Options for generating and analyzing RF/microwave signals have expanded over the first half of this year, with companies introducing a variety of signal analyzers and generators in form factors ranging from handheld to benchtop and rack-mountable. Highlights include a new high-power, low-noise analog signal generator and several arbitrary waveform generators. Signal-analysis news includes a handheld-analyzer-based solution for measuring 5G base-station coverage, a benchtop instrument with an analysis bandwidth that can be extended to 1 GHz, an ultraportable mmWave spectrum analyzer, and an entry-level spectrum analyzer offering frequency ranges to 3 GHz.

Analog signal generators

On the signal-generation front, in June Rohde & Schwarz introduced the R&S SMA100B analog signal generator, which offers a frequency range up to 20 GHz. At a video press conference announcing the new product, Andreas Pauly, vice president for signal generators, audio analyzers, and power meters, said the new instrument delivers signals with low phase noise and high output power with low harmonics, adding that engineers no longer need to compromise between output power and spurs. For customers designing high-end products, he said, “The signal generator should never be the bottleneck.”

The SMA100B comes in several versions. A 6-GHz instrument generates up to 38 dBm RF output power, and a 20-GHz instrument generates up to 32 dBm. Harmonics are low across the entire frequency range; above 6 GHz they are lower than 70 dBc at 18-dBm output power. Nonharmonics are below 110 dBc at an output signal of 1 GHz.

In addition, the instrument comes in 2U-height and 3U-height configurations. Frank-Werner Thuemmler, product manager for signal generators and power meters, said the 3U version comes with a 7-inch display and is suitable for desktop use. The 2U version comes with a 5-inch screen and fits into space-constrained ATE systems (Figure 1). Thuemmler added that the R&S SMA100B is included in the R&S Legacy Pro program and can easily replace obsolete signal generators from Rohde & Schwarz and other manufacturers in automated test environments without the need to modify the test software.

Figure 1. R&S SMA100B in 2U and 3U versions
Courtesy of Rohde & Schwarz

Furthermore, the instruments come with an optional clock-synthesizer output. Juergen Ostermeier, director of R&D for microwave signal generators, explained that the clock-synthesizer output can be set independently of the main analog output. He said the configuration is useful for testing A/D converters, for example, with one box providing the clock signal as well as the analog signal.

“Rohde & Schwarz’s introduction of its low-phase-noise R&S SMA100A signal generator—the predecessor of the R&S SMA100B—nearly a decade ago has helped us evaluate, test, and specify our A/D converters to their maximum capabilities,” said Ron Goga, test director of high-speed A/D converters, Analog Devices, in a press release. “The close cooperation between our two companies and the timely release of the R&S SMA100B with extremely pure analog RF signals up to 20 GHz coincides with the release of Analog Devices’ new RF Series of converters, which includes the AD9208 dual 3-GS/s 14-bit A/D converter and AD9172 dual 12-GS/s 16-bit D/A converter. The state-of-the-art performance of the R&S SMA100B allows us to continue to showcase our RF data converters in the best possible light.”

Arbitrary waveform generators

Tektronix has been focusing on arbitrary waveform generators and recently introduced the AWG5200 Series instruments, which offer a 10-GS/s sample rate, 16-bit resolution, and up to eight channels per unit along with support for multiple-unit synchronization. The instruments target “go wide” technologies like MIMO, EW and radar applications, and quantum computing, said Kip Pettigrew, product marketing manager, during a product demonstration.

In the field of general electronic test, he said, standards are changing fast, leaving traditional test-and-measurement approaches behind, even as legacy standards continue to demand support. Meanwhile, technologies like MIMO require independent high-bandwidth RF streams.
For military and government applications, he said, existing solutions lack the fidelity and precision required to respond to adaptive threats, whereas custom solutions are expensive compared with COTS. And as is the case for general-purpose test, legacy tasks aren’t going away.

Finally, Pettigrew said, as physicists race to build high Q-bit quantum computers, they are finding that existing solutions aren’t meeting their fidelity, latency, and scalability requirements for controlling Q-bits with precision pulsed microwave signals from multiple independent RF channels (Figure 2). Quantum computing and its associated industries are expected to reach $26 billion by 2020, he said.

