Reverberation chamber technology

Antenna efficiency goes under the category of Bluetest passive measurements in the reverberation chamber. An important parameter for all different types of antennas is radiation efficiency and is a basic parameter for all antenna designs. In fact, it is the dominating factor for antenna performance in multipath environments.

Total Radiated Power (TRP) and Total Isotropic Sensitivity (TIS) goes under the category of Bluetest's active measurements. Active measurements means that the transmitter/receiver in the DUT is active and powered up. Active measurements will give you a complete overview of how the whole system in your device is performing. These are parameters directly related to the antenna radiation efficiency, and are well proven measurements in Bluetest's reverberation chambers. The TRP and TIS measurements in a reverberation chamber are standardized and included in the 3GPP Test Specification TS 34.114.

- Robert Rehammar, CTO, Bluetest

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A radio propagation channel describes how the environment can affect the radio signal as it travels between the transmitter and receiver. As devices move and signals bounce off of buildings or vehicles, changes in frequency, phase and power occur. Wireless engineers in the industry broadly model these effects with a few main variables such as:

Internet of Things (IoT) and Machine to Machine or M2M communication is an application area quickly growing in importance both in the professional and domestic market. The professional segment includes different kinds of wireless metering, wireless diagnostics and supervision, while the domestic market focuses on smart home appliances. Together they include devices with a wide range of sizes and shapes increasing the need for flexible test solutions capable of testing small as well as larger wireless devices.

The wireless industry is moving rapidly forward with the deployment of 5G. Bluetest has provided OTA test solutions for 5G since the very start of the 5G development and have a good understanding of customer needs in order to succeed. Our 5G line-up with RTS65 and its 5G extension packages for device testing, as well as RTS85HP for base station testing, is fully prepared to help our customers succeed with the launch of 5G.

Traditionally base stations have been verified by measuring their performance conductively at the antenna interface. With 5G, we enter a new and exciting era for base station design. Base stations and Remote Radio Units (RRU) are moving towards more integrated antenna/radio solutions, as well as Massive MIMO with 64 or more radio/antenna elements. These Advanced Antenna System technologies are applied also on LTE base stations to improve network capacity as well as reduce power consumption. However, this new breed of base stations will introduce new measurement challenges as these new design considerations change or eliminate the traditional antenna connector interface. Without access to these connectors, the test equipment must measure base station performance after the antenna output in a radiated, wireless over-the-air (OTA) environment.

Body phantoms, such as head and hand phantoms, have for a long time been used to simulate the human body, and to evaluate how it affects device performance. The human body absorbs RF energy, but it can also de-tune the device antenna, hence significantly changing the RF performance compared with free-space measurements.

Wireless connectivity is finding its way into all areas of our society. The healthcare industry is not an exception when it comes to embracing the advantages of wireless connectivity, with more and more medical sensors, various aids and diagnostic systems being connected. This transformation has accelerated after the pandemic, and benefits include enhanced productivity, improved life quality, as well as increased patient security and peace of mind.

As the variety of wireless devices and wireless connections in a car increases, there is a corresponding increase in the need for testing to ensure good functionality and performance. Automotive engineers are finding that Bluetest reverberation test systems are often the most convenient solution for understanding the effects of wireless devices in, around and embedded in vehicles.

Base stations and/or terminals with multi-antenna configurations are expected to significantly contribute to much higher bit rates in mobile broadband systems. Higher bit rates using multi-antenna systems can, when there is rich scattering in the communication channel, be achieved 1) by increasing the modulation rate and/or reducing the coding rate as the Signal to Noise Ratio (SNR) is increased through the use of diversity combining, or 2) through the use of simultaneous partially uncorrelated communication channels (Multiple Input Multiple Output, MIMO).

It is common nowadays to add a cover to your mobile phone, both for protection and esthetical reasons. They are available in many different stores including the mobile operator branded stores. The material and form varies considerably from one cover to another. You can get everything from plastic and rubber covers to silicon or metal. Of course the different materials have pros and cons. Some are more protective, even against the delivery of data. The question that follows is; how does a cover affect the performance of the antenna?

Although WLAN has been around for many years it has during the last couple of years grown rapidly in importance, driven mainly by the introduction of WLAN into mobile devices and operators offloading data from their cellular networks. Another force contributing to the strong growth is the trend to have “everything” connected, for example home appliances as well as different types of metering and sensors.

Multipath fading has for many years been a problem for mobile communication engineers, to be overcome by designing systems that have sufficient signal-to-noise ratio (SNR) or signal-to-interference ratio (SIR) margins. The fading is caused by multiple reflections in walls and ceilings (indoors) or cars and buildings (outdoors) that add constructively or destructively at the location of the terminal or base station antennas.

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We are in the forefront of providing measurement solutions for the newest communication systems. We don’t let you wait for measurement solutions supporting technologies that is introduced now. A proof of that is our introduction of MIMO functionality already in 2009 and support for 2 component carrier aggregation (2CC) in 2013. Our system today supports all currently released configurations including up to six downlink or four 4x4 MIMO carriers (TDD, FDD or a mix) as well as two uplink carriers. You can measure the aggregated data throughput as well as throughput per carrier or receiver sensitivity and transmitter power per carrier.

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The rapid increase in number of used carriers and MIMO streams in modern LTE devices introduce new challenges when measuring radio performance. This white paper gives an introduction to Over-the-Air (OTA) measurements of such devices and what to consider when moving from a conducted measurement to measurements in a multipath faded OTA environment.