Test Report

FCC ID: GQ4-26T

Test Report

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FCCID_456546

The University of Michigan Radiation Laboratory 3228 EECS Building Ann Arbor, MI 48109—2122 Tel: (734) 647—0500 Measured Radio Frequency Emissions From TRW Honda 05 Remote Tire Pressure Monitoring Transmitter Models: 42753—SDAY—A710—M1 & 52933—1F000 Report No. 415031—200 June 14, 2004 Copyright © 2004 For: TRW Automotive Electronics 24175 Research Drive Farmington Hills, MI 48335—2642 Contact: Yini Chen Yini.Chen@trw.com Tel: 248—478—7210 ext. 4702 Fax: 248—478—7241 PO:; A4351034805 Tests supervised by: /CZ/ éé fl%&%@ Measurements made by: Report approved by: Valdis V. Liepa Valdis V. Liepa Research Scientist Summary Tests for compliance with FCC Regulations, subject to Part 15, Subpart C, and with RSS—210 of Industry Canada were performed on the TRW Remote Tire Pressure Monitoring Transmitter. This device is subject to Rules and Regulations as a low power (data) transmitter. As a Digital Device it is exempt, but such measurements we routinely perform to assess the transmitter‘s overall emissions. The Sensor was tested "in free space", i.e., without a tire and off the rim. In testing completed March 10, 2004, the device tested in the worst case met the limits for radiated emissions at fundamental by 2.9 dB and at harmonics by 10.0 dB (see p. 6). Besides harmonics there were no other significant spurious emissions found. Conductive emission tests are not applicable, since the transmitter is powered by a 3—volt internal battery.

1. Introduction TRW Remote Tire Pressure Monitoring Transmitter was tested for compliance with FCC Regulations, Part 15, adopted under Docket 87—389, April 18, 1989, and with Industry Canada RSS—210, Issue 5, dated November 1, 2001. The tests were performed at the University of Michigan Radiation Laboratory Willow Run Test Range following the procedures described in ANSI C€63.4—1992 "Methods of Measurement of Radio—Noise Emissions from Low—Voltage Electrical and Electronic Equipment in the Range of 9 kHz to 40 GHz". The Site description and attenuation characteristics of the Open Site facility are on file with FCC Laboratory, Columbia, Maryland (FCC Reg. No: 91050) and with Industry Canada, Ottawa, ON (File Ref. No: IC 2057). 2. Test Procedure and Equipment Used The pertinent test equipment commonly used in our facility for measurements is listed in Table 2.1 below. The middle column identifies the specific equipment used in these tests. Table 2.1. Test equipment. Test Instrument Eqpt Used Manufacturer/Model Spectrum Analyzer (0.1—1500 MHz) Hewlett—Packard, 1821/8558B Spectrum Analyzer (OkHz—22GHz) X Hewlett—Packard 8593A SN: 3107A01358 Spectrum Analyzer (OkHz—26GHz) X Hewlett—Packard 8593E, SN: 3412A01131 Spectrum Analyzer (9kHz—26GHz) Hewlett—Packard 8563E, SN: 3310A01174 Spectrum Analyzer (OkHz—40GHz) Hewlett—Packard $564E, SN: 3745¥01031 Power Meter Hewlett—Packard, 432A Power Meter Anritsu, ML4803A/MP Harmonic Mixer (26—40 GHz) Hewlett—Packard 11970A, SN: 3003A08327 Harmonic Mixer (40—60 GHz) Hewlett—Packard 11970U, SN: 2332A00500 Harmonic Mixer (75—110 GHz) Hewlett—Packard 11970W, SN: 2521A00179 Harmonic Mixer (140—220 GHz) Pacific Millimiter Prod., GMA, SN: 26 S—Band Std. Gain Hormn S/A, Model SGH—2.6 C—Band Std. Gain Horn University of Michigan, NRL design XN—Band Std. Gain Horn University of Michigan, NRL design X—Band Std. Gain Horn S/A, Model 12—8.2 X—band horn (8.2— 12.4 GHz) Narda 640 X—band horn (8.2— 12.4 GHz) Scientific Atlanta , 12—8.2, SN: 730 K—band horn (18—26.5 GHz) FXR, Inc., K638KF Ka—band horn (26.5—40 GHz) FXR, Inc., U638A U—band horn (40—60 GHz) Custom Microwave, HO19 W—band horn(75—110 GHz) Custom Microwave, HO10 G—band horn (140—220 GHz) Custom Microwave, HOSR Bicone Antenna (30—250 MHz) X University of Michigan, RLBC—1 Bicone Antenna (200—1000 MHz) X University of Michigan, RLBC—2 Dipole Antenna Set (30—1000 MHz) X University of Michigan, RLDP—1,—2,—3 Dipole Antenna Set (30—1000 MHz) EMCO 2131C, SN: 992 Active Rod Antenna (30 Hz—50 MHz) EMCO 3301B, SN: 3223 Active Loop Antenna (30 Hz—50 MHz) EMCO 6502, SN:2855 Ridge—horn Antenna (300—5000 MHz) University of Michigan D4 1¥ 4 Amplifier (5—1000 MHz) Avantak, Al11l—1, A25—18 Amplifier (5—4500 MHz) Avantak Amplifier (4.5—13 GHz) Avantek, AFT—12665 Amplifier (6—16 GHz) Trek Amplifier (16—26 GHz) Avantek LISN (50 uH) University of Michigan Signal Generator (0.1—2060 MHz) Hewlett—Packard, 8657B Signal Generator (0.01—20 GHz ) Hewlett—Packard

