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CHAPTER 4 - Impedance Matching 160 4.2.3 Series R-L-C Let us now consider a network that comprises of resistive, inductive and capacitive elements connected in series as shown in Figure 4.2-14, Figure 4.2-15 and Figure 4.2-16. As we have seen in previous cases, we will probably have a phase difference between voltage and current which is somewhat less than 90ι due to the presence of the resistor. However the voltage may either lead or lag the current depending on the values of our capacitor and inductor. In the circuit shown in Figure 4.2-14, the capacitor and inductor values are such that the modulus of the reactance of the cap | | is greater than that of the inductor | | . The overall impedance of the L-C series is , which means that the capacitor dominates, and the current leads the voltage (Figure 4.2-14). | | | | Figure 4.2-14 R-L-C with dominating capacitor, | | | | In the circuit shown in Figure 4.2-15, the capacitor and inductor values are such that the modulus of the reactance of the capacitor | | is smaller than that of the inductor | | . The overall impedance of the L-C series is , which means that the inductor dominates, and the voltage leads the current (Figure 4.2-15). Figure 4.2-15 R-L-C with dominating inductor, | | | | 0 0.5 1 1.5 2 Time (ns) series R_L_C -1 -0.5 0 0.5 1 -20 -10 0 10 20 p2 p1 Vtime(M_PROBE.VP1,1)[*] (L, V) series R_L_C Itime(ACVS.V1,1)[*] (R, mA) series R_L_C p1: Freq = 1000 MHz p2: Freq = 1000 MHz Freq = 1000 MHz 0 0.5 1 1.5 2 Time (ns) series R_L_C -1 -0.5 0 0.5 1 -20 -10 0 10 20 p2 p1 Vtime(M_PROBE.VP1,1)[*] (L, V) series R_L_C Itime(ACVS.V1,1)[*] (R, mA) series R_L_C p1: Freq = 1000 MHz p2: Freq = 1000 MHz Freq = 1000 MHz V mA V mA Conquer Radio Frequency 160 www.cadence.com/go/awr

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