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.