test report

FCC ID: GQ4-32T

Test Report

Download: PDF
FCCID_1011025

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-462 The University of Michigan Radiation Laboratory 3228 EECS Building Ann Arbor, MI 48109-2122 Tel: (734) 764-0500 Measured Radio Frequency Emissions From TRW TPM Transmitter FCC ID: GQ4-32T IC: 1470A-13T Report No. 415031-462 September 26, 2008 Copyright © 2008 For: TRW Inc. 24175 Research Drive Farmington Hills, MI 48335-2642 Contact: Vasudhaa Chalasani vasudhaa.chalasani@trw.com Tel: 248.426.5725 Fax: 248.478.7241 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 TRW model/PN(s) 42607-08010, 42607-0C070. This device is subject to the Rules and Regulations as a Transmitter. In testing completed on July 17, 2008, the device tested in the worst case met the allowed FCC specifications for radiated emissions by 1.0 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 10

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-462 1. Introduction TRW model/PN(s) 42607-08010, 42607-0C070 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 Test Site are on file with FCC Laboratory, Columbia, Maryland (FCC Reg. No: 91050) and with Industry Canada, Ottawa, ON (File Ref. No: IC 2057A-1). 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. The quality system employed at the University of Michigan Radiation Laboratory Willow Run Test Range has been established to ensure all equipment has a clearly identifiable classification, calibration expiry date, and that all calibrations are traceable to national standards. Table 2.1 Test Equipment. Test Instrument Used Manufacturer/Model Q Number Spectrum Analyzer (9kHz-26GHz) X Hewlett-Packard 8593E, SN: 3412A01131 HP8593E1 Spectrum Analyzer (9kHz-6.5GHz) Hewlett-Packard 8595E, SN: 3543A01546 JDB8595E Power Meter Hewlett-Packard, 432A HP432A1 Harmonic Mixer (26-40 GHz) Hewlett-Packard 11970A, SN: 3003A08327 HP11970A1 Harmonic Mixer (40-60 GHz) Hewlett-Packard 11970U, SN: 2332A00500 HP11970U1 Harmonic Mixer (75-110 GHz) Hewlett-Packard 11970W, SN: 2521A00179 HP11970W1 Harmonic Mixer (140-220 GHz) Pacific Millimeter Prod., GMA, SN: 26 PMPGMA1 S-Band Std. Gain Horn S/A, Model SGH-2.6 SBAND1 C-Band Std. Gain Horn University of Michigan, NRL design CBAND1 XN-Band Std. Gain Horn University of Michigan, NRL design XNBAND1 X-Band Std. Gain Horn S/A, Model 12-8.2 XBAND1 X-band horn (8.2- 12.4 GHz) Narda 640 XBAND2 X-band horn (8.2- 12.4 GHz) Scientific Atlanta , 12-8.2, SN: 730 XBAND3 K-band horn (18-26.5 GHz) FXR, Inc., K638KF KBAND1 Ka-band horn (26.5-40 GHz) FXR, Inc., U638A KABAND1 U-band horn (40-60 GHz) Custom Microwave, HO19 UBAND1 W-band horn(75-110 GHz) Custom Microwave, HO10 WBAND1 G-band horn (140-220 GHz) Custom Microwave, HO5R GBAND1 Bicone Antenna (30-250 MHz) X University of Michigan, RLBC-1 LBBIC1 Bicone Antenna (200-1000 MHz) X University of Michigan, RLBC-2 HBBIC1 Dipole Antenna Set (30-1000 MHz) X University of Michigan, RLDP-1,-2,-3 UMDIP1 Dipole Antenna Set (30-1000 MHz) EMCO 3121C, SN: 992 (Ref. Antennas) EMDIP1 Active Rod Antenna (30 Hz-50 MHz) EMCO 3301B, SN: 3223 EMROD1 Active Loop Antenna (30 Hz-50 MHz) EMCO 6502, SN:2855 EMLOOP1 Ridge-horn Antenna (300-5000 MHz) X University of Michigan UMRH1 Amplifier (5-1000 MHz) X Avantek, A11-1, A25-1S AVAMP1 Amplifier (5-4500 MHz) X Avantek AVAMP2 Amplifier (4.5-13 GHz) Avantek, AFT-12665 AVAMP3 Amplifier (6-16 GHz) Trek TRAMP1 Amplifier (16-26 GHz) Avantek AVAMP4 LISN Box University of Michigan UMLISN1 Signal Generator Hewlett-Packard 8657B HPSG1 Page 2 of 10

