Appendix
The linearity of the proposed LNA is analyzed by Volterra series, Vx, Vz, and Vo as the intermediate variable are determined in Fig. 3. The relation between Vs and Vx, Vz, and Vo are expressed up to 3rd-order as:
$$\begin{gathered} \mathop V\nolimits_{O} = \mathop A\nolimits_{1} \left( {\mathop s\nolimits_{1} } \right)o{\kern 1pt} \mathop V\nolimits_{S} + \mathop A\nolimits_{2} \left( {\mathop s\nolimits_{1} ,\mathop s\nolimits_{2} } \right)o{\kern 1pt} \mathop V\nolimits_{S}^{2} + \mathop A\nolimits_{3} \left( {\mathop s\nolimits_{1} ,\mathop s\nolimits_{2} ,\mathop s\nolimits_{3} } \right)o{\kern 1pt} \mathop V\nolimits_{S}^{3} \hfill \\ \mathop V\nolimits_{X} = \mathop B\nolimits_{1} \left( {\mathop s\nolimits_{1} } \right)o{\kern 1pt} \mathop V\nolimits_{S} + \mathop B\nolimits_{2} \left( {\mathop s\nolimits_{1} ,\mathop s\nolimits_{2} } \right)o{\kern 1pt} \mathop V\nolimits_{S}^{2} + \mathop B\nolimits_{3} \left( {\mathop s\nolimits_{1} ,\mathop s\nolimits_{2} ,\mathop s\nolimits_{3} } \right)o{\kern 1pt} \mathop V\nolimits_{S}^{3} \hfill \\ \mathop V\nolimits_{Z} = \mathop C\nolimits_{1} \left( {\mathop s\nolimits_{1} } \right)o\mathop {{\kern 1pt} V}\nolimits_{S} + \mathop C\nolimits_{2} \left( {\mathop s\nolimits_{1} ,\mathop s\nolimits_{2} } \right)o\mathop {{\kern 1pt} V}\nolimits_{S}^{2} + \mathop C\nolimits_{3} \left( {\mathop s\nolimits_{1} ,\mathop s\nolimits_{2} ,\mathop s\nolimits_{3} } \right)o{\kern 1pt} \mathop V\nolimits_{S}^{3} \hfill \\ \end{gathered}$$
(A.1)
im1, im2 and im4 are considered as follows:
$$\begin{gathered} \mathop i\nolimits_{m1} = \mathop g\nolimits_{m1} \mathop {{\kern 1pt} V}\nolimits_{S} + \frac{{\mathop g\nolimits_{m1,2} }}{2}\mathop {\,{\kern 1pt} V}\nolimits_{S}^{2} + \frac{{\mathop g\nolimits_{m1,3} }}{3!}{\kern 1pt} \,\mathop V\nolimits_{S}^{3} \hfill \\ \mathop i\nolimits_{m2} = \mathop g\nolimits_{m2} \left( {\mathop {{\kern 1pt} V}\nolimits_{X} \mathop { - {\kern 1pt} {\kern 1pt} V}\nolimits_{Z} } \right) + \frac{{\mathop g\nolimits_{m2,2} }}{2}\mathop {\left( {\mathop {{\kern 1pt} V}\nolimits_{x} - \mathop {{\kern 1pt} V}\nolimits_{z} } \right)}\nolimits^{2} + \frac{{\mathop g\nolimits_{m2,3} }}{3!}\mathop {\left( {\mathop {{\kern 1pt} V}\nolimits_{x} - {\kern 1pt} {\kern 1pt} \mathop V\nolimits_{z} } \right)}\nolimits^{3} \hfill \\ \mathop i\nolimits_{m4} = \mathop g\nolimits_{m4} \left( {\mathop {{\kern 1pt} V}\nolimits_{X} \mathop { + V}\nolimits_{O} } \right) - \frac{{\mathop g\nolimits_{m4,2} }}{2}\mathop {\left( {\mathop {{\kern 1pt} V}\nolimits_{x} + \mathop V\nolimits_{o} } \right)}\nolimits^{2} + \frac{{\mathop g\nolimits_{m4,3} }}{3!}\mathop {\left( {\mathop {{\kern 1pt} V}\nolimits_{x} + \mathop V\nolimits_{o} } \right)}\nolimits^{3} \hfill \\ \end{gathered}$$
(A.2)
(gmi,1 (i = 1,2,4) is the transconductance of transistor Mi. gmi,2 (i = 1,2,4) is the second-order non-linear coefficient of transistors Mi, gmi,3 (i = 1,2,4) is the third- order non-linear coefficient of transistors Mi.
