HUAWEI MU709 Series HSPA+ LGA Module
Hardware Guide
Description of the Application Interfaces
Issue 09 (2017-12-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
44
Figure 3-24
RF Pad design for MU709
Please use impedance simulation tool to calculate RF MAIN pad impedance. The RF
MAIN pad dimension of the module 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.
3.12 Reserved Interface
The module provides some reserved pins. All reserved pins cannot be used by the
customer.
All of them should be Not Connected
.
Table 3-15
Reserved pin
Pin No.
Pin Name
Pad
Type
Description
Parameter
Min.
(V)
Typ.
(V)
Max.
(V)
28, 29, 31, 35, 43
–46,
60
–65, 91, 102 and 104
Reserved
-
Reserved, please
keep this pin open.
-
-
-
-
3.13 NC Interface
The module has some NC pins. There is no signal connected to these pins.
