M2M (machine-to-machine) communications, smart homes, the smart grid, smart cities, mHealth, wearables—these terms refer collectively to the Internet of Things, which has its own subcomponents, including the Industrial IoT and Intuitive IoT. As the IoT in all its manifestations continues to roll out, developers will need a variety of test strategies to ensure low power consumption, suitable RF performance, and even audio quality for applications with voice input/output.
The available tools for testing connected devices range from power supplies to vector signal transceivers, as described in our December print special report on the topic.
Vector network analyzers
In addition, Anritsu positions its VectorStar and ShockLine VNA product families for connected-device test. Steve Reyes, senior product manager at Anritsu, commented, “VectorStar is often chosen by R&D engineers because it provides them with the most accurate characterization of transistors used in connected devices, which in turn provides them the necessary data for the highest degree of device model accuracy. Accurate device characterization is often contingent upon wide frequency sweeps, well beyond the operating frequency range of the device, for best analysis results.”
He added that after a transistor is integrated into a MMIC, VectorStar can help analyze the performance of the packaged components as well.
“In addition to the standard VNA measurements, VectorStar also offers the unique ability to analyze device, subassembly, and system performance under modulated stimulus conditions with up to 200 MHz modulation bandwidth,” Reyes said. “The ability to capture and display the modulated waveform means the DUT can be analyzed with both CW and modulated stimulation for analysis under more ‘real world’ conditions than CW stimulus alone.”
He added, “Combining this capability with VectorStar’s other suite of measurements, design engineers can measure the linear S-parameter properties of active devices, switch to a power sweep to analyze the nonlinear compression properties, perform detailed CW IMD measurements, and verify real world performance of ACPR under modulated conditions.”
Stan Oda, product manager, outlined the capabilities of the ShockLine instruments. “With 1-, 2-, and 4-port models with frequency ranges up to 43.5 GHz, the ShockLine family of VNAs tests a wide variety of components and products. The ShockLine VNAs are ideal for use in the manufacturing and maintenance of devices and products used in network equipment, UE (cell phones, tablets, etc.), automotive, high-speed data interconnect, and system-integration applications.”
Oda and Reyes emphasized that the graphical user interface is the same for all Anritsu bench-top VNAs, simplifying the correlation of measurements on the VectorStar in R&D and the ShockLine in manufacturing test. “Common calibration standards and calibration routines also help make measurement correlation easier between Anritsu VNAs,” they added.
And within the ShockLine family itself, Oda reported, “ShockLine VNAs share common remote programming software, which allows the same automated program to be run on a performance MS46500B ShockLine VNA in engineering and an economy MS46322A ShockLine VNA in production, enabling easier correlation between the two phases of development.”
Added Oda, “MS46500B Series ShockLine VNAs can improve throughput by using a unique Simultaneous Sweep capability to make S-parameter measurements. Traditional VNAs require forward and reverse sweeps on each port to make S-parameter measurements. With Simultaneous Sweep, the MS46500B Series VNAs capture the forward and reverse sweep data at the same time, significantly reducing the S-parameter measurement time. Compared to a traditional 4-port VNA, the MS46524B 4-port VNA with simultaneous sweep can be four times faster capturing the S-parameter measurement.”
Power and efficiency
Power consumption is a critical issue for connected devices, and one key aspect is power added efficiency. “Accurate VNA measurements with correlation to various parameters such as bias and input power are the optimal method of maximizing PAE performance,” said Reyes. “The versatility of VectorStar to perform a wide range of measurements under various stimulation conditions and with the widest range of frequency coverage ensures that the PAE of the device is optimized for best current consumption and battery life.”
Added Oda, “ShockLine VNAs have the speed and accuracy at an economical price to enable full coverage of RF performance including PAE testing in production.”
Anritsu also offers several other solutions to test power consumption and battery life. “The MD8430A signaling tester was part of a demonstration at CTIA Super Mobility 2015 [September 9-11 in Las Vegas] that showed the ultra-low power consumption enabled by LTE Cat. 0 Power Saving Mode (PSM),” said Jay Torgerson, Anritsu business development manager for the Internet of Things. “This world-first demonstration indicated LTE Cat. 0 technology is ready for deployment into IoT devices.”
