PN544 Antenna Design Guide (NFC匹配计算)
value unit annotation f res Reader =1.356E+07[Hz]Reader Mode target resonance frequency to be filled out omega =8.520E+07[s -1]
fixed/calculated values
L 0 =5.600E-07[H]EMC inductance
f r0 =1.550E+07[Hz]EMC Filter frequency C 0 calculated =1.883E-10[F]C 0 =1.800E-10[F]chosen value for C0
f res EMC =1.585E+07[Hz]EMC Filter frequency 180+56R match =8.000E+01[Ω]Target impedance of final antenna tuning
R tr =1.785E+02
X tr =-5.236E+01
Antenna:linear view unit annotation
L a =1.260E-06[H]antenna inductance measured at 1MHz R s =1.200E+00[Ω]antenna serial resistance measured at
1MHz
R p =1.329E+03[Ω]antenna parallel resistance measured at
self resonance frequency of the antenna
f ra =4.166E+07[Hz]self resonance frequency of the antenna Rp (13.56MHz) = 2.329E+03[Ω]parallel resistance calculated at 13.56MHz based on self resonance
frequency measurement
R a =6.147[Ω]serial and parallel resistor of antenna at
13.56MHz
C a =1.158E-11[F]parallel capacitance of antenna Q a =17.463calculated quality factor of antenna Target Q =30Fill out target quality factor of antenna
R Q =-1.284[Ω]Resistance needed for Target Q
uncheck if no external damping resistor
is required
S t e p 3Antenna:linear view unit annotation
L a =1.809E-06[H]antenna inductance measured at 1MHz R s =1.410E+00[Ω]antenna serial resistance measured at 1MHz
R p =2.461E+03[Ω]antenna parallel resistance measured at self resonance frequency of the antenna f ra =4.136E+07[Hz]self resonance frequency of the antenna Rp (13.56MHz) = 4.298E+03parallel resistance calculated at
13.56MHz based on self resonance
frequency measurement
R a =6.938[Ω]serial and parallel resistor of antenna at 13.56MHz
C a =8.186E-12[F]parallel capacitance of antenna Q a =22.216calculated quality factor of antenna including damping resistors R Q
Antenna:linear view unit annotation L pa =1.809E-06[H]
C pa =8.186E-12[F]
R pa =3.424E+03[Ω]
Q pa =22.216
Matching Circuit:value unit annotation C1 = 3.218E-11[F]
C2 = 1.059E-10[F]solder C2 at place C2A Matching Circuit:value unit annotation C1 = 3.218E-11[F]final values found
C2 = 1.059E-10[F]final values found
Matching Circuit:value unit annotation Card mode target
resonance
frequency 1.600E+07[Hz]choose card mode target resonance frequency between 14.5MHz and 16MHz Cshift 3.080E-11[F]total parallel capacitance for the reader
mode needs to be 3.0803823751914E-
11F higher than in card mode
C2B 6.161E-11[F]calculated value for C2B (card mode
tuning, frequency shift)
C2A 4.428E-11[F]calculated value for C2A C2B impedance at
13.56MHz =190.51[Ω]resistance to be considered during field
current extraction (PbtF)
Matching Circuit:value unit annotation C2B 1.000E-11[F]
C2A 1.900E-11[F]
approximation of C2B
impedance at 13.56MHz
=1,173.71[Ω]resistance to be considered during field
current extraction (PbtF)I n f
o
r m a t i
o n I n f
o r m a
t i o n S t e p
6When Simulating with RFSim99, take care the program is correctly
installed and RFSim working path is set first
color explanation 1st Iteration: Measurement of Antenna parameter L a , R s , R p,f ra choose an appropriate value for R
Q and perform a 2nd antenna measurement for L a , R s , R p ,f ra
2nd Iteration: Measurement of Antenna parameter L a , R s , R p,f ra Parallel equivalent antenna circuit
S t e p
7S t
e p 8PN544 Matching Calculations
Calculated Matching Components Fill out real values for C1 and C2 after finetuning Connection of ANT pins / split C2
Fill out real values for C2A and C2B after finetuning
S t
e p 1S t e p
2S t
e p 4check to use Rq
C:\Data\NXP_NFC\wayne wu\RF\RFsim99\RFSim99.exe