A <i>W</i>-Band 0.01 mm<sup>2</sup> Cavity Resonator Employing Slot-Loaded Shielded Folded Ridged Quarter-Mode in CMOS Technology
Baichuan Chen, Samundra K. Thapa, Adel Barakat, Ramesh K. Pokharel
Abstract
This letter proposes a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$W$ </tex-math></inline-formula> -band compact cavity resonator for future applications of on-chip bandpass filters (BPFs), oscillators, phase shifters, and so on. To mitigate the leakage from the open sides of a folded ridged quarter-mode substrate integrated waveguide (SIW) cavity, shielding structures made of vias are employed. Two parallel inductive slots are etched on the top metal layer for further size reduction. Later, the one-port cavity is converted to a two-port cavity resonator and utilized in the design of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$W$ </tex-math></inline-formula> -band BPF. The proposed design is implemented in a commercial complementary metal-oxide-semiconductor (CMOS) technology, fabricated, and measured. The active size of the proposed cavity resonator is only 99 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}\,\,\boldsymbol {\times }\,\,99\,\,\mu \text{m}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.054 \boldsymbol {\lambda }_{\mathbf {g}}\,\,{ \boldsymbol {\times }}\,\,0.054{} \boldsymbol {\lambda }_{\mathbf {g}}$ </tex-math></inline-formula> ), and the measured insertion loss ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\vert S_{21}\vert$ </tex-math></inline-formula> ) is 2.26 dB.