ETSI EN 302 288-1 V1.3.1 (2008-02)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Electromagnetic compatibility and Radio spectrum Matters (ERM) - Short Range Devices - Road Transport and Traffic Telematics (RTTT) - Short range radar equipment operating in the 24 GHz range - Part 1: Technical requirements and methods of measurement35.240.60Uporabniške rešitve IT v transportu in trgoviniIT applications in transport and trade33.100.01Elektromagnetna združljivost na splošnoElectromagnetic compatibility in general33.060.99Druga oprema za radijske komunikacijeOther equipment for radiocommunicationsICS:Ta slovenski standard je istoveten z:EN 302 288-1 Version 1.3.1SIST EN 302 288-1 V1.3.1:2008en01-oktober-2008SIST EN 302 288-1 V1.3.1:2008SLOVENSKI
STANDARD
ETSI ETSI EN 302 288-1 V1.3.1 (2008-02) 2
Reference REN/ERM-TG31B-004-1 Keywords radar, radio, RTTT, SRD, testing ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE
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Important notice Individual copies of the present document can be downloaded from: http://www.etsi.org The present document may be made available in more than one electronic version or in print. In any case of existing or perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF). In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the current status of this and other ETSI documents is available at http://portal.etsi.org/tb/status/status.asp If you find errors in the present document, please send your comment to one of the following services: http://portal.etsi.org/chaircor/ETSI_support.asp Copyright Notification No part may be reproduced except as authorized by written permission. The copyright and the foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 2008. All rights reserved.
DECTTM, PLUGTESTSTM and UMTSTM are Trade Marks of ETSI registered for the benefit of its Members. TIPHONTM and the TIPHON logo are Trade Marks currently being registered by ETSI for the benefit of its Members. 3GPPTM is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. SIST EN 302 288-1 V1.3.1:2008

ETSI ETSI EN 302 288-1 V1.3.1 (2008-02) 3
Contents Intellectual Property Rights.6 Foreword.6 1 Scope.7 2 References.7 3 Definitions, symbols and abbreviations.8 3.1 Definitions.8 3.2 Symbols.10 3.3 Abbreviations.10 4 Technical requirements specifications.11 4.1 Presentation of equipment for testing purposes.11 4.1.1 Choice of model for testing.11 4.2 Mechanical and electrical design.11 4.3 Auxiliary test equipment.12 4.4 Interpretation of the measurement results.12 5 Test conditions, power sources and ambient temperatures.12 5.1 Normal and extreme test conditions.12 5.2 External test power source.12 5.3 Normal test conditions.12 5.3.1 Normal temperature and humidity.12 5.3.2 Normal test power source.13 5.3.2.1 Mains voltage.13 5.3.2.2 Other power sources.13 5.4 Extreme test conditions.13 5.4.1 Extreme temperatures.13 5.4.1.1 Procedure for tests at extreme temperatures.13 5.4.1.2 Extreme temperature ranges.13 5.4.2 Extreme test source voltages.13 5.4.2.1 Mains voltage.13 5.4.2.2 Other power sources.13 6 General conditions.14 6.1 Test fixture.14 6.1.1 Requirements.14 6.1.2 Calibration.15 6.1.3 General requirements for RF cables.16 6.1.4 Shielded anechoic chamber.17 7 Methods of measurement and limits for transmitter parameters.18 7.1 Methods of measurement and limits for transmitters in the 22,000 GHz to 26,65 GHz band.18 7.1.1 Permitted range of operating frequencies.18 7.1.1.1 Definition.18 7.1.1.2 Method of measurement.18 7.1.1.3 Limits.19 7.1.2 Maximum radiated average power density (e.i.r.p.).19 7.1.2.1 Definition.19 7.1.2.2 Method of measurement.19 7.1.2.3 Limits.21 7.1.3 Maximum radiated peak power density (e.i.r.p.).21 7.1.3.1 Definition.21 7.1.3.2 Method of measurement.21 7.1.3.3 Standard procedure and setup extensions.22 7.1.3.4 Limits.22 7.1.4 Methods of measurement and limits for emissions in the 24,05 GHz to 24,25 GHz band.23 7.1.4.1 Equivalent isotropically radiated power (e.i.r.p.).23 SIST EN 302 288-1 V1.3.1:2008

