I5T-A4EM0101Perimeter Protection System

Senstar Corporation

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Application Details

Equipment Class: DXX - Part 15 Low Power Communication Device Transmitter
Date of Grant: Mar 18, 2007
Application Purpose: Original Equipment
Date of Application: Mar 18, 2007
Equipment Note: Perimeter Protection System
Frequency Range: 32.12500000 - 32.12500000
Company: Senstar Corporation
Country: Canada

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Document Text

Text extracted from the exhibit documents filed with the FCC. Open a document above to read the original.

Internal Photos

1.4 OmniTrax Circuit Card Assembly The OmniTrax circuit card assembly is an 8.25” x 8.5” x 0.093” 8 layer PCB populated with components on both sides of the circuit card. RF shielding is applied on the top side over the sensitive transmitter and receiver signal chains. Figure A-4 Omnitrax PCB Top Side With RF Shields Figure A-5 Omnitrax PCB Top Side With RF Shields Removed Figure A-6 Omnitrax PCB Bottom Side

Test Report

Appendix A - Equipment Used 1.1 Biconical Antenna The antenna used was an APREL biconical. It was calibrated in May. 2005 and is due for recalibration in May 2007. Figure A-1 APREL Biconical Antenna 1.2 Meter The meter used for the tests was a Rohde and Schwarz FSH3 serial number 100415. It was calibrated in March 2006 and is due for recalibration in March 2007. Figure A – 1 Rohde&Schwarz Meter 1.3 OmniTrax Processor A portable OmniTrax processor model number A4EM0101-001 and serial number A000646004 was used as the signal source. A Toshiba laptop computer was used for setting the OmniTrax power level and for recording the sensitivity profile. Figure A-2 Portable OmniTrax Processor and Laptop used for Data Collection Figure A -2 Closeup of OmniTrax PCB The signal carrier frequency is 32.125 MHz and is modulated by a direct sequence PN code which is approximately 50 msec long. The output spectrum is shown below. Note that the peak spectrum occurs at about 32 MHz. The spectrum has a classic sinx/x form with the first nulls away from the center at about 26.8 MHz and 37.5 MHz. The side lobes are not part of the necessary bandwidth. If they were filtered out the device would still transmit the required information. Figure A-3 The spectrum in figure A-4 (0 to 200 MHz) was measured with the TX power set to maximum through a 20 dB attenuator. Figure A-4 The spectrum in figure A-5 shows the spectrum from 200 to 400 MHz and was also recorded with the TX power set to maximum. Figure A-5 From figure A-4 and A-5 it is possible to see that the following harmonics exist 1 32.125 MHz 8.6 dBm (fundamental) 3 96.375 MHz -19.6 dBm 5 160.625 MHz -37.4 dBm 7 224.875 MHz -54.4 dBm 9 289.125 MHz -62.2 dBm 11 353.375 MHz -63.7 dBm All are well below the fundamental – far enough to be well below the noise floor of the field strength meter when measuring fields with the biconical antenna. Note the maximum power setting is TX =100 and produces 8.6 dBm (100 kHz bandwidth).

