Inside an Anechoic Chamber: Wireless RF Performance and Validation Testing

In the last blog in our wireless device performance testing series, we talked about how everyday users need superior connectivity to get them through their day. Service providers and device manufacturers are tasked with this challenge to provide excellent service to their end customers.

An anechoic chamber for RF testing is one test system you can use to understand the performance of your wireless device. Whether you have a prototype in development or need to understand how a device performs before purchasing, it’s a crucial tool that can help shape your business decisions.

In this blog post, I’ll outline various scenarios in which you’d want to test a device in the anechoic chamber, and I’ll also take you on a tour of our in-house RF anechoic chamber.

What Is an Anechoic Chamber?

A fully anechoic chamber is used to measure the RF antenna performance of wireless devices. The anechoic chamber is lined with dense foam cones that eliminate all outside interference and reflections, making it an ideal test environment to get clean, consistent and repeatable results.

Take a look at our onsite Rohde & Schwarz anechoic chamber at our Louisville, Colorado, lab facility:

How Does the Anechoic Chamber Differ from a Semi-Anechoic Chamber?

The key difference between the two types of chambers is that the anechoic chamber can collect data in three dimensions in a spherical pattern in all directions around the device, whereas the semi-anechoic chamber collects data in two dimensions or in a circular pattern around the sides of the device. We run several tests in the various chambers that complement one another other and give a more complete picture of how a device performs.

When Does It Make Sense to Perform Testing in the Anechoic Chamber?

There are several situations where it makes sense to get your device tested in the anechoic chamber, including:

  • Prototype development. If you have a prototype in development, it can be advantageous to test your device for defects before deploying to the field. Not only does this save you time and money, but you also avoid discovering costly defects after your device has been installed to hundreds or thousands of customers. It can save you the expense of having your brand reputation tarnished.
  • Product purchases. If you’re ready to purchase a device and roll it out in your deployments, you’re likely concerned about device quality for your end customers. Anechoic chamber testing is a great option to help narrow down your purchasing decisions for a device, and you can even compare your choice against several other devices.
  • Product development. You may already have a product in the field that’s costing you service calls and other operational costs. If you suspect that a device has issues, you can test it in an anechoic chamber to understand its performance.

What Does the Anechoic Chamber Measure?

Over-the-air (OTA) performance test systems analyze radiated device performance. Businesses that rely on this piece of equipment typically want to validate conformance to industry, network operator and internal company requirements.

Specifically, an OTA test system verifies antenna patterns and transmitter/receiver chain wireless system performance—for example, total radiated power (TRP) and total isotropic sensitivity (TIS), respectively. These measurements follow test plans and detailed test and setup procedures published by industry organizations such as CTIA.

What Types of Tests Can Be Performed in an Anechoic Chamber?

Several power measurements can be tested in an OTA anechoic chamber. These tests are crucial to determine whether the antennas will perform as expected. As many Internet of Things (IoT) and machine-to-machine (M2M) devices become increasingly more compact, antennas are sometimes forced to be physically close to other antennas, displays, computer processors, high-speed memory, and more—all of which can interfere with and degrade the device’s performance.

In addition to power measurements, OTA testing can perform sensitivity measurements to illustrate how the internal components affect the RF radio’s performance. This allows product developers to see where the issues are during normal operation and how they impact the product’s performance.

If you’re looking for an independent third-party lab to perform your testing, be sure to watch for these common tests:

  • Total radiated power (TRP)
  • Total isotropic sensitivity (TIS, per CTIA)
  • Radiated sensitivity on intermediate channels (RSIC)
  • Coexistence measurements
  • Passive antenna measurements/efficiency
  • Signaling vs. non-signaling measurements

I hope I’ve answered your questions about the anechoic chamber and whether it’s right for your needs. Feel free to reach out to me if you have questions or download our fact sheet below for more information.

Download the Fact Sheet Now


For manufacturers and service providers, Kyrio accelerates and deploys new network innovations into the ecosystem. Backed by the power of CableLabs, Kyrio sets technology on a path to commercialization, enabling not just today but tomorrow’s communication.