Fig 14. Typical Antenna Matching Circuit; Antenna Interface; Typical Matching Circuit; Matching Circuit Bom Optimization - NXP Semiconductors PN7150 Hardware Design Manual

NXP Semiconductors

7. Antenna interface

7.1 Typical matching circuit

The PN7150 is intended to be connected to an antenna through a matching circuit.
The typical topology for this circuit is depicted below:

Fig 14. Typical antenna matching circuit

The components values are antenna dependent.
L
0
high frequency range but without altering the meaningful communication signal.
C
1
adapt the equivalent impedance presented on TX1/TX2 at this frequency (70 ohms
recommended).
R
q
already below, which is rather common in embedded equipment environment with ferrite
shielding, R
How to select or design a proper antenna for the PN7150 and how to calculate the value
of the matching components is explained in a dedicated application note. Please refer to
the PN7150 Antenna Design and Matching Guide [4].

7.2 Matching circuit BoM optimization

Based on careful technical consideration, the number of matching circuit components
presented on the above schematics can be lowered.
AN11756
Application note
COMPANY PUBLIC
/ C are a 2 nd order low pass filter used to reduce the spectrum power amplitude in the
0
/ C are used to tune the Poll mode and Listen mode frequency at 13.56MHz and to
2
is optionally used to reduce the qualify factor of the antenna when it is above 35 (if it is
must not be placed)
q
All information provided in this document is subject to legal disclaimers.
Rev. 1.2 — 15 January 2018
347612
AN11756
PN7150 Hardware Design Guide
© NXP B.V. 2018. All rights reserved.
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