A systematic analysis of measurement uncertainties in rectangular waveguide calibrations is condcuted. Uncertainty budgets for different waveguide bands are examined, individual uncertainty contributions are discussed and the significant impact of connection repeatability is highlighted. Consequently, an investigation into misaligned waveguide interfaces is undertaken, emphasizing the importance of precise alignment, supported by simulation and experimental data.

The paper shows the determination and application of the generalized efficiency of waveguide thermoelectric power sensor and the uncertainty in the direct transfer system to establish measurement traceability of the millimeter wave power to the primary standard. The waveguide thermoelectric sensor with its generalized efficiency can be used as a transfer standard to calibrate all types of power sensors to determine both the generalized efficiency and the calibration factor.

The paper gives advice to design sequentially rotated antenna arrays with rotation angles optimized for polarization quality. In antenna arrays perfect single radiators are not realizable. Differences between elements impede efficient operation. A smart approach of placing and rotating the elements improves the radiation characteristics. This effect is very efficient, if the single radiators show medium polarization quality, like e.g., mass produced inexpensive devices used in many applications.

In measurement applications many devices with two ports have different interfaces at their two ports and are commonly referred to as adapters. The interface e.g. can be a coaxial connector, a rectangular waveguide flange, or a coplanar waveguide probe tip. Two suitable methods for the measurement of such adapters are compared. The first one is a VNA measurement method using only one port calibration standards and one port measurements. It will be compared to a two port calibration method.

In an intercomparison organized within the framework of the German Calibration Service (Deutscher Kalibrierdienst – DKD), seven different calibration laboratories participated in the measurement of the antenna factor for three different antennas according to different standards. Between August 2017 and April 2018, measurements have been performed on a hybrid antenna, a logarithmic-periodic antenna and on an Open Ended Waveguide.