Test Report

FCC ID: MRXMERCTX1

Test Report

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FCCID_944405

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 The University of Michigan Radiation Laboratory 3228 EECS Building Ann Arbor, MI 48109-2122 Tel: (734) 764-0500 Measured Radio Frequency Emissions From Schrader TPM Transmitter FCC ID: MRXMERCTX1 IC: 2546A-MERCTX1 Report No. 415031-434 May 19, 2008 Copyright © 2008 For: Schrader Electronics Limited 11 Technology Park, Belfast Road, Antrim BT41 1QS, Northern Ireland Contact: Adrian Condon, acondon@schrader.co.uk Tel: +44 (0) 28 9448 3073 Fax: +44 (0) 28 9446 8440 PO: Verbal Tests supervised by: Measurements made by: Valdis V. Liepa Report approved by: _____________________ Valdis V. Liepa Test Report Prepared by: Joseph D. Brunett Research Scientist Summary Tests for compliance with FCC Regulations Part 15, Subpart C, and Industry Canada RSS-210/GEN, were performed on Schrader model/PN(s) 56029400AC, A 003 540 02 17. This device is subject to the Rules and Regulations as a Transmitter. In testing completed on April 3, 2008, the device tested in the worst case met the allowed FCC specifications for radiated emissions by 5.3 dB (see p. 6). Besides harmonics, there were no other significant spurious emissions found; emissions from digital circuitry were negligible. The conducted emission tests do not apply, since the device is powered from a 3 VDC battery. Page 1 of 12

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 1. Introduction Schrader model/PN(s) 56029400AC, A 003 540 02 17 was tested for compliance with FCC Regulations, Part 15, adopted under Docket 87-389, April 18, 1989 as subsequently amended, and with Industry Canada RSS-210/Gen, Issue 6, September 2005. The tests were performed at the University of Michigan Radiation Laboratory Willow Run Test Range following the procedures described in ANSI C63.4-2003 "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 Area Tes Site are on file with FCC Laboratory, Columbia, Maryland (FCC Reg. No: 91050) and with Industry Canada, Ottawa, ON (File Ref. No: IC 2057). 2. 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, 182T/8558B Spectrum Analyzer (9kHz-22GHz) X Hewlett-Packard 8593A SN: 3107A01358 Spectrum Analyzer (9kHz-26GHz) X Hewlett-Packard 8593E, SN: 3412A01131 Spectrum Analyzer (9kHz-26GHz) Hewlett-Packard 8563E, SN: 3310A01174 Spectrum Analyzer (9kHz-40GHz) Hewlett-Packard 8564E, SN: 3745A01031 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 Millimeter Prod., GMA, SN: 26 S-Band Std. Gain Horn 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, HO5R 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) X University of Michigan Amplifier (5-1000 MHz) X Avantak, A11-1, A25-1S Amplifier (5-4500 MHz) X Avantak Amplifier (4.5-13 GHz) Avantek, AFT-12665 Amplifier (6-16 GHz) Trek Amplifier (16-26 GHz) Avantek LISN Box University of Michigan Signal Generator Hewlett-Packard 8657B Page 2 of 12

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 3. Configuration and Identification of Device Under Test (DUT) 3.1 Design and Identification of the Device The DUT was designed and manufactured by Schrader Electronics Limited, 11 Technology Park, Belfast Road, Antrim BT41 1QS, Northern Ireland. It is identified as: Schrader TPMS Transmitter Model/PN(s): 56029400AC, A 003 540 02 17 FCC ID: MRXMERCTX1 IC: 2546A-MERCTX1 3.2 Variants There are two models of this device but both are electrically identical. Two samples were provided; one capable of CW transmission and one standard module that could be LF actuated. The CW version was used to measure harmonic emissions; all other tests were performed on the pulsed module. 3.3 Modes of Operation The DUT periodically transmits tire pressure data. The device is also capable of being automatically actuated (via LF interrogation) either by in-vehicle LF initiators or by trained personnel during servicing. Per FCC correspondence, service modes fall under FCC part 15.231(a)(5). Figure 6.1 demonstrates compliance with both 15.231(a)(2) and (5). A list of all operating modes is included in the Description of Operation exhibit. 3.4 EMI/EMC Relevant Modifications There were no modifications made to the DUT by this laboratory. 4. Regulatory Limits The DUT tested falls under the category of an Intentional Radiators and the Digital Devices. For FCC, it is subject to Part 15, Subpart C (Section 15.231(a),(c), & (e),15.209) and Subpart A (Section 15.33). For Industry Canada it is subject to RSS-210 (2.6, 2.7). The applicable testing frequencies with corresponding emission limits are given in Tables 4.1 and 4.2 below. 4.1 Radiated Emission Limits Table 4.1. General Radiated Emission Limits (FCC: 15.33, 15.35, 15.209; IC: RSS-210, 2.7 Table 2) (Digital Class B) Freq. (MHz) Elim (3m) µV/m Elim dB(µV/m) 30-88 100 40.0 88-216 150 43.5 216-960 200 46.0 960-2000 500 54.0 Note: Average readings apply above 1000 MHz (1 MHz BW) Quasi-Peak readings apply to 1000 MHz (120 kHz BW) Page 3 of 12

