Wide frequency range, switched band-oscillator

Claim 1

Apparatus for providing a wide frequency range, switched-band, output signal from an oscillator, said apparatus comprising: an oscillator including a network having first and second different types of impedances, said impedances determining the frequency of the output signal of said oscillator; means for switching into and out of said network additional impedance of said first type to switch between two bands of frequencies, an upper band and a lower band, said bands having an overlapping band of frequencies, said switching means comprising frequency-to-voltage converting means having an input terminal for receiving an input signal having a frequency within said wide frequency range and having an output terminal at which is provided an output signal having a magnitude that varies responsive to the frequency of said input signal, voltage comparator means for comparing the magnitude of said output signal of said converting means with the magnitude of a reference signal and producing a control signal having a certain characteristic when said output signal is of a magnitude indicative of said input signal having a frequency within said upper band and a characteristic different from said certain characteristic when said output signal is of a magnitude indicative of said input signal having a frequency within said lower band, switching between said control signals having different characteristics taking place within said overlapping band of frequencies, and means responsive to said control signal for adding or removing additional impedance of said first type to or from said network depending upon the characteristic of said control signal; and means for supplying said input signal to said oscillator.