test report

FCC ID: GQ4-36T

Test Report

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                        University of Michigan Radiation Laboratory
                  FCC Part 15, IC RSS-210/GE$ - Test Report $o. 415031-375



                                    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: GQ4-36T
                                 Model/P(s): 217652-101

                                      Report No. 415031-375
                                          June 17, 2007

                                         Copyright © 2007

                                              For:
                                            TRW Inc.
                                      24175 Research Drive
                                 Farmington Hills, MI 48335-2642

                                  Contact: Abhijeet Brahmandam
                                  abhijeet.brahmandam@trw.com
                                         Tel: 248.615.7801
                                        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) 217652-101. This device is subject to the Rules and Regulations
as a Transmitter.
        In testing completed on M 8, 2007, the device tested in the worst case met the allowed FCC
specifications for radiated emissions by 2.0 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/GE$ - Test Report $o. 415031-375

1. Introduction

TRW model/PN(s) 217652-101 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 10


                         University of Michigan Radiation Laboratory
                   FCC Part 15, IC RSS-210/GE$ - Test Report $o. 415031-375

3. Configuration and Identification of Device Under Test (DUT)

3.1 Design and Identification of the Device
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): 217652-101
                           FCC ID: GQ4-36T
                           IC: 1470A-17T

3.2 Models
There is only a single version/model of the DUT.

3.3 Modes of Operation
The DUT periodically transmits tire pressure data. The device is also capable of being automatically
actuated (via encoded LF interrogation) either by in-vehicle LF initiators or by trained personnel during
servicing. These 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 10


                         University of Michigan Radiation Laboratory
                   FCC Part 15, IC RSS-210/GE$ - Test Report $o. 415031-375


      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


                                              Page 4 of 10


                         University of Michigan Radiation Laboratory
                   FCC Part 15, IC RSS-210/GE$ - Test Report $o. 415031-375

chamber we also recorded the spectrum and modulation characteristics of the carrier. These data are
presented in subsequent sections.

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 .

5.4 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 (either by LF interrogation or motion), it can, in the worst case,
transmit 5 pulses of ASK data, each with an on time of 7.8 ms. In the worst case, two of these
transmissions may occur in a 100 ms window. See Figure 6.1. Computing the duty factor results in:
                             KE = (2 x 7.8 ms) / 100 ms = 0.156 or -16.1 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 105.0 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 =   3.28 V
                        after testing         Voc =   3.01 V
          Ave. current from batteries         I =     3.0 mA (pulsed)

                                              Page 5 of 10


                                    University of Michigan Radiation Laboratory
                              FCC Part 15, IC RSS-210/GE$ - Test Report $o. 415031-375


                                        Table 5.1 Highest Emissions Measured

                                 Radiated Emission - RF                                                    TRW, 36T; 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       -27.1     Pk     18.9    22.0      60.7         67.7      7.0   flat
 2    315.0     Dip     V       -33.1     Pk     18.9    22.0      54.7         67.7     13.0   end
 3    630.0     Dip     H       -61.6     Pk     25.2    19.0      35.5         47.7     12.1   side
 4    630.0     Dip     V       -61.6     Pk     25.2    19.0      35.5         47.7     12.1   end
 5    945.0     Dip     H       -69.8     Pk     28.9    17.1      32.9         47.7     14.7   flat
 6    945.0     Dip     V       -79.6     Pk     28.9    17.1      23.1         47.7     24.5   end
 7   1260.0    Horn     H       -30.3     Pk     20.6    28.0      53.2         54.0     26.0   flat
 8   1575.0    Horn     H       -44.0     Pk     21.5    28.0      40.4         54.0     13.6   end
 9   1890.0    Horn     H       -33.1     Pk     22.2    28.0      52.0         54.0      2.0   flat
10   2205.0    Horn     H       -34.0     Pk     23.0    28.1      51.8         54.0      2.2   side
11   2520.0    Horn     H       -40.4     Pk     23.9    28.3      46.1         54.0      7.9   flat
12   2835.0    Horn     H       -50.6     Pk     24.8    28.2      36.9         54.0     17.1   flat
13   3150.0    Horn     H       -55.6     Pk     25.8    27.9      33.2         54.0     20.8   flat
14
15
16
17
18                                                * Includes 16.1 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 15.103(a)
                                                                                                 Meas. 05/08/2007; U of Mich.



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                       University of Michigan Radiation Laboratory
                 FCC Part 15, IC RSS-210/GE$ - Test Report $o. 415031-375




Figure 6.1(a).       Transmissions modulation characteristics: (top) maximum tx. rate, (center) off
                     time verify, (bottom) expanded transmission.



                                          Page 7 of 10


                        University of Michigan Radiation Laboratory
                  FCC Part 15, IC RSS-210/GE$ - Test Report $o. 415031-375




Figure 6.1(b). Transmissions modulation: (top) tx. pulse width, (bottom) two pulses/100ms worst case.




           Figure 6.2.          Emission spectrum of the DUT (pulsed emission).
                                The amplitudes are only indicative (not calibrated).

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                                   University of Michigan Radiation Laboratory
                             FCC Part 15, IC RSS-210/GE$ - Test Report $o. 415031-375




Figure 6.3.                                    Measured bandwidth of the DUT (pulsed emission).




                            9.00

                            8.50
  Relative Amplitude (dB)




                            8.00

                            7.50

                            7.00

                            6.50

                            6.00

                            5.50

                            5.00
                                   2.0   2.2      2.4     2.6    2.8     3.0    3.2    3.4    3.6   3.8

                                                                 Voltage (V)


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/GE$ - Test Report $o. 415031-375




                                                           DUT on OATS




                                                  DUT on OATS (close-up)




                     Page 10 of 10



Document Created: 2007-06-17 07:14:38
Document Modified: 2007-06-17 07:14:38

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