1、STD.CEPT CEPT/ERC/REC 74-01 E-ENGL 1998 2326414 0014779 549 b CEPTIERUREC 74-01 E Page 1 Distribution: 6 CEFT/ERC/RECOMMENDATION 74-01E (Sifok 1998) SPURIOUS EMISSIONS Recommendation proposed by the Working Group “Spectrum Engineering“ (WGSE) Tent of the Recommendation adopted by the “European Radio
2、communications Committee“ (ERC): Foreword This Recommendation specifies spurious emission limits for different services and types of equipment. It should be used as a gene.ric guide when drafting new, and revising ETSI standards, and also for guidance to administrations in the absence of relevant st
3、andards. It should not be used as a stand-aione document for the purpose of type approval. It is recognised that ceriain existing ETSI standards and a limited number of those in an advanced stage of preparation do not fully align with this Recommendation. Where, for historical reasons, such existing
4、 standards do not align with this Recommendation, the spurious emission limits should be reviewed if revisions are considered. It is also recognised that, largely as a consequence of new technologies emerging, it may be acceptable that specific standards adopt limits which differ from this Recommend
5、ation; these are listed in Annex 8. Where a difference between the limits for a particular standard and this Recommendation might exist, the limits should be agreed following the iterative, consultative procedure given in the ETSI/ERC Memorandum of Understanding (ref. ETSI Collective Letter no. 866
6、of 26 Jan. 941). This procedure should consider the interaction between technical parameters, specirurn efficiency, regulatory and economic aspects. Where there is a difference between the limits for a particular standard and this recommendation CEPT assumes ihe following procedure would be useful:
7、The relevant technical bodies in ETSI and CEFT3 will agree to exchange liaison statements to each other whenever they believe changes to this recommendation, an ETSI standard, or the inclusion of a standard into Annex 8 is required; The ETSI liaison statement should be supported by appropriate techn
8、ical justification and other relevant information. This should include information on economic and market related issues concerning the proposal. In addition ETSI should also provide any information on system spectrum efficiency that they may have available to support their case; The CEPT liaison st
9、atement should include the implications of the proposal on spectrum engineering parameters such as: effective use of the spectmm, requirements of existing services, sharindadjacent band and other regulatory issues; The proposal should be considered in the spirit of the CEPTBTSI MOU with dialogue, fu
10、ll consultation and an iterative process if necessary. Ideally this process should be completed within 6 months; The conclusions should be mutually acceptable and neither party should feel that its views have been disregarded; 1 This is available from the ER0 (many ER0 documents are available on the
11、 ER0 web site htp: www.ero. b) may be placed in operation ; c) that detailed and specific sharing or compatibility studies may lead to different limits and definitions for the spurious emissions from the systems concerned however these are not in the scope of this recommendation which aims to provid
12、e a specific minimum requirement; that the Radio Frequency spectrum is a common resource and it is necessary to keep it as un-polluted as that it is important for CEFT countries to dehe common limits of spurious emissions for all services that d) that ITU-R Recommendation SM.329 provides options for
13、 diferent categories of limits for spurious emissions; moreover it provides some degree of freedom to Administrations, for the defined frequency boundaries for the definition of spurious emissions and the detailed transition of the limits nearby the fundamental emission; in particular it allows, for
14、 digital modulations, definitions, for spurious emissions frequency boundaries, other than the specific f 250% of the Necessary Bandwidth fiom the centre frequency of the emission; however it gives allowance for different definitions when practicak e) that a revised appendix S3 has been approved at
15、WRC97, containing new hits mandatory from 2003; f) that the Radioastronomy Service, the Earth Exploration Satellite Service and the Meteorological Satellite Service using passive sensors are particularly sensitive to interference due to their wide frequency coverage and the weakness of the signals t
16、hey detect. These limits are far lower than the spurious emission limits considered practicable at the antenna port of most transmitters, therefore the protection of these services depends on additional mitigating factors such as antenna decoupling and spatial separation; g) that there may be cases
17、where a permanent source of interference, for example a radar or broadcast transmitter in the near vicinity, or spurious emissions generated at the radio transmitter site due to the interaction amongst various transmitters operating at the same time, cause unacceptable performance degradation to a v