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7.1.4.1.1 Definition.23 7.1.4.1.2 Method of measurement.23 7.1.4.1.3 Limits.25 7.1.4.2 Permitted range of operating frequencies.25 7.1.4.2.1 Definition.25 7.1.4.2.2 Method of measurement for equipment not using FH modulation.25 7.1.4.2.3 Method of measurement for equipment using pulsed FH modulation.26 7.1.4.2.4 Limit.26 7.1.5 Vertical plane transmitter emissions in the 23,6 GHz to 24 GHz range.27 7.1.5.1 Definition.27 7.1.5.2 Measurement procedure.27 7.1.5.3 Vertical emission limits in the 23,6 GHz to 24,0 GHz range.27 7.2 Radiated spurious and out-of-band emissions.27 7.2.1 Definition.27 7.2.2 Measuring receiver.28 7.2.3 Method of measurement for radiated spurious or out-of-band emissions.28 7.2.4 Limits.29 8 Methods of measurement and limits for receiver parameters.29 8.1 Receiver spurious emissions.29 8.1.1 Definition.29 8.1.2 Method of measurement - radiated spurious emissions.29 8.1.3 Limit.30 9 Measurement uncertainty.30 Annex A (normative): Radiated measurements.31 A.1 Test sites and general arrangements for measurements involving the use of radiated fields.31 A.2 Guidance on the use of radiation test sites.31 A.2.1 Substitution antenna.31 A.3 Indoor test site using a fully anechoic RF chamber.31 A.3.1 Example of the construction of a shielded anechoic chamber.31 A.3.2 Influence of parasitic reflections in anechoic chambers.33 A.3.3 Calibration of the shielded RF anechoic chamber.33 Annex B (normative): General description of measurement methods.34 B.1 Radiated measurements.34 B.2 Performance requirements for preamplifier and horn antenna.35 B.3 Measurement of the residual carrier.35 Annex C (informative): Example of modulation schemes.36 C.1 Pseudo Noise Pulse Position Modulation (PN PPM).36 C.1.1 Definition.36 C.1.2 Typical operation parameters.37 C.2 Pulsed FH (Pulsed Frequency Hopping).37 C.2.1 Definition.37 C.2.2 Typical operation parameters.38 C.2.3 Additional requirements for pulsed FH equipment measurement.38 C.2.3.1 Pulsed FH modulation.38 C.2.3.2 Measurement requirements.38 C.3 PN-2-PSK (Pseudo noise binary coded phase shift keying).39 C.3.1 Definition.39 C.3.2 Typical operation parameters.40 Annex D (normative): Installation requirements of 24 GHz Short Range Radar (SRR) systems.41 SIST EN 302 288-1 V1.3.1:2008

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Annex E (informative): Conversion of power density to e.i.r.p.42 E.1 Assumptions.42 E.2 Example.42 Annex F (informative): Bibliography.43 History.44
ETSI ETSI EN 302 288-1 V1.3.1 (2008-02) 6
Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http://webapp.etsi.org/IPR/home.asp). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This European Standard (Telecommunications series) has been produced by ETSI Technical Committee Electromagnetic compatibility and Radio spectrum Matters (ERM). For non EU countries the present document may be used for regulatory (Type Approval) purposes. Equipment compliant with the present document is intended for fitment into road vehicles, therefore it is subject to automotive EMC type approval and has to comply with Directive 95/54/EC [7]. For use on vehicles outside the scope of Directive 95/54/EC [7] compliance with an EMC directive/standard appropriate for that use is required. The present document is part 1 of a multi-part deliverable covering Electromagnetic compatibility and Radio spectrum Matters (ERM); Short Range Devices, Road Transport and Traffic Telematics (RTTT); Short range radar equipment operating in the 24 GHz range, as identified below: Part 1: "Technical requirements and methods of measurement"; Part 2: "Harmonized EN covering essential requirements of article 3.2 of the R&TTE Directive".
