{"id":1870,"date":"2009-02-11T10:17:41","date_gmt":"2009-02-11T01:17:41","guid":{"rendered":"https:\/\/micronix-jp.com\/?p=1870"},"modified":"2023-03-20T17:08:41","modified_gmt":"2023-03-20T08:08:41","slug":"mr2300-vs-site-eng","status":"publish","type":"post","link":"https:\/\/micronix-jp.com\/english\/tech\/technology\/mr2300-vs-site-eng.html","title":{"rendered":"Date comparison between MR2300\/MY5410 system and a formal EMI site"},"content":{"rendered":"
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Summary<\/h2>\n

MR2300\/MY5410 system was developed for a precompliance EMI test. This system enables the harmonics measurement, which is difficult before, of the switching regulator in 40 to 100MHz band. <\/p>\n

The data by this system is compared with the data of 3m method by the formal 10m chamber. <\/p>\n

The differnce of site attenation should be originally less than 2dB. But there is actually possibility of 6dB attenation difference between sites becase the measurement data changes by some conditions such as temperature. And even if there are a lot of NGpoints of PK values, the test passes if QP values are less than the limit line. <\/p>\n

When a chamber manufacturer and a measurement system manufacturer construct a chamber, they do the matching with compensation data based on a formal site to be compatible. However, it is also reported that the difference of the measurement value of maximum 20dB is caused by the difference of the wiring of the power cable. Actually, the 10dB difference might be caused by the difference of wiring on or under the table. <\/p>\n

The radio wave absorbers put on the five faces excepting the floor in the usual 3m chamber. Therefore, the radio wave is reflected on the floor. As a result, it is necessary to put the DUT 80cm apart from the floor. There is a formal site putting the radio wave absorbers on six faces. <\/p>\n

Fig1. Spectrum compa rison between 10m chamber and MR2300\/MY5410 with electric turntable<\/p>\n\"Fig1. <\/section>\n\n

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Measurement<\/h2>\n

A note PC is used as a DUT(Device under Test) in this paper. Fig 1 shows the spectrum date in which each rotation angle of the electric turntable of 10m chamber and MR2300\/MY5410.<\/p>\n

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  1. Measurement in 10m chamber<\/li>\n

    This chamber is equipped with the ferrite of 3m in length and 2m in width between the antenna and the turntable. The EMI receiver with -155dBm average noise floor is used to measure and made by Rohde & Schwarz. <\/p>\n

    The DUT is put on the turntable, and the antenna is rotated within 360 degrees and moved from 1m to 4m upward and downward. The maximum peak power is detected spending about 20 minutes. The measurement data is calculated in consideration of factors such as a preamplifier fain and a cable attenuation. <\/p>\n

    Fig2 shows inside in chamber. <\/p>\n

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    • \"Photo:Electric\n

      Electric turntable<\/p>\n<\/li>\n

    • \"Photo:EMI\n

      EMI receiver <\/p>\n<\/li>\n

    • \"Photo:Antenna\"\n

      Antenna<\/p>\n<\/li>\n<\/ul>\n

    • Measurement by MR2300 and MY5410 <\/li>\n

      The inside dimensions of MY5410 is 2140(W)\u00d71450(H)\u00d71390(D). The antenna is moved from 20 to 80 cm upward and downward, and the polarization is only vertical one. The DUT is put on the electric turntable in MY5410 and measured by rotation angle of 0,145 and 180 degrees, The electric turntable allows the rotation of 360 degrees.<\/p>\n

      Max HOLD is executed 32 times at each angle in the condition of 30 seconds sweep time and the total measurement time is 5 minutes. The spectrum analyzer used MSA338E with a preamplifier and \u2010115dBm noise floor. <\/p>\n<\/ol>\n<\/section>\n\n

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      Consideration of measurement result<\/h2>\n

      Table1. Date comparison between 10m chamber and MR2300\/MY5410 with electric turntable<\/p>\n\n\n\n