Data Sheet

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contact@irnas.eu

IRNAS d.o.o.

Limbuška cesta 76b

2000 Maribor, Slovenija, EU

IANT22: IRNAS small-square antenna datasheet

Ultra-compact 2.4 GHz PCB antenna

Changelog

Revision

Date

Description

V0.1

18.1.2022

Initial versions

V0.2

25.2.2022

Added real-world performance

Introduction

The PCB antenna used on the IRNAS example design of a small product is described in this

application note. Even if the antenna presented is for a custom PCB, it can be used in all

2.4 GHz designs, especially where small space is required for the antenna.

This application note describes the antenna dimensions, the RF performance, and

considerations for complying with regulatory limits when using this design.

The suggested antenna design requires no more than 3 x 5 mm of space and ensures a

VSWR ratio of less than 2 across the 2.4 GHz ISM band when connected to a 50 ohm

source.

Specification

• Operating range: 2400-2500 MHz

• Return Loss S11: < -10dB

• Peak gain: -4.45 dBi

• Polarization: Linear

• Input impedance: 50 ohm

• Dimensions

PAGE 1
IRNAS d.o.o. Limbuška cesta 76b 2000 Maribor, Slovenija, EU IANT22: IRNAS small-square antenna datasheet Ultra-compact 2.4 GHz PCB antenna Changelog Revision V0.1 V0.2 Date 18.1.2022 25.2.2022 Description Initial versions Added real-world performance Introduction The PCB antenna used on the IRNAS example design of a small product is described in this application note. Even if the antenna presented is for a custom PCB, it can be used in all 2.
PAGE 2
IRNAS d.o.o. Limbuška cesta 76b 2000 Maribor, Slovenija, EU Antenna design The PCB antenna on the small board reference design is a coiled in a square antenna which designed to match an impedance of 50 ohm at 2.45 GHz. Due to the small board size, a pinetwork matching is used to optimize the impedance and ensure a good VSWR. Simulation The design has been simulated with CST tool and ANSYS for the specific board shape to determine the maximum antenna gain and performance.
PAGE 3
IRNAS d.o.o. Limbuška cesta 76b 2000 Maribor, Slovenija, EU Real-world performance Given the primary use of such an antenna on wrist-worn devices, the performance of a setup has been evaluated with the wrist setup as well as in free-space. Key expected results of the setup are: • Free-space gain: -5 dBi • Wrist-worn gain: - 8 dBi Figure 3 - Wrist-worn vs. Free-space 3/3 www.irnas.eu contact@irnas.