Patent ID: 6515552
Filing Date: 2003-02-04
Classification: H03L

Abstract:
An apparatus including an integrated circuit with a voltage-controlled oscillator that provides an oscillation signal with an unmodulated frequency that remains constant in response to reception of a bias current having a constant magnitude and with a modulated frequency that varies in response to reception of a modulation voltage, said integrated circuit comprising:a current-to-voltage conversion circuit that includes a portion of a plurality of integrated, like semiconductor devices with a plurality of operating characteristics and that generates, in response to reception of a bias current, a control voltage with a magnitude corresponding to a magnitude of said bias current; a voltage-to-current conversion circuit that includes another portion of said plurality of integrated, like semiconductor devices, that is coupled to said current-to-voltage conversion circuit and that generates, in response to reception of said control voltage and a modulation voltage, a control current with a magnitude that corresponds to a magnitude of said modulation voltage during reception of said modulation voltage, and corresponds to said control voltage magnitude otherwise; and a current-controlled oscillator circuit that includes still another portion of said plurality of integrated, like semiconductor devices, that is coupled to said voltage-to-current conversion circuit and that generates, in response to reception of said control current, an oscillation signal with an unmodulated frequency corresponding to said bias current magnitude and with a modulated frequency corresponding to said modulation voltage; wherein said unmodulated frequency is defined by said bias current magnitude substantially irrespective of variations in respective ones of said plurality of operating characteristics caused by variations in operating temperatures and processes of fabrication of said plurality of integrated, like semiconductor devices.