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March 2010 [Components] Digital Attenuators Master Amplitude In MW Systems Attenuators are part of any design’s amplitude control. Digital attenuators help to simplify that control in microwave and RF systems. In a variety of markets—including commercial communications, military, and test areas—amplitude is used for modulation, detection, linearity improvement, and a number of other functions in a system. Suppliers of digital step attenuators (DSAs) help to provide the means of controlling power levels swiftly and with... March 2010 [Crosstalk] An Interview With Dr. Lawrence Williams NF: A lot of microwave engineers still prefer lab-based measurement techniques to simulation tools. What do you have to say to those folks? LW: Lab-based measurements have their place; simulations have their place. It’s not an either/or decision. Engineers will always perform both. Of course, I believe strongly in the value of simulation because of its flexibility and efficiency. Years ago, at... March 2010 [Research & Development] Algorithm Nails Sweep Calculations Of EM Wave Scatterings WHEN EVALUATING PROBLEMS like the radar cross section (RCS) of an object, the system response must often be calculated at multiple frequencies. If traditional frequency-domain numerical methods are used to accomplish this task, a dense matrix equation must be solved at each frequency. Several approaches can alleviate this time-consuming computational burden. To further speed processing, a model-order reduction algorithm for the volume ... March 2010 [Components] Spin-Torque Nano-Oscillators Eye Frequency-Synthesis ICs GENERALLY, THE SYNTHESIZERS in today’s wireless consumer-electronics products are based on several single-frequency RF voltage-controlled oscillators (VCOs). The leading technology combines standalone high-quality, low-frequency quartzcrystal resonators and integrated high-frequency, low-quality LC tank-based phase-locked loops (PLLs). In future mobile phones, however, a different approach will be needed to cover both current and future communication... March 2010 [Computer-Aided Engineering] Bring Measurement Equipment Into System Simulation DURING THE SIMULATION of a complete subsystem, the quality of the measurement data is critical to determining whether the finished product will meet or exceed the demands faced by the system when in use. Ideally, that measurement data will allow engineers to save time and money by making changes to the system earlier in the design process. Of course, that capability requires a direct link between the system simulation software and measurement equipment. One... March 2010 [Test & Measurement] HSPA+ Paves Way Toward Long-Term Evolution THE 3RD GENERATION PARTNERSHIP PROJECT (3GPP) is the most successful set of telecommunications standards in the world. It is estimated that 85 percent of all cellular calls are set up using 3GPP access technology. To provide 2X the speed and 3X the voice capacity of the previous-generation 3GPP standard, High Speed Packet Access (HSPA), HSPA Evolution (HSPA+) is leveraging multipleinput multiple-output (MIMO) technology and higher-order modulation. In a... March 2010 [Computer-Aided Engineering] LTE Signal-Fading Simulator Profiles Handsets Rather than having to buy and cable together two separate test instruments, engineers working on fourth-generation (4G) Long Term Evolution (LTE) handsets can now rely on a onebox test system for cell-phone signal fading simulation. This fading simulator option is integrated within the 7100 series digital-radio test set. That signal generator and analyzer covers 70 MHz to 6 GHz continuously with resolution of 1 Hz to 3 GHz and 2 Hz above 3 GHz. To... February 2010 [Communications] Wireless Demands Focus Designers On Integration Integration has been a key to the advancement of wireless communications, leading to smaller devices with more functionality. Although the mobile handset is at the forefront of these trends, cost savings and time to market are among the drivers pushing for higher integration in cellular infrastructure as well. As wireless integrators strive for more functions in smaller packages, the trend in ICs continues toward higher levels of analog, digital, and... February 2010 [Crosstalk] An Interview With John Regazzi NF: How has the test and measurement industry changed over the last 30 years? JR: When Giga-tronics was founded, the microwave test industry was much less mature than it is today. The microwave field was evolving rapidly with product advancements occurring on a regular basis. In 1980, a few milliwatts of power at 20 GHz were difficult to achieve and the best synthesizers could fetch up to $70,000... February 2010 [Components] On-Glass Vehicle Antenna Receives FM For RVs AS AN ALTERNATIVE to monopole-type antennas, many commercial vehicles now provide frequencymodulation (FM) reception via antennas that are printed directly on the rear or quarter glasses of a vehicle. Unfortunately, these on-glass antennas tend to possess a low vertical gain and narrow bandwidth. They also exhibit nulls in their radiation patterns, as they are placed in close proximity to the conducting frame of the vehicle and are printed on glass with high... February 2010 [Components] Antenna-In-Package Forges Interconnection At 60 GHz