Integration Manual
Table Of Contents
- Preface
- Contents
- 1 System description
- 1.1 Overview
- 1.2 Architecture
- 1.3 Pin-out
- 1.4 Operating modes
- 1.5 Power management
- 1.6 System functions
- 1.7 RF connection
- 1.8 (U)SIM interface
- 1.9 Serial communication
- 1.10 DDC (I2C) interface
- 1.11 Audio Interface
- 1.12 General Purpose Input/Output (GPIO)
- 1.13 Reserved pins (RSVD)
- 1.14 Schematic for LISA-U series module integration
- 1.15 Approvals
- 2 Design-In
- 2.1 Design-in checklist
- 2.2 Design Guidelines for Layout
- 2.2.1 Layout guidelines per pin function
- 2.2.2 Footprint and paste mask
- 2.2.3 Placement
- 2.3 Thermal aspects
- 2.4 Antenna guidelines
- 2.5 ESD precautions
- 3 Features description
- 4 Handling and soldering
- 5 Product Testing
- Appendix
- A Migration to LISA-U2 series wireless modules
- B Glossary
- Related documents
- Revision history
- Contact
LISA-U series - System Integration Manual
3G.G2-HW-10002-A3 Preliminary Design-In
Page 121 of 160
For integration observe these recommendations:
Ensure 50 Ω antenna termination, minimize the V.S.W.R. or return loss, as this will optimize the electrical
performance of the module. See section 2.4.1
Select antenna with best radiating performance. See section 2.4.2
If a cable is used to connect the antenna radiating element to application board, select a short cable with
minimum insertion loss. The higher the additional insertion loss due to low quality or long cable, the lower
the connectivity
Follow the recommendations of the antenna manufacturer for correct installation and deployment
Do not include antenna within closed metal case
Do not place the main antenna in close vicinity to end user since the emitted radiation in human tissue is
limited by S.A.R. regulatory requirements
Do not use directivity antenna since the electromagnetic field radiation intensity is limited in some countries
Take care of interaction between co-located RF systems since the GSM transmitted power may interact or
disturb the performance of companion systems
Place antenna far from sensitive analog systems or employ countermeasures to reduce electromagnetic
compatibility issues that may arise
The antenna for the Rx diversity should be carefully separated from the main Tx/Rx antenna to ensure
uncorrelated signals received at each antenna, because signal improvement is dependent on the cross
correlation and relative signal strength levels between the two received signals. The distance between the
two antennas should be greater than half a wavelength of the lowest used frequency (i.e. distance greater
than ~20 cm, for 2G/3G low bands) to distinguish between different multipath channels
2.4.1 Antenna termination
The LISA-U series modules are designed to work on a 50 load. However, real antennas have no perfect 50
load on all the supported frequency bands. Therefore, to reduce as much as possible performance degradation
due to antenna mismatch, the following requirements should be met:
Measure the antenna termination with a network analyzer: connect the antenna through a coaxial cable to the
measurement device, the |S
11
| indicates which portion of the power is delivered to antenna and which portion is
reflected by the antenna back to the module output.
A good antenna should have an |S
11
| below -10 dB over the entire frequency band. Due to miniaturization,
mechanical constraints and other design issues, this value will not be achieved. An |S
11
| value of about -6 dB - (in
the worst case) - is acceptable.
Figure 63 shows an example of this measurement:
Figure 63: |S
11
| sample measurement of a penta-band antenna that covers in a small form factor the 4 GSM bands (850 MHz, 900
MHz, 1800 MHz and 1900 MHz) and the UMTS Band I