JP4711640B2 - Receiving apparatus and receiving method - Google Patents

Description

  The present invention relates to a receiving apparatus and a receiving method for performing radiated disturbance measurement of an electronic device, a wireless terminal, and the like that perform wireless communication with high accuracy.

  With the expansion of the use of radio waves and the spread of various electronic devices, it has become a big problem that devices and systems are subject to electromagnetic interference from other devices and systems. For this reason, radio electronic interference (hereinafter referred to as radiated interference) tolerances have been established for various electronic devices, and it is possible to measure and quantitatively understand the radiated interference to generate radio waves that can cause radio interference. It is important from the viewpoint of suppressing

In addition, for wireless devices such as mobile phones, there is an increasing need for measurement of radiated disturbance waves in order to ensure electromagnetic compatibility (EMC) with surrounding electronic devices.

  Conventionally, as shown in FIG. 9, the measurement of radiated disturbance is performed using a receiving apparatus 200 including a measuring receiving antenna 210 (hereinafter referred to as a receiving antenna) and a measuring receiver 220 (hereinafter referred to as a receiver). The reception frequency of the receiver 220 is continuously tuned, for example, in a range from 30 MHz to 18 GHz, and the frequency spectrum of the radiation interference wave is measured.

Moreover, there exists a thing disclosed by patent document 1, for example regarding the radiation interference wave measuring apparatus which measures the interference wave radiated | emitted from a measuring object. According to the technique disclosed in this publication, the radiated emission measuring device is provided with a switch circuit and a broadband coupling circuit for injecting a signal for canceling a radio carrier to the input part of the low noise amplification circuit, and the radio carrier A carrier receiving antenna and a carrier cancel signal generating circuit are provided for generating a signal for canceling the signal. With such a configuration, it is possible to selectively cancel only the carrier signal received by the radiation interference measurement antenna, and even in a wireless device having a direct antenna on the housing, such as a mobile phone, the inside of the wireless device housing It is possible to measure radiated disturbance waves emitted from circuit parts and the like.
JP 2002-148293 A

However, in the case of the prior art as described above, the following problems have occurred.

  In the measurement system as shown in FIG. 8, even if an attempt is made to measure a radiation object of a measurement object, for example, a wireless terminal, the signal level in the frequency band for performing wireless communication is stronger than other frequency components. For this reason, cross modulation tends to occur due to nonlinearity inside the receiver. That is, when such cross modulation occurs, the target interference wave signal is buried by the cross modulation, and there is a problem that the interference wave signal (spectrum characteristic of the interference wave) cannot be measured correctly. In particular, in a wireless terminal in which an antenna and a housing are integrated, such as a mobile phone, the above-described problem is likely to occur.

  The present invention has been made in view of the problems as described above, and the problem is that a receiving apparatus capable of easily and accurately measuring a radiation disturbance wave radiated from an object to be measured, and It is to provide a receiving method.

In order to solve the above-described problem , according to one aspect of the present invention, there is provided a receiving apparatus including an antenna and a receiver, and a plurality of frequency band eliminations for attenuating a frequency band having a predetermined width centered on a predetermined frequency. A filter, a through line, the plurality of frequency band elimination filters, a first changeover switch that selectively switches the through line, a high-pass filter having a predetermined cutoff frequency, the plurality of frequency band elimination filters, and the high pass And a second changeover switch for selectively changing the filter.

Moreover, according to an aspect of the present invention, in the reception device, the first changeover switch selectively switches the plurality of frequency band elimination filters and the through line based on an instruction from the outside. It is characterized by.

According to another aspect of the present invention, the receiving device includes switching control means for controlling switching of the second changeover switch, and the switching control means is based on a switching signal output from a receiver. The plurality of frequency band elimination filters and the high-pass filter are selectively switched.

Further, according to one aspect of the present invention, in the receiving device, the receiver includes frequency insertion means for subtracting a reception frequency, and the reception frequency is set to a predetermined threshold while the reception frequency is being subtracted. A determination unit that determines whether the frequency has reached, and a switching unit that outputs a switching signal for switching the plurality of frequency band elimination filters and the high-pass filter to the switching control unit when the reception frequency reaches a predetermined threshold value. And a signal output means.