National transposition dates Date of adoption of this EN: 10 August 2007 Date of latest announcement of this EN (doa): 30 November 2007 Date of latest publication of new National Standard or endorsement of this EN (dop/e):
31 May 2008 Date of withdrawal of any conflicting National Standard (dow): 31 May 2008
ETSI ETSI EN 302 288-1 V1.3.1 (2008-02) 7
1 Scope The present document specifies the technical requirements and methods of measurement for Short Range Devices (SRD) working as broadband devices with at least 500 MHz bandwidth in the 22,000 GHz to 26,65 GHz frequency range intended for Road Transport and Traffic Telematics (RTTT) applications, such as automotive 24 GHz Short Range Radar (SRR) for e.g. obstacle detection, stop and go, blind spot detection, parking aid, backup aid, precrash and other automotive applications. The present document covers transmitters intended to operate in a temporary frequency designation under the 24 GHz ECC decision CEPT/ECC/DEC/(04)10. The application is also subject to the EU Commission decision on 24 GHz SRR 2005/50/EC. The present document applies to: a) Transmitters in the range from 22,000 GHz to 26,65 GHz operating as broadband devices over the specific bandwidth defined for the individual devices. b) Receivers operating in the range from 22,000 GHz to 26,65 GHz. c) Integrated transceivers. The present document contains the technical characteristics and test methods for short range radar equipment fitted with integral antennas. The present document does not necessarily include all the characteristics which may be required by a user, nor does it necessarily represent the optimum performance achievable. The present document covers short range radar mobile applications. The present document covers only SRR equipment for road vehicles. The present document complies with field limits for human exposure to electromagnetic fields as provided by the EC Recommendation 1999/519/EC (see bibliography) and the methods for compliance demonstration in EN 50371 (see bibliography). 2 References The following documents contain provisions which, through reference in this text, constitute provisions of the present document. • References are either specific (identified by date of publication and/or edition number or version number) or non-specific. • For a specific reference, subsequent revisions do not apply. • For a non-specific reference, the latest version applies. Referenced documents which are not found to be publicly available in the expected location might be found at http://docbox.etsi.org/Reference. NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee their long term validity. [1] Void. [2] CISPR 16 (parts 1-1, 1-4 and 1-5): "Specification for radio disturbance and immunity measuring apparatus and methods; Part 1: Radio disturbance and immunity measuring apparatus". [3] CEPT/ERC/REC 01-06: "Procedure for mutual recognition of type testing and type approval for radio equipment". [4] Void. SIST EN 302 288-1 V1.3.1:2008

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[5] Void. [6] ETSI TR 100 028 (V1.4.1) (all parts): "Electromagnetic compatibility and Radio spectrum Matters (ERM); Uncertainties in the measurement of mobile radio equipment characteristics". [7] Commission Directive 95/54/EC of 31 October 1995 adapting to technical progress Council Directive 72/245/EEC on the approximation of the laws of the Member States relating to the suppression of radio interference produced by spark-ignition engines fitted to motor vehicles and amending Directive 70/156/EEC on the approximation of the laws of the Member States relating to the type-approval of motor vehicles and their trailers. [8] ETSI EN 302 288-2 (V1.2.2): "Electromagnetic compatibility and Radio spectrum Matters (ERM); Short Range Devices; Road Transport and Traffic Telematics (RTTT); Short range radar equipment operating in the 24 GHz range; Part 2: Harmonized EN covering the essential requirements of
article 3.2 of the R&TTE Directive". [9] Void. [10] Void. [11] Void. [12] Void. 3 Definitions, symbols and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and definitions apply: activity factor: actual on-the-air time divided by active session time or actual on-the-air emission time within a given time window antenna scan duty factor: ratio of the area of the beam (measured at its -3 dB point) to the total area scanned by the antenna (as measured at its -3 dB point) assigned frequency band: frequency band within which the device is authorized to operate associated antenna: antenna and all its associated components which are designed as an indispensable part of the equipment average time: time interval on which a mean measurement is integrated blanking period: time