Detail of GB/T 12572-2008

Introduction of GB/T 12572-2008

1 Scope This standard specifies the frequency tolerance, spurious domain emission power limit and universal measurement methods of radio transmitting equipment within 9 kHz~300 GHz frequency band as well as the calculation formula for necessary bandwidth of different types of radio emissions. This standard is applicable to radio transmitting equipment of different power grade and type within 9 kHz~300 GHz frequency band. However, it is not applicable to detection on spurious domain emission index of safety service and special service for survival craft station and overwater transmitter. 2 Normative References The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding amending errors in the text) to, or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest editions of these documents are applicable. For undated references, the latest edition of the normative documents referred to applies. GB 9254-1998 Information Technology Equipment - Radio Disturbance Characteristics - Limits and Methods of Measurement GB/T 6113.1-1995 Specifications for Radio Disturbance and Immunity Measuring Apparatus 3 Terms, Definitions and Abbreviations For the purpose of this standard, the following terms, definitions and abbreviations apply. 3.1 Terms and definitions 3.1.1 Frequency tolerance The maximum permissible deviation where the center frequency of emission frequency band deviates from the assigned frequency, or the characteristic frequency deviates from the reference frequency. The frequency tolerance is expressed by ppm (x×10-6) or several hzs. 3.1.2 Assigned frequency The center frequency assigned to the frequency band of a radio station. 3.1.3 Characteristic frequency In given emission, the frequency easy for identification and measurement. 3.1.4 Reference frequency The frequency which has a specific fixed position relative to the assigned frequency; The displacement of such frequency from assigned frequency and the displacement of characteristic frequency from mid-band frequency have the same absolute value and sign (plus and minus). 3.1.5 Necessary bandwidth In given emission type, the bandwidth which can just meet the requirements of rate and mass for information transmission under specified conditions. 3.1.6 Occupied bandwidth A bandwidth where the mean power emitted between the lower frequency limit and the upper frequency limit of such frequency band is equal to the specified percentage β/2 of the total mean power in certain given emission. Unless otherwise specified, the value β/2 is equal to 0.5%. 3.1.7 Spurious emission Emission of one or more frequency other than necessary bandwidth, where the emission level may be reduced but has no effect on corresponding information transmission. The spurious emission component includes harmonic emission, parasitic emission, intermodulation product and frequency conversion product, but excludes out-of-band emission. 3.1.8 Out-of-band emission Emission, produced during modulation, of one or more frequency which just exceeds the necessary bandwidth, excluding spurious emission. 3.1.9 Unwanted emission Including spurious emission and out-of-band emission. 3.1.10 Out-of-band domain The frequency range just exceeds the necessary bandwidth, but excluding spurious domain; within such frequency range, mainly out-of-band emission. 3.1.11 Spurious domain The frequency range falls beyond out-of-band domain; within such frequency range, mainly spurious emission. 3.1.12 Peak envelope power The arithmetic average of power supplied by a transmitter, under normal operating conditions, to antenna feeder within a RF(radio frequency) period of envelope modulation peak. 3.1.13 Mean power The arithmetic average of power supplied by a transmitter, under normal operating conditions, to antenna feeder within a sufficient interval compared with the lowest frequency period encountered during modulation. 3.1.14 Carrier power The arithmetic average of power supplied by a transmitter, under no modulation condition, to antenna feeder within a RF period. 3.1.15 Equivalent isotropic radiated power (e.i.r.p) The product of the power supplied to antenna and the gain relative to omni antenna on the assigned direction. 3.1.16 Effective radiated power (e.r.p) The product of the power supplied to antenna and the gain relative to half-wave vibrator on the assigned direction.

Contents of GB/T 12572-2008

Forward I 1 Scope 2 Normative References 3 Terms, Definitions and Abbreviations 4 Frequency Tolerance for Transmitting Equipment 4.1 Basic Requirements and Ultimate Design Objectives 4.2 Measurement Methods 5 Determination of Necessary Bandwidth for Transmitting Equipment 5.1 AM Emission Signal 5.2 FM Emission Signal 5.3 PM Emission Signal 6 Spurious Domain Emission Power Limits of Transmitting Equipment 6.1 Limit Application Scope 6.2 Spurious Domain Emission Power Limit 7 Methods for Measuring the Spurious Domain Emission Power 7.1 Measuring Receiver 7.2 Measurement Requirements 7.3 Measurement Methods 8 Methods for Measuring the Spurious Emission Power of Radar System 8.1 Overview 8.2 Setting of the Resolution Bandwidth and Detection Parameters of Measurement System 8.3 Direct Method 8.4 Indirect Method Appendix A (Informative) Units and Conversion Relation of Spurious Domain Emission Appendix B (Normative) Additional Regulations for Determining the Spurious Domain Emission and Out-of-band Domain Emission Limits Appendix C (Normative) Specified Values for Reference Measurement Bandwidth of the Fixed Services Appendix D (Normative) Specified Values for Reference Measurement Bandwidth of the Land Mobile Service Appendix E (Normative) Requirements for Test Site Bibliography