User's Manual
Table Of Contents
- Contents
- Tables
- Figures
- 1 Introduction
- 2 Interface Characteristics
- 2.1 Application Interface
- 2.2 RF Antenna Interface
- 2.3 Sample Application
- 3 Operating Characteristics
- 4 Mechanical Dimensions, Mounting and Packaging
- 5 Regulatory and Type Approval Information
- 6 Document Information
- 7 Appendix
Cinterion
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ELS31-/ELS51-US Hardware Interface Overview
2.2 RF Antenna Interface
29
ELS31-US_ELS51-US_HIO_v01.000a 2016-12-28
Confidential / Preliminary
Page 20 of 46
2.2 RF Antenna Interface
The RF interface has an impedance of 50Ω. ELS31-US/ELS51-US is capable of sustaining a
total mismatch at the antenna line without any damage, even when transmitting at maximum
RF power.
The external antenna must be matched properly to achieve best performance regarding radi-
ated power, modulation accuracy and harmonic suppression. Antenna matching networks are
not included on the ELS31-US/ELS51-US module and should be placed in the host application
if the antenna does not have an impedance of 50
Ω.
Regarding the return loss ELS31-US/ELS51-US provides the following values in the active
band:
Table 5: Return loss in the active band
State of module Return loss of module Recommended return loss of application
Receive >
8dB > 12dB
Transmit not applicable >
12dB