Patent ID: 7362193

Claim:
A balanced crystal oscillator circuit having a piezoelectric element, a first oscillator sub-circuit incorporating a first transistor and a second oscillator sub-circuit incorporating a second transistor, wherein the transistors are of the Bipolar Junction Transistor (BJT) type and each have different types of transistor terminals and wherein the oscillator sub-circuits are configured with a first, second and third interconnection, the circuit further comprising: each interconnection being made at a pair of like type of transistor terminals of the first and second transistors; the first interconnection being between a pair of like type of transistor terminals and a connection to a ground reference; the second interconnection being between a pair of like type of transistor terminals with a first resonator element therein-between; and the third interconnection being between a pair of like type of transistor terminals with a second resonator element therein-between, wherein at least one of the transistors is provided with bias current and said first and second oscillator circuits being arranged to interact by means of said first and second resonator elements to form a balanced oscillator signal; and wherein the first, second, and third of said interconnections consist of a pair of collector-type terminals, base-type terminals, and emitter-type terminals, respectively; thereby configuring the balanced oscillator circuit with a dual common-collector transistor coupling.