Download N 1673

WG8 N 1673
Test PCD Assembly for Additional
(Small) Antenna Classes
Reasoning, Requirements and Definitions
Late DIN comment to FCD Ballot ISO/IEC 10373-6/FPDAM8
= WG8 N 1638 (SC17 N 3836)
Source: Infineon Technologies, NXP Semiconductors
Berlin, April 2010
Table of Contents
 Reasoning
 Requirements
¬ Coupling factor
¬ Homogenous field area
 Definitions
¬ Calibration coil 2
¬ Test PCD antenna 2
¬ Test PCD antenna 2 tuning
¬ Test PCD assembly 2
 Conclusion
10.05.2017
Page 2
Reasoning (1)
 Definition of additional smaller antenna Classes requires
extended operating field strength range.
¬ Hmax value up to 18 A/m (rms) to be generated by Test PCD
assembly
 Power dissipation at Rext may get critical high!
10.05.2017
Page 3
Reasoning (2)
 Calculation:
¬ 18 A/m (rms) ->Simulation-> Iant = 3.75 A (rms)
¬ Power loss at:
– Rant = 1 Ohm: 14 W
– Rant = 4.7 Ohm: 66 W
20
20
18
16
14
12
H1z( xA
, 0 , 0.0375
H(d= 37.5
mm,
r)) 10
[A/m]
8
6
4
2
0
0
0
0
10.05.2017
0.01
0.02
0.03
0.04
0.05
r [m]xA
0.06
0.07
0.08
0.09
0.1
0.1
Page 4
Reasoning (3)
 Low Bit rate Test PCD Assembly
¬ Rant = 1 Ohm
¬
-> Change Power Range from 10 W to 15 W
 High Bit rate Test PCD Assembly
¬ Rant = 4.7 Ohm
¬ Cannot be used for Classes 4, 5, 6
¬ -> New smaller Test PCD assembly antenna required
10.05.2017
Page 5
Requirements (1)
 Coupling factor between new small Test PCD antenna and PICC
antenna of supported Classes shall be less than for current
configuration.
 Coupling factor of current configuration
¬ PICC antenna coil = Reference PICC
¬ k = 5.5 %
¬ Target: k < 5.5 % for
new assembly
10
37.5 mm
9
8
7
6
k%(0 m , z02)
k(d, r = 0)
[%]
5
4
3
2
1
0
0
0.01
0.02
0.03
0.04
0.05
dz02[m]
10.05.2017
Page 6
Requirements (2)
 Distance between new small Test PCD antenna and DUT shall be
chosen in a way to maximize homogenous field area at DUT
position.
¬ Target: Homogenous magnetic field with an area of Class 4.
 Definition of new smaller calibration coil for field strength
determination with Class 4 area.
10.05.2017
Page 7
New Calibration coil 2 (1)
 Coil characteristics
¬ The coil on the calibration coil card 2 shall have one turn. The
outer size of the coil shall be 47 mm × 24 mm with corner radius
2 mm. Relative dimensional tolerance shall be ± 2 %.
– NOTE 1 The area over which the field is integrated is approximately 1100 mm2
¬ The coil shall be made as a printed coil on printed circuit board
(PCB) plated with 35 μm copper. Track width shall be 500 μm with
a relative tolerance of ± 20 %. The size of the connection pads
shall be 1,5 mm × 1,5 mm.
– NOTE 2 At 13,56 MHz the approximate inductance is 140 nH and the
approximate resistance is 0,3 Ω.
¬ The open circuit calibration factor for this coil is 0,118 V (rms)
per A/m (rms) [Equivalent to 333 mV (peak-to-peak) per A/m
(rms)].
10.05.2017
Page 8
New calibration coil 2 (2)
 New Figure
ISO/IEC 7810 ID-1 outline
Coil 46 mm × 24 mm
1 turn
10.05.2017
Connections
Page 9
New Test PCD antenna 2 (1)
 The test PCD antenna 2 shall have a diameter of 100 mm and
its construction shall conform to following drawings.
100 mm
Antenna coil
Ground
compensation coil
10.05.2017
Page 10
New Test PCD antenna 2 (2)
 New test PCD antenna 2 matching for Bit rates fc/128 to fc/16
 Same quality factor (Q ≈10) as with high Bit rate antenna,
inductance approx. 300 nH.
50 
power driver
Antenna coil
impedance
matching
network
C1b
C1a
Z=50 
C2
C3
Rant
C4
Lant
Rext
10.05.2017
Value
Unit
Remarks
C1a
100
pF
Voltage range 200 V
C1b
4.7
pF
Voltage range 200 V
C2
270
pF
Voltage range 200 V
C3
68
pF
Voltage range 200 V
C4
2-27
pF
Voltage range 200 V
Rext
2,7
Ω
Power range 20 W
Page 11
New Test PCD assembly 2 (1)
 The sense coils and test PCD antenna shall be assembled parallel
and with the sense and antenna coils coaxial and such that the
distance between the active conductors is 23 mm as shown in
following figure.
23 mm
23 mm
A ctive
conductors
DUT
Calibration coil 2
Sense coil 2a
10.05.2017
Test PCD antenna
Sense coil 2b
Page 12
New Test PCD assembly 2 (2)
 Area of homogenous field:
H(d, r)
H(d, 0)
d = 37.5 mm, 150 mm antenna
r [m]
10.05.2017
H(d, r)
H(d, 0)
d = 23 mm, 100 mm antenna
r [m]
Page 13
New Test PCD assembly 2 (3)
 Coupling factor
¬ PICC antenna coil = Reference PICC 4 (Class 4)
k(d, r = 0)
[%]
-> k < 5.5 % achieved!
10.05.2017
d [m]
Page 14
Conclusion
 Power losses of new small Test PCD assembly:
¬ 18 A/m (rms) ->Simulation-> Iant = 2.35 A (rms)
¬ Power loss at:
– Rant = 2.7 Ohm: 15 W -> o.k.
20
18
16
14
12
H(d= 23
r))
H1z(mm,
xA , 0 , 0.023
[A/m]
10
8
6
4
2
0
0
0.02
0.04
r [m]
xA
0.06
0.08
0.1
¬ Small Test PCD assembly always with Sense coils 2
¬ Use of Small Test PCD assembly for Class 4, Class 5 and Class 6
10.05.2017
Page 15