Abstract: A rubidium frequency standard control circuit which utilizes an initial sweep hand-off frequency locking process followed by a negative feedback loop for optimization of the stability of the voltage control oscillator employing the rubidium frequency standard.

Abstract: A temperature stabilized CMOS oscillator circuit modifies the gain of a CMOS oscillator transistor to cancel the gain variation over temperature using a bias circuit. The bias circuit utilizes a combination of two current mirrors to establish a temperature compensating supply current to a CMOS oscillator transistor. A primary current mirror and a temperature variable resistor establish a current in the current mirror output to the CMOS oscillator transistor. A secondary current mirror and a temperature variable resistor divert current from the primary current mirror over temperature to vary the current mirror output to the CMOS oscillator transistor to compensate for its gain variation.

Abstract: A stabilized oscillation circuit includes a bias circuit which controllably biases a bipolar-transistor-driven crystal oscillator circuit. The bipolar-transistor-driven crystal oscillator circuit is a modified version of a conventional transistor-driven oscillator, such as a Hartley, Pierce or Colpitts-type circuit. The bias circuit includes a first current providing a reference current through a Schottky diode and a pair of bipolar transistors. The bipolar-transistor-driven crystal oscillator circuit includes an input and an output, where the input of the bipolar-transistor-driven crystal oscillator circuit is coupled to the bias circuit. The bipolar-transistor-driven crystal oscillator circuit includes a second current through a second bipolar transistor. The second current tracks the reference current so that the output of the bipolar-transistor-driven oscillator circuit is substantially constant over variations in ambient temperature.