Further, according to one aspect of the present invention, the receiving device is a receiving antenna different from the receiving antenna, and a frequency detecting unit that detects a receiving frequency of a received signal received via the receiving antenna; The switching control means is configured to select a frequency band removal filter corresponding to a detected frequency band of the reception frequency from the plurality of frequency band removal filters based on a detection result of the frequency detection means. The first changeover switch is controlled.

According to another aspect of the present invention, the reception device includes an amplitude detection unit that detects a level of a reception signal received via the reception antenna, and the switching control unit includes the amplitude control unit. Based on the detection result of the detection means, the first changeover switch is controlled to switch to the through line.

Further, according to an aspect of the present invention, in the reception device, the switching control unit is configured such that the level of the received signal detected from the amplitude detection unit is lower than a predetermined value, or the level of the received signal is When the detection result that the signal level is lower than the signal level of another frequency band is obtained, the first changeover switch is controlled so as to switch to the through line.

A receiving apparatus according to an aspect of the present invention is provided.
A receiving device including a receiving antenna and a receiver,
A plurality of frequency band elimination filters that attenuate a frequency band of a predetermined width centered on a predetermined frequency;
Through line,
A first changeover switch that selectively switches between the plurality of frequency band elimination filters and the through line;
Multiple high-pass filters,
A second changeover switch that selectively switches between any one of the plurality of frequency band elimination filters and a high-pass filter associated with the frequency elimination filter;
The second changeover switch performs the changeover according to whether the reception frequency of the reception signal is less than the cutoff frequency of the high-pass filter,
The cut-off frequency of the high-pass filter is a receiving device that is larger than a target frequency to be removed by a frequency removal filter associated with the high-pass filter and smaller than twice the target frequency.
According to the present invention as described above, a measurement target can be measured by selectively using a band-rejection filter for a radio communication frequency band between a receiving antenna and a receiver and a high-pass filter matched to the band-removal filter with a changeover switch. Since the influence of the frequency component that an object uses for wireless communication can be reduced, high-accuracy radiated disturbance can be measured.

  According to the present invention, by incorporating a radio communication frequency band signal removal function between the receiving antenna and the receiver, it is possible to measure the radiation interference wave of the measurement object with high accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a basic configuration of a receiving apparatus according to an embodiment of the present invention.

  In the figure, the receiving apparatus 1 includes a first receiving antenna 10, a band elimination filter unit 20, and a receiver 30. The first receiving antenna 10 and the band elimination filter unit 20 are connected by the cable 1, and the band elimination filter unit 20 and the receiver 30 are connected by the cable 2. As shown in the figure, in the present embodiment, a band elimination filter unit 20 is provided between the first receiving antenna 10 and the receiver 30, and is transmitted from an electronic device, for example, a wireless terminal, by the band elimination filter unit 20. Wireless communication signals are attenuated. That is, by inserting a band elimination filter (Band Elimination Filter) between the first receiving antenna 10 and the receiver 30, when the object of radiation disturbance measurement is a wireless communication terminal, Only the signal of the radio communication frequency band is attenuated, and the signal of the other frequency, that is, the radiation interference wave can be easily measured.

  Next, a specific embodiment of the present invention will be described with reference to FIG.

(First embodiment)
FIG. 2 is a configuration diagram of the receiving device 2 in the present embodiment.

  As shown in the figure, in the present embodiment, the receiving device 2 includes a band elimination filter unit 50 between the first receiving antenna 10 and the receiver 30, and further includes a switching control circuit 40. The switching signal line 1 is connected between the switching control circuit 40 and the band elimination filter unit 50, and the switching signal line 2 is connected between the receiver 30 and the switching control circuit 40.