period where either no waveform or a constant waveform within the 24 GHz SRD band occurs boresight: axis of the main beam in a directional antenna channel dwell duty cycle: ratio of the time of uninterrupted continuous transmission within a given frequency channel to the channel repetition interval NOTE: Channel dwell time/channel repetition interval. channel dwell time: accumulated amount of transmission time of uninterrupted continuous transmission within a single given frequency channel and within one channel repetition interval duty cycle: the ratio of the total on time of the "message" to the total off-time in any one hour period NOTE: The device may be triggered either automatically or manually, whether the duty cycle is fixed or random depends on how the device is triggered. Equipment Under Test (EUT): radar sensor including the integrated antenna together with any external antenna components which affect or influence its performance SIST EN 302 288-1 V1.3.1:2008

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equivalent isotropically radiated power (e.i.r.p.): total power or power density transmitted, assuming an isotropic radiator NOTE: e.i.r.p. is conventionally the product of "power or power density into the antenna" and "antenna gain". e.i.r.p. is used for both peak or average power and peak or average power density. equivalent pulse power duration: duration of an ideal rectangular pulse which has the same content of energy compared with the pulse shape of the EUT with pulsed modulation or on-off gating far field measurements: measurement at a distance "X" of at least 2d2/λ, where d is the largest dimension of the antenna aperture of the EUT maximum safe level for radiated power density: level which can be transmitted in accordance with the current recommended safety levels in Council Recommendation 1999/519/EC
on-off gating: methods of transmission with fixed or randomly quiescent period that is much larger than the PRF operating frequency (operating centre frequency): nominal frequency at which equipment is operated NOTE: Equipment may be able to operate at more than one operating frequency. operating frequency range: range of operating frequencies over which the equipment can be adjusted through switching or reprogramming or oscillator tuning NOTE 1: For pulsed or phase shifting systems without further carrier tuning the operating frequency range is fixed on a single carrier line. NOTE 2: For analogue or discrete frequency modulated systems (FSK, FMCW) the operating frequency range covers the difference between minimum and maximum of all carrier frequencies on which the equipment can be adjusted. power envelope: power supplied to the antenna by a transmitter during one radio frequency cycle at the crest of the modulation envelope taken under normal operating conditions Power Spectral Density (PSD): ratio of the amount of power to the used radio measurement bandwidth NOTE: It is expressed in units of dBm/Hz or as a power in unit dBm with respect to the used bandwidth. In case of measurement with a spectrum analyser the measurement bandwidth is equal to the RBW. precrash: time before the crash occurs when safety mechanism are deployed Pulse Repetition Frequency (PRF): inverse of the Pulse Repetition Interval, averaged over a time sufficiently long as to cover all PRI variations Pulse Repetition Interval (PRI): time between the rising edges of the transmitted (pulsed) output power quiescent period: time instant where no intentional emission occurs radome: external protective cover which is independent of the associated antenna, and which may contribute to the overall performance of the antenna (and hence, the EUT) spatial radiated power density: power per unit area normal to the direction of the electromagnetic wave propagation NOTE: Spatial radiated power density is expressed in units of W/m2. spread spectrum: telecommunications techniques in which a signal is transmitted in a bandwidth considerably greater than the frequency content of the original information ultra wideband: classification of the spectral width of a transmission system ultra-wideband bandwidth: equipment using ultra-wideband technology means equipment incorporating, as an integral part or as an accessory, technology for short-range radiocommunication, involving the intentional generation and transmission of radio-frequency energy that spreads over a frequency range wider than 50 MHz SIST EN 302 288-1 V1.3.1:2008