Figure 2. AWG5200 Series AWG in a quantum-computing application
Courtesy of Tektronix

At the heart of the AWG5200 Series instruments are new high-performance D/A converters. With its D/A converter cores, the AWG can directly generate highly detailed RF/EW signals or the complex pulse trains used in advanced research. The 16-bit vertical resolution, Pettigrew said, compares with alternatives offering 14-bit resolution.

For military and government applications, Pettigrew said, the instrument delivers accurate replication of real-world signals with a low noise floor. A variety of waveform-generation plugins support fast waveform design iteration times. Digital upconversion functionality coupled with a built-in I/Q modulator provides a wide VSG-like RF output range without the need for additional equipment. In addition, he said, digital interpolation and numerically controlled oscillators enable direct generation of complex RF signals with increased playback times.

Signal generation is becoming increasingly important in a range of advanced research applications, Pettigrew said, including quantum computing, nano/micro technology development, biomedical applications, and physics. However, high-performance signal generators are expensive, inflexible, and often still cannot meet fidelity, latency, and synchronization needs. In response, some researchers have turned to home-built equipment that is uncalibrated, unstable, and lacks support. And none of the current alternatives can scale without additional effort or money.

Pettigrew explained that in quantum computing, for example, scalability is a key requirement as researchers need the ability to send dozens of synchronized signals to quantum compute cores. For additional scalability, multiple AWG5200 units can be synchronized to provide unlimited channel count. The fully integrated platform, he said, allows for faster waveform loading and cleaner RF performance. In addition, the AWG5200 offers up to 32 digital channels for flexible triggering of additional test equipment.

National Instruments and Astronics Test Systems also have been working on AWGs and have paired them with digitizers or oscilloscopes. For example, Astronics recently debuted the new PXIe-1802 arbitrary waveform generator and the new PXIe-1803 digitizer, which serve aerospace, defense, communications, and other high-reliability applications. The PXIe-1802 AWG supports output frequencies of up to 125 MHz and features dual 14/16-bit waveform generator channels, bandwidths of 90 to 140 MHz, and 250-μV measurement accuracy. The PXIe-1802 and PXIe-1803 are described in more detail in a recent article.1

For its part, NI recently released of a new family of PXI arbitrary waveform generators with up to two channels and 80 MHz of analog bandwidth in a single slot. The company also announced a new 100-MHz, eight-channel oscilloscope to form an instrument combination that lets engineers achieve high-performance signal generation and complex waveform measurement.

The new PXIe-5413, PXIe-5423, and PXIe-5433 AWGs deliver -92 dB of spurious-free dynamic range and 435-fs integrated system jitter while providing precise waveform adjustment when used with a dedicated standard waveform generation engine. With a new fractional resampling architecture for arbitrary waveform generation, similar dynamic range and jitter performance is available independent of user sample rate.

“Test engineers need the best technology available at the right price and channel counts to meet their cost, complexity, and time-to-market requirements,” said Luke Schreier, director of automated test product marketing at NI. “The new family of arbitrary waveform generators provide software continuity with our NI-FGEN drivers for simple technology insertion, and the new oscilloscope includes a user-programamable FPGA to customize functionality for different applications. We believe the software-centric and standardized hardware approach in PXI for automated test, both in the laboratory and production environments, offers the flexibility to balance continuous innovation with proven measurement technologies.”

Advanced electronic systems are increasingly turning to parallel design architecture to increase their overall performance in applications such as MIMO, radar, quantum computing, and multilane serial bus testing, according to Spectrum. To support such systems, the company recently introduced the DN6.66xx Series AWGs (Figure 3), which offer up to 24 fully synchronized channels. The DN6.66xx Series adds eight new instruments to the company’s generatorNETBOX AWG line. LXI compliant, they can be integrated into any test system by an Ethernet connection to a PC or LAN. Using 16-bit D/A converter technology, the AWGs offer from six to 24 fully synchronous channels, output rates up to 1.25 GS/s, analog bandwidth as high as 400 MHz, onboard memories up to 1 GS per channel, and output voltage ranges of up to ±5 V into a high impedance and up to ±2.5 V into 50 Ω.

Figure 3. DN6.66xx Series AWGs with 24 channels
Courtesy of Spectrum

All the output channels are clocked and triggered synchronously so they maintain a constant, interchannel clock-phase relationship. The clocking system uses a precision PLL control process that can be generated internally or, alternatively, from an external clock or reference. Time skew between the channels also is minimized with the maximum skew, between all channels, being less than 130 ps.

