Energy dissipation through support structures is one of the dominant loss mechanisms in MEMS resonators, which results in a very low quality (Q) factor. This paper aims to propose a one-dimensional phononic crystal (PnC) structure, namely a compound leaf-shaped phononic crystal (PnC) strip (TYPE_PROP), as anchor tethers to boost the anchor quality factor (Qanchor\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Q_{anchor}$$\end{document}) of a thin-film aluminium nitride (AlN)-on-silicon (Si) MEMS resonator. Thus, its Q can achieve a superior value. The operating frequency and mode of the resonator are 123.49 MHz and a length extensional (LE) mode, respectively. This frequency falls into the band gap frequency range of 52 MHz of the TYPE_PROP. The Qanchor\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Q_{anchor}$$\end{document} of the resonator with unit cell number variation of the TYPE_PROP tether is studied. From these investigations, the effectiveness of the tether in reducing/eliminating the anchor energy loss is evaluated. Furthermore, this Qanchor\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Q_{anchor}$$\end{document} is also compared to the same resonator structure with two conventional tether types. Additionally, the variation of the band gaps' properties versus the dimensional parameters of the TYPE_PROP are also evaluated. The COMSOL Multiphysics platform based numerical results demonstrate that the Qanchor\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Q_{anchor}$$\end{document} of the resonator with the TYPE_PROP based tethers achieves superior values compared to its counterparts. Specifically, this value is about 5.42 x\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document} 1012\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$10<^>{12}$$\end{document} and 23.74 times higher than that of the TYPE_CON1 and TYPE_CON2, respectively. The Qanchor\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Q_{anchor}$$\end{document} improvement of the LE mode MEMS resonator using the TYPE_PROP achieves higher values than that using two conventional tether configurations.
