Electronically Tunable Differential Integrator: Linear Voltage Controlled Quadrature Oscillator

Figure 2

Test responses of proposed ETDI and linear VCQO. (a) Response of integrator with square wave input signals at 500 KHz: Volt(pp), volt,  KΩ, and  nF; measured  pF at  V.d.c. (b) Quadrature oscillator response at the onset of sinusoidal wave build-up at 1.1 MHz with  KΩ,  pF, and volt. (c) Spectrum of the response in (b). (d) Lissajous pattern of quadrature signals. (e) VCQO tuning characteristics: dotted line: hardware test; firm line: simulation; band-spread selection: upper curve:  KΩ,  pF; lower curve:  KΩ,  pF. (f) Quadrature wave modulation: 1.2 MHz input signal  Vpp to ETDI with ; control voltage =  Vpp at 200 KHz to MMCC.

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