K.3.2 provides an example using the data of Figure K.1 for the fast SAR 1 method. The steps of the procedure of 6.6.2 are followed below. This example illustrates the case of a wireless device having only one frequency band and one transmit mode and where the fast SAR method uses the same hardware as the full SAR system. The SAR values reported here are 1 g average values, with the applicable SAR limit of 1,6 W/kg applied. There are twelve test configurations. An example of what would create twelve test conditions is testing at both sides of the head (left and right) in both tilt and cheek positions for a device that has three different battery types.
a) Use the fast SAR method to perform measurements on a number of test configurations.
NOTE Table K.3 shows the results of the fast SAR measurements. All measurements were performed at the middle channel (whose frequency is closest to the centre of the transmit band).
Table K.3 – Measurements conducted according to Step a)
Test configuration number
SARfast SARfull
mid channel low channel middle channel high channel
1 0,570
2 0,565
3 0,958
4 1,403
5 0,470
6 0,978
7 0,789
8 1,320
9 0,586
10 0,593
11 1,125
12 0,915
b) For each of the N frequency bands and modulations evaluated in Step a), find the test configuration having the highest SAR value measured by the fast SAR technique, denoted SARmax,fasti (i = 1 to N). Use the full SAR method (according to the procedure in 6.4) to measure each of the N test configurations identified in this step, denoted SARmax,fulli. Select the maximum value among the N test configurations, SARmax,full = max(SARmax,fulli).
NOTE In this example there is only N = 1 frequency band and modulation and SARmax,fast1 = 1,403 W/kg. This value is shown in bold in Table K.4. The same test configuration is then measured using the full SAR method,
and a value of SARmax,full1 = 1,22 W/kg is found, as shown in Table K.4. Since N = 1,
SARmax,full = SARmax,full1 = 1,22 W/kg.
Table K.4 – Measurements conducted according to Step b)
Test configuration number
SARfast SARfull
mid channel low channel middle channel high channel
1 0,570
2 0,565
3 0,958
4 1,403 1,22
5 0,470
6 0,978
7 0,789
8 1,320
9 0,586
10 0,593
11 1,125
12 0,915
c) From the N groups of frequency bands and modulations defined in Step a), choose the i-th one corresponding to SARmax,full in Step b). For this i-th group, use the full SAR method (according to the procedure in 6.4) to measure all other test configurations (j = 1 to M, where M is the number of test configurations in the i-th group) if the condition of Formula (10) is met.
NOTE As discussed in K.3.1, it is assumed that the relative standard uncertainty is Ufast = 5 % (k = 1). Using Formula (11), with Ufasti = 5 %, Bfasti is calculated as 1,006 8. From Formula (10) with N = 1, fast − fast2−1=0,890
B i
B i
and from Table K.5, SARfasti = 1,403 W/kg. So all test configurations where SARfasti≥ 1,403 W/kg × 0,890 = 1,249 W/kg should be measured with the full SAR method. There are only two test configurations which satisfy this condition, as shown in bold in Table K.5. One of these test conditions has already been measured using the full SAR method (shown in Table K.4). So this step involves only one full SAR measurement, shown in Table K.5 below.
Table K.5 – Measurements conducted according to Step c)
Test configuration number
SARfast SARfull
mid channel low channel middle channel high channel
1 0,570
2 0,565
3 0,958
4 1,403 1,220
5 0,470
6 0,978
7 0,789
8 1,320 0,820
9 0,586
10 0,593
11 1,125
12 0,915
d) From the full SAR measurements that were measured in Step c), denoted SARfulli,j, choose the highest value, SARhighest,full = max(SARfulli,j):
SARhighest,full = max(1,220 W/kg, 0,820 W/kg) = 1,220 W/kg.
e) For each i-th group of frequency bands and modulations (i = 1 to N) that has not been evaluated according to Step c), use the threshold of Formula (12) to determine if Step c) is needed.
This step is not needed for the case where N = 1.
f) Use the full SAR method to measure any other test configurations that have not been tested by the fast SAR method in Step a) and are not excluded from testing by this Standard (e.g. by the test reduction procedures in 6.7) or by applicable national regulations. This includes ensuring that the requirements of 6.3, Step 2) be met regarding the testing of all required frequencies across the applicable frequency band using the procedure of 6.6.3.
g) Identify all test configurations where fast SAR measurements were made at the channel that is closest to the centre of the transmit frequency band and where testing across the applicable frequency band has not been conducted.