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 Table 4.2. Radiated Emission Limits (FCC: 15.231(e), 15.205(a); IC: RSS-210; 2.7 Table 5). (Transmitter) Fundamental Spurious** Frequency Ave. Elim (3m) Ave. Elim (3m) (MHz) (µV/m) dB (µV/m) (µV/m) dB (µV/m) 260.0-470.0 1500-5000* 150-500 315.0 2417 67.7 241.7 47.7 433.9 4399 72.9 439.9 52.9 322-335.4 Restricted 399.9-410 200 46.0 Bands 608-614 960-1240 1300-1427 1435-1626.5 Restricted 500 54.0 1660-1710 Bands 1718.9-1722.2 2200-2300 * Linear interpolation, formula: E = -2833.2 + 16.67*f (MHz) ** Measure up to tenth harmonic; 120 kHz RBW up to 1 GHz, 1 MHz RBW above 1 GHz 4.3 Exemptions For devices operating in transportation vehicles, digital emissions are exempt (FCC 15.103(a), IC correspondence) and need not be reported. 4.4 Power Line Conducted Emission Limits The power line conducted emission limits and tests do not apply here, as the DUT is powered by a 3 VDC battery. 4.5 Supply Voltage Variation Measurements of the variation in the fundamental radiated emission shall be performed with the supply voltage varied between 85% and 115% of the nominal rated value. For battery operated equipment, the equipment tests shall be performed using a new battery. 5. Test Procedures 5.1 Semi-Anechoic Chamber Radiated Emission Testing To become familiar with the emission behavior of the DUT, the DUT was first studied and measured in a shielded semi-anechoic chamber. In the chamber is set-up similar to that of an outdoor 3-meter site, with a turntable, antenna mast, and a ground plane. Instrumentation includes spectrum analyzers and other equipment as needed. In testing for radiated emissions, a transmitter was provided by the manufacturer that is capable of repeated emissions. It was placed on the test table flat, on its side, and on its end. In the chamber we studied and recorded all the emissions using a Bicone antenna up to 300 MHz and a ridged horn antenna above 200 MHz. The measurements made in the chamber below 1 GHz are used for pre-test evaluation only. The measurements made above 1 GHz are used in pre-test evaluation and in final compliance assessment. We note that for the horn antenna, the antenna pattern is directive and the measurement is essentially that of free space (no ground reflection). Consequently, it is not essential to measure the DUT for both antenna polarizations, as long as the DUT is measured on all three of its major axis. In the chamber we also recorded the spectrum and modulation characteristics of the carrier. These data are presented in subsequent sections. Page 4 of 12

