to be measured. Broadband frequency characteristics can be measured simultaneously and at low cost.

  In addition, since the filters 141, 142, and 143 have different pass frequency bands, the frequency characteristics of the high frequency signals after passing through the filters 141, 142, and 143 do not overlap and the frequency characteristics are measured with high accuracy. can do.

  Furthermore, since the frequency conversion units 151, 152, and 153 perform frequency conversion to the same frequency band, measurement using the receiver 190 corresponding to a narrower frequency range is possible, and measurement is performed at a lower cost. be able to.

In FIG. 1, the power distribution unit 130 is used. However, the power distribution unit 130 may be replaced with a demultiplexing unit including a so-called filter function to directly extract signals in different frequency bands.
In that case, the M filters 141, 142, and 143 in the subsequent stage are not necessary.

Embodiment 2. FIG.
An antenna measurement apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings.
FIG. 3 is a block diagram showing an antenna measurement apparatus according to Embodiment 2 of the present invention, and shows a measurement example when an antenna to be measured is installed on the transmission side.
In the first embodiment, there is no restriction on the characteristics of the high-frequency signal, but the second embodiment shows a configuration that can compress the frequency bandwidth more efficiently.
In addition, in each figure, the same code | symbol shows the same or an equivalent part.

3, most of the configuration is the same as in FIG. 1, and the operation of each component is the same or equivalent.
As a difference, the high-frequency signal generation unit 100 is replaced with a multicarrier signal generation unit 210.
Further, a demultiplexing unit 220 is added after the receiver 190, and the output signal is connected to the amplitude / phase detection unit 200.
Multicarrier signal generation section 210 generates a multicarrier signal in which a plurality of subcarriers are arranged.
The demultiplexing unit 220 separates each subcarrier according to the signal detected by the receiver 190.

Next, the operation will be described.
FIG. 4 is a flowchart showing an antenna measurement method according to Embodiment 2 of the present invention.
First, the frequency range and frequency points to be measured are set (step ST201: carrier frequency setting step).
Multicarrier signal generation section 210 generates a multicarrier signal in which a plurality of subcarriers 301 for measuring amplitude phase characteristics are arranged as shown in FIG. 5 based on the set frequency range and frequency points (step ST202). : Measurement signal generation step).
Each subcarrier 301 may be a sine wave of an unmodulated signal.
The subcarriers 301 are respectively arranged in the frequency bandwidth B to be measured at intervals that can be demultiplexed by the receiver 190 and the subsequent receivers.
In addition, although the example of arrangement | positioning at equal intervals is shown in FIG. 5, it is not restricted to this and arrangement | positioning at unequal intervals, such as a random interval, is also possible.

The multicarrier signal is radiated from the antenna 110 to be measured and received by the measurement antenna unit 120 (steps ST203 and ST204: measurement signal transmission step, measurement signal reception step).
After that, the multicarrier signals distributed to M by the power distributor 130 of FIG. 3 are demultiplexed by M filters 141, 142, and 143 having different pass frequency bands as shown in FIG.
311 is a subcarrier of the output signal of the filter (1) 141 in FIG. 3, 312 is a subcarrier of the output signal of the filter (2) 142 in FIG. 3, 313 is a subcarrier of the output signal of the filter (3) 143 in FIG. In consideration of the subcarriers passed from all the filters 141, 142, and 143, all the subcarriers 301 of the transmission signal in FIG. 5 are included (step ST205: demultiplexing process step).

Next, the output signals of the filters 141, 142, and 143 are frequency-converted to a lower frequency band. Regarding how to set the frequency (local oscillation frequency) of the sine wave used at this time, each frequency converter 151 , 152 and 153 are different values.
Specifically, although the center frequencies of the multicarrier signals included in the output signals of the filters 141, 142, and 143 are different, the frequency setting unit 170 performs each frequency conversion so as to frequency-convert them into substantially the same frequency range. The local oscillation frequency of the sine wave generated by the signal sources 161, 162, and 163 is set.
FIG. 7 shows the frequency spectrum of the subcarriers 321, 322, 323 output from the frequency converters 151, 152, 153, which are frequency converted to the same frequency band.
However, as will be described later, each subcarrier 321, 322, 323 performs frequency setting so as not to overlap.
FIG. 7 shows an example in which frequency conversion is performed in accordance with the lower frequency, but the present invention is not limited to this.
Each output signal only needs to be converted to the same frequency band (step ST206: frequency conversion processing step).

Next, each signal is synthesized by the power combiner 180 as in the first embodiment.
FIG. 8 shows the frequency spectrum of the combined signal, and it can be seen that each subcarrier 331 is superimposed on the same frequency band.
By doing so, the frequency bandwidth of the combined signal can be compressed to approximately 1 / M times that of the original multicarrier signal (step ST207: combining processing step).

