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Digital transmission system (DTS) test guidance document

   发布人:广东中合国际检测  发布时间:2017-09-16 21:51

  FCC released the new digital transmission system (DTS) test guidance document, KDB 558074, D01 DTS Meas Guidance V04, in April 2017, replacing the old version of KDB 558074 D01 DTS Meas Guidance v03r05

  What are the differences between the old and new editions?

  1. apply the duty factor to the measurement of radiation intensity.

  The old version of KDB 558074 D01 DTS Meas Guidance v03r05, at (I) Chapter fourth, remarks: do not allow duty factor to reduce the emission intensity of the measurement. Its conformity is based on measuring the emission intensity produced during emission, rather than averaging over the turn-on and closing times of the transmitter.

  But in the new version of KDB 558074 on this point and made changes: article 15.35 (c) in said reduced duty cycle factor can be used to determine according to clause 15.247 DTS approved equipment (such as equipment such as 2483.5-2500 MHz ZigBee) in the limited frequency band useless emission (including spurious emission), if the following conditions are met:

  (I) the unwanted emission is related to the main frequency emission (e.g., the main wave edge falls into the 2483.5-2500MHz forbidden frequency band)

  II) spurious emission falls into a restricted frequency band (e.g., 2483.5-2500MHz)

  III) the maximum duty cycle used to determine the reduction factor must be "fixed" and cannot be changed or modified by the device or end user in any case

  (IV) section 15.35 (c), used to determine the worst-case duty cycle, requires proof of reason to be recorded in the test report

  2. changes in peak power measurement methods for broadband products.

  The new version of KDB 558074, described in section 9.1.2, measures the peak power of broadband products. The preferred method is to use integral power measurements based on the average detector, as described in KDB 558074, section 9.2. The integral power method of 11.9.1 based peak detector in ANSI C63.10-2013 is not applicable to this document.

  Popular science: what is KDB 558074?

  KDB 558074 is a digital transmission system defined under the FCC15.247 regulations (DTS) test method of guidance document, it is suitable for work in the 902-928 MHz digital transmission system 2400-2483.5 MHz and 5725-5850 MHz, not suitable for frequency hopping system.

  Popular science: what does KDB 558074 guide?

  KDB 558074 standardizes the test methods for the following test items:

  No.DescriptionFCC Part No.

  1Output Power15.247 (b)

  2DTS Bandwidth15.247 (a)

  3Conducted Spurious Emission15.247 (d)

  4Radiated Spurious Emission15.247 (d)

  5Band Edge15.247 (d)

  6Power spectral density (PSD) 15.247 (E)