Test Report

Appendix B – Table of Radial Measurements 1.1 Hammond Farm Lateral Range (meters) Rx (dBμV) Antenna Factor Tx Power From Eq 1 (dBm) Test Signal Power dBm Field Strength (dBμV/m) Radial 1 25 meters Vertical 1 meter 1 56.913.8-168.2 46.5 2 52.713.8-168.2 42.3 3 48.913.8-168.2 38.5 5 42.813.8-168.2 32.4 10 33.313.8-168.2 22.9 20 22.613.8-168.2 12.2 30 17.213.8-168.2 6.8 50 11.613.8-168.2 1.2 Vertical 2 meter 1 55.413.8-168.2 45 2 51.713.8-168.2 41.3 3 48.513.8-168.2 38.1 5 42.313.8-168.2 31.9 10 33.813.8-168.2 23.4 20 23.613.8-168.2 13.2 30 18.213.8-168.2 7.8 50 11.513.8-168.2 1.1 Horizontal 1 meter 1 53.813.8-168.2 43.4 2 46.713.8-168.2 36.3 3 42.113.8-168.2 31.7 5 34.613.8-168.2 24.2 10 23.713.8-168.2 13.3 20 11.913.8-168.2 1.5 30 913.8-168.2 -1.4 Radial 2 70 meters Vertical 1 meter 1 5513.8-168.2 44.6 2 50.813.8-168.2 40.4 3 4613.8-168.2 35.6 5 3713.8-168.2 26.6 10 24.513.8-168.2 14.1 20 23.113.8-168.2 12.7 30 19.413.8-168.2 9 50 16.113.8-168.2 5.7 Vertical 2 meter 1 52.913.8-168.2 42.5 2 49.213.8-168.2 38.8 3 45.313.8-168.2 34.9 5 37.113.8-168.2 26.7 10 24.613.8-168.2 14.2 20 24.313.8-168.2 13.9 30 20.313.8-168.2 9.9 50 16.213.8-168.2 5.8 0 Horizontal 1 meter 0 1 50.913.8-168.2 40.5 2 43.713.8-168.2 33.3 3 38.713.8-168.2 28.3 5 3113.8-168.2 20.6 10 17.513.8-168.2 7.1 20 14.513.8-168.2 4.1 30 12.513.8-168.2 2.1 50 8.913.8-168.2 -1.5 Radial 3 130 meters Vertical 1 meter 1 56.513.8-168.2 46.1 2 50.913.8-168.2 40.5 3 4613.8-168.2 35.6 5 37.913.8-168.2 27.5 10 25.513.8-168.2 15.1 20 16.213.8-168.2 5.8 30 1713.8-168.2 6.6 50 1313.8-168.2 2.6 Vertical 2 meter 1 52.513.8-168.2 42.1 2 48.513.8-168.2 38.1 3 44.413.8-168.2 34 5 3813.8-168.2 27.6 10 24.913.8-168.2 14.5 20 1613.8-168.2 5.6 30 17.513.8-168.2 7.1 50 12.713.8-168.2 2.3 Horizontal 1 meter 1 50.913.8-168.2 40.5 2 44.213.8-168.2 33.8 3 39.113.8-168.2 28.7 5 3013.8-168.2 19.6 10 13.713.8-168.2 3.3 20 10.113.8-168.2 -0.3 Radial 4 165 meters Vertical 1 meter 1 56.813.8-168.2 46.4 2 52.413.8-168.2 42 3 48.413.8-168.2 38 5 41.113.8-168.2 30.7 10 2413.8-168.2 13.6 20 20.813.8-168.2 10.4 30 17.713.8-168.2 7.3 50 14.413.8-168.2 4 Vertical 2 meter 1 54.613.8-168.2 44.2 2 51.313.8-168.2 40.9 3 47.613.8-168.2 37.2 5 40.113.8-168.2 29.7 10 2413.8-168.2 13.6 20 20.913.8-168.2 10.5 30 17.313.8-168.2 6.9 50 14.813.8-168.2 4.4 Horizontal 1 meter 1 52.513.8-168.2 42.1 2 45.713.8-168.2 35.3 3 41.413.8-168.2 31 5 30.513.8-168.2 20.1 10 10.713.8-168.2 0.3 20 10.213.8-168.2 -0.2 1.2 SITE Lateral Range (meters) Rx (dBμV) Antenna Factor Tx Power From Eq 1 (dBm) Test Signal Power dBm Field Strength (dBμV/m) Radial 1 75 meters Vertical 1 meter 1 50.813.8-10.514.5 39.6 2 46.313.8-10.514.5 35.1 3 42.713.8-10.514.5 31.5 5 33.313.8-10.514.5 22.1 10 2513.8-10.514.5 13.8 20 11.113.8-10.514.5 -0.1 30 2313.8-10.514.5 11.8 50 13.913.8-10.514.5 2.7 Vertical 2 meter 1 49.913.8-10.514.5 38.7 2 47.613.8-10.514.5 36.4 3 45.513.8-10.514.5 34.3 5 36.913.8-10.514.5 25.7 10 25.113.8-10.514.5 13.9 20 13.113.8-10.514.5 1.9 30 22.713.8-10.514.5 