u-blox LEXI-R422, Руководство по системной интеграции

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LEXI-R422 - System integration manual
UBX-23007449 - R02 Design-in Page 57 of 108
C1-Public
u-blox host PCB
LEXI-R422
A3 ANT
A5
ANT_DET
R2
C2 D1
L2
C1
J1
Z
0
= 50
Ω
Z
0
= 50
Ω
GND
L1
Figure 34: Antenna trace design implemented on the u-blox host PCB, with additional antenna detection circuit
Reference Description Part number – Manufacturer
C1 47 pF capacitor ceramic C0G 0201 2% 50 V GRM0335C1H470GA01 – Murata
C2 39 pF capacitor ceramic C0G 0201 5% 50 V GRM0332C1H390JA01 – Murata
D1 Low capacitance ESD protection CG0402MLE-18G – Bourns
L1 39 nH multilayer inductor 0402 (SRF ~1 GHz) Not Installed
L2 82 nH multilayer inductor 0402 (SRF ~1 GHz) LQG15HS82NJ02B – Murata
R2 10 k  resistor 0402 1% 0.063 W Generic manufacturer
J1
SMA connector 50  through hole jack
SMA6251A1-3GT50G-50 – Amphenol
Table 23: Parts in use on the u-blox host PCB for the antenna trace design, with additional antenna detection circuit
The u-blox host PCB has a structure of 6 copper layers with 35 µm thickness (1 oz/ft 2 ) for all the layers
except the two inner buried layers, having 18 µm thickness (1/2 oz/ft 2 ), using FR4 dielectric substrate
material with 4.3 typical permittivity and 0.013 typical loss tangent at 1 GHz.
The top layer layout of the u-blox host PCB is described in Figure 35 , implementing the RF antenna
trace designed as a 50  grounded coplanar waveguide, with ~24 mm length from the pad designed
to accommodate the ANT pad of LEXI-R422 module up to the pads designed to accommodate the
SMA RF connector for an external cellular antenna and/or RF coaxial cable.
500 µm
500 µm
550 µm
D1
C2
RF Trace
R1
L2
C1
SMA Connector
J1
ANT pad
0.6 x 0.6 mm
ANT_DET
LEXI
Figure 35: Top layer (L1) layout of the u-blox host PCB with the antenna RF trace design