Next, the combined signal is detected as a baseband signal by analog / digital conversion (A / D conversion), for example, by the receiver 190 (step ST208: detection processing step).
Further, the subcarriers are separated by the demultiplexing unit 220 (step ST209: separation process step).
By doing so, the amplitude phase detection unit 200 can detect the amplitude and phase of each separated subcarrier accurately and without interference (step ST210: amplitude phase detection step).
As processing in the demultiplexing unit 220, if the subcarriers are arranged so as to have an orthogonal frequency relationship, they can be easily separated by discrete Fourier transform based on the principle of OFDM (Orthogonal Frequency Division Multiplexing).

  As described above, according to the second embodiment, by using a multicarrier signal for measurement, interference between subcarriers after frequency conversion can be avoided. In addition to the effect, an efficient antenna measurement device can be realized.

  In addition, since the frequency setting unit 170 sets the frequency values of the local oscillation signals so that the subcarriers 321, 322, and 323 output from the frequency conversion units 151, 152, and 153 do not overlap each other, The frequency characteristics can be measured with high accuracy without the subcarriers 331 overlapping.

Embodiment 3 FIG.
An antenna measurement apparatus according to Embodiment 3 of the present invention will be described with reference to the drawings.
FIG. 9 is a configuration diagram showing an antenna measurement apparatus according to Embodiment 3 of the present invention, and shows a measurement example when an antenna to be measured is installed on the transmission side.
In the third embodiment, a configuration of an array antenna in which a measurement target includes a plurality of element antennas is shown.
In addition, in each figure, the same code | symbol shows the same or an equivalent part.

9, most of the configuration is the same as in FIG. 3, and the operation of each component is the same or equivalent.
The difference is that the configuration on the transmitting side has been changed.
The change is the addition of a subcarrier allocation unit 400 and an array antenna 410 made up of K (K is an arbitrary natural number) element antennas.
Subcarrier allocation section 400 allocates each subcarrier constituting the multicarrier signal to each element antenna of array antenna 410.

Next, the operation will be described.
In Embodiment 3, by assigning each subcarrier 301 constituting the multicarrier signal shown in FIG. 5 to each element antenna of array antenna 410, the characteristics of a plurality of element antennas can be measured simultaneously.
FIG. 10 shows an example of subcarrier allocation, in which 421 is a subcarrier allocated to the element antenna # 1, 422 is a subcarrier allocated to the element antenna # 2, and 423 is a subcarrier allocated to the element antenna # 3.
In the figure, an example in which each element antenna is assigned in order is shown. However, the present invention is not limited to this, and the subcarrier frequencies used in each element antenna may be assigned so as not to overlap.

  As described above, according to the third embodiment, by assigning each subcarrier of the multicarrier signal to each element antenna of the array antenna 410, the array antenna 410 is added to the effect of the first embodiment. It is possible to measure the frequency characteristics of each constituent element antenna.

Embodiment 4 FIG.
An antenna measurement apparatus according to Embodiment 4 of the present invention will be described with reference to the drawings.
FIG. 11 is a configuration diagram showing an antenna measurement apparatus according to Embodiment 4 of the present invention, and shows a measurement example when an antenna to be measured is installed on the receiving side.
In the first embodiment and the second embodiment, since the antenna 110 to be measured is installed on the transmission side, the frequency characteristics of the antenna on the transmission side can be measured.
Embodiment 3 shows a configuration in which an antenna 110 to be measured is installed on the receiving side.
In addition, in each figure, the same code | symbol shows the same or an equivalent part.

11, most of the configuration is the same as in FIG. 1, and the operation of each component is the same or equivalent.
The change from FIG. 1 is that an antenna 110 is installed on the receiving side, and a transmitting antenna unit 500 for transmitting a high-frequency signal used for measurement is installed on the transmitting side.
That is, the antenna is simply replaced by transmission / reception, and other configurations and processes are the same as those of the other embodiments.

  As described above, according to the fourth embodiment, since the antenna 110 to be measured is installed on the reception side, the frequency characteristics of the antenna on the reception side can be measured.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  100 high frequency signal generation unit, 110 antenna, 120 measurement antenna unit, 130 power distribution unit, 141, 142, 143 filter, 151, 152, 153 frequency conversion unit, 161, 162, 163 reference signal source, 170 frequency setting unit, 180 Power combiner, 190 receiver, 200 amplitude phase detector, 210 multicarrier signal generator, 220 demultiplexer, 301, 311, 312, 313, 321, 322, 323, 331, 411, 412, 413 subcarrier, 400 subcarrier allocation unit, 410 array antenna, 500 transmission antenna.

