JODY-W5 antenna reference design

Abstract

This application note describes the module and integrated antenna reference design, which was subsequently used to acquire the appropriate FCC and ISED grant. It highlights the module and antenna requirements, performance expectations, and explains the RF path implemented between the various components of the test setup used during the certification.

1 Introduction

This document describes the antenna reference design integrated with JODY-W5 modules, which was subsequently used to acquire the appropriate FCC and ISED grant. To leverage this existing u-blox grant, customers must copy this design exactly into their application product. Any proposed deviation from this reference design must be filed with the FCC/ISED to determine whether it can be considered as a "permissive change" to the original grant or is significantly different to warrant the application of a completely new equipment grant of certification (new FCC ID). See also the FCC Permissive Change Policy [3].

The given information should be sufficient to allow for a skilled person to implement the antenna design on an application product. It provides the designer with the necessary PCB layout details including microstrip type, dimensions, and antenna interface requirements.

The JODY-W5 antenna design supports a connector-based design for use with two (JODY-W562) external antennas.

2 General description and requirements

The antenna ports ANTO and ANT1 have a nominal characteristic impedance of 50 Ω. To allow proper impedance matching along the RF path, each port must be connected to the related antenna through a 50 Ω transmission line. A bad termination of the pin can result in poor performance or even damage the RF section of the module. Antenna interface and antenna requirements are described in Table 1.

Table 1: Summary of antenna interface requirements

For optimal performance in multiradio mode, the isolation between the antennas must meet the requirements specified in Table 2.

Table 2: Summary of MIMO and Wi-Fi/Bluetooth coexistence requirements

3 RF design of antenna path

The PCB traces connecting the module antenna pins to the U.FL connectors on the module board are designed with coplanar microstrips, as shown in Figure 1. The artwork is shown in Figure 2 and Figure 3. The schematic including RF antenna matching components is shown in Figure 4.

      εr
      S
      W
      T
      H
Coplanar microstrip

Table 3: Coplanar microstrip specification

The antenna ports shown in Figure 2 are from left to right: ANT1 and ANTO. ANT2 to the far right is not used. It also shows the artwork of the RF traces with dimensions listed in Antenna coplanar microstrip dimensions.

[Diagram of module board showing antenna microstrip implementation with labels ANT1, ANTO, ANT2, RFCON1, RFCON2, RFCON3, and various GND and power connections.]

The antenna pin configuration is described in the JODY-W5 data sheet [2].

[Diagram showing PCB assembly of M.2-JODY-W5 with labels ANT1, ANTO, ANT2.]

[Schematic diagram of the RF path showing components for Pi network impedance matching, including U.FL connectors, resistors, capacitors, and inductors, connected to ANT0, ANT1, and ANT2.]

Appendix

A Glossary

Table 7: Explanation of the abbreviations and terms used

Related documentation

• [1] JODY-W5 system integration manual, UBX-23001477
• [2] JODY-W5 series data sheet, UBX-23002865
• [3] FCC Permissive Change Policy, KDB 178919

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Revision history

Contact

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