SAR test requirements for netbooks with built-in 3G or WIFI modules

    The Federal Communications Commission (FCC) of the United States has introduced a series of test requirements for various mobile transmitters. These mainly include the corresponding regulations and requirements for the placement and limit values ​​of wireless transmitters such as 3G modules and WIFI modules in the SAR test. This article will explain the setting, placement and limit value requirements of 3G modules and WIFI modules in SAR testing. 1.
    SAR test requirements for netbooks with built-in 3G modules
    The test requirements for 3G modules are mainly defined according to the FCC procedure file KBD447498. The specific main contents are as follows:
    1. When a single module has no restrictions on the use platform, the SAR limit value of the test 1g standard material is <0.4W/kg.
    2. A single module can be used for designated products such as PDAs, laptops, e-books, etc., and the SAR limit value of the test 1g material is <0.8W/kg. 3.
    A single module can only be used for products of the same model, and the SAR limit value of the test 1g standard material is <1.2W/kg.
    The placement of the test position needs to be determined according to the antenna position of the use platform. If the wireless module is in the laptop, according to the position of the laptop's antenna (Figure 1), the laptop needs to be placed in three states during the test (Figure 2). Figure 1 The red circle is the wireless module antenna Figure 2 SAR test placement Figure     2. SAR test requirements for netbooks with built-in WIFI modules     The WIFI module test requirements are mainly defined according to the FCC procedure file KBD248227. Its restrictions and location access definitions are consistent with the 3G module requirements introduced earlier, but there are a few points that need to be explained:     1. Test equipment requirements: WIFI module control software must be provided, and the software must have functions such as selecting channels, data rates, and setting fixed-frequency transmission.     2. Working mode requirements         802.11 a/g (OFDM)         rates: 6, 9, 12, 18, 24, 36, 48, 54 Mbps         802.11 b (DSSS)         rates: 1, 2, 5.5, 11 Mbps     3. Common channel requirements for WIFI testing (as shown in Figure 3).

802.11a		802.11b/g
Channel No.	Frequency （GHz）	Channel No.	Frequency（GHz）
42	5.21	6	2.437
50	5.25
58	5.29
152	5.76
160	5.80

The above contents in Figure 3
    are mainly for the SAR test requirements when applying for FCC certification for netbooks with built-in 3G modules and WIFI modules. In addition, for SAR tests of special types of products (such as: data card antennas can rotate, products with HSUPA functions, etc.), it is necessary to communicate the test methods directly with the FCC before testing in order to obtain the KDB inquiry number. The KDB inquiry number must be indicated in the test report of this type of SAR, so that the TCB can accept the review. For this type of special product, the FCC certification process is usually much longer than that of ordinary wireless products, so it is necessary to apply in advance and leave enough certification period.