Millimeter-wave Channel-Sounder Performance Verification using Vector Network Analyzer in a Controlled RF Channel.

A new comparison-to-reference performance verification technique compares an E-band channel-sounder and reference vector network analyzer measurements of the same controlled, static channel. This new technique reduces the number of inaccurate assumptions that exist in other methods providing a stronger verification of the channel-sounder hardware and processing performance. This technique compares the channel-sounder and VNA derived channel metrics from these measurements.

NB-IoT Devices in Reverberation Chambers: A Comprehensive Uncertainty Analysis.

New protocols related to internet-of-things applications may introduce previously unnoticed measurement effects in reverberation chambers due to the narrowband nature of these protocols. Such technologies also require less loading to meet the coherence-bandwidth conditions, which may lead to higher variations, hence uncertainties, across the channel. In this work, we extend a previous study of uncertainty in NB-IoT and CAT-M1 device measurements in reverberation chambers by providing, for the first time, a comprehensive uncertainty analysis of the components related to the reference and DUT measurements.

Precision Millimeter-Wave-Modulated Wideband Source at 92.4 GHz as a Step Toward an Over-the-Air Reference.

As the next-generation communications technology continues to evolve to utilize millimeter-wave frequencies, calibration methods are needed for the nonidealities related to these frequencies in communications electronics. In this article, we demonstrate a 1-GHz bandwidth, 64-quadrature-amplitude-modulated signal source at 92.4-GHz carrier frequency with relative phase and magnitude that may be made traceable to primary standards.

Millimeter-Wave Radio Channels vs. Synthetic Beamwidth.

High-gain narrow-beam antennas or beamformed antenna arrays will likely be used in millimeter-wave (mmWave) bands and 5G to mitigate the high path loss. Since many multipath components may be excluded by the narrow beam, the mmWave radio channel (consisting of the transmit antenna, the propagation channels, and the receive antenna) strongly depends on the beamwidth, orientation, and shape of the narrow beam. In this article, a procedure is proposed to measure and model the channels vs.

Correlation-Based Uncertainty in Loaded Reverberation Chambers.

When reverberation chambers are loaded to increase the coherence bandwidth for modulated-signal measurements, a secondary effect is decreased spatial uniformity. We show that an appropriate choice of stirring sequence, consisting of a combination of mode-stirring mechanisms such as paddle and antenna-platform stirring, can mitigate the potential for increased uncertainty. We develop a new mode-stirring sample correlation model for uncertainty due to the stirring sequence.

Analysis of E-Band Path Loss and Propagation Mechanisms in the Indoor Environment.

Millimeter-wave transceivers will feature massive phased-array antennas whose pencilbeams can be steered toward the angle of arrival of the propagation path having the maximum power, exploiting their high gain to compensate for the greater path loss witnessed in the upper spectrum. For this reason, maximum-power path-loss models, in contrast to conventional ones based on the integrated power from an omnidirectional antenna, may be more relevant. Yet to our knowledge, they do not appear in the literature save for one reference.

A Significance Test for Reverberation-Chamber Measurement Uncertainty in Total Radiated Power of Wireless Devices.

We develop a significance test that determines whether the component of uncertainty due to the finite number of stepped mode-stirring samples or the component due to the lack of spatial uniformity dominates for a particular chamber set-up and stirring sequence, as well as expressions for uncertainty for both cases. The significance test is illustrated with a measurement example comparing unloaded and loaded chambers for the measurement of a large-form-factor machine-to-machine device transmitting the W-CDMA protocol. Based on this example, we illustrate a method that allows users to estimate the minimum number of stepped mode-stirring samples needed to ensure that the component of uncertainty due to spatial uniformity dominates for a given chamber set-up, allowing use of a simplified expression for uncertainty.