Microwave Filters Based on the Structures with Resonators in Parallel Channels as Metamaterial Cells

Abstract

Background. Many of the properties of metamaterials are similar to those found in filters with mutually detuned by frequency unrelated resonators. The bridge filters are used as a low-frequency prototypes of such microwave filters. For further development and design of new types of metamaterials it is necessary to establish an analogy between metamaterials and filters with mutually detuned by frequency unrelated resonators. Objective. Creating a model of metamaterials based on the bandstop microwave filters with mutually detuned resonators and on the low-frequency prototypes. Methods. Checking the equivalence of metamaterials characteristics and microwave filters with mutually detuned resonators, identifying their inherent laws (oscillation types in parallel channels, location of the attenuation poles above or below the bandwidth), which appear regardless of the types of resonators, studying the possibility of using prototype bridge filters for modeling of metamaterials. Results. The basic model of an 8-pole network with resonators in parallel channels has been studied in detail. Analytical expressions are obtained for the transmission and reflection coefficients for all inputs of an 8-pole network. The 4-pole networks implemented on the basis of the aforementioned basic model are investigated. Experimental studies are performed that confirm the adequacy of analytical models. An analogy between metamaterials and microwave filters with mutually detuned resonators is established, the possibility of the use as a low-frequency prototype bridge bandpass filters is shown. Conclusions. Microwave filters with mutually detuned resonators can be used for modeling of metamaterials, and bridge bandpass filtersas low-frequency prototypes, which design techniques are well developed.

Y-type hexagonal ferrite-based band-pass filter with dual magnetic and electric field tunability

“…It follows from Ref. 36 that the full 3 dB linewidth of the two-side coupled resonator is given by where f c is the center frequency, K i > 0 are the coupling coefficients with the input and output transmission lines, and Q 0 is the unloaded quality factor that accounts for internal losses in resonator. In turn, Q 0 is determined by the internal magnetic field and the FMR linewidth.…”