3. Configuration and Identification of Device Under Test The DUT is a 7.0 x 6.00 x 1.5 cm in size (including valve stem) potted tire pressure sensor/transmitter that mounts on a rim inside the tire. When the vehicle is in motion, it transmits the tire pressure information to the receiver in the vehicle. It can also be activated by exposing a 125 kHz signal; this procedure is used in factory/set—up operations. When the vehicle is in motion, the transmission consists of four quasi—Manchester encoded words repeated typically every 60 seconds. Transmitter 315 MHz carrier is generated by a SAW stabilized oscillator. The coding is generated by a micro and is ASK encoded on the carrier. The DUT was designed and manufactured by TRW Automotive Electronics, 24175 Research Drive, Farmington Hills, MI 48335—2642. It is identified as: TRW Remote Tire Pressure Monitoring Transmitter Models: 42753—SDAY—A710—M1 and 52933—1FO00 SN: A000O8DE FCC ID: GQ4—26T IC: 1470A—77T One device (production) was provided. The two models are identical, except for the model number. For testing, the DUT was activated by LF in alert (set—up) mode. Under such, the transmission consisted of 8 word packets and lasted for 4 seconds.. 3.1 EMI Relevant Modifications There were no modifications made to the DUT by this laboratory. 4. Emission Limits 4.1 Radiated Emission Limits The DUT tested falls under the category of an Intentional Radiators and the Digital Devices. For FCC it is subject to Subpart C, Section 15.231; Subpart B, Section 15.109; and Subpart A, Section 15.33. For Industry Canada it is subject to RSS—210, Sections 6.1 and 6.3. The applicable testing frequencies with corresponding emission limits are given in Tables 4.1 and 4.2 below. As a digital device, the DUT is considered a Class B device. Table 4.1 Radiated Emission Limits (FCC: 15.231(e); IC: RSS—210; 6.1, 6.3, Table 4). Data transmission. Fundamental Spurious** Frequency Ave. Eim (3m) Ave. Ejim (3m) (MHz) (uV/m) dB (uV/m) (uV/m) dB (uV/m) 260—470 1500—5000* 150—500 315 2418 67.7 241 .8 47.7 * Linear interpolation, formula: E = —2833.2 + 16.67*f (MHz) sck Measure up to tenth harmonic; 120 kHz BW up to 1 GHz, 1 MHz BW above 1 GHz