  The band removal filter unit 50 includes band removal filters 51 to 55 for frequency bands (800 MHz band, 1.5 GHz band, 2 GHz band, 2.4 GHz band, and 5 GHz band) used in wireless communication, and a through line 71. Is provided. In this example, the frequency band used for the wireless terminal is set to the above five types, and the aspect including the band removal filters 51 to 55 according to the frequency band is exemplified. However, the band removal filter of the band removal filter unit 50 is the measurement object. However, the present invention is not limited to the mode of the present embodiment.

  Each of the band elimination filters 51 to 55 is switched by the first changeover switch 81 and attenuates the radio frequency band used in the target measurement object (in this example: equivalent to a radio terminal) of the radiation interference wave. This makes it possible to extract a weak radiated disturbance wave and accurately measure the radiated disturbance wave. On the other hand, when the target measurement object is not a wireless terminal, measurement is performed by switching to the through line by the first changeover switch.

  The first changeover switch 81 can be controlled by manual control operation, remote operation from the outside (for example, controlling the first changeover switch 81 by an external control signal), and the like. May be.

  By the way, when the signal of the radio communication frequency band is attenuated using only the band elimination filters 51 to 55, the frequency component twice or three times the frequency band to be attenuated is also attenuated. Therefore, in the present embodiment, high-pass filters a to e 61 to 65 having thresholds higher than the band elimination filters 51 to 55 as predetermined cutoff frequencies are provided for each band elimination filter and are incorporated in the band elimination filter unit 50. It is.

  The band elimination filters 51 to 55 and the corresponding high pass filters (high pass filters a to e) 61 to 65 are switched by the second changeover switches a to e 91 to 95, and only unnecessary frequency components are attenuated.

As shown in FIG. 3, the characteristics of the high-pass filters a to e 61 to 65 are larger than the target frequency (f ₀ ) of the band elimination filter in accordance with the frequency band of each band elimination filter, and double the target frequency (2f ₀ )) having a threshold value (f ₁ ) smaller than the cutoff frequency.

  The band elimination filters 51 to 55 attenuate the desired frequency band as described above, but have a property of attenuating N-fold frequency components as shown in FIG. Therefore, in this embodiment, a high-pass filter having characteristics as shown in FIG. 3 is used.

  Next, the switching control operation between the band elimination filter and the high pass filter will be described with reference to the flowchart of FIG. Here, as an example, a case where a radiation interference wave of a wireless terminal having a radio frequency band of 800 MHz is measured will be described. Therefore, it is assumed that the 800 MHz band elimination filter 51 is selected at the start of measurement of the radiated disturbance.

First, the receiver 30 sets an initial value of the reception frequency (step S1) in order to insert (sweep) the reception frequency. This initial value is, for example, the lower end frequency (sweep start frequency) and is determined according to the radio frequency band of the measurement object.
After setting the initial value of the reception frequency, the receiver 30 starts the reception frequency sweep (step S2).

  The receiver 30 determines whether or not the reception frequency has reached the threshold value of the high pass filter (HPF) after the start of the sweep (step S3), and determines that the reception frequency has reached the threshold value (step S3). When the result of S3 is Yes, the determination result is output to the switching control circuit 40. When it is determined that the reception frequency has not reached the threshold (No in Step S3), the process returns to Step S2. Continue the receive frequency sweep. Note that the frequency sweep range is set from the sweep start frequency to the upper end frequency (sweep stop frequency).

  The switching control circuit 40 recognizes that the reception frequency falls within the high-pass filter use range from the determination result received from the receiver 30, and switches the 800 MHz band elimination filter 51 selected previously to the high-pass filter a61. The switching signal is output to the second switching switch a91 via the switching signal line 1, and the second switching switch a91 is controlled to switch from the 800 MHz band removal filter 51 to the high pass filter a61. Thereby, the interference wave radiated | emitted from this measuring object can be measured in the state which attenuate | damped only the radio frequency band component which a measuring object uses (refer FIG. 6).

  As described above, according to the present embodiment, by incorporating a band elimination filter for a radio communication frequency band between the first receiving antenna and the receiver, measurement of radiation interference waves of radio terminals having different radio frequency bands. Can be easily performed.

  In addition, by preparing a band elimination filter for each frequency band used for wireless communication in advance, and using a different band elimination filter with a changeover switch, it is possible to cope with the measurement of radiated disturbances of various wireless terminals. There is an effect that the convenience can be improved.

