Before revision: Operating frequency For a low-pass prototype, the cut-off frequency is given by the same expression as for the m-type and the k-type; The pole of attenuation occurs at; Image impedanceSee also Image impedance#DerivationImage impedance plot of an optimised mm'-type shunt section (ZiTmm', in black ) compared with an m-derived prototype shunt image impedance (ZiTm, in red) for .
After revision: Operating frequency For a low-pass prototype, the cut-off frequency is given by the same expression as for the m-type and the k-type; The pole of attenuation occurs at; Image impedanceSee also Image impedance#DerivationImage impedance plot of an optimised mm'-type shunt section (ZiTmm', in blue ) compared with an m-derived prototype shunt image impedance (ZiTm, in red) for .