Table 4.2. Radiated Emission Limits (FCC: 15.33, 15.35, 15.109; IC: RSS—210, 6.2.2(r)). Digital (Class B). Freq. (MHz) Eiim (3m) uV/m Eiiyp dB(uV/m) 30—88 100 40.0 88—216 150 43.5 216—960 200 46.0 960—2000 500 54.0 Note: Quasi—Peak readings apply to 1000 MHz (120 kHz BW) Average readings apply above 1000 MHz (1 MHz BW) 4.2 Conductive Emission Limits The conductive emission limits and tests do not apply here, since the DUT is powered by a 3 V internal battery. 5. Radiated Emission Tests and Results 5.1 Anechoic Chamber Measurements To familiarize with the radiated emission behavior of the DUT, the DUT was first studied and measured in a semi—shielded anechoic chamber. In the chamber there is a set—up similar to that of an outdoor 3—meter site, with a turntable, an antenna mast, and a ground plane. Instrumentation includes spectrum analyzers and other equipment as needed. In the chamber we studied and recorded all the emissions using a ridged horn antenna up to 3.15 GHz. The measurements made in the chamber below 1 GHz are used for pre—test evaluation only. The measurements made above 1 GHz are also used in pre—test evaluation and in final compliance assessment. We note that for the horn antenna, the antenna pattern is more directive and hence the measurement is essentially that of free space (no ground reflection). In the chamber we also recorded the spectrum and modulation characteristics of the carrier. These data are presented in subsequent sections. We also note that in scanning from 30 MHz to 3.15 GHz, there were no other significant spurious emissions observed. 5.2 Outdoor Measurements After the chamber measurements, the emissions were re—measured on the outdoor 3—meter site at fundamental and harmonics up to 1 GHz using tuned dipoles and/or the high frequency bicone. Photographs in Appendix (at end of this report) show the DUT on the open in site test table (OATS). 5.3 Computations and Results To convert the dBm measured on the spectrum analyzer to dB(uV/m), we use expression E3(dBuV/m) = 107 + Pg + Ka — Kg + Kp where Pr = power recorded on spectrum analyzer, dB, measured at 3m Ka = antenna factor, dB/m EKg = pre—amplifier gain, including cable loss, dB Kg = pulse operation correction factor, dB (see 6.1) When presenting the data, at each frequency the highest measured emission under all of the possible orientations is given. Computations and results are given in Table 5.1. There we see that the DUT meets the limits by 2.9 dB at fundamental and by 10.0 dB at harmonics. 4

6. Other Measurements and Computations 6.1 Correction For Pulse Operation In normal operation the transmitter is activated by rotation of the wheel and transmits approximately once every minute. The transmission consists of four words each about 15 ms long. In the worst case there can be three words in a 100 ms window. In a word there are 0.201 ms and 0.504 ms lead— in pulses followed by 69 Manchester format encoded pulses, which are 0.102 ms wide. Note, Manchester encoding uses low— high, high—low transition logic and when the highs are back—to—back, that appears as a wide pulse that actually contains two pulses. See Figure 6.1. Thus, the averaging factor is Kg = 3 x (0.201 + 0.504 + 69 x 0.102) ms / 100 ms = 0.23229 or —12.7 dB 6.2 Emission Spectrum Using the ridge—horn antenna and DUT placed in its aperture, emission spectrum was recorded and is shown in Figure 6.2. 6.3 Bandwidth of the Emission Spectrum The measured spectrum of the signal is shown in Figure 6.3. The allowed (—20 dB) bandwidth is 0.25% of 315.0 MHz, or 786 kHz, and from the plot we see that the —20 dB bandwidth is 55.0 kHz, and the center frequency is 315.105 MHz. 6.4 Effect of Supply Voltage Variation The DUT has been designed to be powered by a single 3 V battery. For this test, the battery was paralelled by a laboratory variable power supply and relative power radiated was measured at the fundamental as the voltage was varied from 2.14 to 3.51 volts. The emission variation is shown in Figure 6.4. 6.5 Input Voltage and Current at Battery Terminals V start = 3.0 V V stop = 2.8 V I = 9.5 mA at 2.9V (CW operation) The University of Michigan Radiation Laboratory 3228 EECS Building Ann Arbor, Michigan 48109—2122 (734) 647—0500