ETSI ETSI EN 302 288-1 V1.3.1 (2008-02) 10 3.2 Symbols For the purposes of the present document, the following symbols apply: λ Wavelength ac alternating current B Bandwidth BFH Frequency hopping bandwidth d largest dimension of the antenna aperture Dfb distance of ferrite beads E Field strength Eo Reference field strength fc Carrier frequency fhop Hopping frequency fh highest frequency fl lowest frequency Ga Antenna gain Prad Radiated power P PK 3 MHz Radiated peak power measured in 3 MHz bandwidth Ps Signal generator power R Distance Ro Reference distance Rx Receiver τ Pulse width Tblk Blank time period Tc Chip period Tdw Dwell time Tfr Frame time Tpw Pulse power duration Tx Transmitter 3.3 Abbreviations For the purposes of the present document, the following abbreviations apply: BPSK Binary Phase Shift Keying CW Continuous Wave dB decibel dBi gain in decibels relative to an isotropic antenna DSB Dual Side Band DSS Direct Sequence Signal e.i.r.p. equivalent isotropically radiated power ECC Electronic Communications Committee EMC Electro Magnetic Compatibility ERC European Radiocommunication Committee EUT Equipment Under Test FH Frequency Hopping FHSS Frequency Hopping Spread Spectrum FMCW Frequency Modulated Continuous Wave FSK Frequency Shift Keying IF Intermediate Frequency LNA Low Noise Amplifier PDCF Pulse Desensitization Correction Factor PM Pulse Modulation PN Pseudo Noise PPM Pulse Position Modulation (staggered) PRF Pulse Repetition Frequency SIST EN 302 288-1 V1.3.1:2008

ETSI ETSI EN 302 288-1 V1.3.1 (2008-02) 11 PRI Pulse Repetition Interval PSK Phase Shift Keying R&TTE Radio and Telecommunications Terminal Equipment RAS Radio Astronomy Site RBW Resolution BandWidth RF Radio Frequency RMS Root Mean Square RTTT Road Transport and Traffic Telematics Rx Receiver (Receive) SA Spectrum Analyser SNR Signal to Noise Ratio SPM Staggered Pulse Position Modulated SRD Short Range Device SRR Short Range Radar Tx Transmitter VBW Video BandWidth VSWR Voltage Standing Wave Ratio 4 Technical requirements specifications 4.1 Presentation of equipment for testing purposes Each equipment submitted for testing, where applicable, shall fulfil the requirements of the present document on all frequencies over which it is intended to operate. EMC type approval testing to Directive 95/54/EC [7] shall be done on the vehicle. The provider shall provide one or more samples of the equipment, as appropriate for testing. Additionally, technical documentation and operating manuals, sufficient to allow testing to be performed, shall be supplied. The performance of the equipment submitted for testing shall be representative of the performance of the corresponding production model. In order to avoid any ambiguity in that assessment, the present document contains instructions for the presentation of equipment for testing purposes, conditions of testing (clause 5) and the measurement methods (clauses 7 and 8). Instructions for installation of the equipment in a road vehicle are provided in annex D. Stand alone equipment submitted for testing shall be offered by the provider complete with any ancillary equipment needed for testing. The provider shall declare the frequency range(s), the range of operation conditions and power requirements, as applicable, in order to establish the appropriate test conditions. The EUT will comprise the sensor, antenna and radome if needed and will be tested as a stand alone assembly. The EUTs test fixtures may be supplied by the provider to facilitate the tests (clause 6.1). These clauses are intended to give confidence that the requirements set out in the present document have been met without the necessity of performing measurements on all frequencies. 4.1.1 Choice of model for testing If an equipment has several optional features, considered not to affect the RF parameters then the tests need only to be performed on the equipment configured with that combination of features considered to be the most complex, as proposed by the provider and agreed by the test laboratory. 4.2 Mechanical and electrical design The equipment submitted by the provider shall be designed, constructed and manufactured in accordance with good engineering practice and with the aim of minimizing harmful interference to other equipment and services. Transmitters and receivers may be individual or combination units. SIST EN 302 288-1 V1.3.1:2008

