Even during a year beset by economic challenges, creative high-frequency firms found ways to transform innovative engineering ideas into practical products.
Attendance was modest at this year's IEEE Microwave Theory & Techniques Society (MTT-S) annual conference and exhibition, held recently in Boston, MA. But bleak economic forecasts didn't stop this industry's resourceful engineers from unleashing a host of new product ideas that can only help to turn business in a positive direction.
Among the most noticeable of display booths were those hosted by the major test and measurement and computeraided- engineering (CAE) software suppliers. Those riding the "down" escalator at the entrance of the exhibit floor, for example, were greeted by the outline figure of "Microwave Legend" James Clerk Maxwell overlooking the Sonnet Software booth. Sonnet's high-quality planar electromagnetic (EM) analysis software and generous offers of free trial copies of their EM software suites drew more than their fair share of visitors from that escalator with scores of booths beyond promoting new software, hardware, and test equipment.
For Ansys subsidiary Ansoft, IMS provided an opportunity to introduce new high-performance computing capabilities for its three-dimensional (3D), full-wave high-frequency-structuresimulator (HFSS) electromagnetic (EM) field simulation software. Among the planned enhancements to this software is domain decomposition, a high-performance- computing (HPC) option. This technology enables engineers to solve problems like electromagnetic-induced heating in high-power microwave structures and antenna performance while under mechanical deformation via links with the ANSYS Workbench platform.
Analysis of the 3D EM effects of components like radio-frequency integratedcircuit (RF IC) packages, antennas, and printed-circuit-board (PCB) interconnects is performed by Electromagnetic Professional (EMPro), which hails from Agilent EEsof EDA (www.agilent.com). It allows designers to create 3D components that can be simulated together with planar two-dimensional (2D) circuit layouts and schematics within the firm's Advanced Design System (ADS) suite of software tools using EM-circuit cosimulation. Engineers can set up and run analyses using both frequency-domain and time-domain 3D EM simulation technologies.
HSPICE RF from Synopsys performs both frequencyand time-domain steady-state and noise analysis for RF ICs. It offers harmonic balance for weakly to mildly nonlinear circuits, Shooting Newton for strongly nonlinear circuits, and envelope analysis for complex modulated RF waveforms. S-parameter analysis targets smallsignal, linear distributed components. This software promises to quickly and accurately simulate more than 10,000 active devices.
Perhaps the most noticeable trend among the larger test and measurement companies was the engineering efforts devoted to nonlinear vector network analysis. The use of X-parameters, as Agilent Technologies terms its nonlinear versions of small-signal S-parameters, allows designers of amplifiers and other active components to understand the behavior of their circuits under largesignal or nonlinear conditions, such as under saturation or gain compression. Such behavior is of particular interest to developers of systems that must operate with high ratios of peak to average output power. The measurements can be used to build device and component models in CAE tools like ADS.
One of the system-level solutions on display at the Agilent booth included impedance tuners from Maury Microwave Corp. (Fig. 1) bundled with a model PNA-X microwave VNA from Agilent. Additional solutions added mechanical impedance tuners from Focus Microwaves to a microwave PNA-X VNA Nonlinear VNA measurement solutions were also on display at the Rohde & Schwarz booth as well as the Anritsu Co. booth, where the company showed its VectorStar Broadband ME7828A VNA with frequency range of 70 kHz to 110 GHz.
Anritsu also announced its MN469xA series four-port test sets for its high-performance VectorStar MS4640A VNAs. The test sets provide four-port measurement capability through 70 GHz without rerouting test cables. The combination of test sets and VNAs team for accurate measurements at speeds to 30 microseconds per point with 103-dB dynamic range through 67 GHz. The company also displayed several additions to its VNA Master line of handheld VNAs for in-field testing..
