Page 91 - Circuit Analysis II with MATLAB Applications
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Solutions to Exercises


           Equating real and imaginary parts we get
                                               R IN  =  R +  3.5
                                                       1
                                                 0 =  jX +  j0.5
                                                        1

           and while R 1  can be any real number, we must have jX =  – j0.5  and thus
                                                               1
                                               Z =   R –  j0.5 :
                                                1
                                                      1
         3.
           a. BW =   f – f =  1075 –  925 =  150 KHz . Then,
                         1
                      2
                                  f =  f +  BW 2 =  925 +  150 2 =  1000 KHz
                                                             e
                                              e
                                   0
                                       1
                                                                 f
           b. The exact value of   is the geometric mean of   and   and thus
                                f
                                                          f
                                                           1
                                 0
                                                                  2
                                                               3
                                f =    f ˜ f =     925 + 1075 10 =  997.18 KHz

                                 0
                                           2
                                       1
                       f      1000                       Z C
                        0
                                                          0
           c. Q 0P  =  -------------- =  ------------ =  20 3  . Also, Q 0P  =  ---------- . Then
                                         e
                     f –
                                                          G
                         f
                               150
                          1
                      2
                                                         6
                                  Z C    2Sf C    2S u  10 u  10 – 6  3S
                                   0
                                            0
                            G =   ---------- =  --------------- =  -------------------------------------- =  ------ =  0.94 : – 1
                                  Q 0P    Q 0P         20 3         10
                                                         e
              and
                                    1        1              1
                              L =  ---------- =  ------------------- =  ------------------------------------------- =  0.025 PH
                                  Z C     4S f C    4S u  10 12  u  10 – 6
                                            2 2
                                                       2
                                    0
                                              0
         4.
                      f     500                    Z C
                       0
                                                     0
           a. Q 0P  =  --------- =  --------- =  25  . Also, Q 0P  =  ----------  or
                                                    G
                             20
                     BW
                                  Q   ˜  G    25 u  10 – 3         – 9
                                    0P
                             C =  ------------------ =  ------------------------------ =  7.96 u  10  F =  7.96 nF
                                     Z 0     2S u  5 u  10 5
                      1        1                   1                          – 6
                L =  ---------- =  ------------------- =  ------------------------------------------------------------------------ =  12.73 u  10  H =  12.73 PH
                    Z C     4S f C     4S u  25 u  10 10  u  7.96 u  10 – 9
                                         2
                               2 2
                      0
                                0
                                   I =  V Y =   V G =  20 u 10 – 3  A =  20 mA
                                         0 0
                                                 0
                                    0
            b. f =  f –  BW 2 =  500 –  10 =  490 KHz  and f =  f + BW 2 =  500 +  10 =  510 KHz
                                                                      e
                           e
                                                          2
                                                               0
               1
                    0
        Circuit Analysis II with MATLAB Applications                                            2-25
        Orchard Publications
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