Towards the Study of Dual-Band Quasi-Yagi Antennas and Band-Notched Re-entrant Filters

In this paper, a number of research results, recently carried out at the department of Radio Receivers and Radio Transmitting Devices of NSTU-NETI, related to the construction of layout schemes, methods of analysis and optimization are presented. More than that the peculiarities of practical implementation of the dual-frequency/dual-band linearly polarized cylindrical and printed-circuit-board aerials as well as the dual-band band-stop reentrant microwave radiofrequency filters are mentioned. The results described below may be useful to construct the microwave telecommunications in various areas of the radio frequency technologies including the radio transmitters, radio receivers, radio frequency identification equipment, radio frequency energy harvesting, satellite and another telecommunications, and so on. Additionally, it is useful to note that proposed dual-band dipole-like aerials radiate in the Fraunhofer far-zone the linearly polarized electromagnetic waves with high polarization purity of radiation. This means that the little axis’s value of the polarization ellipse, which is depicted at the perpendicularly oriented with respect to the Poynting vector virtual plane, is much less than another ellipse axis’s value. The following technical solutions are based on well-known principles and methods of system-technical design in the microwave region of the whole frequency band. The use of these approaches and techniques made it possible to implement the compact aerials and filters with additional degrees of freedom.