NOTE These are all 12 test configurations of Table K.3.
h) Group all of the test configurations found in Step 1) together, regardless of frequency band or modulation, and sort them in descending order according to the ratio Rk = SARfastk / SARlimit (where SARlimit is the applicable SAR limit for that test configuration).
NOTE The applicable SAR limit is SARlimit = 1,6 W/kg for all test configurations. The sorted list is shown in Table K.6 below.
Table K.6 – Measurements conducted according to 6.4.2, Step 2)
Test configuration
number
SARk,fast
k
Rk SARfull
mid channel mid
channel low channel middle
channel high
channel
4 1,403 1 0,877 1,22
8 1,320 2 0,825 0,820
11 1,125 3 0,703
6 0,978 4 0,611
3 0,958 5 0,599
12 0,915 6 0,572
7 0,789 7 0,493
10 0,593 8 0,370
9 0,586 9 0,367
1 0,570 10 0,356
2 0,565 11 0,353
5 0,470 12 0,294
i) Perform full SAR measurements (according to the procedure in 6.4.2) on each test configuration identified in Step 2) in the sequence k = 1, 2, 3, etc. (unless this measurement has been conducted already) when the k-th configuration to be measured meets the condition of Formula (K.4).
− −
×
×
≥ 1
2limit fast fast2 min
fast R SAR B B
SAR k (K.4)
where
Rmin is the minimum of all available fast SAR and corresponding full SAR measurement results ratios Rmin =min{SARk,fast/SARk,full}, and Bfast = 1 / [1 – (1,64 max(Ufasti)2]. In other words, Bfast is the smallest of the Bfasti values in Formula (11) over all considered frequency bands (i.e. the one with the highest uncertainty Ufasti).
From the available data, Rmin = min(1,403/1,22, 1,320/0,820) = 1,15. Full SAR measurements
should be performed on all k test configurations where
SARfastk≥ 1,15 W/kg × (1,6 / 2) × (0,890 W/kg) = 0,819 W/kg. This corresponds to k = 1 to 6.
The full SAR measurements are already performed for k = 1 and k = 2. Four additional full SAR measurements are needed, as shown in Table K.7.
Table K.7 – Measurements conducted according to 6.4.2, Step 3)
Test configuration number
SARk,fast
k
SARfull
mid channel low channel middle
channel high channel
4 1,403 1 1,220
8 1,320 2 0,820
11 1,125 3 0,780
6 0,978 4 0.767
3 0,958 5 0,708
12 0,915 6 0,690
7 0,789 7
10 0,593 8
9 0,586 9
1 0,570 10
2 0,565 11
5 0,470 12
j) For all test configurations where SARfull is within 3 dB of the applicable SAR limit in Step 3), measure the SAR at all of the required test frequencies in 6.2.5. Either a fast SAR method or the full SAR method may be used for this purpose.
There are only two test conditions where SARfullk > 0,8 W/kg. Therefore, four tests are to be performed in this step (corresponding to k = 1 and k = 2). In this example it is assumed that the full SAR method is used for these tests. The results are shown in Table K.8.
Table K.8 – Measurements conducted according to 6.4.2, Step 4)
Test configuration number
SARfast
k SARfull
mid channel low channel mid channel high channel
4 1,403 1 1,140 1,220 1,210
8 1,320 2 0,734 0,820 0,777
11 1,125 3 0,780
6 0,978 4 0,767
3 0,958 5 0,708
12 0,915 6 0,690
7 0,789 7
10 0,593 8
9 0,586 9
1 0,570 10
2 0,565 11
5 0,470 12
k) If a fast SAR method was used in Substep 4), apply Step e) of 6.6.2 to check if full SAR measurements are required for those test configurations.
This step does not need to be applied, given that Substep 4) used the full SAR method.
For this example, twelve fast SAR tests and ten full SAR tests were performed. If fast SAR testing had not been applied, sixteen full SAR tests would have been required (twelve test configurations plus low and high channels for two of the test configurations).