ETSI ETSI EN 302 288-1 V1.3.1 (2008-02) 12 4.3 Auxiliary test equipment All necessary test signal sources and set-up information shall accompany the equipment when it is submitted for testing. 4.4 Interpretation of the measurement results The interpretation of the results recorded on the appropriate test report for the measurements described in the present document shall be as follows: • the measured value relating to the corresponding limit shall be used to decide whether an equipment meets the requirements of the present document; • the measurement uncertainty value for the measurement of each parameter shall be included in the test report; • the recorded value of the measurement uncertainty shall, for each measurement, be equal to, or lower than, the figures in the table of measurement uncertainty (table 7). 5 Test conditions, power sources and ambient temperatures 5.1 Normal and extreme test conditions Testing shall be carried out under normal test conditions, and also, where stated, under extreme test conditions. The test conditions and procedures shall be as specified in clauses 5.2 to 5.4. 5.2 External test power source During tests the power source of the equipment shall be an external test power source, capable of producing normal and extreme test voltages as specified in clauses 5.3.2 and 5.4.2. The internal impedance of the external test power source shall be low enough for its effect on the test results to be negligible. The test voltage shall be measured at the point of connection of the power cable to the equipment. During tests the external test power source voltages shall be within a tolerance of ±1 % relative to the voltage at the beginning of each test. The level of this tolerance can be critical for certain measurements. Using a smaller tolerance provides a reduced uncertainty level for these measurements. 5.3 Normal test conditions 5.3.1 Normal temperature and humidity The normal temperature and humidity conditions for tests shall be any convenient combination of temperature and humidity within the following ranges: • temperature: +15 °C to +35 °C; • relative humidity: 20 % to 75 %. When it is impracticable to carry out tests under these conditions, a note to this effect, stating the ambient temperature and relative humidity during the tests, shall be added to the test report. SIST EN 302 288-1 V1.3.1:2008

ETSI ETSI EN 302 288-1 V1.3.1 (2008-02) 13 5.3.2 Normal test power source The internal impedance of the test power source shall be low enough for its effect on the test results to be negligible. For the purpose of the tests, the voltage of the external test power source shall be measured at the input terminals of the equipment. 5.3.2.1 Mains voltage The normal test voltage for equipment shall be the nominal mains voltage. For the purpose of the present document, the nominal voltage shall be the declared voltage, or any of the declared voltages, for which the equipment was designed. The frequency of the test power source corresponding to the ac mains shall be between 49 Hz and 51 Hz. 5.3.2.2 Other power sources For operation from other power sources the normal test voltage shall be that declared by the provider. Such values shall be stated in the test report. 5.4 Extreme test conditions 5.4.1 Extreme temperatures 5.4.1.1 Procedure for tests at extreme temperatures Before measurements are made, the equipment shall have reached thermal balance in the test chamber. The equipment shall not be switched off during the temperature stabilizing period. If the thermal balance is not checked by measurements, a temperature stabilizing period of at least one hour, or such period as may be decided by the accredited test laboratory, shall be allowed. The sequence of measurements shall be chosen, and the humidity content in the test chamber shall be controlled so that excessive condensation does not occur. 5.4.1.2 Extreme temperature ranges For tests at extreme temperatures, measurements shall be made in accordance with the procedures specified in clause 5.4.1.1, at the upper and lower temperatures of one of the following limits: • Temperature: -20 °C to +55 °C. 5.4.2 Extreme test source voltages 5.4.2.1 Mains voltage The extreme test voltages for equipment to be connected to an ac mains source shall be the nominal mains voltage ±10 %. 5.4.2.2 Other power sources For equipment using other power sources, or capable of being operated from a variety of power sources, the extreme test voltages shall be that declared by the provider. These shall be recorded in the test report. SIST EN 302 288-1 V1.3.1:2008

ETSI ETSI EN 302 288-1 V1.3.1 (2008-02) 14 6 General conditions Detailed descriptions of the radiated measurement arrangements are included in annexes A and B. In general, measurements shall be carried out under far field conditions. The far field condition for the EUTs is considered to be fulfilled in a minimum radial distance "X" that shall be a minimum of 2d2/λ, where d is the largest dimension of the antenna aperture of the EUT, for a single device measurement. Absolute power measurements shall be made using an appropriate method to ensure that the wave front is properly formed (i.e. operating in far field conditions). The test site shall meet the appropriate requirements as defined in published guidelines/standards. 