NXP Semiconductors
AN145715
PN544 Antenna Design Guide
145715
© NXP B.V. 2006. All rights reserved.
Application Note
Rev. 1.5 — 28th August 2009
8 of 43
4.
3B3B
Step 1 – Antenna Matching
The
RF block diagram
shows the circuitry design with all relevant components required
to connect an antenna to the PN544. It also ensures the transmission of energy and data
to the target device as well as the reception of a target device answer.
Fig. 3 Block diagram of the complete RF part
59H59H59H
Fig 6 shows only the RF part. For a proper operation the supplies and the host interface
have to be connected
The
EMC filter
reduces 13.56MHz harmonics and performs an impedance
transformation.
The
Matching Circuit
acts as an impedance transformation block and joins the antenna
to the EMC-filter.
The
Antenna
coil itself generates the magnetic field.
The
RX path
provides the signal to the PN544 internal receiving stage.
R2
Rx
