LN920 HW Design Guide
1VV0301730 Rev. 1
Page 54 of 81
2021-08-11
Not Subject to NDA
Figure 5: MHF-4 Receptacle
If FCC certification is required for an application using LN920, according to FCC KDB
996369 for modular approval requirements, the transmission line must be similar to the
one implemented on the LN920 interface board and described in the following chapter.
7.4.2.1.
Antenna Cable
Connecting cables between the module and the LTE/WCDMA antenna must have 50
Ω
impedance.
If the impedance of the module does not match, RF performance is significantly reduced.
Minimize Antenna Cable
Recommendations
Item
Value
Impedance
50 Ohm
Max cable loss
Less than 0.5 dB
Avoid coupling with other signals.
Table 27: Minimize Antenna Cable Recommendations
Warning: Impedence of RF connector and RF cable must be
matched to 50 Ohm. Impedance mismatching will cause poor RF
performance,especially i.e. RF cable with high insertion loss will
affect on Tx power and Rx sensitivity.
7.4.2.2.
Antenna Installation Guidelines
•
Each antenna must be installed with 20dB isolation.
•
Install the antenna in a location with access to the network radio signal.
•
The Antenna must not be installed inside metal cases.
•
The Antenna must be installed according Antenna manufacturer instructions.
•
Antenna integration should optimize the Radiation Efficiency. Efficiency values >
50% are recommended on all frequency bands.
•
Antenna integration should not perturb the radiation pattern described in the
Antenna manufacturer documentation.
•
It is preferable to get an omnidirectional radiation pattern.