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-462 3. Configuration and Identification of Device Under Test (DUT) 3.1 Design and Identification of the Device The DUT is a 315 MHz TPMS, Tire Pressure Monitor Sensor (transmitter), 2.5 x 0.75 x 3 inches in size, and is FSK modulated. The transmitter consists of an RF MMIC that is stabilized by a 9.84 MHz crystal. The stem and PCB are used as the antenna. The DUT was designed and manufactured by TRW Inc., 24175 Research Drive, Farmington Hills, MI 48335-2642. It is identified as: TRW TPMS Transmitter Model/PN(s): 42607-08010, 42607-0C070 FCC ID: GQ4-32T IC: 1470A-13T 3.2 Models There are two versions of the DUT, one with a 20 degree bend (42607-08010) between the tire stem and the PCB and one with a 40 degree bend (42607-0C070) between the stem and the PCB. All electronic components are identical. The DUT with the 20 degree stem demonstrated the highest fundamental output power, and was fully tested. 3.3 Modes of Operation The DUT periodically transmits tire pressure data and is subject to FCC part 15.231(e) emissions limits. The device is also capable of being remotely actuated (via LF interrogation) by trained service personnel, and (per FCC correspondence) those 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 10

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-462 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 10

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-462 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 XX 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 the transmitter is activated (with 3 second resting period or by single LF interrogation), it can, in the worst case, transmit four 7.75 ms words, two of which may occur within any given 100 ms window. See Figure 6.1. Computing the duty factor results in: KE = (2 x 7.75 ms) / 100 ms = 0.155 or -16.2 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 315 MHz MHz, or 787.25 kHz. From the plot we see that the -20 dB bandwidth is 138.0 kHz, and the center frequency is 315 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 = 3.23 V after testing Voc = 3.03 V Ave. current from batteries I = 9.1 mA (cw) Page 5 of 10

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-462 Table 5.1 Highest Emissions Measured Radiated Emission - RF TRW 32T; 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 1 315.0 Dip H -28.3 Pk 18.6 21.3 59.8 67.7 7.9 flat 20 deg. Stem 2 315.0 Dip V -35.5 Pk 18.6 21.3 52.6 67.7 15.1 end 3 630 0 630.0 Dip H -60 5 -60.5 Pk 24 4 24.4 18 2 18.2 36 5 36.5 47 7 47.7 11 2 11.2 flat 4 630.0 Dip V -61.2 Pk 24.4 18.2 35.8 47.7 11.9 end 5 945.0 Dip H -75.2 Pk 28.8 16.2 28.2 47.7 19.4 flat, noise 6 945.0 Dip V -75.6 Pk 28.8 16.2 27.8 47.7 19.8 end, noise 7 1260.0 Horn H -39.2 Pk 20.6 28.1 44.1 54.0 9.9 flat 8 1575.0 Horn H -51.4 Pk 21.5 28.1 32.8 54.0 21.2 flat 9 1890.0 Horn H -31.9 Pk 22.2 28.1 53.0 54.0 1.0 end 10 2205.0 Horn H -35.9 Pk 23.0 26.5 51.4 54.0 2.5 flat 11 2520.0 Horn H -37.8 Pk 23.9 26.0 50.9 54.0 3.1 end 12 2835.0 Horn H -53.2 Pk 24.8 24.7 37.7 54.0 16.3 flat 13 3150.0 Horn H -58.3 Pk 25.8 23.6 34.7 54.0 19.2 flat 14 15 16 17 315.0 Dip H -28.3 Pk 18.6 21.3 59.8 67.7 7.9 flat 40 deg. stem 18 1890.0 Horn H -33.6 Pk 22.2 28.1 51.3 54.0 2.7 end 19 20 21 22 23 24 * Includes 16.2 dB duty factor 25 26 Digital emissions more than 20 dB below FCC/IC Class B Limit. 27 C Conducted Emissions i i Freq. Line Det. Vtest Vlim Pass # MHz Side Used dBµV dBµV dB Comments Not applicable Meas. 07/24/08; U of Mich. Page 6 of 10

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-462 Figure 6.1. Transmissions modulation characteristics: (top) complete transmission after LF interrogation, (center) expanded transmission 4-words, (bottom) expanded word. Page 7 of 10

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-462 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 8 of 10

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-462 Figure 6.4. Relative emissions at 315 MHz vs. supply voltage. (pulsed emission) Page 9 of 10

University of Michigan Radiation Laboratory FCC Part 15, IC RSS-210/GEN - Test Report No. 415031-462 DUT on OATS – one of three axes tested DUT on OATS (close-up) – one of three axes tested Page 10 of 10


Document Created: 2008-09-28 20:43:27
Document Modified: 2008-09-28 20:43:27
© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC