Nonlinear optimization tools for the design of microwave high-conversion gain harmonic self-oscillating mixers

New Non-Linear Approach for the Evaluation of the Linearity of High Gain Harmonic Self Oscillating Mixers

“…In this work, the auxiliary generator technique is used to set the autonomous solution of the HSOM [1][2][3]23]. The auxiliary generator is connected at the gate port of the transistor and works with frequency f AG = f o and amplitude V AG = V o .…”

“…The auxiliary generator is connected at the gate port of the transistor and works with frequency f AG = f o and amplitude V AG = V o . The frequency f o and the amplitude V o of the fundamental harmonic component of the autonomous signal are imposed through an optimization process in which several parameters of the circuit, including those of the multi-harmonic load, are modified in order to satisfy the non-perturbation condition of the auxiliary generator Y AG = I AG /V AG = 0 [1][2][3]. When this condition, expressed in terms of the real and imaginary parts of the admittance of the auxiliary generator, is fulfilled, the current through the auxiliary generator is zero.…”

“…When all the three conditions expressed in (1) are fulfilled, the circuit is able to maintain an autonomous solution with frequency f o and amplitudes of the fundamental and third harmonic components V o and V 3 o = ψ, respectively. Note the difference with respect to [3], where the amplitude of the desired harmonic component of the autonomous signal is imposed through a substitution generator.…”

“…In recent years, several techniques based on Harmonic Balance (HB) have been developed to design and analyze HSOM and other autonomous circuits by using commercial simulators [1][2][3]. These techniques are based on the use of an auxiliary generator and allow the control of the frequency and the harmonic content of the autonomous signal.…”

“…This technique combines the control of the harmonic content of the autonomous signal [3] with the careful selection of the HSOM operating regime, which will be established in the vicinity of a Hopf bifurcation point [5][6][7]. Thus, the high amplification effect associated with this working point will be used in order to improve the conversion gain of the HSOM.…”