Tunable Antenna Control - Huawei ME909u-523 Hardware Manual

HUAWEI ME909u-523 LTE LGA Module
Hardware Guide
Figure 3-24 RF Pad design for ME909u-523
Layer 01
Layer 02
Layer 03
Please use impedance simulation tool to calculate RF MAIN pad impedance. The RF
MAIN pad dimension of ME909u-523 is 1.1 mm (L) x 0.9 mm (W). You can get the
impedance with lower than 50 Ω calculated by the impedance simulation tool. Since
the target impedance is 50 Ω for RF trace, the recommended solution is that to carve
out the copper area of the second layer that projected by the RF MAIN pad at top
layer. How many layers should be carved out depend on the PCB permittivity, track
width, and distance from the floor of your own PCB. Our target is to make the RF
MAIN pad impedance as closer to 50 Ω as possible.
3.13

Tunable Antenna Control

The ME909u-523 module provides 4 tunable antenna control pins. The mapping of
each band to ANT_TUNE outputs is configurable.
The firmware function is planning.
Table 3-15 List of tunable antenna control pins
PIN Pin Name
No.
21 ANT_TUNE0
22 ANT_TUNE1
23 ANT_TUNE2
24 ANT_TUNE3
Issue 01 (2014-05-24)
Pad Description
Type
O Tunable antenna
control signal, bit 0
O Tunable antenna
control signal, bit 1
O Tunable antenna
control signal, bit 2
O Tunable antenna
control signal, bit 3
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Description of the Application Interfaces
A = RF pad length + 50 mils
B = RF pad width + 40 mils
RF pad
reference
ground
Parameter
V
OH
V
OL
V
OH
V
OL
V
OH
V
OL
V
OH
V
OL
Min. (V) Typ. (V)
1.35 1.8
0 -
1.35 1.8
0 -
1.35 1.8
0 -
1.35 1.8
0 -
Max. (V)
1.8
0.45
1.8
0.45
1.8
0.45
1.8
0.45
44