A Novel IPD-Based Dual-Band Filtering Power Divider Chip Across X-Band and K-Band

This letter presents a compact dual-band filtering power divider (DBFPD) based on a novel dual-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi $</tex-math> </inline-formula>-type matching circuit (MC). The proposed dual-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi $</tex-math> </inline-formula>-type MC achieves precise dual-band matching through analytical design, and integrated hybrid resonators (HRs) significantly enhance the bandwidth of passbands. Three independently controllable transmission zeros (TZs) of DBFPD improve stopband rejection and frequency selectivity. To validate the design, a DBFPD working at 8.9 and 21.6 GHz with a compact size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.9\times 3.1$</tex-math> </inline-formula> mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> is fabricated and measured using integrated passive device (IPD). The design achieves low insertion loss (IL) and wide bandwidth, with minimum ILs of 0.43 and 0.47 dB and 3-dB bandwidths of 50% and 33.5%, respectively.