One of the more intriguing nonlinear measurement solutions was offered by little-known Mesuro Ltd. based in Cardiff, UK. The firm's MB series of test sets (Fig. 2) support active load-pull measurements in contrast to mechanical impedance tuners. The test systems are ideal for measuring the nonlinear behavior of PAs with output levels as high as 150 W CW. The systems were used in tandem with the Microwave Office Design Environment 2009 of CAE tools from Applied Wave Research (AWR) to develop the "Cardiff Model" to characterize power transistors and amplifiers with any type of signal waveform and in any impedance environment.
According to Dr. Richard Emsley, CEO of Mesuro, "The Mesuro active load pull solutions are an exciting advancement in measurement technology that will greatly reduce challenges facing device and PA designers today. The scientists at Cardiff University have worked closely with industry leaders for many years and Mesuro has developed a very practical commercial solution." The new openloop, active load-pull technique replaces the use of passive tuners with an RF source that adjusts the amplitude, phase, and power level to vary the effective impedance at the DUT interfaces. The solution allows absolute control of all in-band and out-of-band impedances, enabling the designer to control the harmonic source/load impedance over the entire Smith chart.
OEwaves addressed phase-noise measurements at MTT-Sspecifically with its automated phase-noise measurement system based on a homodyne receiver. The test system is available for a standard measurement range of 6 to 12 GHz with extensions bringing the frequency coverage as high as 40 GHz. The base phase noise is as low as 120 dBc/Hz offset 1 kHz from the carrier and 170 dBc/Hz offset 10 MHz from the carrier using resolution bandwidths from 0.1 Hz to 200 kHz. The test system can display spectral density, spurious content, and full spectrum information. It also can be configured for pulsed CW input signals.
Thanks to a new synthesizer design, the model 2820A VSA from Keithley Instruments offers a low-phase-noise option (Fig. 3). At a 300-kHz offset from a 2-GHz carrier, for example, phase noise is less than 140 dBc/Hz. The dynamic range of errorvector- magnitude (EVM) measurements can therefore be as low as 48 dB for 20-MHz IEEE 802.11n measurements. The standard VSA provides a 40-MHz signal-acquisition bandwidth with a frequency range of 400 MHz to either 4 or 6 GHz. To provide higher testing speed, it can tune to a new frequency in 250 s.
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The Swiss company AnaPico Ltd. unveiled its compact but capable APSIN3000 batterypowered signal generator with as much as +13 dBm output power from 9 kHz to 3.3 GHz. With 0.001-Hz frequency resolution and 0.1-deg. phase resolution, the generator provides an output power range of 100 to +13 dBm with 0.1-dB power resolution. For a portable source, it features impressive spectral purity with 35 dBc harmonics, 60 dBc spurious content, and 130 dBc/Hz phase noise offset 20 kHz from a 1-GHz carrier. It measures just 106 x 172 x 220 mm and weighs less than 3 kg but provides FM, AM, pulse, and phase modulation. For higher-frequency coverage, the company offers the APSIN6000 source with a frequency range of 9 kHz to 6.5 GHz and output-power range of 140 to +13 dBm with similar spectral purity.
A more specialized test signal generator, the model GSG-L1 signal generator from Pendulum Instruments, provides a precise L1 Global Positioning System (GPS) signal to verify the performance of GPS receivers. Measuring just 140 x 140 x 70 mm and with an RS-232 interface for control, the GPS signal generator can be supplied with a standard temperature-compensated crystal oscillator (TCXO) or optional oven-controlled crystal oscillator (OCXO) reference source. The signal generator provides BPSK-modulated test signals with C/A code and navigation signal and can control output levels from 73 to 175 dBm. As many as 1023 codes can be carried on a test signal using a 50-b/s data format with GPS frame structure at 1575.42 MHz. The test generator achieves 1-kHz accuracy with the OCXO and 6-kHz accuracy with the TCXO reference.
