User's Guide

LM940 HW Design Guide

1VV0301352 Rev. 2 Page 45 of 68 2017-07-19

7. RF SECTION

Antenna requirements

The antenna connection is one of the most important aspect in the full product design as it

strongly affects the product overall performance. Hence read carefully and follow the

requirements and the guidelines for a proper design.

The LM940 is provided with three RF connectors.

The available connectors are:

 Main RF antenna: TX/RX path

 Auxiliary RF antenna: Combined Diversity and GNSS

 GNSS RF antenna: Dedicated GNSS

Main Antenna Requirements

The antenna for the LM940 device must meet the following requirements:

WCDMA / LTE Antenna Requirements

Frequency range

Depending by frequency band(s) provided by the network

operator, the customer shall use the most suitable antenna for

that/those band(s)

The bands supported by the LM940 is provided in Section 2.2,

Product Variants and Frequency Bands.

Impedance 50 Ohm

Input power > 24 dBm average power in WCDMA & LTE

VSWR absolute max <= 10:1

VSWR recommended <= 2:1

Antenna Diversity Requirements

This product includes an input for a second Rx antenna to improve radio sensitivity. The

function is called Antenna Diversity.