Novel Miniaturized Self-Packaged Filters Based on Metasubstrate in SISL Platform

In this brief, a novel strategy is proposed to design miniaturized self-packaged filter based on the proposed metasubstrate in substrate integrated suspended line (SISL) platform. Multi-layer SISL and periodic metasubstrate structures contribute to the miniaturization and self-packaging of second- and fourth-order quarter-wavelength hairpin filters, caused by the higher permittivity. The designed dumbbell-shaped metasubstrate shows a high relative permittivity of 15.4. The proposed FR4-based second/fourth-order filters with a reduced insertion loss of 1.13 dB/1.49 dB only show the miniaturized size of
$0.26\,\,\lambda _{\mathrm{ g}} \times 0.19\,\,\lambda _{\mathrm{ g}}$
and
$0.27\,\,\lambda _{\mathrm{ g}} \times 0.32\,\,\lambda _{\mathrm{ g}}$
, respectively. And the circuit areas of the above two designed filters with metasubstrate are reduced by 46% and 34%, compared with the cases without metasubstrate, successively.