Claims (12)

A high frequency generator for generating a high frequency signal;
A first antenna unit for transmitting the high-frequency signal;
A second antenna unit for receiving a high-frequency signal from the first antenna unit;
A power distribution unit that distributes the high-frequency signal from the second antenna unit to M (M is an arbitrary natural number);
M filters for filtering the high-frequency signal distributed by the power distribution unit;
A frequency setting unit for setting M frequency values;
M reference signal sources that respectively generate local oscillation signals having frequencies set by the frequency setting unit;
M frequency converters for frequency-converting each high-frequency signal that has passed through the filter with each local oscillation signal generated by the reference signal source;
A power combiner that combines the signals frequency-converted by the frequency converter;
A receiver for detecting the output signal of the power combiner;
An amplitude phase detector for detecting the amplitude and phase of the signal detected by the receiver;
An antenna measurement device comprising: A multicarrier signal generation unit that generates a multicarrier signal in which a plurality of subcarriers are arranged;
A first antenna unit for transmitting the multicarrier signal;
A second antenna unit for receiving a multicarrier signal from the first antenna unit;
A power distribution unit that distributes multicarrier signals by the second antenna unit to M (M is an arbitrary natural number);
M filters for filtering the multicarrier signal distributed by the power distribution unit;
A frequency setting unit for setting M frequency values;
M reference signal sources that respectively generate local oscillation signals having frequencies set by the frequency setting unit;
M frequency converters for converting the frequency of each subcarrier that has passed through the filter by the respective local oscillation signals generated by the reference signal source;
A power combiner for combining the subcarriers frequency-converted by the frequency converter;
A receiver for detecting the output signal of the power combiner;
A demultiplexing unit that separates the subcarriers according to the signal detected by the receiver;
An amplitude and phase detector for detecting the amplitude and phase of each subcarrier separated by the branching unit;
An antenna measurement device comprising: The first antenna part is
An array antenna composed of a plurality of element antennas,
In addition to this,
The antenna measurement apparatus according to claim 2, further comprising a subcarrier allocation unit that allocates each subcarrier of the multicarrier signal by the multicarrier signal generation unit to each element antenna of the array antenna. The filter
The antenna measurement device according to any one of claims 1 to 3, wherein the antenna measurement devices have different pass frequency bands. The frequency converter
The antenna measurement apparatus according to any one of claims 1 to 4, wherein frequency conversion is performed in the same frequency band. The frequency setting section
4. The antenna measurement apparatus according to claim 2, wherein the frequency values of the local oscillation signals are set so that the subcarriers output from the frequency converter do not overlap each other.   The antenna measurement apparatus according to any one of claims 1 to 6, wherein one of the first antenna unit and the second antenna unit is set as a measurement target. A frequency setting process for setting a frequency range to be measured;
A measurement signal generating step for generating a high-frequency signal based on the frequency range;
A measurement signal transmission step of transmitting the high-frequency signal from the first antenna unit;
A measurement signal receiving step of receiving a high-frequency signal from the first antenna unit by a second antenna unit;
A demultiplexing step of demultiplexing the received high frequency signal into M (M is an arbitrary natural number) high frequency signals;
A frequency conversion process for converting the frequency of the M high-frequency signals;
A synthesizing process for synthesizing the frequency-converted high-frequency signal;
A detection processing step of detecting the synthesized high-frequency signal by a receiver;
An amplitude phase detection step of detecting the amplitude and phase of the detected signal;
An antenna measurement method comprising: A carrier frequency setting step for setting the carrier frequency of each subcarrier based on the frequency range and frequency points to be measured;
A measurement signal generation step for generating a multicarrier signal in which a plurality of subcarriers are arranged based on the carrier frequency;
A measurement signal transmission step of transmitting the multicarrier signal from a first antenna unit;
A measurement signal receiving step of receiving a multicarrier signal from the first antenna unit by a second antenna unit;
A demultiplexing step of demultiplexing the received multicarrier signal into M (M is an arbitrary natural number) subcarrier groups;
A frequency conversion processing step of performing frequency conversion on the M subcarrier groups;
A synthesis processing step of synthesizing the frequency-converted subcarrier group;
A detection processing step of detecting each of the combined subcarriers by a receiver;
A separation process step of separating the subcarriers according to the detected signal;
An amplitude phase detection step of detecting the amplitude and phase of each of the separated subcarriers;
An antenna measurement method comprising: The demultiplexing process is
10. The antenna measurement method according to claim 8, wherein the demultiplexing is performed for each different frequency band. The frequency conversion process
10. The antenna measurement method according to claim 8, wherein frequency conversion is performed to the same frequency band. The frequency conversion process
10. The antenna measurement method according to claim 9, wherein frequency conversion is performed so that subcarriers do not overlap.

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