  Furthermore, by preparing a high-pass filter suitable for the band elimination filter of each frequency band and using the band elimination filter and the high-pass filter properly by a changeover switch, it is possible to realize accurate radiation interference wave measurement.

  Further, there is a method of realizing a multi-frequency filter by switching the switch, but this method cannot avoid attenuation of frequency components that are an integral multiple of the frequency band to be attenuated. In the method of the present invention, the configuration including the second changeover switch and the high-pass filter is advantageous in terms of improving the accuracy of the radiation interference wave measurement because attenuation of the frequency component of the integral multiple is avoided.

(Second Embodiment)
FIG. 7 is a configuration diagram of the receiving device 3 in the present embodiment. Since the receiving apparatus 3 in the present embodiment has the same basic configuration as the receiving apparatus 2 shown in FIG. 2, the same reference numerals are given to the respective components, and the description thereof is omitted. Here, FIG. Description will be made by paying attention to the operations of the second receiving antenna 100 and the frequency detector 110, which are differences from the receiving apparatus 2 shown in FIG.

  Usually, the component of the radio frequency band has a very large signal level compared to other frequencies. Therefore, in the present embodiment, the frequency detector 110 provided with the second receiving antenna 100 separately from the first receiving antenna 10 for radiated disturbance measurement and connected to the second receiving antenna 100 via the cable 3, The radio frequency band used by the measurement object is detected (recognized).

  The frequency detector 110 outputs the detection result of the radio frequency band detected as described above to the switching control circuit 40 via the switching signal line 4. The switching control circuit 40 switches the first selector switch 81 so that the band elimination filters 51 to 55 corresponding to the frequency band recognized based on the detection result received from the frequency detector 110 are selected. Is output to the first changeover switch 81 via the changeover signal line 3 to control the first changeover switch 81.

As described above, according to the present embodiment, since the second receiving antenna and the frequency detector are provided, the radio communication frequency can be identified in advance even when the frequency band used by the wireless terminal to be measured is not known. It is possible to select an appropriate band elimination filter.
(Third embodiment)
FIG. 8 is a configuration diagram of the receiving device 4 in the present embodiment. Since the receiving apparatus 4 in the present embodiment has the same basic configuration as that of the receiving apparatus 3 shown in FIG. 7, the same reference numerals are given to the respective constituent elements and the description thereof will be omitted. Here, FIG. An explanation will be given focusing on the operation of the amplitude detector 120, which is the difference from the receiver 3 shown in FIG. The amplitude detector 120 is connected to the second receiving antenna 100 via the cable 4.

  Normally, the signal component of the radio frequency band is sufficiently large, and the frequency band used in the radio terminal can be known by using the frequency detector 110 described above, and therefore it is necessary to use a band elimination filter suitable for the frequency. . However, when the output of the wireless terminal is small and there is no significant difference from other frequency components, cross modulation does not occur, so there is no need to use a band elimination filter. Therefore, in this embodiment, the amplitude detector 120 is used to compare the signal level of the frequency band used in the wireless terminal with the signal level of the other frequency band, and the comparison result is sent via the switching signal line 5. Output to the switching control circuit 40. When the switching control circuit 40 receives the comparison result “the signal level of the frequency band used in the wireless terminal is low” from the amplitude detector 120, the switching control circuit 40 sends the switching signal to be switched to the through line 71 to the switching signal line 3. To the first changeover switch 81, and the first changeover switch 81 is controlled to switch to the through line 71.

  As described above, according to the present embodiment, by providing the amplitude detector, when the output of the wireless terminal is weak or when the measurement target is an electronic device that does not use wireless, the radiation interference measurement is performed using the through line. Is possible.

  In each of the above embodiments, a mode in which a band elimination filter is provided for each frequency band of the wireless terminal is illustrated, but a frequency variable filter capable of controlling the center frequency and bandwidth of the filter can also be used. In that case, the number of parts of the band elimination filter unit is reduced, and the size and cost can be reduced.

