A Monolithic Miniature Multi-Conductor Strip-Resonator Bandpass Filter

https://doi.org/10.1134/S106378502107004X

A new monolithic design of a miniature bandpass filter for manufacture by means of multilayer printed-circuit-board technology has been developed. It is demonstrated using a fourth-order filter that multi-conductor strip resonators used in the design ensure both miniaturization and high selectivity of the device. The passband center frequency of the manufactured filter is  f0 = 546 MHz, the fractional bandwidth is Δf/f0 = 25%, and the insertion loss is 0.8 dB. The filter has a wide high-frequency stopband, which extends up to a frequency of 10f0 at a level of –30 dB. The filter dimensions are 15.0 × 12.0 × 4.3 mm (0.027λ0 × 0.021λ0 × 0.007λ0, where λ0 is the wavelength in vacuum at frequency f0) and the mass is only 1.8 g. The performances of the filter and the accessibility of its design for surface mounting show that the device has great potential.