Tektronix enters VNA market with low-cost USB models
We keep hearing about small companies and "makers" developing products that use wireless connectivity, but these product developers may not have to test their products until something goes wrong. In many cases, these product integrators marry an off-the-shelf cellular or Wi-Fi modem with their embedded systems and they assume the wireless features will just work. That's not always the case. When wireless connectivity fails, it's time to troubleshoot, and that means test equipment.
Small companies and makers often lack the cash to acquire traditional RF test equipment. Even worse, they may not be versed in RF troubleshooting because their expertise resides in other disciplines. To address the issue, Tektronix has developed a pair of vector-network analyzers (VNAs) that let you characterize RF paths by measuring S-Parameters, among others. Having that data can help you find the cause of the problem, such as an impedance match between to RF components and cables.
The TTR500 is a two-port VNA that's available with bandwidths to 3 GHz (TTR503A, $9000) or 6 GHz (TTR506A, $12,000). Aimed at the embedded, IoT, and education markets, these low-priced instruments connect to a PC (Windows 7 and higher) over a USB link. You can operate the instrument using VectorVu software, available as a free download. VectorVu produces plots such as Smith Charts, return-loss plots, and voltage standing wave ratio (VSWR) plots. Applications include component evaluation (connectors, cables, filters amplifiers, etc.) and antenna matching. In addition, the TTR500 lets you automate measurement using the same SCPI commands used to control other VNAs.
The TTR500 lets you measure S11, S12, S21, and S22. Each port has a signal generator and three receivers. Both ports include a built-in bias-T, which lets you inject DC into the RF source signal generated by the VNA for testing active devices such as amplifiers. Optional calibration kits let you remove losses from test setups, insuring that you're measuring the device under test, not the cables and test fixtures.
- Dynamic range: 122 dB
- Putout power: −50 dBm to +7 dBm
- Trace Noise: 0.008 dB
- Bias tee: 0 to ±24 V, 0 to 200 mA
Textronix, TTR500 product page.
- IMS2014: RF Instruments go faceless
- What are S-parameters, anyway?
- EDN's collection of articles on S-Parameters
- Avoid a common S-parameter problem
- Review: Tektronix RSA306 spectrum analyzer (part 1)