Radio frequency oscillator-modulator circuit

摘要

A radio frequency oscillator-modulator for use in a video game includes an oscillator circuit, formed from a first differentially connected, emitter-coupled transistor pair having base/collector cross-coupling, that is dc coupled to the differential inputs of a second differentially connected, emitter-coupled transistor pair that forms the modulator circuit. The modulation signal is applied through a resistance to the connected emitters of the modulator circuit to vary the drive current thereof. The radio frequency oscillator-modulator includes bias circuitry that establishes a low level of operation that provides for great linearity and low R.F. radiation.