Table 5.1 Highest Emissions Measured Radiated Emission — RF TRW TPS Tx; FCC/IC Freq. Ant. Ant. Pr Det. Ka Kg E3* EB3lim Pass # MHz Used Pol. dBm Used dB/m dB __|dBuV/m|dBuV/m| _dB Comments 1| 315.0 Dip H —264 Pk 18.9 22.0 64.8 67.7 2.9 {flat | 2| 315.0 Dip V —31.7 Pk 18.9 22.0 59.5 67.7 8.2 |end | 3| _630.0 Dip H —61.6 Pk 25.2 20.3 37.7 | 47.7 10.0 |side oc 4]} 630.0 Dip V —62.1 Pk 25.2 20.3 37.2 477 10.5 |end | 5| 945.0 Dip H —674 Pk 28.9 18.1 37.7 47.7 10.0 |side U _ 6| 945.0 Dip V —70.6 Pk 28.9 18.1 34.5 47.7 13.2 |jend _ 7| 1260.0 Horn | H —44.1 Pk 204 28.1 42.5 54.0 11.5 |flat _ 8| 1575.0 Hom | H —53.4 Pk 214 28.2 34.1| 54.0 19.9 |flat 9| 1890.0 Horn H —45.8 Pk 22.1 28.1 42.5 54.0 11.5 |flat 10| 2205.0 Horn H —56.6 Pk 22.9 27.0 33.6 54.0 204 |side 11| 2520.0 Hom H —50.9 Pk 24.0 26.6 |. 40.8 54.0 13.2 |end 12| 2835.0 Horn H —52.0 Pk 24.9 25.4 41.8 54.0 12.2 lend _______ 13| 3150.0 Horn H —50.7 Pk 25.2 24.8 44.0 54.0 10.0 |end 14 e _ _ 15 | 16 _ ce 17 18 * Includes 12.7 dB duty factor 19 20 21 Digital Emissions Freq. Ant. Ant. Pr Det. Ka Kg E3* EB3lim Pass # MHz Used Pol. dBm Used dB/m dB dBuV/m|dBuV/m| _dB Comments 1 2 |3 Digitzlll emissi(ins are r‘nore thaln 20 dB blelow FCCl Class B |limit 4 Conducted Emissions Line Det. Vtest Vlim Pass Side Used| dBuV |dBuV| dB Comments Not licable Meas. 03/10/04; U of Mich.

»2o M ar 18 . «B dB m #aT 1A ¢} ts Anreinnmnnetintnonoeaintenothens © drgnstughsasePngoial i4 > : ; & . 00B _ x> EH #4 . Figure 6.1. Transmissions modulation characteristics: (top) transmission repetition, (center) transmission pulses, (bottom) pulse width. 7

MH xz W i# dl Figure 6.2. Emission spectrum of the DUT in free space (CW emission). The amplitudes are only indicative (not calibrated). BB 46 ki Figure 6.3. Measured bandwidth of the DUT (repeated pulsed emission).

20— «22 " —24 _ Relative Amplitude, dB —26 - —28 - 30 < ~32 7 —34 { —36 T T y T T T T 2.0 2.5 3.0 3.5 4.0 Supply Voltage, VDC Figure 6.4. Relative emission at 315.0 MHz vs. supply voltage. (CW emission)

Appendix: DUT on OATS Appendix: Close-up of the DUT on OATS 10


Document Created: 2004-08-02 22:50:21
Document Modified: 2004-08-02 22:50:21
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