Trusted Resource for the Working RF Engineer
Search MWRF
Home
Product Directory
Topics
Video Interviews
Back Issues
Subscribe
News
Online News
Design Features
Web Seminars
PartFinder
Whitepapers
Microwave Legends
WebConnect
RF Design
RSS
RSS
 |
August 2010 [Communications] Fast-Locking Techniques Benefit PLLs A PHASE-LOCKED LOOP (PLL) -BASED frequency synthesizer requires a certain amount of time for the loop to settle and acquire phase/frequency lock. This settling time, which is determined by the loop characteristics, is inversely proportional to the loop bandwidth. Generally, a PLL’s locking time is shortened by widening that loop bandwidth. At Taipei’s National Taiwan University, a novel fast-locking technique for PLLs has been developed by Wei-Hao Chiu, Yu-Hsiang Huang, and... August 2010 [Components] PA Achieves 25 Percent Efficiency At 60 GHz AT 60 GHZ, A NUMBER OF POWER AMPLIFIERS (PAs) in CMOS have boasted output power to +16 dBm. Yet their power-added efficiency (PAE) was less than 15 percent. Recently, a 60-GHz wideband PA was reported with PAE above 20 percent for all applied VDD values. This development was the work of Alexandre Siligaris, Christopher Mounet, and Pierre Vincent from France’s CEA, LETI, MINATEC together with Christine Raynaud from CEA, LETI, MINATEC and STMicroelectronics, ... August 2010 [Applications] VNAs Replace Legacy RF Test Systems TODAY’S RF TEST SYSTEMS must test S-parameters, compression, intermodulation distortion (IMD), spurs, and noise figure while performing faster and more accurate measurements at a lower cost of ownership. Conventional “rack and stack” RF test systems comprise multiple instruments, such as a vector network analyzer (VNA), spectrum analyzer, signal generators, and power meters. Additional equipment is required to test lownoise amplifiers (LNAs) and provide an interface to the... August 2010 [Applications] Properly Select Ports During Circuit Simulation FOR DESIGNERS USING SOFTWARE circuit simulators, the correct use of ports is critical—in addition to the drawing of the structure itself—to the attainment of successful, meaningful simulation results. In a white paper titled, “A Plethora of Ports: Making Sense of the Different Types of Ports in EM Simulators,” AWR’s John Dunn provides the reader with a fundamental understanding of ports. The nine-page document focuses on the ports common to electromagnetic... August 2010 [Components] Voltage-Variable Attenuator Covers 250 To 4000 MHz DESIGNED AS A GENERAL-PURPOSE block for wireless-infrastructure applications, a new voltage-variable attenuator (VVA) delivers 44 dB of linearly controlled dynamic range from 250 to 4000 MHz. Dubbed the MAX19790, it actually comprises two VVAs integrated in one monolithic integrated circuit (IC). By leveraging a proprietary, silicongermanium (SiGe) BiCMOS process, each attenuator incorporates a patented control circuit to provide a 22-dB attenuation range... August 2010 [Components] 10-MHz OCXO Increases Test-System Stability TEST-EQUIPMENT PERFORMANCE is typically curtailed by phase noise. To improve the measurement capabilities of phase-noise test sets, signal generators, and spectrum analyzers, the 10-MHz OX-045 oven-controlled crystal oscillator (OCXO) promises to lower close-in phase noise by 10 dB. The OCXO flaunts typical phase noise of –142 dBc/Hz with worstcase performance of –140 dBc/ Hz at an offset of 10 Hz. With an offset of 100 kHz, it boasts typical ... August 2010 [Devices & ICs] Front-End Module Serves 900-MHz ISM Band WITH ADVANCED METERING INFRASTRUCTURE (AMI) and other applications in the Industrial, Scientific, and Medical (ISM) band gaining in popularity, the RF3858 front-end module is a promising solution for portable equipment in need of size reduction. It also reduces the number of components outside of the core chipset. The RF3858 contains a power amplifier (PA) transmit/receive (Tx/Rx) transfer switch, low-noise amplifier (LNA) with bypass mode, and matching components. That LNA... August 2010 [Computer-Aided Engineering] Software Supports Nonlinear Behavioral Modeling WITH THE RELEASE OF the 2010 Microwave Office (MWO) design suite, engineers are promised new functionality and tools to increase productivity in the design of high-frequency monolithic microwave integrated circuits (MMICs), microwave integrated circuits (MICs), RF printed-circuit boards (PCBs), and modules. The release supports nonlinear behavioral modeling via Agilent’s X-parameters, Mesuro’s Cardiff model, and more. In addition, it delivers improved speed in ... August 2010 [People] Microwave Legends To those outside this industry, microwave engineers and dealmakers probably seem to be involved in some kind of dark art. They use terms and acronyms not widely understood. In addition, they not only understand electronic systems that few can comprehend, but can also imagine ways to improve them. It is this vision that marks all of the hall of famers inducted into the “Microwave Legends” over the last four years. It also is a characteristic of the... August 2010 [Computer-Aided Engineering] Software Speeds Simulation Of Phased-Array Antenna BECAUSE OF MAIN-BEAM SCANNING, assessing the performance of a phased-array antenna usually involves the repeated calculation of its far field. Unfortunately, the time-consuming brute-force method comprises the calculation followed by the summation of a large number of complex exponentials, which represent the individual contributions of the array elements to the far