In support of low phase noise, VIDA Products unveiled its model V-10 oscillator. Measuring just 1.8 x 0.9 x 0.9 in. with an SMP male connector, it operates from 8 to 18 GHz with +7 dBm output power. It features 24-MHz/mA main coil tuning sensitivity and FM coil tuning sensitivity of 0.8 MHz/mA. Harmonics are better than 15 dBc while spurious content is better than 70 dBc. The YIG-based oscillator, which draws less than 100 mA current from a voltage supply of +5 to +7 VDC, achieves phase noise of 95 dBc/Hz offset 10 kHz from the carrier, 120 dBc/ Hz offset 100 kHz from the carrier, and 140 dBc/Hz offset 1 MHz from the carrier.
OMNIYIG, Inc. showed the M3043D and M3043DD YIG-based bandpass filters with analog or 12-b digital drivers. They tune a 25-MHz-wide, 3-dB filter bandwidth across a total frequency range of 8 to 18 GHz. The maximum passband insertion loss is 6 dB while minimum offresonance isolation is 80 dB. The four-stage bandpass filter has a minimum limiting level of +10 dBm and provides linearity of 15 MHz. Sweep speed is 115 ms.
EM Research displayed its THOR series of compact frequency synthesizers including the model THOR-14280 for use in test equipment and VSAT radios at 14.28 GHz. With +7 dBm output power, less than 20 dBc harmonics, 40 dBc subharmonics, and 60 dBc spurious content, the compact frequency synthesizer exhibits phase noise of 80 dc/Hz offset 1 kHz from the carrier, 90 dBc/Hz offset 10 kHz from the carrier, and 110 dBc/Hz offset 100 kHz from the carrier.
Phase Matrix introduced its version of a "Heathkit" test signal source with the QuickSyn line of microwave frequency synthesizers (p. 96). Based on a voltagecontrolled oscillator (VCO), the model FSW-0010 synthesizer, for example, operates from 0.5 to 10.0 GHz with 0.001-Hz frequency resolution and an output-power control range of 25 to +15 dBm. Harmonics are 40 dBc or less and spurious content is 70 dBc or less. The phase noise is typically 132 dBc/Hz offset 1 kHz from a 1-GHz carrier and 140 dBc/Hz offset 1 MHz from the same carrier.
Tucked away on the back of the show floor, LPKF Laser & Electronics displayed the ProtoLaser S laser-based printed-circuit-board (PCB) prototyping system as the missing link between CAE and layout software tools and the rapid development of prototype circuit boards. The compact system uses high-power laser technology to quickly create high-resolution PCBs from digital layout files, handling circuit boards as large as 9 x 12 in. (229 x 305 mm). The tool-less system selectively ablates the conductive layer from the microwave substrate to precisely form insulation and conductive channels. It can be used with a wide range of substrate materials including ceramic, PTFE, and flexible substrates.
To boost signals, MicroWave Technology introduced the model MMA-020624-L3 GaAs MESFET MMIC amplifier in LCC lead-frame package. Designed for applications from 2 to 6 GHz, the tiny amplifier provides 17 dB typical gain to 4 GHz and 13 dB typical gain to 6 GHz. It features 1.3 dB typical gain flatness across the full range with +18 dBm typical output power at 1-dB compression and 3.5 dB typical noise figure. The amplifier draws 250 mA current at +8 VDC and achieves an output third-order intercept point (IP3) of +40 dBm. It delivers +18.5 dBm average output power at 2/5 percent EVM with 17 dB gain.
Herotek unveiled a line of low-leakage limiters for applications from 10 MHz to 18 GHz. Models LL2018-1, LL2018-2, and LL2018-3 operate from 2 to 18 GHz with typical leakage levels of 10 to 5 dBm, 5 to 0 dBm, and 0 to +5 dBm, respectively, and typical threshold levels of 10, 5, and 0 dBm, respectively. Maximum VSWR is 2.0:1 for all three units. Each model exhibits maximum insertion loss of 4 dB. The limiters can handle 1 W CW power and 100 W peak input power.
