Page 153 - Complementarity and Variational Inequalities in Electronics
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144  Complementarity and Variational Inequalities in Electronics


                           Here we have
                                                 ⎛                      ⎞
                                                     R i   R 1     0
                                                 ⎜                      ⎟
                                          −PA = ⎝ −γR i    R 1  (R 2 + R 0 ) ⎠ .
                                                     1    −1       1
                           The matrix −PA is a P-matrix since

                                   1 (−PA) = R i > 0,  2 (−PA) = R 1 > 0,  3 (−PA) = 1 > 0,
                                      12 (−PA) = (1 + γ)R 1 R i > 0,  13 (−PA) = R i > 0,
                                               23 (−PA) = R 1 + R 2 + R 0 > 0,

                           and

                                   123 (−PA) = R i (R 1 + R 2 + R 0 ) + R 1 (γ R i + R 2 + R 0 )> 0.
                                             3
                           Moreover,   ∈ D (R ;R ∪{+∞}) (with   1 ≡ ϕ ZD ,  2 ≡   3 ≡ 0). We may
                           thus apply Theorem 7 to ensure that the system in NRM(A,B,C,D,U i ,ϕ ZD )
                           has a unique solution.
                              Thus, for a driven time-dependent input t  à  U i (t), the output time-
                           dependent voltage t  à  U o (t) defined by (see Fig. 4.15)

                                               U o (t) = γR i I i (t) − R o I 2 (t)

                           is uniquely defined with the current functions t  à  I i (t) and t  à  I 2 (t) that are
                           uniquely determined in solving VI(−PA,−PDU i (t), ).
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