Exact calculation of amplitudes and frequency of RC-oscillator with quadrature outputs

A calculation of exact frequency and amplitudes in an RC-oscillator with quadrature outputs is given. The oscillator includes two multivibrators synchronized by the cross-coupling comparators measuring the voltages at the timing capacitors and providing coupling currents in the collector resistors of the multivibrators. It is shown that the outputs are in quadrature only when both multivibrators are symmetric (yet the parameters of one multivibrator may be different from the parameters of another). The theoretical results are confirmed by simulation.