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ISSUE DATE: MARCH 2010 | |
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March 2010 - In This Issue [Cover Story] Speedy Switches Minimize Gate Lags Switching speed is a complex parameter that includes a number of events, each with its own duration. By means of a patent-pending pseudomorphic-high-electronmobility- transistor (pHEMT) technology, M/A-COM Technology Solutions has found a way to dramatically shorten the duration of one of these events—a switch’s settling time—to the benefit of systems requiring tight control of time-domain parameters, such as packet-based... — [News] 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... — Nancy Friedrich [News] 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... — Nancy Friedrich [Design Features] Tune Out Spurious In Dual-Mode BPFs Miniature filters are essential for wireless communications systems although they often suffer from limited rejection bandwidths. However, through the use of a modified coupling structure for harmonic suppression, it has been possible to design a dual-mode filter capable of wide rejection bandwidth and 20-dB rejection through 8.5 GHz. A number of dual-mode filters1-4 have been developed based on microstrip square loop... — Wei Hong , et al. [Design Features] Analyze Phase Noise In A Sampled PLL (Part 3) Some have suggested that PLL noise degrades with frequency because the charge pumps are powered on for longer periods compared to the sampling period and therefore allow more noise to be transferred to the loop filter. In fact, the noise follows exactly what would be expected from FM theory and sampling theory. From FM theory, the noise is expected to increase by 6 dB for every doubling of frequency (20logfs). However, from sampling theory, the noise ... — Peter Beeson [Design Features] Image-Reject Mixer Arms Direct-Conversion Receivers Mixer linearity is critical to the performance of direct-conversion receivers with low intermediate frequencies (IFs). By biasing a low-IF image-reject mixer designed for a fully duplex system, such as UMTS, it is possible to achieve outstanding linearity even in the presence of large blocking (interference) signals, and even in a UMTS system, where the transmit signal is often the largest blocking signal for the receiver. The mixer is designed for... — J.G. Gardiner , et al. [Design Features] Forecast Rain Effects On Microwave Links Propagation of electromagnetic (EM) waves through the air is difficult to predict, due to atmospheric effects. Raindrops, for example, can act as scatterers that attenuate and affect the polarization of the propagating EM waves. Scattering theory has treated effects on the far-field regions of receive and transmit antennas in communications links, but not near-field effects. In this first of a two-part article, this analysis examines the nearfield ... — Dr. John Howard [Design Features] Semiconductors Simplify Direct-Conversion Design Direct-conversion architectures enable the broadband radios needed to support multimode, multiple standards in third-generation (3G) and fourth-generation (4G) wireless networks. The capability of handling signals from 400 MHz to 4 GHz across the globe has pushed infrastructure and mobile-device developers to seek new levels of performance for the components in those systems. Fortunately, improved silicon germanium (SiGe) and CMOS... — Cecile Masse [Product Technology] Suppliers Enhance Substrate Performance Electronic substrate materials are like the foundation in a building: rarely noticed, but critical to the overall architecture. For RF/microwave circuits, the printed-circuitboard (PCB) substrate or laminate material is an essential building block that must be stable over time and temperature with low signal losses at microwave frequencies. Although PTFE has long been a substrate of choice at microwave frequencies, pure PTFE tends to suffer... — Jack Browne [Product Technology] Synthesizers Shave Size, Not Performance Size, speed, and power savings are key drivers for frequency synthesizers. A sign of the current trend in frequency synthesizers is the growing number of integrated miniature phase-lock-loop (PLL)/voltage-controlled- oscillator (VCO) combinations. What were once multiple components on a printed-circuit board (PCB) are now in a single surface-mount device. Requirements for frequency synthesizers in commercial and industrial applications are... — Jack Browne [Editorial] Doing More With Passive Components Improvements in passive components often come slow and hard, but they still come. Amazingly, after all these years of living with well-established passive circuit designs, such as Wilkinson power dividers, one might think that there was no longer room for improvements. But most manufacturers of RF/microwave passive components take great pride in their products, even those that have been in the catalog for a number of years, and most relentlessly pursue ways to... — Jack Browne [Feedback] Feedback Finding The Missing Piece Mr. Browne, Your article in the March 4 MWRF UPDATE e-newsletter titled, “Making Wireless ICs A Commodity,” got off to an interesting start. But it appears to have been cut short on the MWRF web site. Is it available elsewhere? Best regards, Steve Preston Hi Steve, Thanks for asking, and for reading. I’ve been hearing from folks that it is not obvious what I am... — Various Readers [The Front End] Wireless Sensor Networks Build On Successes UNITED KINGDOM—Wireless sensor networks (WSNs), which are self-organizing, self-healing networks comprising small “nodes,” offer much potential for industrial, military, and many other sectors. Although appreciable sales have already been established, major progress depends on the success of standards and products achieving a 20-year life. The new IDTechEx report by Dr. Peter Harrop, Chairman of IDTechEx, draws lessons from the many successful installations of WSNs in... — Dawn Hightower [The Front End] NASA Breaks Ground For Deep-Space Network Antennas WASHINGTON—NASA officials broke ground near Canberra, Australia to begin a new antenna-building campaign to improve Deep Space Network communications. Following the recommendations of an independent study, NASA embarked on an ambitious project to replace its aging collection of 230-ft.