Representatives from IMST GmbH were on hand to explain their array of RF test services including nonlinear measurements of power amplifiers and mixers and on-wafer and coaxial measurements of microwave and millimeter-wave components. Test functions include output power, noise figure, load-pull testing, conversion loss/gain, and testing under different environmental conditions. The firm, which provides consulting services on RF testing, also supports transistor modeling for MESFET, HEMT bipolar, and LDMOS devices.
Rohde & Schwarz offered a host of demonstrations including a new method to obtain group-delay measurements, which does not require access to the local oscillator (LO) of the device under test (DUT). The firm also spotlighted new capabilities for evaluating differential devices. When equipped with the R&S ZVA-K6 true differential option, both the R&S ZVA and AVT series of VNAs can take advantage of coherent signal sources to adjust them to a selected phase or amplitude offset. Together with Noisecom, Rohde & Schwarz set up a test solution for making Y-factor noise-figure measurements in the 60-GHz range. This system does not require downconversion using harmonic mixers.
Noisecom, a Wireless Telecom Group Company, offers two versions of its 60-GHz noise-figure test set: the NC5115-60G with a waveguide flange and the NC5115-60GT with a coaxial transmission. The systems comprise precision noise sources that cover the 60-GHz band together with isolators for optimal VSWR match. In addition, low-noise amplifiers offer 30 dB gain to increase the output of the device under test (DUT) if it is too low for direct measurement. The noise source delivers 17.5 dB excess noise ratio (ENR).
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On display at the National Instruments booth was a wireless-local-area-network (WLAN) test suite, which combines the NI WLAN Measurement Suite software for National Instruments LabVIEW and LabWindows/CVI development environments with 6.6-GHz, PXI Express RF hardware. The included PXIe-5663 6.6- GHz RF VSA can perform signal analysis from 10 MHz to 6.6 GHz with up to 50 MHz of instantaneous bandwidth. In contrast, the PXIe-1075 chassis provides per-slot bandwidth to 1 GB/s with total system bandwidth to 4 GB/s. The measurement system produces residual EVM measurements down to 44 dB.
Of course, both active and passive components were being exhibited in droves on the show floor. Freescale Semiconductor expanded its RF power-transistor portfolio for GSM EDGE networks by introducing three high-performance transistors based on laterally diffused metal oxide semiconductor (LDMOS) technology. The MRFE6S9046N covers 920 to 960 MHz while delivering 17.8-W average RF power output with 19 dB of gain, efficiency to 42.5 percent, and EVM to 2.1 percent RMS. It is housed in Freescale's over-molded plastic package. Its 28-V siblings, the MRF8S9100H/ HS covering 920 to 960 MHz and the MRF8S18120H/HS spanning 1805 to 1880 MHz, are designed for Class AB and Class C operation in GSM and EDGE systems.
To more thoroughly cover the RF signal chain, Analog Devices spotlighted several new RF ICs including a phase-locked-loop (PLL) synthesizer, two RF/IF gain blocks, a driver amplifier, and a TruPwr RMS power detector. The new ADF4150 PLL synthesizer, which offers a noise floor figure of merit of 222 dBc/Hz, is capable of fractional-N or integer-N operation. Operating to 4.4 GHz, the ADF4150 is software-compatible with the firm's ADF4350 PLL/voltage-controlled oscillator (VCO). For their part, the ADL5601 and ADL5602 broadband RF/IF gain blocks operate from 50 MHz to 4 GHz. The ADL5601, for example, offers a noise figure of 3.7 dB and output third-order intercept point of +43.7 dBm at 900 MHz. The ADL5604 broadband 1-W driver amplifier offers 1 W of power from 400 to 2700 MHz. Lastly, the ADL5902 TruPwr RMS root-to-mean square detector precisely measures signals with highly varying crest factors to 9 GHz.