Signal analyzers

Making news with regard to signal analysis, in June Keysight Technologies announced Nemo Outdoor, which combines with FieldFox handheld RF and microwave analyzers to form a solution for measuring, analyzing, and visualizing the coverage generated by 5G base stations. The solution uses the Nemo Outdoor analytics tools to provide capabilities for visualizing and post-processing data, enabling network equipment manufacturers and mobile operators to evaluate and verify 5G base-station propagation models for indicating 5G cellular coverage levels.

“Since there are currently no 5G devices and very few 5G radio field measurement solutions available, mobile operators face the challenge of verifying that propagation models used in 5G network planning match reality,” said Juha Laukkanen, director, drive test and benchmarking products, in a press release. “Keysight’s solution, which combines Nemo Outdoor and FieldFox [Figure 4], offers users a unique tool to ensure that the accuracy of 5G planning models. Measuring signal power levels from 5G base stations in the field enables operators and network vendors to verify 5G propagation models, securing the deployment of the network and, ultimately, speeding up time-to-market.”

Figure 4. Nemo Outdoor with FieldFox analyzer
Courtesy of Keysight Technologies

5G and wideband test

Anritsu also is focusing on 5G. It recently debuted the MS2850A signal analyzer, which the company said can cost efficiently and accurately evaluate 5G signals with the 800-MHz modulation bandwidth (8 x 100-MHz channels) associated with 5G designs. With analysis bandwidth up to 1 GHz, the MS2850A provides wireless equipment manufacturers and mobile operators with a comprehensive tool to evaluate base stations and terminals as well as satcom and broadband communications equipment.

Engineers can use the MS2850A to evaluate Tx performance. The MS2850A supports 5G standards currently under development by 3GPP as well as legacy technologies such as LTE, W-CDMA, TD-SCDMA, and GSM. Anritsu said the MS2850A fills a market void for an economical solution to accurately measure infrastructure under development for the emerging 5G market as well as for other communications applications that have similar requirements, such as larger data capacity at faster speeds.

Two models, with frequency coverage up to 32 GHz and 44.5 GHz, are available. At 28 GHz, the MS2850A has amplitude flatness of ±1.2 dB and phase flatness of 5 degrees peak-to-peak at a 500-MHz center frequency. The analyzers also feature a 0-dBm A/D converter clipping level, DANL of -141 dBm/Hz, and SFDR of -70 dBc.

Three software packages are available for the MS2850A to measure critical 5G characteristics. The CP-OFDM modulation software leverages the high dynamic range of the MS2850A to achieve EVM performance of less than 1%. Other measurements that can be conducted with the MS2850A when the software is installed include uplink and downlink signal frequency error and power. A multicarrier analysis function improves measurement and testing efficiency of downlink measurements by shortening times for relative comparisons of characteristics for each carrier as well as timing errors and general characteristics for all mobile operators.

In addition, Anritsu earlier this year introduced the Spectrum Master MS2760A family (Figure 5), which Russel Lindsay, product marketing engineer, Service Infrastructure Solutions Division, described as the first ultraportable, millimeter-wave spectrum analyzers that verify high-frequency designs, including those used in 5G and E-band applications. The USB MS2760A Series has models that support maximum frequencies from 32 GHz to 110 GHz. The series is described in further detail in an earlier article.1

Figure 5. Spectrum Master MS2760A analyzer
Courtesy of Anritsu

Rohde & Schwarz has been busy on the spectrum-analysis as well as signal-generation fronts. It recently introduced the R&S FPC1000, which the company describes as an entry-class spectrum analyzer that features a flexible keycode upgrade concept, a 10.1-inch high-resolution display, and integrated Wi-Fi for wireless remote control via mobile apps. The analyzer targets basic research, production, service, and educational applications that require spectrum analysis.

The base model covers a frequency range from 5 kHz to 1 GHz, which can be expanded to 2 GHz or 3 GHz via software upgrades. Upgrades can be purchased as needed; recalibration is not required.

The R&S FPC1000 provides a low noise floor level of -150 dBm (typ), which can be further extended to -165 dBm (typ) with an optional keycode-activated preamplifier. Its high maximum input power allows users to measure RF signals up to +30 dBm.