6.1 Test fixture 6.1.1 Requirements The test fixture for radio equipment operating in the 24 GHz range shall enable the EUT to be physically supported, together with a wave guide horn antenna RX which is used to measure the transmitted energy, in a fixed physical relationship to the EUT or calibration antenna TX (see figure 1). The test fixture shall be designed for use in an anechoic environment and allow certain measurements to be performed in the far field, i.e. at a distance greater than 2d2/λ, where d is the largest dimension of the antenna aperture of the EUT. The test fixture shall incorporate at least one 50 Ω RF connector, a device for electromagnetic coupling to the EUT and a means for repeatable positioning of the EUT. Its compactness shall enable the whole assembly to be accommodated within a test chamber, usually a climatic facility. The circuitry associated with the RF coupling device shall not contain active or non-linear components. Only after it has been verified that the test fixture does not affect performance of the EUT, the EUT can be confidently tested. At set-up, the EUT shall be aligned in the test fixture so that the maximum power is detected at the coupled output (see also clause 7.1.2.2) Orientation of the horn antenna will take into account the polarization of the EUT. In addition, the test fixture shall provide a connection to an external power supply. The test fixture shall be provided by the provider together with a full description, which shall meet the approval of the selected accredited test laboratory. The performance characteristics of the test fixture shall be measured and shall be approved by the accredited test laboratory. It shall conform to the following basic parameters: • the gain of the waveguide horn shall not exceed 20 dB; • the physical distance between the front face of the EUT and the waveguide horn shall be between 50 cm and 1 m; • the minimum distance between the transmitting and receiving antenna shall guarantee mutual far field conditions (distance greater than 2d2/λ, where d is the largest dimension of the antenna aperture of the EUT); • the physical height between the centre of the EUT and the supporting structure of the test fixture shall be between 50 cm and 60 cm; NOTE: Information on uncertainty contributions, and verification procedures are detailed in clauses 5 and 6, respectively, of TR 102 273-2 (see bibliography). • the Voltage Standing Wave Ratio (VSWR) at the waveguide flange at which measurements are made shall not be greater than 1,5; • the performance of the test fixture when mounted in the anechoic chamber or in a temperature chamber, shall be unaffected by the proximity of surrounding objects or people inside the chamber. The performance shall be reproducible if the EUT is removed and then replaced; SIST EN 302 288-1 V1.3.1:2008

ETSI ETSI EN 302 288-1 V1.3.1 (2008-02) 15 • the performance of the test fixture shall remain within the defined limits of the calibration report, when the test conditions are varied over the limits described in clauses 5.3 and 5.4. The characteristics and calibration of the test fixture shall be included in a calibration report. 6.1.2 Calibration The calibration of the test fixture establishes the relationship between the detected output from the test fixture, and the transmitted power (as sampled at the position of the antenna) from the EUT in the test fixture. This can be achieved by using a calibrated horn with a gain of equal to or less than 20 dB, fed from an external signal source, in place of the EUT to determine the variations in detected power with temperature and over frequency. The calibration setup is shown in figure 1. Test arrangement antenna max. 20 dBi@ 24 GHzFree space loss60.05 dB @ 24 GHz and 1 m distanceLNA Cable 2 Cable 1 SIGNAL GENERATOR min. 26 GHz Cable 3 Calibrated antenna max. 20 dBi@ 24 GHzRx TxP_reading G_cable1 G_LNA G_Rx G_cable2 G_fs_loss G_TxG_ATTG_cable3 P_SG Test arrangement antenna max. 20 dBi@ 24 GHzFree space loss60,05 dB @ 24 GHz and 1 m distanceLNA Cable 2 Cable 1 SIGNAL GENERATOR min. 26 GHz Cable 3 Calibrated antenna max. 20 dBi@ 24 GHzRx TxP_reading G_cable1 G_LNA G_Rx G_cable2 G_fs_loss G_TxG_ATT G_cable3 P_SG SPECTRUM ANALYZER min. 26 GHz ATT Figure 1: Calibration set-up configuration (example for 1m Rx to Tx free space distance) The calibration of the test fixture shall be carried out by either the provider or the accredited test laboratory. The results shall be approved by the accredited test laboratory. It is the responsibility of the tester to obtain enough measurement accuracy. The following description is an example of a proven and accurate calibration method: a) Calibrate all instruments usi
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