Aside from making news with the launch of gallium-nitride (GaN) foundry services, RFMD introduced a PA targeting WiFi and WiMAX applications. The RF5602 2-GHz, linear PA offers 2-percent error vector magnitude at +25 dBm output power and 4.2 V. Small-signal gain ranges from 32 to 34 dB. The PA operates from a 3.3-to- 5.0-V supply.
Both WiMAX and fourth-generation Long Term Evolution (LTE) were targeted by Renaissance Electronics Corp. Its TCA-based repeaters and macro cells target point-to-point and point-to-multipoint deployment. This design covers 400 MHz to 6 GHz while handling up to 4 X 4 MIMO for maximum bandwidth efficiency. Skyworks entered the high-definition videostreaming market with the SKY65137, a monolithic microwave integrated circuit (MMIC) PA fabricated using indiumgallium- phosphide (InGaP) heterojunction- bipolar-transistor (HBT) technology. To enable higher data rates at extended ranges, the SKY65137 delivers +24 dBm linear output power at less than 2.5- percent EVM.
Among the products being shown at MITEQ were extremely rugged solidstate power-amplifier (SSPA) systems for satellite-uplink applications. At P1dB, for example, the PA-G/T-790840-40 provides +46 dBm/40 W.
Quite a few process-technology advancements were made at this year's show. For instance, NXP debuted its QUBIC4 BiCMOS silicon technology. This silicon germanium: carbide (SiGe:C) process vows to speed the migration from GaAs components to silicon by enabling low-noise performance and IP availability. The newest SiGe:C technology, dubbed QUBiC4Xi, offers improved Ft (above 200 GHz) and a lower noise figure than its predecessor.
To enable an efficient RF IC design flow, Agilent Technologies announced two process design kits (PDKs) for Jazz Semiconductor's 0.18-m SiGe BiCMOS process offerings, which are used with Agilent's ADS 2009 software. The PDKs promise to accelerate time to market for IC development in automotive collision avoidance, emerging HDTV wireless standards, and more.
Numerous transistors composed of both GaAs and GaN were announced by Toshiba. For example, the firm's first commercial C-band GaN HEMT for satellite-communications applications, the TGI 7785-120L, operates from 7.7 to 8.5 GHz. It offers output power of 120 W. It typically features output power of +51.0 dBm with +44 dBm input power, linear gain of 11.0 dB, and drain current of 10.0 A. The merits of GaN were touted by Nitronex while proprietary Indium-gallium-phosphide (InGaP)-Plus technology is at the heart of a family of WCDMA/HSPA PAs from ANADIGICS, Inc. They incorporate daisy-chainable power couplers, which typically have 20-dB directivity and a 20-dB coupling factor.
Among the product highlights at American Microwave Corp. was a phase-invariant digital programmable attenuator. Dubbed the PI-DVAN-6018, this attenuator delivers essentially constant phase, adjustable attenuation over 40 dB from 6 to 18 GHz. At 18 GHz, the attenuator exhibits 8 dB insertion loss.
Connecting the female SMA side of the RF Pocket Reference Oscillator (RFPRO series) from Crystek to +3.3-VDC will output a clean 135 dBc/Hz phase-noise signal at 10 kHz offset from the carrier (Fig. 4). In effect, each RFPRO is a fixed-frequency portable signal generator. The RFPRO series oscillator offers frequency stability of 150 ppm from 20 to 70C.
Cable and connector companies also were showing their wares. Firms like W.L. Gore and Astrolab offered a representative sampling of diverse offerings. Times Microwave showed the Phase Track II, a thermally stable, flexible coaxial cable that promises to improve performance in phase-sensitive systems. With its highly stable base material, TF5, the firm asserts that it virtually eliminates the wide phase changes suffered by other high-performance PTFE dielectric cables during temperature changes. The overriding theme with this year's show was that the slow economy did not affect innovation. These examples of the multitude of product launches certainly prove that trend to be correct.