11.5 50 15.213.8-10.514.5 4 Horizontal 1 meter 1 52.913.8-10.514.5 41.7 2 46.413.8-10.514.5 35.2 3 42.713.8-10.514.5 31.5 5 3613.8-10.514.5 24.8 10 22.713.8-10.514.5 11.5 20 17.713.8-10.514.5 6.5 30 9.913.8-10.514.5 -1.3 Radial 2 95 meters Vertical 1 meter 1 55.913.8-10.514.5 44.7 2 52.313.8-10.514.5 41.1 3 47.713.8-10.514.5 36.5 5 42.713.8-10.514.5 31.5 10 21.413.8-10.514.5 10.2 20 2313.8-10.514.5 11.8 30 15.713.8-10.514.5 4.5 50 1313.8-10.514.5 1.8 Vertical 2 meter 1 54.713.8-10.514.5 43.5 2 50.113.8-10.514.5 38.9 3 46.113.8-10.514.5 34.9 5 42.913.8-10.514.5 31.7 10 22.313.8-10.514.5 11.1 20 22.613.8-10.514.5 11.4 30 15.413.8-10.514.5 4.2 50 12.613.8-10.514.5 1.4 Horizontal 1 meter 1 57.413.8-10.514.5 46.2 2 51.513.8-10.514.5 40.3 3 44.513.8-10.514.5 33.3 5 39.713.8-10.514.5 28.5 10 32.413.8-10.514.5 21.2 20 13.713.8-10.514.5 2.5 Radial 3 150 meters outside cable Vertical 1 meter 1 54.913.8-10.514.5 43.7 2 52.513.8-10.514.5 41.3 3 50.713.8-10.514.5 39.5 5 43.813.8-10.514.5 32.6 10 33.613.8-10.514.5 22.4 20 30.613.8-10.514.5 19.4 30 30.613.8-10.514.5 19.4 50 21.413.8-10.514.5 10.2 Vertical 2 meter 1 5313.8-10.514.5 41.8 2 51.613.8-10.514.5 40.4 3 49.313.8-10.514.5 38.1 5 4313.8-10.514.5 31.8 10 34.713.8-10.514.5 23.5 20 31.213.8-10.514.5 20 30 30.913.8-10.514.5 19.7 50 22.713.8-10.514.5 11.5 Horizontal 1 meter 1 53.613.8-10.514.5 42.4 2 49.713.8-10.514.5 38.5 3 44.113.8-10.514.5 32.9 5 35.713.8-10.514.5 24.5 10 24.413.8-10.514.5 13.2 20 22.613.8-10.514.5 11.4 30 20.513.8-10.514.5 9.3 50 14.313.8-10.514.5 3.1 Radial 4 150 meters inside cable Vertical 1 meter 1 62.913.8-10.514.5 51.7 2 59.413.8-10.514.5 48.2 3 55.213.8-10.514.5 44 5 46.813.8-10.514.5 35.6 10 34.413.8-10.514.5 23.2 20 31.413.8-10.514.5 20.2 30 30.813.8-10.514.5 19.6 50 23.913.8-10.514.5 12.7 Vertical 2 meter 1 59.313.8-10.514.5 48.1 2 58.513.8-10.514.5 47.3 3 54.513.8-10.514.5 43.3 5 49.313.8-10.514.5 38.1 10 36.213.8-10.514.5 25 20 31.613.8-10.514.5 20.4 30 30.813.8-10.514.5 19.6 50 22.813.8-10.514.5 11.6 Horizontal 1 meter 1 60.113.8-10.514.5 48.9 2 56.413.8-10.514.5 45.2 3 51.713.8-10.514.5 40.5 5 41.113.8-10.514.5 29.9 10 25.313.8-10.514.5 14.1 20 21.513.8-10.514.5 10.3 30 20.413.8-10.514.5 9.2 50 11.613.8-10.514.5 0.4 1.3 JWP Lateral Range (meters) Rx (dBμV) Antenna Factor Tx Power From Eq 1 (dBm) Test Signal Power dBm Field Strength (dBμV/m) Radial 1 40 meters Vertical 1 meter 1 62.513.8-916.8 50.5 2 60.113.8-916.8 48.1 3 57.313.8-916.8 45.3 5 51.913.8-916.8 39.9 10 40.813.8-916.8 28.8 20 32.513.8-916.8 20.5 30 28.213.8-916.8 16.2 50 24.113.8-916.8 12.1 Vertical 2 meter 1 60.313.8-916.8 48.3 2 5813.8-916.8 46 3 55.513.8-916.8 43.5 5 5113.8-916.8 39 10 43.113.8-916.8 31.1 20 3113.8-916.8 19 30 28.413.8-916.8 16.4 50 26.413.8-916.8 14.4 Horizontal 1 meter 1 5913.8-916.8 47 2 52.113.8-916.8 40.1 3 4713.8-916.8 35 5 39.413.8-916.8 27.4 10 28.513.8-916.8 16.5 20 23.213.8-916.8 11.2 30 16.113.8-916.8 4.1 Radial 2 355 meters Vertical 1 meter 1 61.713.8-916.8 49.7 2 56.813.8-916.8…

