Ultra-Wideband TestingThe future of industry has begun with Ultra-Wideband (UWB) and will change the way we run factories and other industrial processes. Thanks to their ability to communicate with smart cars and other smart devices, UWB products are well on their way to global success.
What is Ultra-Wideband (UWB)?
Ultra-Wideband is a technology that distributes the transmission power over a wide frequency range thanks to extremely short transmission pulses in the time domain. On the one hand, this reduces the power levels in such a way that UWB signals cannot interfere with other narrowband transmission methods. On the other hand, UWB devices are very robust against several simultaneously present narrowband signals: narrowband interferers can be easily filtered out due to the large bandwidth of the UWB signal in the frequency domain. A high data rate is achieved thanks to short pulses in the time domain with a high repetition rate. UWB devices are usually used at distances of up to 40 meters (130 ft).
All this gives UWB significant security advantages over previous narrowband technologies. For example, to copy the 100 kHz wide signal of a car key with a carrier frequency of 433 MHz, a simple radio relay (a briefcase with equipment for a few thousand euros) is sufficient. Copying UWB signals and then reproducing them is much more complicated, not only because of the characteristics of the UWB signal, but also because of the antenna array on the car itself, which makes it possible to determine the exact position of the car key.
Ultra-Wideband Use Cases
UWB technology is being used in more and more industries
Precise localization and tracking
Tag/anchor systems in logistics or consumer electronics, cell phones (Apple, Samsung, Huawei), automotive industry (car keys)
Digital radio transmission
High data rate on short distances
Civil (Ground Penetrating Radars, Through-Wall Imaging Systems) and military sectors (Synthetic Aperture Radars)
Spectrum & Measurement Bandwidths
UWB measurements are coupled with numerous challenges. You need modern spectrum analyzers with measurement bandwidths up to 50 MHz, low-noise amplifiers with high gain and at the same time lowest inherent noise, and a set of high-precision horn antennas that work in the narrow frequency ranges. For precise UWB measurements, our experts work with a Rohde & Schwarz FSW50 spectrum analyzer, various low-noise amplifiers from B&Z (the best models currently available), a range of horn antennas from Pasternack and Flann, as well as engineers who have successfully completed dozens of UWB test projects.
All you need to know about UWB testing
- Do we need to provide only a normal or also a modified sample device with SMA connector (hereafter "modified device") for conducted testing?
Most measurements for FCC, ISED and ETSI are generally carried out radiated, with normal (not modified) samples.
Parameter measurements (for example bandwidth measurement, etc.) can also be performed conducted. Those tests always require much less time than radiated ones. Therefore, especially when the equipment under test (EUT) has several channels, the availability of a modified device can help to save test time.
In Japan, measurements can only be performed conducted with modified devices. The limits applicable there do not allow radiated measurements because of the noise level.
- In what mode should the samples for the test work be delivered?
Testing for all countries (FCC, ISED, MIC, ETSI) requires a continuous modulation mode for all channels. For all portable UWB devices, a normal operating mode is additionally required. We also need a companion device for the EUT to have the possibility to perform tests in normal mode. For the tests according to the standards of ETSI and MIC we furthermore need a receiver mode. Receiver mode means that the EUT waits for a signal from the companion device and does not send any signals itself. If it is technically possible, the receiver mode should be implemented to work without a companion device. The presence of a companion device in receiver mode during the test may cause additional emissions.
- Is it important for FCC/ISED testing whether I have an indoor or hand held UWB device for testing?
Yes, it is important. For portable UWB devices, the limits are stricter. There is also an additional test that must be performed, which is the transmission pause test. The FCC refers to portable UWB devices as follows: "A small UWB device intended for frequent outdoor operation and capable of operating without fixed infrastructure." If a UWB device is intended for indoor operation, it should include the following notice on the device itself or in the user guide that accompanies it, "This device is intended for indoor operation only. Outdoor operation is a violation of 47 U.S.C. 301 and may result in serious legal consequences to the operator." Other important information for the device is that it only works in conjunction with fixed wire networks and the lack of an internal battery, which results in AC or PoE power.
- Is there a difference between the FCC and ISED testing requirements?
Yes, there are some important differences here. For ISED (RSS-220), the limits for radiated emission in the lower frequency range are: -70 dBm for 1610 MHz - 4750 MHz. For FCC, this value is -41.3 for 3100 MHz - 100600 MHz for handheld and indoor equipment. In practice, this means that it is almost impossible to use UWB devices in Canada in the frequency range below 4750 MHz.
- What should I look for when choosing a lab to test my UWB equipment?
The FCC requires that peak power is measured within a bandwidth of 50 MHz. This means that the spectrum analyzer used in the selected laboratory should be able to measure with a resolution bandwidth (RBW) of 50 MHz. There is also a method for measuring with a lower RBW. Laboratories that do not have a suitable spectrum analyzer and use this procedure for a lower RBW usually face the problem of obtaining correct results for the measured power. This leads to delays in testing and quite often to the handover of the project to a laboratory with suitable equipment.
