NXP Semiconductors
AN11740
PN5180 Antenna design
AN11740
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Application note
COMPANY PUBLIC
Rev. 1.1 — 19 June 2018
345311
3 of 62
1. Introduction
The antenna design for the PN5180 is not much different than the antenna design for
most of the other NXP reader ICs in general. However, some PN5180 specific details
need to be considered to get an optimum performance.
This document describes the generic NFC and RFID antenna design rules in section 3 as
simple as possible, considering the different requirements due to ISO/IEC 14443, NFC or
EMVCo as introduced in section 2 and 3.
The section 4 describes the antenna design for the PN5180 in detail for mainly the
standard “asymmetrical” antenna tuning. The “symmetrical” tuning is shown, but requires
the “Dynamic Power Control” (DPC). Dedicated ANs describing the DPC related
“symmetrical” tuning in detail together with the calibration and use of the DPC (see [14]
and [15]).
In the Annex in section 5 some basics about the antenna impedance measurement and
the related tools can be found.
1.1 Dynamic Power Control
The Dynamic Power Control (DPC) feature of the PN5180 allows an improved antenna
design (called “DPC antenna design”) with improved transfer function. The DPC antenna
design and the specifics of the DPC are described in detail in [14] and [15].
2. NFC Reader Antenna design
For the NFC operation three different communication modes are specified in [4]:
1. In the
card emulation mode (CM)
the NFC device can be used in (existing)
NFC reader infrastructure. In the CM the NFC device behaves in principle like a
PICC, as defined in [2]. This mode is optional.
2. In the
card reader mode (RM)
the NFC device can be used with (existing) NFC
cards. In the RM the NFC device behaves in principle like a PCD, as defined in
[2]. This mode is mandatory.
3. In the
peer to peer mode (P2P)
the NFC device can communicate to other NFC
devices, either being the initiator, starting the communication, or being the target,
answering the communication.
The Fig 1 shows the NFC device in the center, offering all three NFC communication
modes. For the communication between two NFC devices the two different P2P modes
are available:
1.
Active P2P
: Both NFC devices, the initiator as well as the target, are required to
generate their own magnetic field, when sending data. This mode is optional.
2.
Passive P2P
: The initiator always generates the magnetic field, while the target
uses the load modulation principle to send its data. This mode is mandatory.
In this document only the analog topics are discussed, which are relevant for the antenna
design. Neither the digital protocol nor the advantages/disadvantages for different use
cases are content of this document.
