Integration Instructions

Document Information Page 14 of 31
FSS JODY-W263 Integration Instructions Rev 02.docx
www.foresightsports.com
▪ A numerical example for estimating the physical restrictions on a PCB is
given here: Frequency = 2.4 GHz → Wavelength = 12.5 cm → Quarter
wavelength = 3.5 cm
o Radiation performance depends on the whole product 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.
Table 7 summarizes the requirements for the antenna RF interface while Table 8
specifies additional requirements for dual antenna design implementation.
Item
Requirements
Remarks
Impedance
50 Ω nominal characteristic
impedance
The impedance of the antenna RF
connection must match the 50 Ω
impedance of Antenna pins.
Frequency range
2400 - 2500 MHz
5150 - 5850 MHz
For 802.11b/g/n and Bluetooth.
For 802.11a/n/ac.
Return loss
S11 < -10 dB (VSWR < 2:1)
recommended
S11 < -6 dB (VSWR < 3:1)
acceptable
The Return loss or the S11, as the
VSWR, refers to the amount of
reflected power, measuring how
well the primary antenna RF
connection matches the 50 Ω
characteristic impedance of antenna
pins.
The impedance of the antenna
termination must match as much as
possible the 50 Ω nominal
impedance of antenna pins over the
operating frequency range, to
maximize the amount of 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 antenna input: the
efficiency is a measure of how well
an antenna receives or transmits.
Maximum gain
The maximum antenna gain must
not exceed the value specified in
type approval documentation to
comply with regulatory agencies
radiation exposure limits.
Table 7: Summary of antenna interface requirements