The test lab should also have a set of low noise amplifiers with high gain and low noise figure values and a set of antennas with small frequency range and high antenna gain. Using only a small selection of antennas and an amplifier or amplifiers with inappropriate parameter values will certainly not be sufficient for most UWB projects. IB-Lenhardt AG has the best equipment available on the market for UWB testing.
- Is it enough to send sample devices by mail for testing? Or do I have to come in person to help set the devices in operating mode?
For the testing of all devices we need a detailed test instruction. It is also recommended to make some videos how to put the EUT in a proper operation mode. If the EUT is properly prepared for testing, all tests can be performed by us without your personal appearance. If any problems occur during the tests, we will use remote control SW (e.g. TeamViewer) and video calls to solve them. In any case, it is possible to perform all tests without your presence at our site.
European Union (ETSI)
Standard: ETSI EN 302 065 (Part 1, 2, 3, 4, 5)
Part 1: Requirements for Generic UWB applications
Part 2: Requirements for UWB location tracking
Part 3: Requirements for UWB devices for ground based vehicular applications
Part 4: Material Sensing devices using UWB technology below 10,6 GHz
Part 5: Devices using UWB technology onboard aircraft
The correct classification of the corresponding standards for the respective device is crucial, as the requirements can differ greatly depending on the standard.
International Market Standards
Standard: CFR 47 Part 15 F (Ultra-Wideband Operation), KDB 393764 D01.
Most devices that are approved on the market fall into Part 15.517 (indoor devices) and 15.519 (hand-held devices). It is very important to correctly determine the classification from the beginning, as the requirements for devices differ significantly as a result. One of the parameters here is a corresponding proof that an indoor device is really only used inside buildings and not outside (e.g. AC or LAN cable connection, no battery operation etc.).
Standard: ISED RSS-220.
It is a common misconception that the UWB frequency ranges are the same for FCC and IC. If FCC allows a UWB signal with maximum E.I.R.P. -41.3 dBm in the frequency range 3.1 GHz - 10.6 GHz, for IC the same limits apply only for the frequency range 4.75 GHz - 10.6 GHz. Since this is often not taken into account during development, expensive rework measures (firmware, recertification) can arise later.
Standard: ARIB STD-T91
The transmission bandwidth at -10 dB is at least 450 MHz.
Frequently Asked Questions
General information about UWB
- What is Ultra-Wideband and how does it work?
Ultra-Wideband is a radio-based communication technology for close range that is used for fast and stable data transmission over distances up to 40 meters (130 ft). Ultra-Wideband technology has characteristics such as high precision, high transmission speed and high reliability and is used to locate people and objects for access control and data communication. Compared to other radio technologies that modulate sinusoidal carrier frequencies, UWB transmits short transmission pulses with low power over a wide frequency range (at least 500 MHz). UWB signals cannot interfere with other narrowband transmission methods and are therefore perceived only as noise.
- Why is it called Ultra-Wideband?
It is called Ultra-Wideband due to the wide bandwidth of the UWB signal in the frequency domain. Thanks to short pulses in the time domain with a high repetition rate, a high data rate is achieved.
- How does UWB measure distance?
The distance between two objects can be calculated based on the Time of Flight (ToF). ToF assumes the speed of light and measures the time it takes to travel a distance from the transmitter to the target and back. The time difference between the transmission and the reception multiplied by the speed of light provides the actual distance of the target in millimeters with a high accuracy.
- What is the range of UWB?
Ultra-Wideband is a short-range technology within which the detection of devices is possible under 200 meters. However, it operates most accurately over distances between 1-50 meters and works best with line of sight between the devices.
- What is the difference between UWB and Wi-Fi?
The difference between Ultra-Wideband and Wi-Fi is that UWB is a short-range technology that covers a wide frequency bandwidth of 500 MHz and transmits with low power. Wi-Fi is a radio network that operates in a bandwidth approximately between 20-40 MHz. Besides, it is not only used for data communication but also for positioning and access control. UWB provides a higher degree of accuracy and security because distance is measured by ToF, not by measuring signal strength like Wi-Fi does. Another difference is that UWB can be located real time and in all directions, even when multiple wireless connection technologies are operating. Wi-Fi can overlap with neighboring channels.
- Which regulatory requirements are necessary?
For launching a product on the market with Ultra-Wideband technology official approval is required for the relevant national and international markets.
The following are the most important:
Standard: ETSI EN 302 065 (Part 1, 2, 3, 4, 5)
Standard: CFR 47 Part 15 F (Ultra-Wideband Operation), KDB 393764 D01
Standard: ISED RSS-220
Standard: ARIB STD-T91
UWB Testing for your Needs
We gladly perform electrical Ultra-Wideband tests tailored to your special demands and support you along the evolution of your product through development-accompanying tests. Send us your inquiry!