Smart Machine Smart Decision
SIM68R_Hardware Design_V1.02
20
2013-01-22
4.7.1
Antenna Interface
The SIM68R receives L1 band signals from GNSS and GALILEO satellites at a nominal frequency of 1574
～
1606 MHz. The RF signal is connected to the RF_IN pin.
And
the trace from RF_IN to antenna should be 50
Ω
controlled.
To suit the physical design of individual applications the RF interface pad can lead to three alternatives:
z
Recommended approach: solderable
RF
coaxial cable assembly antenna connector, such as HRS’
U.FL-R-SMT(10) connector or I-PEX’s 20279-001E-01 RF connector.
z
SMA connector.
4.7.2
GNSS Antenna Choice Consideration
To obtain excellent GNSS receiving performance, a good antenna will always be required. The antenna is the
most critical item for successful GNSS receiving in a weak signal environment. Proper choice and placement of
the antenna will ensure that satellites at all elevations can be seen, and therefore, accurate fix measurements are
obtained.
4.7.2.1
Passive Antenna
Passive antenna contains only the radiating element, e.g. the ceramic patch, the helix structure, and chip
antennas. Sometimes they also contain a passive matching network to match the electrical connection to 50 Ohms
impedance.
The most common antenna type for GNSS applications is the patch antenna. Patch antennas are flat, generally hav
e a ceramic and metal body and are mounted on a metal base plate.
Figure 5 shows a minimal setup for a PVT GNSS receiver with SIM68R module.