18、ictim receiver. These cases are considered site engineering problems and are not in the scope of this Recommendation provided that it is possible to use special protection applied to either the source of interference, or the victim, or both, h) responsibilities of the two bodies. The MOU text is ava
19、ilable from the ERO; that CEPT and ETSI have developed a Memorandum of Understanding describing the relative i) that within CEPTERC, a statistical simulation methodology based on the Monte Carlo method has been developed and accepted as the basis for the future development of a software tool to enab
20、le the assessment of the effect of spurious limits in terms of probability of interference. The tool developed for ERC will be made available under the conditions of the MOU on development of the Monte Carlo simulation tool. The text of this MOU is available from the ERO: j) that Spurious Emissions
21、may be delivered to the antenna port with consequent radiation fiom the antenna or produced by direct unwanted radiation from the system enclosure, due to insufficient shielding; however the latter effect is outside the scope of this Recommendation; STD*CEPT CEPT/ERC/REC 74-01 E-ENGL 1998 I 2326414
22、DD1478L IT7 CEPTIERUREC 74-01 E Page 3 k) that fast switching transients of burst transmission systems may produce specific spurious emission patterns with high peak factor, which may affect victim receivers more severely than that due only to the spurious emissions associated with the average power
23、 during the burst duration; 1) contribute to generate spurious emissions; Note: that transmission systems may be coupled to an “Active Antenna System” which may further an “Active Antenna System” (AAS) is an antenna with embedded capability for electronic amplification andor other RF processing. The
24、 total gain of an AAS may be functionally split into an “active” gain of the electronic functions (AG) and a conventional “passive” gadloss (directivity) due to the geometrical design performance of the antenna (PG). that receivers may also radiate spurious components from the antenna, which are pre
25、sently not covered m) by ITU-R Recommendation SM.329; recommends 1. that spurious emission limits apply at frequencies above and below the fundamental transmitting frequency but separated from the centre fiequency of the emission by 250% of the necessary bandwidth. However, this frequency separation
26、 may be dependent on the type of modulation used, the maximum bit rate in the case of digital modulation, the type of transmitter, and frequency coordination factors. Por example, where practical the k 250% of the relevant chanriel Separation (CS) may be used. Note 1: According to the Radio Regulati
27、ons, the Necessary Bandwidth is, for a given class of emission, the width of the frequency band which is just sufficient to ensure the ansmission of infomtion at the rate and with the quality required under specified conditions. However, the necessary bandwidths of most digital modulation formats ar
28、e presently not referred to ITU-R Recommendations of SM series. Note2: Considering the flexibility allowed by ITU-R Recommendation SM.329 on the 250% boundary definition, it is recognised that this figure may be appropriate for medium-band systems, while the physical constraint of filtering in narro
29、w-band systems and the resultkg amount of spectrum polluted by wide-band systems may require further adaptation (e.g. by a wider or a reduced percentage, respectively), however this will require further study; therefore the 250% figure for narrow-band and wide-band systems is considered provisional.
30、 2. that for the purpose of this Recommendation, only Spurious Emissions conducted to the antenna port or subsequently radiated by any integai antenna, are subject to the required limits; STDmCEPT CEPT/ERC/REC 74-01 E-ENGL 1778 W 232b4L4 0014782 033 Fundamental frequency range CEF“T/ERCYREC 74.01 E
31、Page 4 Spurious frequency measurement range lower frequency upper frequency (The test should include the entire harmonic band and not be truncated at the precise upper frequency limit 9kHz 4. 9kHz 30 MHz 30 MHz 30 MHz 30 MHz 30 MHz 9kHz - looMHz looMHz -300MHz 300MHz - 600MHz 600MHz - 5.2GHz 5.2GHz
32、- 13GHz 13GHz - 150GHz 150GHz - 300GHz 1 GHz 10* harmonic 3 GHz 5a harmonic 26 GHz 2nd harmonic 300 GHz These parameters reflect the increasing difficulty in undertaking practicable tests, especially at frequencies approaching or beyond 110 GHz, takirig into account such factors as availability and
33、usability of suitable measurement equipment. In some circumstances, it may be necessary to extend the range of test frequencies in order to facilitate better protection of other services such as Radioastronomy. In any case, systems having an integral antenna incorporating a waveguide section, or wit
