  Rugate, HL, and hybrid methods are used to design Notch Filters. Achieving a
design that fits the notch characteristics of the filter and reducing
transmission band ripples are the most influential factors in this topic. The
ability of easy fabrication and choosing the right manufacturing method to have
a notch filter with better characteristics should be noted. The main idea of
this work is to design a notch filter structure with a narrow notch width and
maximum reflection while reducing fabrication challenges. In addition, using
anti-reflection layers in the outermost part of the designed structure, the
pass-band ripples are reduced. In designed systems, various quarter-wave
factors were used, which have less challenge in the manufacturing step. In
addition, the stability of the deposition conditions and the density of the
layers affect their quality and consequently the result of environmental tests.
Therefore, the sputtering method with RF and DC sources is used to construct
the designed structure. Finally, the samples were subjected to environmental
tests such as abrasion, humidity, temperature, and adhesion. Some of the
significant results of the manufactured single-band notch filter are presented.
