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.

UAV-based antenna measurements are of particular interest for physically large antennas, where traditional antenna measurement techniques are not applicable. Precise position information is obtained by GNSS, where the receiving GNSS antenna is a critical system component. An additional antenna groundplane may be beneficial or even required, depending on the antenna design. Appropriate groundplane configurations improved the achievable position accuracy in the majority of investigated cases.

The technology of ridged-waveguide filters provides high midband frequencies as well as the suppression of spurious passbands up until very high frequencies. Due to the concept of these filters, broad bandwidths lead to reduced filter dimensions that are very difficult to fabricate. The interdigital arrangement of resonators guarantees a more reliable fabrication of these filters. The research was done in order to supply filters for the different frequency bands in the 5G communication standard.