Antenna trace layout

FCC ID: XPYVERAP174

Users Manual

Download: PDF
FCCID_3919004

VERA-P1 series antenna reference design
Topic :                VERA-P1 antenna reference design
Doc.No:                UBX-18022092
Revision               R01
                       Date:                                                    Name                                                           Signature
Created                09-Nov-2017                                              Stefan May                                                     smay
Checked
Released               04-Jun-2018                                              Daniel Dietterle                                               ddie
We reserve all rights in this document and in the information contained therein. Reproduction, use or disclosure to third parties without express authority is strictly forbidden.   © 2018 u-blox AG




1 Scope
This document defines the essential specifications necessary to implement the VERA-P173 /
VERA-P174 antenna reference designs. The information contained herein and its references
should be sufficient to guide a skilled person in an attempt to implement the design on a host
carrier. It will provide the designer with PCB layout details and expected performance
specifications.
The document supports a connector-based designs for the use of external antennas (one for each
antenna pin of the module).


2 FCC ID reference
Model                                                              FCC ID

VERA-P173-00A                                                      XPYVERAP174
VERA-P174-00A                                                      XPYVERAP174
Table 1: FCC IDs for different models of VERA-P1 series modules




3 General description and requirements
The antenna reference design provides two RF interfaces for connecting the external antennas.
Antenna ports ANT1 and ANT2 have a nominal characteristic impedance of 50  and must be
connected to the related antenna through a 50  transmission line to allow proper impedance
matching along the RF path; a bad termination of the pin may result in poor performance or even
damage to the RF section of the module.
For optimal antenna performance in multi-radio mode, the isolation between the antennas must be
maximized; the designer must follow the requirements specified in Table 2 and Table 3 to ensure
good performance.




VERA-P1 antenna reference design
UBX-18022092                                                                                                                                                                         Page 1 of 3


Item               Requirements                       Remarks

Impedance          50  nominal characteristic        The impedance of the antenna RF connection must match the
                   impedance                          50  impedance of the ANTx pin.
Frequency          5850 - 5925 MHz                    For 802.11p.
Range
Return Loss        S11 < -13 dB (VSWR < 1.5:1) Abs.   The return loss or the S11, as the VSWR, refers to the amount of
                   Max.                               reflected power, measuring how well the primary antenna RF
                                                      connection matches the 50  characteristic impedance of the
                                                      ANTx pin.
                                                      The impedance of the antenna termination must match as much
                                                      as possible the 50  nominal impedance of the ANTx pin over the
                                                      operating frequency range thus, maximizing the amount of the
                                                      power transferred to the antenna.
Efficiency         > -1.5 dB ( > 70% ) recommended    The radiation efficiency is the ratio of the radiated power to the
                   > -3.0 dB ( > 50% ) acceptable     power delivered to the antenna input. The efficiency is a measure of
                                                      how well an antenna receives or transmits.

Table 2: Summary of antenna interface requirements

Item                  Requirements                               Remarks

Isolation             |S21| > 50 dB recommended                  The antenna to antenna isolation is the loss between the
(in-band)             |S21| > 43 dB minimum                      primary and the secondary antenna; high isolation
                                                                 results from low coupled antennas.
Isolation             |S21| > 35 dB recommended                  Out-of-band isolation is evaluated in the band of the
(out-of-band)         |S21| > 30 dB acceptable                   aggressor to ensure that the transmitting signal from
                                                                 the other radio is sufficiently attenuated by the receiving
                                                                 antenna to avoid saturation and intermodulation effects
                                                                 at the receiver’s port.

Table 3: Summary of antenna isolation requirements




4 Reference design of RF path
The reference design of the 50 Ω path to connect the modules antenna pins with a SMA connector
is displayed in Figure 1 and the dimensions concerning the board stack-up (Table 4) are specified in
Table 5. An SMA connector is used to mount the antenna from Table 6.


PCB Layer                               Material                                   Thickness

Solder mask top                         General LPI solder mask                    20 µm

Top                                     Copper Foil                                35 µm
Dielectric                              Pre-preg                                   600 µm

L2                                      Copper Foil                                35 µm

Dielectric                              Core                                       240 µm
L3                                      Copper Foil                                35 µm

Dielectric                              Pre-preg                                   600 µm
Bottom                                  Copper Foil                                35 µm

Solder mask bottom                      Generic LPI Soldermask                     20 µm

Table 4: Stack-up of VERA-P1-EVK with standard FR4 substrate (εr = 4.6)




VERA-P1 antenna reference design
UBX-18022092                                                                                                      Page 2 of 3


Figure 1: Coplanar waveguide with ground dimension specification


Item                         Value

S                            400 µm

W                            900 µm

T                            35 µm

H                            600 µm

Spacing between ANT1 and     16 mm
ANT2 waveguides

Table 5: Coplanar waveguide with ground specification



5 Antenna
The module has been approved for use with any dipole antenna with less or equal to 6 dBi peak
gain. An example of an approved antenna is listed in Table 6.
Model name                   Manufacturer and description                     Gain [dBi] (peak)

TD.10.5113                   Taoglas, Dipole Terminal Antenna SMA Connector   5.88 dBi

Table 6: Approved antenna example




VERA-P1 antenna reference design
UBX-18022092                                                                                  Page 3 of 3



Document Created: 2018-06-11 15:49:13
Document Modified: 2018-06-11 15:49:13

© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC