Test and Measurement Channel
October 18, 2012
A ready reference poster of multiple RF/microwave amplifier graphs and tables from AR RF/Microwave Instrumentation .
October 16, 2012
Software-defined RF test system architectures have become increasingly popular over the past several decades. Almost every commercial off-the-shelf (COTS) automated RF test system today uses application software to communicate through a bus interface to the instrument. As RF applications become more complex, engineers are continuously challenged with the dilemma of increasing functionality without increasing test times, and ultimately test cost. While improvements in test measurement algorithms, bus speeds, and CPU speeds have reduced test times, further improvements are necessary to address the continued increase in the complexity of RF test applications.
October 15, 2012
Higher data rates introduce new challenges for test solutions. There are several 20+ Gbit/s high speed standards (Table 1) that are driving the upper end of the test spectrum to 70 GHz and even 110 GHz. Accurate measurements are needed to better understand higher order harmonics, as will new challenges related to conductor skin effects and dielectric losses on PC boards, along with the design trade-offs related to choices of vias, stackups, and connector pins.
September 18, 2012
The "Testing New-generation Wireless LAN" application note discusses the differences between 802.11ac (designed for Very High Throughput - VHT) and previous WLAN standards, the test requirements and the new challenges VHT brings. The application note also introduces the WLAN new-generation testing technology of 802.11ac and explains in detail Agilent's 802.11ac software which allows engineers to view and troubleshoot all 802.11ac modulation formats.
September 18, 2012
This application note is designed to provide you with the latest insights on how to best address the long list of test requirements when testing the voice quality of LTE UE, with the right VoIP test building blocks. Successfully providing voice support on LTE will require UE developers to bring together a host of new features and capabilities. Many of these items have been around for a while but have not yet been applied to mobile networking. Others are completely new. Regardless, bringing them together will likely cause significant test pain, as they will need to be tested in conjunction with LTE and/or IMS to be fully exercised.
September 17, 2012
The complexity of modern digital equipment has caused EMI/EMC susceptibility
testing to become increasingly important. Many EMC standards have been created
including MILSTD- 461, IEC 61000, ISO 11451 Automotive, EN 50, and FCC
part 15 that provide specific guidelines for EMC and EMI test methodologies. Early
standards required a CW carrier, or single tone with constant modulation as the
disturbance test signal. This article will discuss how a peak power sensor can replace an average
diode detector in a field probe to measure pulse power, improve repeatability and
increase dynamic range of the power measurement.
September 17, 2012
This paper provides a comprehensive review of modern automated load-pull, including a discussion of early impedance synthesis methods, and how they were improved with breakthrough innovations such as Focus MPTTM technology and systematic high-VBW sub-1 Ω test-fixture design techniques. More recent developments are next treated, including active-loop and active-injection impedance synthesis architectures, time-domain data acquisition, and advanced data processing and
visualization.
August 13, 2012
The Anritsu VectorStars Noise Figure Option 041 enables the capability to measure noise figure (NF), which is the degradation of the signal-to-noise ratio caused by components in a signal chain. The NF measurement is based on a cold source technique for improved accuracy. Various levels of match and fixture correction are available for additional enhancement. VectorStar is the only VNA platform offering a Noise Figure option enabling NF measurements from 70 kHz to 125 GHz. It is also the only VNA platform available with an optimized noise receiver for measurements from 30 to 125 GHz.
July 17, 2012
The next frequency frontier is the millimeter wave (mm-wave) band, which occupies the 30 GHz to 300 GHz spectrum (wavelengths from 10 to 1 mm). Emerging applications now span radio astronomy, communication, imaging, space research, and homeland security, and are starting to seriously populate this vast spectrum resourse. Market forecast and limited available spectrum suggest that attractive growth is just over the horizon so explorers are naturally migrating to stake their claim in this next frontier.
July 17, 2012
Intermodulation distortion or IMD has always existed in RF transmission paths. Until about the early 1990s, cellular communications had relatively low power carrier levels. Intermodulation distortion in passive devices was not necessarily a problem because the distortion levels were significantly below the noise floor of the broadcast system. Typical RF connectors such as the N connector satisfied the earlier demands but as the sensitivity of the receivers increased, a condition within RF connectors was exposed.
