Explore the intricacies of wireless signal propagation in indoor environments through detailed measurements and insightful observations.

Oscar Appelman, oscar.appelman@aptab.nl

This article was also published in Microwave & RF magazine.

1.    Introduction

In a world where wireless devices have become an integral part of daily life, the guarantee of reliable wireless networks is more crucial than ever. Accurately predicting the propagation characteristics of wireless signals is highly desirable.

However, due to the complex nature of wireless signal propagation in volatile environments, simulating such scenarios is notoriously difficult and lacks accuracy [1]. As a result, characterizing wireless signal propagation is often neglected and wireless networks are set up based on intuition and simple measurements.

Beside Horizontal and Vertical polarizations there is a technique called Circular Polarization. This article explains what that is, how it behaves and how it can be measured.

This article was also published in Microwave & RF magazine.

This application note describes a case study of the power and radiation pattern measurements on a Wifi Access Point. It shows several ways of using the RMS-0660 to measure antenna radiation and power properties.

"Using two completely different methods, with only 0.4dB difference, the radiated and conducted results were nearly identical."

MegiQ RMS

The RMS system is a turnkey system for measuring radiated properties of wireless devices and antennas. It consists of a turn table, dual polarized measurement antenna, dual channel receiver and PC software. There are several RMS types with frequency ranges between 400MHz and 6GHz, covering most popular communication bands of wireless and IoT devices.

The RMS allows measuring radiation patterns of wireless devices that transmit their own signal, as well as measuring standalone antennas by feeding a signal from the built-in RMS generator.

Both methods were used to reconcile the results of the two measurements.

Time Domain Reflectometry (TDR) functions in our VNA software can be used to analyze local impedances in networks. This is useful to analyze both cable networks as PCB trace impedances.

For many Wireless Devices the Total Isotropic Sensitivity (TIS) can be derived from Total Radiated Power (TRP) together with the transceiver properties.

Learn about VNA concept and operation, measurement calibration, measuring and matching antennas and circuits

RMS measures antenna patterns, harmonic levels and multifrequency antenna patterns.

Everything goes wireless, also luminaires, mostly using mesh-kind of RF communication for control. There are all kinds of off-the-shelf RF electronics available for the Luminaire Designer. This leaves the Luminaire Designer with a big question mark: “How to design a luminaire for reliable RF communications in the field.”

Although a very good design will help to achieve high yield on antenna performance, batch to batch tolerances in PCB and components can suddenly influence resonance frequencies of on-board antennas.
There is an easy way to determine the resonance frequency by wireless without having to probe electrically. Just as with the old grid-dippers

Connectors can be vulnerable. In your RF test set-up you make use of connectors like SMA, UFL or WFL. These connectors have a limited amount of mating actions, they wear down. Specially in T&M setups, there where you want to be sure of reliably & repeatable connections, you should take good care of connectors

These are some of the approaches to make sure that a wireless product works to full satisfaction.

Sometimes it is desirable to test or verify the operation of an antenna without physically connecting to it. This can be useful for verifying a series of products, in production, or to avoid disturbing the ground current in its ‘natural’ state. This article describes a technique for measuring antennas without physically contacting it.

Most VNA manufacturers focus on using the best possible connectors and accessories for test setups: N-connectors, phase stable cables and golden calibration standards. These are so bulky that it is almost impossible to get to a real-life circuit board. On the other end of the spectrum are the small and cheap UFL connectors and cables. Are they suited for VNA measurements and circuit optimization?