Vector network analyser expands to 24 test ports

April 30, 2014 // By Graham Prophet
Rohde & Schwarz has released the first network analyser with up to 24 integrated test ports: the R&S ZNBT. The instrument allows users to characterise devices under test with multiple test ports and enables production lines to maintain high throughput by measuring multiple DUTs in parallel.

The ZNBT offers the high RF performance of a two-port network analyser at each of its test ports; it

covers the frequency range from 9 kHz to 8.5 GHz, and the base model is equipped with four test ports. Depending on application requirements, the analyser can be enhanced to include 24 ports. The ZNBT is primarily used in the development and production of active and passive multiport components such as front-end modules for multiband mobile phones.

When fitted with its maximum number of test ports, the ZNBT is capable of determining all 576 S-parameters of a 24-port DUT. It requires no switching, and therefore carries out multiport measurements faster than switch matrix-based multiport systems. For example, the ZNBT can cover all 576 S-parameters at 201 frequency points in less than 260 msec. That is 10 times faster than the ZNB and ZN-Z84 switch matrix solution from Rohde & Schwarz, which is already high-speed. The latter requires more than 2.7 sec for this measurement. Alternatively, the ZNBT can also measure multiple DUTs in parallel. Previously, users had to operate several network analysers in parallel to achieve such high throughput.

The ZNBT also does away with the loss introduced by matrix switches, making it possible to deliver measurements with the instrument's full dynamic range of 130 dB, a high output power level of 13 dBm and low trace noise. This makes multiport measurements highly stable, reproducible and precise.

The network analyser has no display – a space-saving feature that is especially beneficial in automated production. It can be controlled via an external monitor, mouse and keyboard or via an external touchscreen. It features the same intuitive operation as the ZNB, and all of its functions can be accessed in no more than three operating steps. As a result, defining even complex multiport measurements is just as fast and easy as configuring conventional two-port measurements. Automatic multiport calibration units save users time when