Text truncated - open the document above for the full version.

Test Report

Appendix C Test Site Descriptions 1 Hammond Farm – 12 January 2007 The site is located on the Hammond farm which is 2.8 km south east of Ashton Station on Hwy 7. Coordinates are 45 deg 09’26.70” N 76 deg 05’16.07” W. The cables had 25 meters of lead-in, 400 meters of active cable and 20 meters of lead-out with 50 ohm terminations at the end of the lead-out. The cables were on the surface of a hay stubble field and were about 1.5 meters apart. Test personnel were John Patchell and Bill Hodgins. Figure C-1 Hammond Farm - Satellite View and Cable Location Radial 2 70 meters Radial 1 25 meters Radial 3 130 meters Radial 4 165 meters Terminations Test Equipment Non Leaky Lea d-in Figure C-2 Hammond Farm - Looking North West from Start of Cables – Vehicle with test equipment in left background Figure C-3 Antenna in Horizontal Position Figure C-4 Antenna in 2m Vertical Position 2 SITE – 11 April 2006 This site is at Senstar-Stellar’s facility at 119 John Cavanagh Drive, Carp, Ontario. The cables have 25 meters of lead-in and 400 meters of active cable. Cable separation is 1.5 m and burial depth is 23 cm. Both cables are terminated with 50 ohm loads. Test personnel were John Patchell and Ashley Bridges. Figure C - 5 SITE Satellite Photo and Cable Location 100 10 85 195 m 195 10 Trailer #2 205 m Radial #1 Radial #2 Radial #3 and #4 Figure C-6 SITE Cable Location Figure C-77 SITE - Looking North near Radial 1 3 JWP – 1 May 2006 This site is at located at 681 Cram Rd, Beckwith Twp, Ontario. The cables have 25 meters of lead-in and 400 meters of active cable. Cable separation is 1.5 m and burial depth is 23 cm. Both cables are terminated with 50 ohm loads. Test personnel was John Patchell. Figure C-8 JWP Satellite Photo and Cable Location Figure C-9 JWP Cable Layout Figure C-10 JWP site Looking North near fence line

