Investigation of Bagaev oscillator circuit intended for sensor and dual-mode application

Single-transistor circuits of oscillators are not always convenient when working with "problem" crystal resonators that have high dynamic resistance and active parasitic modes. In these cases dual-transistor oscillators having a greater ability of resonator excitation and higher degree of adjustment freedom are preferable. In the given work the dual-cascade circuit of an active oscillator with a crystal resonator, one terminal of which is connected to a common wire, is analyzed. Such a circuit can be convenient when the resonator-sensor is distanced from the circuit by a cable. The results of circuit simulation with a computer are presented. The peculiarities of the operation of such a circuit with the resonator attached to a cable, with resonators that excite oscillations by a parallel field, and with dual-mode resonators, are considered. Besides sensory application, the circuit can be used in a DTCXO for excitation of dual-mode oscillations