Many of today’s communication formats, such as W-CDMA, cdma2000®, and WLAN, produce signals that are noise-like in nature. Accurately measuring these types of signals requires tools and setups that are different than traditionally used for continuous-wave (CW) signals. To get a better understanding of how to deal with noise-like signals, let’s examine the best approach for measuring them, and look at the tools available in modern spectrum analyzers for quickly and accurately making absolute and relative power measurements.

By Bob Nelson, Agilent Technologies

One of the more common measurements made with an RF/microwave spectrum analyzer is determination of third-order-intercept (TOI) point for a device under test (DUT), which is often an amplifier. TOI point is a parameter used to evaluate the linearity of components that are utilized in applications where nonlinear effects can cause distortion—for example, in digitally modulated signals. This measurement can be challenging, as uncertainties vary significantly based on the spectrum analyzer’s settings. To optimize these settings using traditional, manual measurement techniques, the engineer often has to make difficult tradeoffs between dynamic range, measurement time, repeatability, and uncertainties. Is there a better way? Let’s take a closer look.

By Bob Nelson, Agilent Technologies

Various multiple-input multiple-output (MIMO) antenna techniques are being used by TD-LTE, FDD-LTE, and LTE-Advanced (LTE-A) wireless technologies. Given the growing complexity in MIMO systems, related test methodologies will also become more challenging. For example, currently deployed MIMO technologies implement two antennas to improve channel performance. Yet some LTE communities are pioneering eight-antenna technologies to reap even higher performance gains. Such advanced technologies will make the choice of test methodology even more critical.

By Kang Chen

It’s no secret that wireless communications standards continue to evolve to provide ever-increasing data throughput capabilities. The boost in data rates is largely accomplished through enhancements in the physical layers of the protocols. These enhancements often take years to develop—allowing us to envision both the communications systems of tomorrow and the changes in RF test needs.

By David Hall

Many see drive testing–the process of testing cellular systems and equipment by literally driving around with live mobile devices in a car or van—as the ultimate test of a cell phone or base station. However, drive testing incurs significant costs and liabilities while offering very little in terms of repeatability.

By Paul Collins and Madhusudhan Gurumurthy