The KCL equation for this circuit can be written as:
$$\begin{gathered} \frac{{\mathop {{\kern 1pt} V}\nolimits_{O} }}{{\mathop R\nolimits_{L} }} = \mathop i\nolimits_{m4} \hfill \\ \mathop i\nolimits_{m4} + \mathop i\nolimits_{m1} + \mathop c\nolimits_{gs2} S\left( {\mathop {\,V}\nolimits_{X} - \mathop V\nolimits_{Z} } \right) = 0 \hfill \\ \mathop i\nolimits_{m2} + \mathop c\nolimits_{gs2} S\left( {\mathop {\,V}\nolimits_{X} - \mathop V\nolimits_{Z} } \right) = \frac{{\mathop {{\kern 1pt} V}\nolimits_{z} + \mathop V\nolimits_{S} }}{{\mathop R\nolimits_{S} }} \hfill \\ \end{gathered}$$
(A.3)
To find the first, second, and third order Volterra kernels, im1, im2, and im4 in (A.2) are substituted by the first, second, and third order components of gm polynomials in (A.3). The first order Volterra kernels can then be expressed as follows:
$$\begin{gathered} \mathop A\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right) = \frac{{ - \mathop g\nolimits_{m4,1} \mathop R\nolimits_{L} \mathop g\nolimits_{m1,1} \left( {1 + \mathop g\nolimits_{m2,1} \mathop R\nolimits_{S} } \right)}}{{ - \mathop g\nolimits_{m4,1} \left( {1 + \mathop g\nolimits_{m2,1} \mathop R\nolimits_{S} } \right) + \mathop c\nolimits_{gs2} \mathop R\nolimits_{S} \mathop g\nolimits_{m2,1} \mathop S\nolimits^{{}} }} \hfill \\ \mathop{\longrightarrow}\limits^{{\mathop g\nolimits_{m2} \approx 0}}\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right) = \mathop R\nolimits_{L} \mathop g\nolimits_{m1,1} \hfill \\ \mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right) = \frac{{ - \mathop g\nolimits_{m1,1} \left( {1 - \mathop g\nolimits_{m4,1} \mathop R\nolimits_{L} } \right)\left( {1 + \mathop g\nolimits_{m2,1} \mathop R\nolimits_{S} } \right)}}{{\mathop g\nolimits_{m2,1} \mathop R\nolimits_{S} \mathop c\nolimits_{gs2} S - \mathop g\nolimits_{m4,1} \left( {1 + \mathop g\nolimits_{m2,1} \mathop R\nolimits_{S} } \right)}} \hfill \\ \mathop{\longrightarrow}\limits^{{\mathop g\nolimits_{m2} \approx 0}}\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right) = \frac{{\mathop g\nolimits_{m1,1} \left( {1 - \mathop g\nolimits_{m4,1} \mathop R\nolimits_{L} } \right)}}{{\mathop g\nolimits_{m4,1} }} \hfill \\ \mathop C\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right) = \frac{{\mathop { - g}\nolimits_{m4,1} \left( {1 + \mathop R\nolimits_{L} \mathop R\nolimits_{S} \mathop g\nolimits_{m1,1} \mathop g\nolimits_{m2,1} } \right) + \mathop R\nolimits_{S} \mathop g\nolimits_{m1,1} \mathop g\nolimits_{m2,1} }}{{\mathop g\nolimits_{m4,1} \left( {1 + \mathop g\nolimits_{m2,1} \mathop R\nolimits_{S} } \right)}} \hfill \\ \mathop{\longrightarrow}\limits^{{\mathop g\nolimits_{m2} \approx 0}}\mathop C\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right) = - 1 \hfill \\ \end{gathered}$$
(A.4)
The second order Volterra kernels can then be given as:
$$\begin{gathered} \hfill \\ \mathop B\nolimits_{2} \left( {\mathop S\nolimits_{1} ,\mathop S\nolimits_{2} } \right) = \frac{1}{{\frac{{\mathop g\nolimits_{m2} \mathop R\nolimits_{S} }}{{\mathop g\nolimits_{m2} \mathop R\nolimits_{S} + 1}} + \frac{{\mathop g\nolimits_{m4} }}{{\left( {\mathop g\nolimits_{m4} \mathop R\nolimits_{L} - 1} \right)\mathop c\nolimits_{gs2} S}}}}\left[ \begin{gathered} \frac{1}{{\mathop c\nolimits_{gs2} S}}\left( {\frac{{\mathop g\nolimits_{m4,2} }}{{2\left( {\mathop g\nolimits_{m4} \mathop R\nolimits_{L} - 1} \right)}}\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right) + \frac{{\mathop g\nolimits_{m1,2} }}{2}} \right) \hfill \\ \frac{{ - \mathop R\nolimits_{S} }}{{\mathop g\nolimits_{m2} \mathop R\nolimits_{S} + 1}}\left( {\frac{{\mathop g\nolimits_{m2,2} }}{2}\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop C\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop C\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right) - \frac{1}{{\mathop R\nolimits_{S} }}} \right) \hfill \\ \end{gathered} \right] \hfill \\ \mathop{\longrightarrow}\limits^{{\mathop g\nolimits_{m2} \approx 0}}\frac{{\mathop g\nolimits_{m4,2} }}{{2\mathop g\nolimits_{m4} }}\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right) + \frac{{\mathop g\nolimits_{m1,2} }}{2} \times \frac{{\mathop g\nolimits_{m4} \mathop R\nolimits_{L} - 1}}{{\mathop g\nolimits_{m4} }} + \frac{{\left( {\mathop g\nolimits_{m4} \mathop R\nolimits_{L} - 1} \right)\mathop c\nolimits_{gs2} S}}{{\mathop g\nolimits_{m4} }} \hfill \\ \mathop A\nolimits_{2} \left( {\mathop S\nolimits_{1} ,\mathop S\nolimits_{2} } \right) = \frac{{\mathop R\nolimits_{L} }}{{\mathop {1 - g}\nolimits_{m4} \mathop R\nolimits_{L} }}\left[ {\mathop g\nolimits_{m4} \mathop B\nolimits_{2} \left( {\mathop S\nolimits_{1} ,\mathop S\nolimits_{2} } \right) - \frac{{\mathop g\nolimits_{m4,2} }}{2}\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)} \right] \hfill \\ \mathop C\nolimits_{2} \left( {\mathop S\nolimits_{1} ,\mathop S\nolimits_{2} } \right) = \frac{{\mathop R\nolimits_{S} }}{{\mathop g\nolimits_{m2} \mathop R\nolimits_{S} + 1}}\left[ {\mathop g\nolimits_{m2} \mathop B\nolimits_{2} \left( {\mathop S\nolimits_{1} ,\mathop S\nolimits_{2} } \right) + \frac{{\mathop g\nolimits_{m2,2} }}{2}\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop C\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop C\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right) - \frac{1}{{\mathop R\nolimits_{S} }}} \right] \hfill \\ \end{gathered}$$
(A.5)
The third order Volterra kernels can then be given as:
$$\begin{gathered} \mathop B\nolimits_{3} \left( {\mathop S\nolimits_{1} ,\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right) = \frac{1}{{\frac{{\mathop g\nolimits_{{m2,1}} \mathop R\nolimits_{S} }}{{1 + \mathop g\nolimits_{{m2,1}} \mathop R\nolimits_{S} }} + \frac{1}{{\mathop C\nolimits_{{g\,s2}} {\kern 1pt} \,\mathop S\nolimits_{{}} \left( {\mathop {1 - g}\nolimits_{{m4}} \mathop R\nolimits_{L} } \right)}}}}\left[ \begin{gathered} \frac{1}{{\mathop C\nolimits_{{g{\kern 1pt} s2}} \mathop {\,S}\nolimits_{{}} }}\left( \begin{gathered} \frac{{y\mathop g\nolimits_{{m4,3}} }}{{6\left( {\mathop {1 - g}\nolimits_{{m4,1}} \mathop R\nolimits_{L} } \right)\left( {\mathop g\nolimits_{{m4,1}} + \mathop C\nolimits_{{g{\kern 1pt} s2}} \mathop S\nolimits_{{}} } \right)}} + \hfill \\ \frac{1}{{\mathop g\nolimits_{{m4,1}} + \mathop C\nolimits_{{g\,s2}} {\kern 1pt} \mathop S\nolimits_{{}} }} \times \frac{{\mathop g\nolimits_{{m1,3}} }}{6} \hfill \\ \end{gathered} \right) \hfill \\ - \frac{{\mathop R\nolimits_{S} }}{{1 + \mathop g\nolimits_{{m2,1}} \mathop R\nolimits_{S} }}\left( \begin{gathered} - \frac{1}{{\mathop R\nolimits_{S} }} + \hfill \\ \frac{{\mathop g\nolimits_{{m2,3}} }}{6}\mathop C\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop C\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop C\nolimits_{1} \left( {\mathop S\nolimits_{3} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{3} } \right) + \hfill \\ \overline{{\mathop g\nolimits_{{m2,2}} \mathop C\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop C\nolimits_{2} \left( {\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{2} \left( {\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right)}} \hfill \\ \end{gathered} \right) \hfill \\ \end{gathered} \right] \hfill \\ \xrightarrow{{\mathop g\nolimits_{{m2}} = \,0}}\mathop C\nolimits_{{g\,s2}} {\kern 1pt} \,\mathop S\nolimits_{{}} \left( {\mathop {1 - g}\nolimits_{{m4}} \mathop R\nolimits_{L} } \right)\left[ \begin{gathered} \frac{1}{{\mathop C\nolimits_{{g{\kern 1pt} s2}} \mathop S\nolimits_{{}} }}\left( \begin{gathered} \frac{{y\mathop g\nolimits_{{m4,3}} }}{{6\left( {\mathop {1 - g}\nolimits_{{m4,1}} \mathop R\nolimits_{L} } \right)\left( {\mathop g\nolimits_{{m4,1}} + \mathop C\nolimits_{{g\,s2}} \mathop S\nolimits_{{}} } \right)}} + \hfill \\ \frac{1}{{\mathop g\nolimits_{{m4,1}} + \mathop C\nolimits_{{g\,s2}} {\kern 1pt} \mathop S\nolimits_{{}} }} \times \frac{{\mathop g\nolimits_{{m1,3}} }}{6} \hfill \\ \end{gathered} \right) \hfill \\ + 1 \hfill \\ \end{gathered} \right] \hfill \\ y = \mathop A\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{3} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{3} } \right) - \overline{{\mathop g\nolimits_{{m4,2}} \mathop A\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop A\nolimits_{2} \left( {\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{2} \left( {\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right)}} \hfill \\ \mathop C\nolimits_{3} \left( {\mathop S\nolimits_{1} ,\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right) = \frac{{\mathop R\nolimits_{S} }}{{1 + \mathop g\nolimits_{{m2,1}} \mathop R\nolimits_{S} }}\left[ \begin{gathered} - \frac{1}{{\mathop R\nolimits_{S} }} + \hfill \\ \frac{{\mathop g\nolimits_{{m2,3}} }}{6}\mathop C\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop C\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop C\nolimits_{1} \left( {\mathop S\nolimits_{3} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{3} } \right) + \hfill \\ \overline{{\mathop g\nolimits_{{m2,2}} \mathop C\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop C\nolimits_{2} \left( {\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{2} \left( {\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right)}} + \mathop g\nolimits_{{m2,1}} \mathop B\nolimits_{3} \left( {\mathop S\nolimits_{1} ,\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right) \hfill \\ \end{gathered} \right] \hfill \\ \mathop A\nolimits_{3} \left( {\mathop S\nolimits_{1} ,\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right) = \frac{{\mathop R\nolimits_{L} }}{{\mathop {1 - g}\nolimits_{{m4,1}} \mathop R\nolimits_{L} }}\left[ \begin{gathered} \mathop g\nolimits_{{m4,1}} \mathop {{\kern 1pt} B}\nolimits_{3} \left( {\mathop S\nolimits_{1} ,\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right) + \hfill \\ \frac{{\mathop g\nolimits_{{m4,3}} }}{6}\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop A\nolimits_{1} \left( {\mathop S\nolimits_{3} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{2} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{3} } \right) - \hfill \\ \overline{{\mathop g\nolimits_{{m4,2}} \mathop {{\kern 1pt} A}\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop A\nolimits_{2} \left( {\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right)\mathop B\nolimits_{1} \left( {\mathop S\nolimits_{1} } \right)\mathop B\nolimits_{2} \left( {\mathop S\nolimits_{2} ,\mathop S\nolimits_{3} } \right)}} \hfill \\ \end{gathered} \right] \hfill \\ \hfill \\ \end{gathered}$$
(A.6)