User's Manual

13
2016-03-18
NUR-10W HW Implementation Guide v1.4
4 OEM DESIGN CONSIDERATIONS
4.1 RF OUTPUT AND ANTENNA REQUIREMENTS
The RF output / input impedance is 50Ω so the trace leaving from the RF pin shall be kept in that same
impedance level to avoid reflections and mismatch of the RF signal. From the RFID reader module’s point of
view it is important that the used antenna has a low VSWR value. The VSWR shall be better than 1.5:1 in
order to avoid decrease in the sensitivity performance of the receiver because of the TX power reflecting
back from the antenna. In the NUR-10W module, there is also an automatic leakage cancellation system
that decreases the effect of the reflected signal, and it also improves the isolation of the RX signal from the
TX signal. The automatic leakage cancellation can be triggered using SW API command. For further
information on the leakage cancellation see the section 5.3.
4.1.1 LAYOUT RECOMMENDATIONS
Figure 4. RF output layout of the reference design.
Component places R2, R3, and R12 are for additional output matching. Additional matching is not used in a
reference design. Thus values are as follow: R3 = No assembly, R12 = No assembly and R2 = 100pF 0402
capacitor.
Because NUR-10W is a wireless device, the RF section must be the top priority in terms of layout. It is very
important that the layout design is made by following the proper RF design guidelines to get to optimal