It is a figure which shows the basic composition of the receiver which concerns on one Embodiment of this invention. It is a block diagram of the receiver 2 in 1st Embodiment. It is a figure which shows the characteristic of a high pass filter. It is a figure which shows the characteristic of a zone | band removal filter. It is a flowchart which shows the switching control operation | movement in this embodiment. It is a figure which shows the signal after a band elimination filter passage. It is a block diagram of the receiver 3 in 2nd Embodiment. It is a block diagram of the receiver 4 in 3rd Embodiment. It is a figure which shows the basic composition of the conventional receiver.

Explanation of symbols

1, 2, 3, 4, 200 Receiver 10 First receiving antenna 20, 50 Band elimination filter unit 30, 220 Receiver 40 Switching control circuit 51-55 Band elimination filter 61-65 High-pass filters a to e
71 through line 81 first changeover switch 91-95 second changeover switch ae
100 Second receiving antenna 110 Frequency detector 120 Amplitude detector 210 Receiving antenna

Claims (8)

A receiving device including a receiving antenna and a receiver,
A plurality of frequency band elimination filters that attenuate a frequency band of a predetermined width centered on a predetermined frequency;
Through line,
A first changeover switch that selectively switches between the plurality of frequency band elimination filters and the through line;
Multiple high-pass filters,
And a second changeover switch for selectively switching between a high pass filter associated with one of the frequency removing filter and the frequency rejection filter of the plurality of frequency band-elimination filter, the second switch The switch performs the switching according to whether the reception frequency of the reception signal is less than the cutoff frequency of the high-pass filter,
The receiving apparatus , wherein the cut-off frequency of the high-pass filter is larger than a target frequency to be removed by a frequency removal filter associated with the high-pass filter and smaller than twice the target frequency . The receiving device according to claim 1,
The receiving device, wherein the first changeover switch selectively switches between the plurality of frequency band elimination filters and the through line based on an instruction from the outside. The receiving device according to claim 1,
Comprising switching control means for controlling switching of the second selector switch;
It said switching control means, based on the switching signal outputted from the receiver, performing the selective switching, the reception apparatus. The receiving device according to claim 3,
The receiver includes a frequency sweep means for sweeping the received frequency,
Determining means for determining whether or not the reception frequency has reached the cut-off frequency during the insertion of the reception frequency;
When the receiving frequency has reached the cut-off frequency, and a switching signal output means for outputting a switching signal for obtaining before switching the distichum frequency band elimination filter in the high-pass filter to said switching control means, the receiving device . The receiving device according to claim 1,
Comprises a frequency detection means to detect the reception frequency of the reception signal received through the different receive antenna and said receiving antenna,
The switching control means is configured to select the frequency band elimination filter corresponding to the frequency band of the detected reception frequency from the plurality of frequency band elimination filters based on the detection result of the frequency detection means. It controls the switch, the receiving apparatus. The receiving device according to claim 5,
Comprising an amplitude detection means to detect the level of the signal received via the different receiving antennas,
The switching control means based on a detection result of said amplitude detection means, for controlling said first selector to so that switching example in the through line, the receiving apparatus. The receiving device according to claim 6,
It said switching control means, the level of detection issued the received signal is lower than a predetermined value, or the detection result indicating that the level of the received signal is lower than the signal level of the other frequency bands, before Symbol amplitude detecting means or al when obtained, controlling the first selector to so that switching example in the through line, the receiving apparatus. A receiving method in a receiving device including a receiving antenna and a receiver,
By performing the frequency band-elimination filter to be attenuate the frequency band of a predetermined width centered on a predetermined frequency, a selective switching between the high-pass filter having a predetermined cutoff frequency, the predetermined frequency band A step of attenuating
Receiving a radiated wave from an object after attenuating the predetermined frequency band;
And in the step of attenuating a predetermined frequency band, performing the selective switching according to whether the reception frequency of the reception signal is less than the predetermined cutoff frequency,
The reception method , wherein the cutoff frequency is larger than a target frequency to be removed by the frequency removal filter and smaller than twice the target frequency .

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