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 5.2 Open Area Test Site (OATS) Radiated Emission Testing After the chamber measurements are complete, emissions are re-measured on the outdoor 3-meter open area test site at the fundamental and harmonics up to 1 GHz using tuned dipoles and/or a high frequency biconical antenna. The DUT is placed on the test table flat, on its side, and on its end, and worst case emissions are recorded. Photographs included in this filing show the DUT on the OATS. 5.3 Field Calculation for Radiated Emission Measurements To convert the dBm's measured on the spectrum analyzer to dB(µV/m), we use expression E3(dBµV/m) = 107 + PR+ KA – KG where PR = power recorded on spectrum analyzer, dB, measured at 3m KA = antenna factor, dB/m KG = pre-amplifier gain, including cable loss, dB 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 limit by 5.3 dB. 5.4 Power Line Conducted Emission Testing These tests do not apply, since the DUT is powered from a 3 VDC battery. 6. Test Results 6.1 Correction For Pulse Operation When activated (either by LF interrogation or motion) the device can, in the worst case, transmit up to 4.7 seconds of Manchester encoded ASK data. Each word lasts 17.0 ms and the minimum separation between any two words is 99.5 ms. Within each word, there is a preamble consisting of one 0.490 ms pulse followed by 67 Manchester pulses. All Manchester pulses demonstrate a 0.1275 ms / 0.2425 ms on time. See Figure 6.1. Computing the duty factor results in: KE = ( 0.490 ms + 67 x 0.1275) / 100 ms = 0.09 < -20.0 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. We note that in scanning from 30 MHz to 4.5 GHz using Bicone and the ridge horn antennas, there were no other significant spurious emissions observed. 6.3 Bandwidth of the Emission Spectrum The measured spectrum of the signal is shown in Figure 6.3. The allowed (-20 dB, 99%) bandwidth is 0.25% of 433.92 MHz, or 1.085 MHz. From the plot we see that the -20 dB bandwidth is 50.0 kHz, and the center frequency is 433.92 MHz. 6.4 Effect of Supply Voltage Variation and Test Battery Voltages The DUT has been designed to be powered by a 3 VDC battery. For this test, the battery was replaced by a laboratory variable power supply. Relative power radiated was measured at the fundamental as the voltage was varied from 2 to 4 volts. The emission variation is shown in Figure 6.4. Batteries: before testing Voc = 3.16 V after testing Voc = 2.90 V Ave. current from batteries I = 1.8 mA (cw) Page 5 of 12

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 Table 5.1 Highest Emissions Measured Radiated Emission - RF Schrader C9 TPM Tx; FCC/IC Freq. Ant. Ant. Pr Det. Ka Kg E3* E3lim Pass # MHz Used Pol. dBm Used dB/m dB dBµV/m dBµV/m dB Comments 1 433.9 Dip H -20.4 Pk 21.5 20.6 67.6 72.9 5.3 end 2 433.9 Dip V -22.0 Pk 21.5 20.6 66.0 72.9 6.9 side 3 867.8 Dip H -62.1 Pk 27.8 17.1 35.6 52.9 17.3 flat 4 867.8 Dip V -65.5 Pk 27.8 17.1 32.2 52.9 20.7 side 5 1301.8 Dip V -51.2 Pk 0.0 22.0 13.8 54.0 40.2 side 6 1735.7 Horn H -56.5 Pk 21.9 28.1 24.3 54.0 29.7 end 7 2169.6 Horn H -58.0 Pk 22.9 26.5 25.4 54.0 28.5 flat 8 2603.5 Horn H -52.5 Pk 24.1 25.7 32.9 54.0 21.1 end 9 3037.4 Horn H -55.7 Pk 25.5 23.9 32.8 54.0 21.1 end 10 3471.4 Horn H -47.5 Pk 26.8 23.2 43.1 54.0 10.8 flat 11 3905.3 Horn H -49.5 Pk 28.1 22.4 43.3 54.0 10.7 end 12 4339.2 Horn H -58.7 Pk 29.5 16.2 41.5 54.0 12.5 end 13 14 15 16 17 18 * Includes 20 dB duty factor 19 20 21 22 23 24 25 26 27 Digital Radiated Emissions* Freq. Ant. Ant. Pr Det. Ka Kg E3 E3lim Pass Comments # kHz Used Pol. dBm Used dB/m dB dBµV/m dBµV/m dB 1 2 3 4 Digital emissions more than 20 dB below FCC/IC Class B Limit. 5 6 7 8 9 * For devices used in transportation vehicles, digital emissions are exempt from FCC regulations per FCC 15 Meas. 04/03/2008; U of Mich. Page 6 of 12

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 Figure 6.1(a). Transmissions modulation characteristics: (top) Normal Drive Mode complete transmission, (middle) WAL Drive Mode complete transmission, (bottom) LF Interrogation complete transmission Page 7 of 12

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 Figure 6.1(b). Transmissions modulation characteristics: (top) worst case complete transmission, (center) worst case word period in transmission, (bottom) single word. Page 8 of 12

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 Figure 6.1(c). Transmissions modulation characteristics: (top) Wake pulse, (center) Manchester pulse width, (bottom) Manchester period. Page 9 of 12

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 Figure 6.2. Emission spectrum of the DUT (pulsed emission). The amplitudes are only indicative (not calibrated). Figure 6.3. Measured bandwidth of the DUT (pulsed emission). Page 10 of 12

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 Figure 6.4. Relative emissions at 433.92 MHz vs. supply voltage. (pulsed emission) Page 11 of 12

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-434 DUT on OATS DUT on OATS (close-up) Page 12 of 12


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Document Modified: 2008-05-19 10:49:58
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