34、h an antenna connection in such form, and of length equal to at least twice the cut-off wavelength, should not require spurious emissions measurement below 0.7 times the waveguide cut-off frequency; Note: Mer simplifications of measuring techniques to achieve timekost savings, while still guaranteei
35、ng the fulfilment of the requirement, are outside the scope of this Recommendation, but may be taken from the relevant system ETS or Conformance Test Standards when available. lo* 4. that the following reference bandwidths are to be used: 1kHZ between 9 and 150 kHz 10 kHz between 150 kHz and 30 MHz
36、100 kHz between 30 MHZ and 1 GHz 1 MKz above 1 GHz Note 1: A reference bandwidth is a bandwidth in which the spurious emission level is specified. Note 2: Some services may use, close to the carrier, reference bandwidth values different from the above; these differences are quoted in the relevant se
37、rvice Annex. As a special case, the reference bandwidth of all space stations spurious emissions should be 4 kHz. CEPTIERCIREC 74-01 E Page 5 The reference bandwidths required for proper measurement of radar spurious emissions must be calculated for each paaicular radar system, and the measurement m
38、ethods should be guided by Recommendation ITU-R M.1177. Thus, for the three general types of radar pulse modulation utilised for radionavigation, radiolocation, acquisition, tracking and other radiodetermination functions, the reference bandwidth values in MHz should be: A) (e.g. if the radar pulse
39、length is 1 microsecond, then the reference bandwidth is 1/1ps = 1 MHz); for fixed frequency or non-pulse-coded radar, the reciprocal of the radar pulse length in microseconds B) (e.g. if the phase coded chip is 2 microseconds long, then the reference bandwidth is 112p = 0.5 MHz); for fured frequenc
40、y, phase coded pulsed radar, the reciprocal of the phase chip length in microseconds C) for Frequency Modulated (FM) or chirped radar, the square root of the quantity obtained by dividing the swept frequency range in MHz by the pulse length, in microseconds (e.g. if the swept frequency range is fiom
41、 1250 to 1280 MHz or 30 MHz during the pulse of 10 microseconds, then the reference bandwidth is (30 MHz / 10ps)s = 1.73 MHz.) As a general de, the resolution bandwidth of the measuring receiver should be equal to the reference bandwidth as given in this recommend. To improve measurement accuracy, s
42、ensitivity and efficiency, the resolution bandwidth can be different from the reference bandwidth. When the resolution bandwidth is smaller than the reference bandwidth, the result should be integrated over the reference bandwidth. When the resolution bandwidth is greater than the reference bandwidt
43、h, the result for broadband spurious emissions should be normalised to the bandwidth ratio. For discrete spurii, normalisation is not applicable, while integration over the reference bandwidth is stiii applicable; 5. that the levels of spurious emissions should be defined within a reference bandwidt
44、h, 6. that the appropriate spurious emissions limit is to be applicable to all services as detailed by Table 1. Unless PEP is explicitly quoted the spurious emission limits, quoted in Table 1, from the transmitter into the antenna port are in terms of mean power. The mean power (P) of any spurious t
45、ransmission from a burst transmitter is the mean power averaged over the burst duration. Note 1: in special cases such as those referred by considering g), tighter limits may be required. Note 2: It is recognised that, in principle, in some cases of narrowband and/or high power transmitters for all
46、categones of services, there may be objective difficulties in meeting limits close to +I- 250% of the necessary bandwidth, these cases are reported in the specific annexes summarised in Table 1. Note 3: when a system is coupled to an Active Antenna System, the limits of Table 1 should be met by the
47、combined system: therefore compliance should be verined through an e.i.r.p. measurement (either near- field or far-field) and subsequent conversion to absolute power/attenuation values delivered to the transmission line, taking into account only the conventional “passive“ gain (directivity) of the a
48、ntenna. 7. that for fast switching induced spurious emissions, an additional limit for their peak power will be necessary, however further study should be carried on to investigate the nature of the phenomenon prior to fixing specific limits; 8. that, the limits specified within this Recommendation
49、should be considered for new ETSI standards developed after the date at which the Recommendation is adopted. in the case where the limits referred to in this Recommendation are found to be more stringent than existing ETSI Standards (TBR/ETS/EN/ES) a revision process may need to be considered. If revised, the standard should, whenever technically and economically feasible, meet the limits in this Recommendation. Where either CEPT or ETSI consider the limits defined in this Recommendation are inappropriate for a particular standard an agreement on alternative limits should be reache
