LENA-R8 series - System integration manual
UBX-22015376 - R02
Design-in
Page 55 of 116
C1-Public
As a numerical example, physical restriction to the PCB design can be considered as following:
Frequency = 617 MHz
→
Wavelength
48 cm
→
Minimum GND plane size
12 cm
The isolation between the primary and the secondary antennas must be as high as possible
and the correlation between the 3D radiation patterns of the two antennas must be as low as
possible. In general, a separation of at least a quarter wavelength between the two antennas
is required to achieve a good isolation and low pattern correlation.
o
Radiation performance depends on the whole PCB and antenna system design, including
product mechanical design and usage. Antennas should be selected with optimal radiating
performance in the operating bands according to the mechanical specifications of the PCB and
the whole product.
o
It is recommended to select a pair of custom antennas designed by an antennas’ manufacturer
if the required ground plane dimensions are very small (as less than 6.5 cm long and 4 cm wide).
The antenna design process should begin at the start of the whole product design process.
o
It is highly recommended to strictly follow the detailed and specific guidelines provided by the
antenna manufacturer regarding correct installation and deployment of the antenna system,
including PCB layout and matching circuitry.
o
Further to the custom PCB and product restrictions, antennas may require tuning to obtain
the required performance for compliance with all the applicable required certification schemes.
☞
It is recommended to consult the antenna manufacturer for the design-in guidelines for antenna
matching relative to the custom application.
In both cases, independently of external or internal antennas, these recommendations should be
observed:
•
Select antennas providing optimal return loss / VSWR / efficiency figure over all the operating
frequencies.
•
Select an antenna providing the worst possible return loss / VSWR / efficiency figure in the GNSS
frequency band, to optimize the RF coexistence between the cellular and the GNSS systems (see
section
for further details and guidelines regarding Cellular / GNSS RF coexistence).
•
Select antennas providing appropriate gain figure (i.e. combined antenna directivity and efficiency
figure) so that the electromagnetic field radiation intensity do not exceed the regulatory limits
specified in related countries (see the FCC United States notice reported in section
, the ISED
Canada notice reported in section
, the RED Europe notice reported in section
2.4.2.2
Examples of cellular antennas
This section contains example antennas that satisfy the aforementioned requirements. There are
numerous other part numbers and manufacturers, many offering customized solutions.
lists some examples of internal on-board surface-mount antennas.
Manufacturer
Part number Product name
Description
Taoglas
PA.760.A
WarriorX
Wideband LTE SMD antenna
600..6000 MHz
40.0 x 5.0 x 6.0 mm
Taoglas
PCS.26.A
Havok
LTE SMD dielectric antenna
617..960 MHz, 1710..2690 MHz
54.6 x 13.0 x 3.0 mm
Taoglas
PCS.66.A
Reach
Wideband LTE SMD antenna
600..6000 MHz
32.0 x 25.0 x 1.6 mm
Taoglas
PCS.06.A
Havok
GSM / WCDMA / LTE SMD Antenna
698..960 MHz, 1710..2170 MHz, 2500..2690 MHz
42.0 x 10.0 x 3.0 mm