Test Report

Appendix D - Measurement Procedure Introduction Two variations for making the measurements where used depending on the overall site sensitivity. At the Hammond site the sensitivity was high enough that not power amplifier was needed while at the other two sites because the cables were buried a power was needed to make measurements at 30 meters. Hammond Site For setup the equipment was connected as in Figure 1 OmniTr ax Processor RX Cable USB USB TX A RX A 50 Ohm Ter m i nation 110 AC Laptop computer PRINT HELP ALPHA SHIFT ENTER RUN D G E R F I A J B K C L 7 M 8 N 9 O D G D G D G D G T 3 U 0 V . W X Y Z TAB % UTILIZATION HUB/MAUNIC 2 BNC 4Mb/s FSH3 Figure 1 The laptop was used to set the OmniTrax TX gain at 80. The resulting spectrum form the FSH is shown in Figure 2 Figure 2 The value of 8.2 dBm is used as the test signal in equation 2. For the radial field measurements the equipment configuration shown in Figure 3 was used. OmniTrax Processor RX Cable USB USB TX A RX A Tx Cable 50 Ohm Ter m i nati on 110 AC Laptop computer PRINT HELP ALPHA SHIFT ENTER RUN D G E R F I A J B K C L 7 M 8 N 9 O D G D G D G D G T 3 U 0 V . W X Y Z TAB % UTILIZATION HUB/M AUNIC 2 BNC 4Mb/s FSH3 50 Ohm Ter m ination Figure 3 SITE and JWP At these sites the configuration shown in figure 4 was used OmniTr ax Processor RX Cable USB USB TX A RX A Attenuator 50 Ohm Ter m i nation 110 AC TRW Amplifier 24 Volt DC Supply Laptop computer PRINT HELP ALPHA SHIFT ENTER RUN D G E R F I A J B K C L 7 M 8 N 9 O D G D G D G D G T 3 U 0 V . W X Y Z TAB % UTILIZATION HUB/MAUNI C 2 BNC 4Mb/s FSH3 Figure 4 For the radial measurements the configuration of figure 5 was used. OmniTr ax Processor RX Cable USB USB TX A RX A TX Cable 50 Ohm Ter m i nati on 110 AC TRW Amplifier 24 Volt DC Supply Laptop computer PRINT HELP ALPHA SHIFT ENTER RUN D G E R F I A J B K C L 7 M 8 N 9 O D G D G D G D G T 3 U 0 V . W X Y Z TAB % UTILIZATION HUB/MAUNIC 2 BNC 4Mb/s FSH3 50 Ohm Ter m i nati on Figure 5 At site for the setup a 10 dB attenuator was used and the peak measured signal was 4.5 dBm so the test signal used in equation 2 was 14.5 dBm. For JWP a 20 dB attenuator was used and the peak measured signal was -3.2 dBm so the test signal used in equation 2 was 16.8 dBm. This method of measuring the test signal ensures that the gain of the TRW amplifier does not enter into the equation. However it was tested and is shown in figure 6. 101001 . 10 3 0 5 10 15 20 dB 20 0 TRW i 35010F i MHz Figure 6 Gain of TRW Power Amp The attenuators used were also tested and the result is shown in figure 7. 101001 . 10 3 20 15 10 5 0 dB 0 19.66− A10 i A20 i 35010F i MHz Figure 7 Attenuation of 10 and 20 dB pads The attenuator results are also listed in tabular form. Freq (MHz) 10 dB 20 dB 10 -9.8 -19.5 19 -9.8 -19.5 27 -9.8 -19.5 36 -9.8 -19.5 44 -9.8 -19.6 53 -9.8 -19.5 61 -9.8 -19.5 70 -9.7 -19.4 78 -9.7 -19.4 87 -9.7 -19.5 95 -9.8 -19.6 104 -9.8 -19.5 112 -9.9 -19.6 121 -9.9 -19.5 129 -9.8 -19.5 138 -9.8 -19.5 146 -9.9 -19.5 155 -9.8 -19.5 163 -9.8 -19.5 172 -9.9 -19.5 180 -9.8 -19.5 189 -9.8 -19.5 197 -9.9 -19.6 206 -9.9 -19.5 214 -9.9 -19.6 223 -9.8 -19.5 231 -9.9 -19.5 240 -9.9 -19.5 248 -9.9 -19.5 257 -9.8 -19.5 265 -9.9 -19.5 274 -9.9 -19.5 282 -9.8 -19.5 291 -9.9 -19.6 299 -10.0 -19.6 308 -9.9 -19.5 316 -9.9 -19.5 325 -10.0 -19.6 333 -10.0 -19.6 342 -9.9 -19.5 350 -10.0 -19.6 Table of 10 and 20 dB attenuators

Test Report

Receiver Results: 120VAC, 60Hz Conductor Frequency (MHz) Detector Emission Level (dBuV) LISN Loss (dB) Cable Loss (dB) Result (dBuV) Limit (dBuV) Margin (dB) Quasi Peak 40.2 0.20 0.00 40.40 66.0 25.6 Phase 0.1500 Average 34.5 0.20 0.00 34.70 56.0 21.3 Quasi Peak 39.3 0.20 0.00 39.50 66.0 26.5 0.1500 Average 33.7 0.20 0.00 33.90 56.0 22.1 Quasi Peak 41.0 0.10 0.10 41.20 56.1 14.9 0.4928 Average 38.6 0.10 0.10 38.80 46.1 7.3 Quasi Peak 39.4 0.00 0.60 40.00 56.0 16.0 4.8585 Average 38.7 0.00 0.60 39.30 46.0 6.7 Quasi Peak 39.6 0.00 0.58 40.18 56.0 15.8 4.5763 Average 38.5 0.00 0.58 39.08 46.0 6.9 Quasi Peak 39.6 0.00 0.27 39.87 56.0 16.1 0.6340 Average 39.1 0.00 0.27 39.37 46.0 6.6 Quasi Peak 38.3 0.00 0.20 38.50 56.0 17.5 0.7038 Average 37.9 0.00 0.20 38.10 46.0 7.9 Quasi Peak 39.2 0.00 0.60 39.80 56.0 16.2 4.7868 Average 38.4 0.00 0.60 39.00 46.0 7.0 Quasi Peak 39.5 0.00 0.50 40.00 56.0 16.0 Neutral 4.5050 Average 38.7 0.00 0.50 39.20 46.0 6.8 Equipment List – Conducted Emissions CAL Cycle Equipment Manufacturer Model No. Asset/Serial No. Next Cal. 1 Year LISN FCC FCC-LISN-50-100-1-02 FA001775 May 01/07 1 Year LISN FCC FCC-LISN-50-100-1-02 FA001777 May 01/07 1 Year Receiver Rohde & Schwarz ESHS 10 FA001929 May 26/07 1 Year Spectrum Analyzer Hewlett-Packard 8566B FA001431 May 16/07 1 Year Spectrum Analyzer Display Hewlett-Packard 85662A FA001432 May 16/07 1 Year Transient Limiter Hewlett-Packard 1194 7A FA001150 May 18/07 1 Year Power Source California Instruments 5001ix FA001770 May 23/07 Note: N/A = Not Applicable, NCR = No Cal Required, COU = CAL On Use, OUT = Out For CAL/Repair