-wide dishes with a new 112-ft. antenna by 2025. The three 70-m antennas are more than 40 years old and located at the NASA Deep Space Network complexes at Goldstone, CA, Madrid, Spain, and... — Dawn Hightower [The Front End] SoC Cuts PA Distortion While Raising Efficiency LAFOX, IL—Richardson Electronics Ltd. has teamed with Scintera, Inc. to bring Scintera’s SC1887 system-on-a-chip (SoC) to market. The SC1887 promises to deliver power-amplifier (PA) linearity improvements without requiring access to in-phase/quadrature (I/Q) baseband signals. The SoC supposedly eliminates any need for software development. Because the SC1887 automatically calibrates and adjusts to the signal environment, a training algorithm is not required. ... — Dawn Hightower [Financial News] Companies Pursue Technology Alliance CASCADE MICROTECH, INC. and sUss Microtec aG have pursued a strategic alliance to address the growing device complexities of emerging semiconductor technologies. the two companies hope to bring innovative approaches to three-dimensional (3d) through-silicon-via (tsV) manufacturing processes. Both firms expect to use their associations with leading research organizations like iMeC as well as industry partnerships to gain insight into this cutting-edge... — Dawn Hightower [Company News] Company News CONTRACTS Northrop Grumman Corp.—Has been awarded a contract to supply navigation and communications systems for nine 35-m patrol boats being built for the Iraqi navy. The $19-million firm, fixed-price contract was awarded to Northrop Grumman’s Sperry Marine business unit by Swiftships Shipbuilders LLC of Morgan City, LA. Work will be performed by Northrop Grumman’s Ocean Springs, MS facility. Each of the vessels will be fitted... — Dawn Hightower [People] People McLean Takes Reins At Ozmo Devices BILL MCLEAN has joined Ozmo Devices as Chief Executive Officer. McLean was Co-founder and CEO of GloNav, a fabless semiconductor company that manufactured GPS receivers for the cellular market. He sold that company to NXP (part of ST Ericsson) for $110 million in 2008. Formerly, McLean was President and CEO of Anadigm, a fabless-semiconductor company producing field-programmable analog arrays... — Dawn Hightower [Educational Meetings] Educational Meetings MEETINGS ISQED 2010 11th International Symposium & Exhibits on Quality Electronic Design March 22-24, 2010 (San Jose, CA) DoubleTree Hotel For more information, visit: www isqed.org Exhibitions are free of charge Australian EW and IO Convention 2010 April 12-13, 2010 (Adelaide, South Australia) Hilton Hotel Adelaide For... — Dawn Hightower [R&D Roundup] 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 ... — Nancy Friedrich [R&D Roundup] 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... — Nancy Friedrich [Application Notes] 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... — Nancy Friedrich [Application Notes] 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... — Nancy Friedrich [Editor's Choice] 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... — Nancy Friedrich [RF Primer] Gauge Power Limits On Passive Components Passive components are often required to handle large amounts of RF/microwave power. When subjected to high continuous-wave (CW) or peak power levels, the signal path or paths through a passive component can also be thought of as thermal paths, and any impediment to the conduction of heat can limit the power-handling capabilities of the component. Understanding how well different passive components were designed for thermal flow can provide some... — Jack Browne [Focus] GaN Power Transistors Gain Ground In Military And Commercial Applications — Ashok Bindra [Focus] Amplifier Extends Function Generators To 50 V Peak-To-Peak — The Editors of Microwaves & RF [Focus] Raise Network-Analyzer Accuracy For High-Frequency Connectors — Ronnie Rice [Focus] Cable Assemblies Promise Reliable Performance Through 6 GHz — The Editors of Microwaves & RF [Focus] Cable Assemblies Wrap PTFE Dielectric In Copper Braid — The Editors of Microwaves & RF [Focus] TIA Explores Design Structures For Small Wind Turbines — The Editors of Microwaves & RF [Focus] Hybrid Coupler Covers 1.0 To 4.2 GHz — The Editors of Microwaves & RF [Focus] Compact Monopole And Dipole Antennas Reach 916 MHz — The Editors of Microwaves & RF [Focus] Passives-Model Library Offers Multiple-Simulator Licensing — The Editors of Microwaves & RF [Focus] Four-Way Power Divider Spans 6 To 18 GHz — The Editors of Microwaves & RF [Focus] Precision Thick-Film Resistors Target Consumer Applications — The Editors of Microwaves & RF [Focus] Six-Way Power Divider Seals Out Moisture — The Editors of Microwaves & RF [Focus] Broadband Resistive Coupler Covers DC To 15 GHz — The Editors of Microwaves & RF [Microwaves in Europe] Power Efficiency Takes Center Stage At Mobile World Congress In addition to drawing enormous crowds, the Mobile World Congress (MWC) in Barcelona, Spain hosted an array of 1300 companies. Those companies were hoping to attract the attention of original-equipment-manufacturing (OEM) designers, mobile-phone system designers, and network operators. They occupied exhibition booths that came in all sizes—from large enough to accommodate the population of a small town to those that could just about squeeze in a couple of items of ... — Paul Whytock [Microwaves in Europe] SoC Makes Breakthrough For Global Foundries—in conjunction with ARM—Spain’s mobile-communications techfest offered an opportunity to unveil a system-on-a-chip (SoC) technology for powering next-generation wireless products and applications. The chip manufacturing platform involves the merging of two Global Foundries process variants: the 28-nm super-low-power (SLP) process for mobile and consumer applications and 28-nm high-performance (HP) process. Compared to 40/45-nm technologies, the... — Paul Whytock |
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