3. Results

At 900MHz the addition of the hand on the phone caused a drop in the peak SAR

levels, possibly due to the larger volume of tissue available for dissipating the power.

The temperature rise at 900MHz was higher without the hand although the distribution of

heat appears about the same, with and without the hand.  The peak temperature rise is

centered in the muscle of the jaw near the body of the phone. The results are summarized

in the following table and are shown graphically in Figure 2.

900MHz at 250mW

Peak 1g Avg

Peak 10g Avg

Peak Trise

Peak

Trise

(oC)

o

1800MHz at 125mW

SAR (W/kg)

SAR (W/kg)

( C) In Head

900 MHz no hand

1.22

0.78

0.065

0.065

900 MHz hand

0.89

0.57

0.051

0.051

1800 MHz no hand

0.72

0.42

0.036

0.036

1800 MHz hand

1.43

0.82

0.066

0.029

Figure 2: 1g SAR levels (top) and temperature rise (bottom) in the human head at 900MHz. The left

images are for the head alone. The right images include a hand on the phone and the scales are

adjusted to the peak values of the head-only images. The hand reduces the SAR and temperature

levels in the head but does not change the peak locations.

At 1800MHz the SAR levels are higher with the hand, the opposite of the

situation at 900MHz (see Figure 3). The thumb of the hand is located near the feed of the