Microwave Journal

Thermal Power Sensors

January 17, 2011

New coaxial power sensors, R&S NRP-Z56 and R&S NRP-Z57, are the first to perform thermal power measurements up to 67 GHz.

Munich, March 23, 2010 — Rohde & Schwarz has expanded its extensive range of power sensors by adding two new models to the R&S NRP family. The new sensors are the first on the market to measure thermal power from DC up to 50 GHz and 67 GHz respectively. They are also the only thermal power sensors that can be used even without a base unit. Connection to a PC takes place via USB. In addition to saving cost and space, the sensors offer outstanding performance for calibration labs as well as for manufacturers of microwave transmission systems and RF/microwave components. A standing wave ratio (SWR) of 1.35 is achieved from 50 GHz to 67 GHz. This is so far unparalleled and results in exceptionally high precision. Linearity surpasses that of commercial products by a factor of ten across the entire frequency range and allows accurate relative power measurements.

The new R&S NRP-Z56 and R&S NRP-Z57 thermal power sensors (up to 50 GHz and 67 GHz respectively) offer outstanding measurement accuracy. Sensitivity has been significantly improved by minimizing zero drift and noise. The resulting increase in dynamic range (55 dB) enables thermal power measurements for powers as low as -35 dBm. In addition, measurement speed exceeds that of conventional instruments by a factor of three. This is especially beneficial in production applications, where short cycle times are just as important as maximum precision.

Measurement uncertainty in power measurements is largely attributable to mismatching. This effect is aggravated if the sensor is improperly connected to the DUT. To solve this problem, Rohde & Schwarz has developed a new type of connector that incorporates a ball bearing, which greatly simplifies correct attachment of the sensor to the DUT. This provides a reliable and user-friendly solution that also enhances measurement reproducibility.

The R&S NRP-Z56 and R&S NRP-Z57 thermal power sensors (up to 50 GHz with 2.4 mm connector and up to 67 GHz with 1.85 mm connector respectively) are now available from Rohde & Schwarz.