14.53 Figure P14.53 shows a generalized form of the Antoniou circuit of Fig. 14.20(a). Here, R5 is eliminated and the other four components are replaced by general impedances Z1, Z2, Z3, and Z4. (a) With an impedance Z5 connected between node 2 and ground, show that the input impedance looking into port 1 (i.e., between node 1 and ground) is (b) From the symmetry of the circuit, show that if an impedance Z6 is connected between terminal 1 and ground, the input impedance looking into port 2, which is between terminal 2 and ground, is given by (c) From the expressions above, observe that the two-port network in Fig. P14.53 acts as an “impedance transformer.” Since by the appropriate choice of Z1, Z2, Z3, and Z4, the transformation ratio can be a general function of the complex frequency variable s, the circuit is known as a generalized impedance converter, or GIC.