Cover Story

 104 results found for Cover Story, displaying items 1 - 20

July 2010   [Components]
SMT Couplers Build On Legacy
Generational improvements in product lines are often incremental in nature, especially for passive components. But for the third generation of Xinger hybrid and directional couplers from Anaren, the improvements from the first- and second-generation products are dramatic, with significantly less insertion loss and greatly improved power-handling capability per square inch. The new patent-pending Xinger- III...  — Jack Browne

June/July 2010 Defense Electronics Supplement   [Systems & Subsystems]
OpenVPX Speeds Time To Market
VME is one of the oldest commercial off-the-shelf (COTS) buses still being designed into new military systems. At one time, it offered the industry’s fastest backplane bus. Its 320-MB/s speed was impressive when the format was first introduced in 1997. But today, the parallel VME bus has been superceded by high-speed serial interfaces like Serial RapidIO and Gigabit Ethernet. For military systems designers, high-speed bus options are many, but the...  — Bill Wong

June 2010   [Components]
TO-8 YIG Oscillators Tune From 2 To 8 GHz
For years, tunable oscillators based on yttrium- iron-garnet (YIG) resonators have been the first choice for many broadband systems and test instruments, valued for their low phase noise and excellent tuning linearity. The one drawback of the technology has been the size, since the oscillators have traditionally been housed in large cube-shaped or cylindrical packages with SMA connectors. But with refinements to YIG oscillator designs over the...  — Jack Browne

May 2010   [Devices & ICs]
MMICs Serve Key Transceiver Functions
Monolithic microwave integrated circuits (MMICs) based on gal l ium arsenide (GaAs) have been a part of this industry for a quarter century. And Freescale Semiconductor, the former Motorola Semiconductor, has enjoyed a long history of product development in analog and digital integrated circuits (ICs) and high-power RF transistors. But, although the firm has not lacked for the technological ...  — Monte Miller , et al.

March/April 2010 Defense Electronics Supplement   [Components]
Producing Power With Tubes And Transistors
High-power amplification at RF and microwave frequencies still involves vacuum tubes in many military systems. Such devices as traveling wave tubes (TWTs) in TWT amplifiers (TWTAs) and cross-field amplifiers (CFAs) are capable of hundreds of watts of continuous-wave (CW) power and kilowatts of pulsed (peak) power in ground-based and airborne systems, and they have served as reliable RF/microwave amplifiers even in space-based applications. But in recent years, claims of “vacuum-tube...  — Jack Browne

March 2010   [Components]
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...  —

February 2010   [Test & Measurement]
USB Devices Simplify RF/Microwave Testing
Computer-controlled test equipment once evoked images of racks of instruments connected to a “technical” computer via the general-purpose interface bus (GPIB). While GPIB-controlled gear is still a staple of many automatic-test-equipment (ATE) applications, newer test interfaces, such as the Universal Serial Bus (USB), are quickly gaining ground for their ease of use and flexibility. In fact, the availability of a growing number of measurement functions...  — Jack Browne

January 2010   [Test & Measurement]
Broadband VNAs View Nonlinear Behavior
Last year, the new Vectorstar microwaVe Vector network anaLyzers (Vnas) from Anritsu created a stir in the industry, with their powerful combination of high accuracy, fast measurement speed, and broad bandwidths (see Microwaves & RF, January 2009 Cover Feature). Since then, the industry’s appetite for nonlinear S-parameter measurements has grown. To satisfy that need, the firm has made its MS4640A family of VNAs...  — Steve Reyes

December 2009   [Products]
Top Products Of 2009
Launching a new product can be thrilling as well as stressful. Introducing a new product to the RF/microwave industry, after all, is the “moment of truth” in which all that market research, technology, and engineering comes together to be judged by the industry at large. Having a product reviewed in the pages of magazines such as this is one form of recognition of a product’s worth; being named to the list of Top Products of The Year is one indication that a product is making its mark in...  — Jack Browne , et al.

November 2009   [Test & Measurement]
Measure Group Delay Without Direct LO Access
Group delay that is well controlled in frequency-conversion components, such as mixers, is essential for many high-speed, highfrequency systems. It is critical for achieving low bit-error-rate (BER) performance in wireless and satellite communications receivers and for high target resolution in phased-array radar systems. The typical approach for measuring group delay requires access to the converter’s local oscillator (LO) signal. However, the LO is often...  — Gregory M. Bonaguide

October 2009   [Components]
Compact PLLs Integrate VCOs
Low-noise local oscillators (LOs) are critical to many RF/microwave systems in commercial, industrial, and military applications. Simply put, the higher the performance of the LO, the better the performance of the system in terms of receive signal sensitivity and bit error rate (BER) capability. One of the most common methods of generating a stable LO source is to combine a low-phase-noise voltage-controlled oscillator (VCO) with a stable reference oscillator to form a...  — Hittite Microwave

September 2009   [Devices & ICs]
Integrated Devices Arm Infrastructure Radios
Integration has been critical to RF electronics in mobile handsets, although elusive to achieve in infrastructure equipment. The classic tradeoff in achieving integration has been the choice between using discrete components, with their superior performance, or integrated circuits (ICs), with their small size. Recently, Analog Devices has developed a series of highly integrated phase-lock-loop (PLL) circuits that also...  — Ed Balboni , et al.