field. For an array antenna populated by 1000 array elements, calculating that far field... July 2010 [Devices & ICs] DDS RFIC Performs Direct Digital Modulation With the increasing availability of ultra-highspeed digital-to-analog converters (DACs), a direct digital synthesizer (DDS) can generate waveforms exceeding 1 GHz. Until now, however, no higheroutput DDSs have been able to provide the desired modulation capabilities. Now, what is thought to be the first DDS RFIC with greater than 1 GHz output and direct digital FM and PM capabilities has been presented by Xueyang Geng, Fa Foster Dai, J. David Irwin, and Richard C.... July 2010 [Applications] Grasp Ground Concepts In EM Simulators Many engineers do not understand how grounding is implemented in circuit simulation. As a result, electromagnetic (EM) simulators are often misused—with erroneous results. An 11-page white paper from AWR titled “Understanding Grounding Concepts in EM Simulators” defines ground connections in EM simulators. It also shows how to correctly choose among various grounding options. For example, many modern simulators support “local grounding,” whereby different ports ... July 2010 [Components] 16-W GaAs FETs Cover 6.4 To 8.5 GHz The “EL” series of three galliumarsenide (GaAs) field-effect transistors (FETs) provides +42.5 dBm output power at 1-dB compression. The TIM6472-16EL operates from 6.4 to 7.2 GHz with 11.0 dB power gain at 1-dB compression and power-added efficiency (PAE) of 37 percent. Its sibling, the TIM7179-16EL, covers 7.1 to 7.9 GHz. It typically provides 10.5 dB power gain at 1-dB compression with 37 percent PAE. Finally, the TIM7785-16EL spans 7.7 to 8.5 GHz while... July 2010 [Communications] Satellite Markets Enjoy An Uptick The term “satellite” conjures many images ranging from television service to cutting-edge military applications like the “mystery” satellites that provide surveillance over troubled areas. With so many automobile drivers equipped with Global Positioning Satellite (GPS) systems, however, satellite applications have become rather commonplace. Yet that does not mean they have lost their innovative edge. Emerging needs continue to open new markets and ... July 2010 [Components] Tri-Band Monopole Antenna Covers WiMAX And WiFi Bands Systems with mulitple wireless communications protocols require compact, low-cost, multiband antennas. Recently, a compact tri-band monopole antenna was proposed. It uses reactive loading, which was inspired by previous transmission-linemetamaterials (TL-MTM) work, and a “defected” groundplane. In doing so, it can meet the specifications of the WiFi and WiMAX standards while maintaining a small form factor. The antenna was developed by Jiang Zhu, Marco A.... July 2010 [Components] 2.45-GHz Rectenna Transmits Power Wirelessly For energy-harvesting devices, the rectifying antenna (rectenna) is crucial. A broadband rectenna that uses a printed monopole antenna and bandpass stub bandpass filter has been developed by Tae-Ui Hong, Kyoung-Min Oh, Hyun-Wook Lee, Hee Nam, and Tae-Soon Yun from Seoul’s Kwangwoon University together with Dae-Sung Lee, Hak-In Hwang, and Jong-Chul Lee from the Korea Electronics Technology Institute. This antenna was designed at 2.45 GHz for the wireless ... July 2010 [Applications] Use Diversity Techniques In Low-Power Radios The term "diversity" in radio systems refers to the use of multiple signal paths, such as in multipath conditions, as an advantage. The goal is to maximize the likelihood that a transmitted data packet will be correctly received. According to an application note titled “Implementing ‘Diversity’ Using Low Power Radios” by Mike Burns and Tim Starr, such techniques can be implemented using one or two low-power radios, a low-power microcontroller, and an ... July 2010 [Components] RMS Detector Provides 57-dB Dynamic Range To 10 GHz A 10-GHz RMS detector offers ±0.2-dB linearity over a 43-dB dynamic range at 2.14 GHz—even for signals with high-crest-factor modulation used in 3G and 4G broadband wireless networks. Dubbed the LTC5582, it vows to accurately measure signal levels as low as -56 dBm to +1 dBm to ±1 dB error. The RMS detector provides a 57-dB dynamic range from 450 MHz to 2.7 GHz. The device offers 46 dB of useful dynamic range at 6 GHz and 38 dB at 10 GHz. From... July 2010 [Components] Limiter Handles 10 W CW From 2 To 6 GHz To keep the RF input signals experienced by low-noise amplifiers (LNAs) and receiver frontend components to safe levels, a new limiter is designed to attenuate signals above a specific threshold. Dubbed model ACLM-4805FM15, this microwave limiter covers 2 to 6 GHz. It is rated to handle continuous-wave (CW) signal levels of 10 W and peak levels of 1 kW (1 µs pulse width, 0.1 percent duty cycle) over a temperature range of -55° to +85°C or 20 W CW and 1 kW peak at ... July 2010 [Test & Measurement] Oscilloscope Characterizes Designs Beyond 40 Gb/s A wide-bandwidth oscilloscope is vowing to help engineers see the true performance of their designs on signals from 50 Mb/s to more than 40 Gb/s. The mainframe platform of the 86100D DCA-X permits engineers to make next-generation measurements that include integrated de-embedding capability. It scales from 2 ps/div to 1 s/div. The oscilloscope offers delays of 24 ns minimum with a maximum of 1000 screen diameters or 10 s (whichever is smaller). It provides time ...  prev. page
[1]
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
next page 
|
|
||||||
Resources
Electronic Design