USB-powered real time spectrum analyser

Paul Boughton

Tektronix has introduced a new class of affordable, portable spectrum analysers based on a USB architecture.

The new RSA306 sets a new price/performance threshold for spectrum analysers and features a broad 9 kHz to 6.2 GHz frequency range, 40MHz real time bandwidth. When used with Tektronix SignalVu-PC software, it offers advanced analysis capabilities for such applications as budget-conscious research and development, mobile radio network installation, interference hunting and university level lab classes. 

Spectrum analysers are inherently expensive and often there are not enough instruments for everyone to use in many labs, field organisations and universities so at £2,340 the RSA306 puts a real-time spectrum analyser within reach for the entire technical team.

In addition, Tektronix is providing its SignalVu-PC software at no cost, giving open access to powerful signal analysis tools that have previously been only available with the purchase of expensive bench instruments.

The RSA306 is Tektronix’ first USB spectrum analyser and will be joined by similar instruments taking advantage of the availability of affordable desktop computers and laptops with sufficient processing power to handle complex test and measurement analysis along with high-speed USB 3.0 interfaces that also power the device, eliminating the need for a battery pack. 

At its introductory price point, the RSA306 is a fraction of the cost of a conventional spectrum analyzer while offering comparable or even superior sensitivity, accuracy and dynamic range. The device is based on Tektronix' own FPGA architecture to deliver the real time digital signal processing. This data is then fed to a PC or tablet running Windows on an Intel Core i7 processor for analysis and display. The SignalVu-PC can display multiple linked analysis windows which is particularly useful for interference hunting and monitoring transient signals.

“Today we are bringing real time technology to a new price point that's completely disruptive,” said Dean Miles, European technical marketing manager for Tektronix. “The digitised RF is downconverted and transferred over USB3, which makes it faster than any benchtop instrument because we are not going through the legacy bus of the benchtop.”

The analyser opens up new opportunities for testing low cost wireless devices used in applications such as the Internet of Things, he said. “You would not be manufacturing low cost consumer wireless devices and need a top of the range spectrum analyser, but you could use this on the production line,” he said.

With a 9kHz to 6.2GHz frequency range with 40MHz instantaneous bandwidth, the real-time processing capability is at least 1,000 times faster than other spectrum analyzers. An open API allows customers to use their own custom Windows-based interface such as Matlab or Python to manipulate raw data coming from the instrument.

The RSA306 is aimed at areas such as budget RF design and development of RF components where inexpensive Wi-Fi modules dramatically increase the need for spectrum analysis. Now labs working on wireless-enabled designs can afford to give everyone on the design team the RF signal analysis tools they require.

Mobile radio network installers can take advantage of the convenience, analysis capabilities and user-friendly operation so that engineers and technicians need to get a fast handle on network health. Full spectrum analyser measurement capabilities provide far more versatility than the limited pass/fail of a dedicated tester.

Miles also sees interference hunters using the RSA306 in a backpack while still offering the sensitivity needed to quickly discover signals as short at 100µs. This is key for Spectrum Managers and Regulatory Agencies who need a basic spectrum analyser and interference hunter in the field. 

University lab classes can also use the analyser, sharing the .iqt files to any tablet or PC to help students become better RF and microwave engineers by giving them the hands-on experience. Vector analysis, frequency and phase trends, and other tools allow educators to teach concepts well beyond basic frequency and amplitude.