August 2009   [Components]
Hybrid Amp Modules Drive 6 To 18 GHz
Wideband amplifier modules find uses in a variety of industries, including in communications and test applications. A new line of hybrid power amplifier modules (HPMs) from AR RF/Microwave Instrumentation provides coverage from 6 to 18 GHz with a wide range of choices in signal gain and output power, including two models with noise figures as low as 3 dB. The simple-to-integrate modules are cascadable 50-Ohm system building blocks designed to operate on a...  — Jack Browne

July 2009   [Components]
VVAs Control Amplitude To 6 GHz
Voltage variable attenuators (VVAs) provide electronic control over signal levels, ideally with little or no distortion of the signals being controlled. In the case of the new VVA series of attenuators from Mini-Circuits, output waveforms are reduced in level with minimal distortion. The VVAs can provide level reductions as small as a few tenths of a decibel, or as large as typically 30 dB or more. The...  — Jack Browne

June 2009   [Test & Measurement]
Nonlinear VNAs Extend To 50 GHz
Vector network analyzers (VNAs) provide measured information about active and passive devices that can be invaluable when developing models for those devices. Recognizing the growing need for scattering-parameter (S-parameter) device characterization through millimeter-wave frequencies, Agilent Technologies has expanded its high-performance PNA-X series of VNAs to include a model with a frequency range of 10 MHz to 50 GHz (model N5245A). And for those not needing the full...  — Jack Browne

May 2009   [Devices & ICs]
Agile Sources Reach 50 GHz
MMillimeter-wave test signals are essential for evaluating a wide range of systems and their components, including aerospace, defense, and satellite communications systems. Those test signals should feature low phase noise, minimal harmonics and spurious content and, ideally, fast switching speed to cut the time needed for production testing of components. To fill those requirements, Giga-tronics (www.gigatronics.com) has introduced a new line of six frequency-agile synthesized...  — Jack Browne

April 2009   [Components]
VCOs Tune Miniature Synthesizers To 12 GHz
Miniaturization of voltage-controlled oscillators (VCOs) at lower microwave frequencies has long been limited by the size of the resonator. For the popular 4-to-8-GHz band, however, Synergy Microwave Corp. (Paterson, NJ) has managed to shrink multi-octave VCOs in that frequency range to a mere 0.3 x 0.3 in., with a companion line of frequency synthesizers that measure just 0.6 x 0.6 in. The discrete-device VCOs feature patented technology that achieves the high-stability...  — Ulrich L. Rohde , et al.

March 2009   [Components]
Rack-Mount Amplifiers Power 0.5 To 31.0 GHz
Rack-mount amplifiers serve a variety of purposes in commercial, industrial, and military systems, where power, gain, efficiency, and linearity are important. In line with these requirements, noted amplifier supplier CTT, Inc. (www. cttinc.com) has expanded its lines of rack-mount power amplifiers to cover the frequency range of 500 MHz to 31 GHz with as much as 50 W output power. The amplifiers can be used for antenna profiling, dielectric heating, ...  — Jack Browne

January 2009   [Test & Measurement]
Speedy VNA Spans 70 kHz To 70 GHz
Bandwidth is crucial to a vector network analyzer (VNA), which is often called upon to make critical measurements on a passive or active device in order to develop a software model that is then used to optimize the design. In terms of VNA bandwidth, it doesn’t get much better than the new VectorStar VNAs from Anritsu Co., which includes a model (MS4647A) with standard bandwidth of 10 MHz to 70 GHz (and optional extension to 70 kHz). The new family of premium,...  — Harry Momjian

December 2008   [Components]
Miniature VCOs Shrink Wideband Synthesizers
Compact frequency synthesizers fill many needs in modern communications systems. To achieve fullsized performance in miniature packages, Synergy Microwave has developed a line of compact frequency synthesizers that leverage novel, patented voltage-controlled-oscillator (VCO) technology1- 8 for the stability and low noise needed for emerging wideband, high-datarate wireless communications systems. ...  — Ulrich L. Rohde , et al.





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