Magnetically tunable filters for cellular communication terminals

Dielectric-ferrite film heterostructures for magnetic field controlled resonance microwave components

“…In general, electronic control could be realized if device includes ferroelectric [9], semiconductor [10] or ferrite [11] constituent. This is, in essence, the practical realization of the composite materials concept.…”

“…While tuning mechanism is similar with that, utilized in [11], we exploited thick-film tape-casting ferrite component instead of a bulk ferrite, which, as expected, should decrease mass and dimensions of composite structure, and also make it compatible with planar technology. Large area of contact between ferrite and dielectric in such heterostructure favors substantial penetration of DR main mode high-frequency electromagnetic field into magnetic film, resulting in noticeable impact of ferrite permeability on the DR resonance mode even for marginal relative volume of the ferrite component.…”

Design of varactor tuned bandpass filter

“…Known tunable filter realizations [1][2][3][4][5][6][7][8][9] can be divided into several groups i.e. mechanically tuned [5], electricaly tuned (magnetically tuned [6], optically tuned, voltage tuned [1,3,4,7,9]), tuned in a narrow frequency range (usually related to high quality filters) [6], tuned in a wide frequency range (usually realted to LC or stripline realizations) [1,3,8,9] and many more.…”

“…mechanically tuned [5], electricaly tuned (magnetically tuned [6], optically tuned, voltage tuned [1,3,4,7,9]), tuned in a narrow frequency range (usually related to high quality filters) [6], tuned in a wide frequency range (usually realted to LC or stripline realizations) [1,3,8,9] and many more. Due to specific requirements concernig a size our filter has been designed as a varactor tuned microstrip filter.…”

Voltage tunable bandpass filter

“…There is a lot of known tunable filter realizations [1][2][3][4][5][6][7][8][9]. They can be divided into several groups i.e.…”