A. A. Yelizarov, A. S. Kukharenko
At the modern state of UHF-technique development the special interest is in simultaneous use of periodic slow-wave structures and a dielectric in microstrip frequency-selective devices, which gives a new physical internals to devices and new opportunities of their applications.
The construction of a microstrip lowpass filter presents metallic conductors in the form of parallel sections of zigzag-lines and symmetrically located between them dielectric zigzag insertion, made on a dielectric subscript of policor, and has a much more coefficient of dieing (S21 parameter) and the steepness of the front of the amplitude-frequency characteristic, in the difference of the construction of three parallel metallic zigzag-lines.
The simultaneous use of periodic slow-wave structures of metal and dielectric in the microstrip devices also allows us to make a bandpass filter. Constructively such a filter is made on a dielectric subscript of policor, contains a metallic conductor in the form of a section of a zigzag-line and a periodic structure of dielectric insertions. Such a construction demonstrates a presence of the second, lower frequency of shearing, caused by the periodicity of the insertions-resonators, what allows us to get a filter with the band 2,0...2,7 GHz. The connecting of the opposite ends of the dielectric insertions with the metallic screen allows us to change the band width of the filter.
So the made analysis and the computer modeling show the possibility of development of new microstrip frequency-selective devices on the base of resonant sections of slow-wave metal-dielectric systems, which provide a precise of border frequencies, the privation of the higher band passes, and a profile sizes of the device lower, than the central wavelength with the high enough corpulence of the structure in the UHF-range.