G. F. Zargano, V. V. Zemlyakov
The development of micro-wave technologies in antenna-feeder systems relates to permanent requirements increasing for elements and devices characteristics. The necessity of high power transmission in wide frequency band with big dynamic range and low losses even in millimeter range comes to waveguide elements demand, moreover to waveguides of complex cross section. High urgency in this field has a wide class of selective devices such as channel-selective devices (directional couplers, di- and multiplexers), frequency-selective devices (filters), and also mode-selective devices or mode waveguides transformers.
The problems of analysis and synthesis of directional couplers with the system of small rectangular and crossline apertures, band-pass filters on transverse junctions and mode transformers on double ridge waveguides are solved. Electromagnetic fields and cutoff wave numbers are calculated by method of partial regions including field singularities at the edge.
The synthesis results for each type of devices are given. The comparison of calculation results with the results of computer simulation by numerical techniques confirms the efficiency of developed algorithms.