SAR test report 102040

FCC ID: LDK102039

RF Exposure Info

Download: PDF
FCCID_100711

SAR COMPLIANCE TESTING OF CISCO/AIRONET MODEL LDK102040 WIRELESS PC April 28, 2000 Submitted to: Mr. David A. Case NCE Senior Compliance Engineer Cisco Systems 3875 Embassy Parkway Akron, OH 44333 Submitted by: Om P. Gandhi Professor of Electrical Engineering University of Utah 50 S Central Campus Dr., Rm. 3280 Salt Lake City, UT 84112-9206

SAR COMPLIANCE TESTING OF CISCO/AIRONET MODEL LDK102040 WIRELESS PC I. Introduction The U.S. Federal Communications Commission (FCC) has adopted limits of human exposure to RF emissions from mobile and portable devices that are regulated by the FCC [1]. The FCC has also recently issued Supplement C (Edition 97-01) to OET Bulletin 65 defining both the measurement and the computational procedures that should be followed for evaluating compliance of mobile and portable devices with FCC limits for human exposure to radiofrequency emissions [2]. We have used the measurement procedure given in [2] to obtain peak 1-g SARs for the Cisco/Aironet Model LDK102040 Wireless PC. A photograph of this unit is shown in Fig. 1. As seen in Fig. 1, the RF antenna operating in the ISM frequency band 2412-2462 MHz is mounted at the back of the right-hand side of the keyboard. The Cisco/Aironet Model LDK102040 operates with a transmit power of up to 100 mW radiated from a printed patch antenna. Since the wireless PC may also be potentially placed on the lap where the RF antenna would be the closest to the body, a planar phantom model was used for all SAR measurements. II. The Tissue-Simulant Model The testing for the SAR distribution for the Cisco/Aironet Model LDK102040 Wireless PC was done with a planar rectangular box phantom model shown in Fig. 2. This box phantom of external dimensions 30 × 50 cm is filled with a tissue-simulant fluid up to a depth of 15.5 cm. To maintain flatness of the plantom, the rectangular box is made of acrylic 1

(εr = 2.56) of thickness 6.35 mm. The tissue-simulant fluid uses a composition developed at the University of Utah which consists of 62.0% water, 37.0% sugar and 1% HEC. 1

For this composition, we have measured the dielectric properties using a Hewlett Packard (HP) Model 85070B Dielectric Probe in conjunction with HP Model 8720C Network Analyzer (50 MHz-20 GHz). The measured dielectric properties at the midband frequency of 2450 MHz are as follows: εr = 51.3 ± 1.7 and σ = 1.76 ± 0.07 S/m. From reference 3, we obtain the desired dielectric properties to simulate the muscle tissue to be εr = 52.7 and σ = 1.74 S/m. Thus, the measured properties for the muscle-simulant fluid are close to the desired values. III. The Measured SAR Distributions The SAR distribution was determined using the automated SAR measurement system developed at the University of Utah [4]. As described in [4], this SAR measurement system has been validated using a number of wireless telephones at 835 and 1900 MHz, respectively. The highest SAR region was identified in the first instance by using a coarser sampling with a step size of 8.0 mm over three overlapping areas for a total scan area of 8.0 × 9.6 cm. After identifying the region of the highest SAR, the SAR distribution was measured with a resolution of 2 mm in order to obtain the peak 1 cm3 or 1-g SAR. The measured SAR distribution for the Cisco/Aironet Model LDK102040 Wireless PC operated in the maximum radiation mode (maximum radiated power of 30 mW) is given in Table 1. The peak 1-g SAR is determined to be 0.160 W/kg. IV. Comparison of the Data With FCC 96-326 Guidelines According to the FCC 96-326 Guidelines [1], the peak SAR for any 1-g of tissue should not exceed 1.6 W/kg. For the maximum radiated power condition, the Cisco/Aironet Model LDK102040 Wireless PC has been measured to give a peak 1-g SAR of 0.160 W/kg which is considerably smaller than 1.6 W/kg. 2

REFERENCES 1. Federal Communications Commission, "Guidelines for Evaluating the Environmental Effects of Radiofrequency Radiation," FCC 96-326, August 1, 1996. 2. K. Chan, R. F. Cleveland, Jr., and D. L. Means, "Evaluating Compliance With FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields," Supplement C (Edition 97-01) to OET Bulletin 65, December, 1997. Available from Office of Engineering and Technology, Federal Communications Commission, Washington D.C., 20554. 3. http://Sparc10.iroe.fi.cnr.it/tissprop/. 4. Q. Yu, O. P. Gandhi, M. Aronsson, and D. Wu, "An Automated SAR Measurement System for Compliance Testing of Personal Wireless Devices," IEEE Transactions on Electromagnetic Compatibility, Vol. 41(3), pp. 234-245, August 1999. 3

Table 1. The SARs measured for Cisco/Aironet Model LDK102040 Wireless PC. The SARs in W/kg are measured with a step size of 2 mm for the highest SAR region. 1-g SAR = 0.160 W/kg a. At depth of 1 mm 0.268 0.293 0.308 0.327 0.337 0.299 0.299 0.323 0.338 0.336 0.310 0.327 0.328 0.347 0.328 0.298 0.316 0.334 0.332 0.331 0.302 0.315 0.312 0.328 0.298 b. At depth of 3 mm 0.192 0.205 0.215 0.224 0.228 0.209 0.215 0.225 0.235 0.232 0.213 0.222 0.226 0.235 0.229 0.206 0.220 0.228 0.229 0.226 0.205 0.215 0.217 0.222 0.213 c. At depth of 5 mm 0.129 0.134 0.140 0.141 0.141 0.135 0.147 0.146 0.152 0.148 0.136 0.138 0.145 0.145 0.148 0.133 0.143 0.144 0.146 0.143 0.129 0.135 0.141 0.139 0.144 d. At depth of 7 mm 0.080 0.079 0.083 0.080 0.077 0.079 0.093 0.086 0.089 0.086 0.077 0.077 0.084 0.078 0.088 0.077 0.084 0.080 0.084 0.081 0.072 0.076 0.084 0.077 0.089 e. At depth of 9 mm 0.044 0.041 0.044 0.039 0.035 0.039 0.054 0.045 0.046 0.044 0.039 0.038 0.043 0.033 0.047 0.040 0.045 0.039 0.042 0.040 0.035 0.037 0.045 0.037 0.048 4

5

Fig. 1. Photograph of Cisco/Aironet Model LDK102040 Wireless PC with RF antenna inserted at the back on the right-hand side of the keyboard. 6

Fig. 2. Photograph of Cisco/Aironet Model LDK102040 Wireless PC mounted with its bottom pressed against the bottom of the planar tissue-simulant phantom. 7


Document Created: 2000-05-17 23:34:03
Document Modified: 2000-05-17 23:34:03
© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC