NORA-W30 series - System integration manual
UBX-22021119 - R02
Design-in
Page 21 of 52
C1-Public
summarizes the requirements for the antenna RF interface:
Item
Requirements
Remarks
Impedance
50
nominal characteristic
impedance
The impedance of the antenna RF connection must match
the 50
impedance of the
ANT
pin.
Frequency Range
2400
–
2500 MHz
5150
–
5850 MHz
Wi-Fi and Bluetooth
Wi-Fi
Return Loss
S
11
< -10 dB (VSWR < 2:1)
recommended
S
11
< -6 dB (VSWR < 3:1) acceptable
The Return loss or the S
11
, as the VSWR, refers to the
amount of reflected power, measuring how well the primary
antenna RF connection matches the 50
characteristic
impedance of the
ANT
pin.
The impedance of the antenna termination must match as
much as possible the 50
nominal impedance of the
ANT
pin over the operating frequency range, thus maximizing
the amount of the power transferred to the antenna.
Efficiency
> -1.5 dB ( > 70% ) recommended
> -3.0 dB ( > 50% ) acceptable
The radiation efficiency is the ratio of the radiated power to
the power delivered to the antenna input; the efficiency is a
measure of how well an antenna receives or transmits.
Maximum Gain
Refer to Data sheet
The maximum antenna gain must not exceed the value
specified in type approval documentation to comply with
the radiation exposure limits specified by regulatory
agencies.
Table 8: Summary of antenna interface (ANT) requirements for NORA-W301
Observe the following recommendations while selecting external or internal antennas:
•
Select antennas that provide optimal return loss (or VSWR) figure over all the operating
frequencies.
•
Select antennas that provide an optimal efficiency figure over all the operating frequencies.
•
Select antennas that provide an appropriate gain figure (that is, combined antenna directivity and
efficiency figure) so that the electromagnetic field radiation intensity does not exceed the
regulatory limits specified in some countries (for example, by FCC in the United States).
3.2.2.1
RF connector design
If an external antenna is required, the designer should consider using a proper RF connector. It is the
responsibility of the designer to verify the compatibility between plugs and receptacles used in the
design.
suggests several RF connectors that can be used by the designers to connect RF coaxial
cables based on the declaration of the respective manufacturers. The Hirose U.FL-R-SMT RF
receptacles (or similar parts) require a suitable mated RF plug from the same connector series. Due
to wide usage of this connector, several manufacturers offer compatible equivalents.
Manufacturer
Series
Remarks
Hirose
U.FL® Ultra Small Surface Mount Coaxial Connector Recommended
I-PEX
MHF® Micro Coaxial Connector
Tyco
UMCC® Ultra-Miniature Coax Connector
Amphenol RF
AMC® Amphenol Micro Coaxial
Lighthorse Technologies, Inc. IPX ultra micro-miniature RF connector
Table 9: U.FL compatible connectors
