Ublox JODY-W164-03A, JODY-W164-07A Reference Design

JODY-W1 antenna reference design
UBX-18017767 Page 1 of 3

JODY-W1 antenna reference design

Topic :

JODY-W1 antenna reference design

Doc.No:

UBX-18017767

Revision

R01 Date:

Name

Signature

Created

24-Apr-2018

Stefan May

smay

Checked

Released

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 JODY-W1 antenna
reference designs. It is part of the equipment certification application issued to FCC and IC. 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/IC ID reference

Model

FCC ID

IC ID

JODY-W164-03A

XPYJODYW164

8595A-JODYW164

JODY-W164-07A

XPYJODYW164-07A

8595A- JODYW16407A

Table 1: FCC and IC IDs for different models of JODY-W1 series

3 General description and requirements

JODY-W1 series module provides three RF interfaces for connecting the external antennas.
Antenna ports ANT0 and ANT1 have a nominal characteristic impedance of 50 Ω and must be
connected to the related antenna through a 50 Ω 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.

The ANT2 antenna port is not used on the JODY-W164-03A and JODY-W164-07A modules.

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.

JODY-W1 antenna reference design
UBX-18017767 Page 2 of 3

Item

Requirements

Remarks

Impedance

50  nominal characteristic
impedance

The impedance of the antenna RF connection must match
the 50  impedance of Antenna pins.

Frequency Range

2400 - 2500 MHz
5150 - 5850 MHz

For 802.11b/g/n and Bluetooth.
For 802.11a/n/ac.

Return Loss

S11 < -10 dB (VSWR < 2:1)
recommended

S11 < -6 dB (VSWR < 3:1) acceptable

The Return loss or the S11, as the VSWR, refers to the
amount of reflected power, measuring how well the
primary antenna RF connection matches the 50 
characteristic impedance of antenna pins.

The impedance of the antenna termination must match as
much as possible the 50  nominal impedance of antenna
pins over the operating frequency range, to maximize the
amount of power transferred to the antenna.

Efficiency

> -1.5 dB ( > 70% ) recommended
> -3.0 dB ( > 50% ) acceptable

The radiation efficiency is the ratio of the radiated power
to the power delivered to antenna input: the efficiency is a
measure of how well an antenna receives or transmits.

Maximum Gain

The maximum antenna gain must not exceed the value
specified in type approval documentation to comply with
regulatory agencies radiation exposure limits.

Table 2: Summary of antenna interface requirements

Item

Requirements

Remarks

Isolation
(in-band)

S

21

> 25 dB recommended

S

21

> 20 dB acceptable

The antenna to antenna isolation is the S21 parameter
between the two antennas in the band of operation.

Isolation
(out-of-band)

S

21

> 35 dB recommended

S

21

> 30 dB acceptable

Out-of-band isolation is evaluated in the band of the
aggressor to ensure that the transmitting signal from
the other radio is sufficiently attenuated by the receiving
antenna to avoid saturation and intermodulation effect
at the receiver’s port.

Envelope
Correlation
Coefficient (ECC)

ECC < 0.1 recommended
ECC < 0.5 acceptable

The ECC parameter correlates the far field parameters
between antennas in the same system. A low ECC
parameter is fundamental to improve performance in
MIMO-based systems.

Table 3: Summary of MIMO and Wi-Fi/Bluetooth coexistence 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. The specification can be found in Table 4. The two coplanar ground planes
beside the signal trace should be connected to the lower ground plane using vias (illustrated in
Figure 2). It is recommended that this vias are placed with a maximum distance of 0.5 mm to the
coplanar ground edge and a maximum pitch of 2 mm. The top side should be coated with generic
LPI solder stop mask. The antenna traces should have a minimum distance of 20 mm, preferably
more, to ensure the required antenna to antenna isolation.

The SMA connector is used to mount an antenna. For Bluetooth and Wi-Fi operation in the 2.4 GHz
band and Wi-Fi operation in the 5 GHz band, the module has been tested and approved for use with
antennas up to 2 dBi antenna gain.