In related news, the distributor Saelig announced it is now offering the Spectran HF-80200 V5 RSA rack-mounted, real-time 9-kHz to 20-GHz spectrum analyzer, manufactured in Germany by Aaronia AG, a maker of RF site survey tools, handheld spectrum analyzers, antennas, and EMC test probes.

The Spectran HF-80200 V5 RSA (Figure 6) can scan from 9 kHz to 20 GHz in less than 20 ms, allowing the capture of erratic transmissions or interference. The 1U-height instrument can be mounted on a desktop, in an equipment rack, or at a distant location for remotely assessing signal conditions without requiring personnel to be present.

Figure 6. Spectran HF-80200 V5 spectrum analyzer
Courtesy of Saelig

The HF-80200 V5 is controllable through a USB interface or LAN/Ethernet, allowing continuous logging and streaming of almost any frequency range and direct access to the analyzer through an Internet-connected PC.

Analyzer software

In addition to introducing its new AWG, Tektronix also has been working on signal-analyzer technology. Wilson Lee, technical marketing manager for Tektronix mainstream products within the Americas region, said that Tektronix recently released Version 1.0.16 of its DataVu-PC analysis software. “DataVu-PC makes short work of searching and recording through large datasets for signals of interest,” he said. “You can measure pulses and mark signals for export to other analysis programs, reducing time spent in post-capture analysis.”

He added, “When combined with the signal recording capabilities of all Tektronix USB and PCIe-based spectrum analyzers, DataVu-PC can turn hours of attended monitoring into fast post-acquisition search, mark, and measurement tasks of up to 2 million pulse records.” An article2 in last month’s issue offers more details on software for various instrument classes.

Baseband VST

If you are looking for a signal generator and analyzer in one unit, you could select National Instruments’ Vector Signal Transceiver. The NI PXIe-5840 VST combines a 6.5-GHz RF vector signal generator, 6.5-GHz vector signal analyzer, high-performance user-programmable FPGA, and high-speed serial and parallel digital interfaces into a single two-slot PXI Express module. With 1 GHz of bandwidth, the latest VST is suited for a range of applications including 802.11ac/ax device testing, mobile/Internet of Things device testing, 5G design and testing, and radar prototyping.

NI’s latest VST innovation is the PXIe-5820 baseband model, introduced in June at the International Microwave Symposium in Honolulu. NI describes the PXIe-5820 module as the industry’s first baseband VST with 1 GHz of complex I/Q bandwidth; it is designed to address challenging RF front-end module and transceiver test applications, such as envelope tracking, digital predistortion, and 5G test.

“In 2016, NI disrupted the industry by introducing the RF model of our second-generation VST with 1 GHz of instantaneous bandwidth,” said Charles Schroeder, vice president of RF and wireless, in a press release. “We’re continuing the disruption with the baseband model of our second-generation VST. Engineers can use the baseband VST with LabVIEW system design software to address the evolving and changing needs of transceiver test applications. Engineers can take advantage of the software-designed architecture of NI’s VSTs to help accelerate the pace of design, reduce the cost of test, and solve measurement problems previously unsolvable through traditional test approaches.”

“The baseband VST is a deliberate evolution of our original software-designed architecture,” added Ruan Lourens, chief architect of R&D for RF at NI. “We have managed to optimize in every possible domain, from thermal and electrical to digital signal processing, to deliver 1-GHz complex I/Q bandwidth in a small form factor. The baseband VST can be tightly synchronized with the PXIe-5840 RF VST to subnanosecond accuracy to offer a complete solution for RF and baseband differential I/Q testing of wireless chipsets.”

 


References

  1. Nelson, R., “Boosting measurement capability from pocket to benchtop,” EE-Evaluation Engineering, April 2017, p. 18.
  2. Nelson, R., “Speeding instrument setup, control, and communication,” EE-Evaluation Engineering, July 2017, p. 6

 


 

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Rick Nelson
Rick became Executive Editor for EE in 2011. Previously he served on several publications, including EDN and Vision Systems Design, and has received awards for signed editorials from the American Society of Business Publication Editors. He began as a design engineer at General Electric and Litton Industries and earned a BSEE degree from Penn State.

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