e discussed, some remarks concerning the construction of the loop equations (4.80) are made and the resulting symbolic expressions are verified through numer- ical simulations. As a notational convention, we use uppercase for the large-signal currents/voltages and lowercase for the (time-varying) small-signal components. The Laplace transforms of the latter are also denoted in uppercase but are recognized by their argument S or jw. 4.3.7.1 Modeling the mixer components In order to construct a block diagram representation for the mixer topology shown in Fig. 4.24, we transform it to the single-sided equivalent circuit shown in Fig. 4.25. Table 4.1 4.3 AUTOMATED SYMBOLIC LPTV SYSTEM ANALYSIS Symbol Value Symbol Value 0.1 mS 1.6 pF 2.8 mS 70 fF gm2,0 3.8 mS 16 pF 60 fF 8m2,0 gout2 Cout2 10 pF 0.5 mS/V 0.15 V Vin,DC - VT 0.2 V Table 4.1: Numerical values for some important mixer design parameters. lists the values for some of the most important parameters as they were set for numeri- cal evaluation of the mixer's behavior. In the equivalent model, transistors are replaced by (nonlinear) voltage-controlled current sources. The single-sided input transistor current model is based upon the level-1 equations for a MOST in triode region, or (4.86) Here, VT is the threshold voltage and Y a parameter introduced to capture the mismatch between the two input transistors in the original balanced configuration in Fig. 4.24. Vosc(t) is the oscillator signal, Vin(t) is the input signal as applied to the gates of the in- put transistors and Vn1 (t) is the voltage at the OTA input terminal n1. Furthermore, due to nonlinear behavior, the effective small-signal transconductance gm2 of the second OTA stage depends on the voltage Vn2(t) on the node N2, as is indicated in Fig. 4.25. As a consequence, the periodic large-signal swing of this voltage causes a periodic modulation of the small-signal transconductance gm2. The voltage swing Vn1 at the input of the first OTA stage is small enough to allow us to neglect this effect for the tran