**7.3.2 Results of surface-scanning measurement**

From the results of noise level measurement, we first obtained the interference frequencies generated from LCD panel. We then used the magnetic near-field probe to observe the noise influence on wireless communication bands via antenna ports from LVDS cables, connectors, and driver ICs of the LCD panel control circuits when LCD panel was set to various operation modes, (such as off, standby, and key-in alphbat H pattern mode). Figures 61-63 show the change of transmission coefficients between antenna port and LVDS cables of the LCD panel control circuits. The measured result on left is for horizontal orientation of near-field probe placement, and the one on right is for vertical orientation. When magnetic probe is placed in vertical orientation, it is in parallel with routing traces of LVDS connector and thus results in higher sensitivity. We also observed that the coupling level are much higher for LCD panel operated in standby or key-in alphbat H pattern mode than shut off.

Figures 64 and 65 show the change of transmission coefficients between antenna port and driver IC of the LCD panel control circuits. The measured result on left is for horizontal orientation of near-field probe placement, and the one on right is for vertical orientation. We observed that the noises coupled to antenna port are much higher for LCD panel is turned on or displays H pattern mode than shut off, because the control IC is activated.

of Camera is 48 MHz, we can conclude that its 50th and 54th harmonics just fall at 2400MHz and 2592MHz, the most significant noise level frequencies, respectively. Therefore, the receiving sensitivity and thus the communications performance in 2.4 GHz band are

> **CCD off/on/record Noise floors Background CCDoff CCDon CCDrecord**

From the results of noise level measurement, we first obtained the interference frequencies generated from LCD panel. We then used the magnetic near-field probe to observe the noise influence on wireless communication bands via antenna ports from LVDS cables, connectors, and driver ICs of the LCD panel control circuits when LCD panel was set to various operation modes, (such as off, standby, and key-in alphbat H pattern mode). Figures 61-63 show the change of transmission coefficients between antenna port and LVDS cables of the LCD panel control circuits. The measured result on left is for horizontal orientation of near-field probe placement, and the one on right is for vertical orientation. When magnetic probe is placed in vertical orientation, it is in parallel with routing traces of LVDS connector and thus results in higher sensitivity. We also observed that the coupling level are much higher for LCD panel operated in standby or

**2286 2336 2386 2436 2486 2536 2586 2636 2686 Frequency(MHz)**

Figures 64 and 65 show the change of transmission coefficients between antenna port and driver IC of the LCD panel control circuits. The measured result on left is for horizontal orientation of near-field probe placement, and the one on right is for vertical orientation. We observed that the noises coupled to antenna port are much higher for LCD panel is turned

on or displays H pattern mode than shut off, because the control IC is activated.

degraded by the activation of Camera functions.

Fig. 60. Noise level for different Camera operation mode.

**7.3.2 Results of surface-scanning measurement** 

**-120**

**-115**

**-110**

**-105**

**dB**

**m**

**-100**

**-95**

**-90**

**-85**

key-in alphbat H pattern mode than shut off.

(a) Measurement position

(b) Measured result of S21

Fig. 61. Measurement position (a) and (b) result of LCD Panel control circuit.

(b) Measured result of S21

Fig. 62. Measurement position (a) and (b) result of LCD Panel control IC.

(a) Measurement position

(b) Measured result of S21

Fig. 63. Measurement position (a) and (b) result of LCD Panel control circuit.

(b) Measured result of S21

Fig. 64. Measurement position (a) and (b) result of LCD Panel control circuit.