TO ENABLE VERY-HIGH-DATA-RATE applications, the IEEE 802.15.3c standards group is defining specifications for 60-GHz radios that use only a few gigahertz of unlicensed spectrum. Typically, those radios have been designed by assembling several monolithic microwave integrated circuits (MMICs) in gallium-arsenide (GaAs) semiconductor technology. Yet a recently proposed antenna, which targets highly integrated 60-GHz radios, is specifically designed to exhibit... February 2010 [Components] Filter Mitigates Interference For Astronomy Observations TO BLOCK UNWANTED frequencies, it is common to place a very-high-Q high-temperature-semiconductor (HTS) filter before the low-noise amplifier (LNA) of a radio telescope’s front end. A miniaturized HTS four-pole filter for the RF interference mitigation of the 900-MHz cellular band in radio telescopes was recently presented by Alonso Corona-Chavez from Mexico’s National Institute for Astrophysics, Optics, and Electronics; Ignacio Llamas-Garro from Spain’s... February 2010 [Applications] Leverage COTS Approach For SDR Designs SOFTWARE-DEFINED-RADIO (SDR) technology has emerged as a way to help the communications industry easily modify radio devices to support new and emerging technologies. Compared to traditional radios, SDRs offer an efficient and less expensive way to enable multimode, multiband, and/or multifunctional wireless devices that can be configured via software upgrades. Despite these obvious benefits, many obstacles must be overcome in the design and test of SDRs. ... February 2010 [Applications] Transceiver System Meets Unique Needs Of AMI Standard ADVANCED-METERING-INFRASTRUCTRE (AMI) systems have enabled utility companies to more efficiently collect energy, gas, and water-consumption data. Eventually, these systems will allow consumers to monitor and control their own energy consumption in real time. Yet such capabilities will require interoperability between different manufacturers’ systems. In Europe, the Wireless M-Bus protocol, which is now detailed in the European normative (EN) standard... February 2010 [Test & Measurement] Handheld VNA Lowers Drift Errors With 0.01 dB/°C Stability FIELD ENGINEERS who characterize or troubleshoot RF components for mission-critical communication systems have a new option in the N9923A FieldFox RF vector network analyzer (VNA). At 6.2 lbs., this full two-port VNA provides measurement stability of 0.01 dB/°C. It spans 2 to 4 or 6 GHz. The N9923A offers more than 42 dB directivity with a typical dynamic range of 100 dB. The VNA provides 0.01 dBm RMS trace noise. It allows operators to simultaneously measure... February 2010 [Components] 13.5-GHz SPDT Switch Boosts Test Performance THE PE42556 SINGLE-POLE DOUBLE-THROW (SPDT) RF switch vows to augment test-equipment performance while enabling the reliable testing of next-generation RF ICs. The absorptive switch, which is designed on the proprietary Ultra- CMOS silicon-on-sapphire process technology, spans 9 kHz to 13.5 GHz with low 1.7-dB insertion loss at 13.5 GHz and typical return loss of 13 dB at that frequency. It also guarantees fast switch-settling time of typically 3.3... January 2010 [Test & Measurement] Nonlinear S-Parameters And SDR Impact Test And Measurement Equipment Test and measurement is crucial for research and development through production. As a result, test-equipment manufacturers have had to speed the evolution of their instruments to keep up with rapidly changing wireless-communications standards. They also are relying more on software—either through links to electronic-design-automation (EDA) tools or via software-designed-radio (SDR) architectures. At the same time, test equipment is increasingly being ... January 2010 [Computer-Aided Engineering] An Interview With Jim McGillivary NF: Software—especially EDA software—is increasingly playing a bigger role in test and measurement. How do you see that trend growing? JM: There’s currently a disaggregation of the design process as manufacturers focus on being a system integrator and trying to build software ecosystems. For example, handset designers have sockets and they want vendors to compete for those sockets. They need a... January 2010 [Editorial] Sniff Out The Best Security Solution For decades, generations of children have fantasized about what they could do if they had Superman’s x-ray vision. Now, privacy advocates are worried that airline and other screeners will soon have comparable capabilities. The call for the widespread use of full-body scanners in airports is a response to Umar Farouk Abdulmutallab’s attempt to blow up an airliner over Detroit this past December 25. The question is whether such scanners are actually the most effective... January 2010 [Research & Development] Modulation Approach Uses Arrays With Driven Elements IN CONVENTIONAL PHASED-ARRAY TRANSMISSION, information is transmitted in undesired directions through sidelobes. To provide more secure communications, some research has delved into time modulation in arrays. While conventional arrays have static-element phase shifts and weighting, time-modulated arrays exploit an additional degree of freedom—time—in order to raise performance. At the University of Illinois at Urbana-Champaign, Michael P. Daly and Jennifer...  prev. page
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