Test Report

OmniTrax Field Strength Test 1 March 07 This test was performed to verify compliance with FCC field strength limits. We were requested to do the following: 1) Test the device without the amplifier at the transmitter. An amplifier can and should be used at the receiving antenna. 2) In this case, you can perform final testing on the worst case site determined from the sites already tested. 3) Because of the design of the device, when testing above 30 MHz, you can make measurements at a distance greater than 3 meters. Since the levels of the device are too low when testing at 30 MHz, test at a closer distance (e.g. 10 meters) in order to get the level of the EUT above the ambient. Extrapolate the levels to 3 meters using a 20 dB per decade factor and compare to the 3 meter limit. The strongest fields were observed at the SITE test facility at the 150 meter mark of the A cable set. (see Figure 5 of the test report). Therefore this location was chosen for the verification measurement. The test set up is shown in figure 1. OmniTrax Processor RX Cable USB USB TX A RX A Tx Cable 50 Ohm Ter m i nati on 110 AC Laptop computer PRINT HELP ALPHA SHIFT ENTER RUN D G E R F I A J B K C L 7 M 8 N 9 O D G D G D G D G T 3 U 0 V . W X Y Z TAB % UTILIZATION HUB/M AUNIC 2 BNC 4Mb/s FSH3 50 Ohm Ter m ination ZFL-500 Figure 1 An amplifier was used at the input to the FSH3 spectrum analyzer to boost the signal so that it could be read. The biconical antenna was set up 10 meters from the cable. The output power of the OmniTrax unit was adjusted to -11.1 dBm. Equation 1 of the test report calls for a transmit power setting of -10.5 dBm and -11.1 dBm was the closest setting available. First the back ground field was measured before the cable was connected to the OmniTrax processor. The result is shown in Figure 2. Figure 2 Next the transmit cable was connected to the OmniTrax processor and the field measured as shown in Figure 3 Figure 3 Note that is reading is about 6 dB above the peak background reading from Figure 2. The field strength is then calculated as follows: FSH3 Reading 32.9dBμV Antenna Factor dB 13.8dB ZFL-500 Gain -19.8dB Field Strength 26.9 dBμV/m Extrapolated to 3 m distance 10.5dB Extrapolated Field Strength 37.4 dBμV/m FCC Limit at 3 meters 40.0dBμV/m Pass The measured field is below the FCC limit.

Test Report

OmniTrax Field Strength Test Report Submitted to NEMKO Canada 7 March 2007 1 1 Introduction This report describes tests made to establish the compliance of the OmniTrax leaky cable security system with FCC Part 15. The tests made use of OmniTrax prototype processors and OC2 400 meter cable sets installed at: 1) Hammond Farm near Ashton Ontario 2) SITE test area at the Senstar-Stellar facility near Carp Ontario. 3) JWP Test Site near Carleton Place Ontario Appendix A is a list of equipment used. Appendix B is a table of radial field measurements for the three sites. Site descriptions are included in Appendix C including addresses, test personnel and site photos. Appendix D gives details of the radial field strength procedure. 2 Objectives OmniTrax transmits a signal on one buried leak-coaxial cable and receives that signal on a parallel leaky cable. Spacing between the receive and transmit cables is about 1.5 meters When a person enters the area near or between the cables there is a small change in the received signal. This change is termed sensitivity and is a function of the transmitted power, the cable design and soil conditions. The received signal from a person can be from -100 dB to -150 dB below the transmitted signal. The variation is primarily due to different soil conditions from one site to the next. Radiated field strength is also directly proportional to the same three factors - transmitted power, cable design and soil type. The first two factors are under the designers control but soil type is site dependant. In order to achieve reliable detection it is necessary to transmit enough power to maintain an adequate signal to noise ratio. At the same time it is necessary to limit transmitted power so as not to exceed permitted field strength limits. In order for the system to comply with field strength regulations and at the same time have adequate signal to noise ratio over the expected range of soil conditions it will be necessary to vary the transmit power as a function of soil type. What is effectively happening is that the gain of the antenna (in the cable) attached to the processor changes from site to site and the transmit power is being adjusted to compensate for the changed antenna. Section 15.203 of the FCC regulations anticipates this situation by allowing for variations in antenna gain for systems “such as perimeter protection systems” that are professionally installed. Since the OmniTrax transmission is in the frequency range of 26 to 37 MH two different limits apply. Section 15.209 states that below 30 MHz the maximum permitted field is 30 μV/m measured at 30 meters while above 30 MHz the maximum field is 100 μV/m measured at 3 meters. In accordance with ANSI C63.4-2003 below 30 MHz the measurement bandwidth shall be 9 kHz while above 30 MHz the measurement bandwidth shall be 100 kHz. Because OmniTrax uses a spread spectrum signal this change in bandwidth is very significant and results in the limit being effectively much lower above 30 MHz. 2 The field produced by OmniTrax takes the form of a surface wave over the cables. For this reason the field decays as a modified Bessel function of the first kind for the region nearest the cables. So the measurement at 3 meters is always significantly more than 20 dB higher (the decay expected for a normal antenna) than the measurement at 30 meters. Because the goal is to measure radiated (as opposed to guided fields) the OmniTrax fields have been calculated from the measurement at 30 meters and extrapolated back to 3 meters There is a precedent for making the measurements above 30 MHz at 30 meters rather than at 3 meters. 1 In this case the limit is extrapolated at 20 dB per decade so that limit used becomes 10 μV/m at 30 meters for frequencies above 30 MHz. The two factors taken together (field limit and bandwidth) mean that the effective limit for OmniTrax drops 22 dB at 30 MHz. For this reason we will concern ourselves primarily with the regulations for frequencies above 30 MHz. Fortunately field strength and sensitivity both vary in a similar way with soil type so that it is possible to both comply with the field strength limit and at the same time have adequate SNR. It is proposed to set the OmniTrax transmit power according to 63 2 − − = AbsSensdB TxPower (1) Where Tx Power is the power transmitted in dBm as measured with the CISPR 120 kHz bandwidth and quasi peak detector. AbsSensdB is the absolute sensitivity in dB For examples the peak sensitivity for the Hammond Site is -94 dB. So the maximum power that can be tramsitted at that site is: Tx Power = -(-94)/2 -63 Tx Power = -16 dBm Note that the power is set inversely proportionally to the square root (divide by 2 in dB) of the peak sensitivity. This is because sensitivity depends on the antenna gain of both the receive and transmit cables. The higher the sensitivity the lower the transmitter power that can be allowed and still maintain an acceptable field strength. In this report it will demonstrated that 1) Field strength is directly related to the square root of the sensitivity. 2) When the Tx power is set according to equation 1 the field strength is within the FCC field strength limits. The measurements made at each site are: 1) Recording the system sensitivity. 1 See FCC Part 15:31 f (1) and f(2). 3 2) Recording the field strength for each cable over the system center line (midway between the two cables). 2 3) At the four locations of highest field strength over the system center line measuring the field strength out to 30 meters radial distance from the cable. 3 OmniTrax Transmitted Signal 3.1 Field Strength Calculation Because the field levels are very low it is impractical to measure the fields directly. What has been done is to increase the transmit power to make the fields measurable and then correct the readings for the operational transmit level (as determined by equation 1). The measurements have also been made with a meter measuring 100 kHz bandwidth wi…

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Test Setup Photos