Showing papers on "Comb generator published in 1970"

Voltage-controlled oscillator selectively injection locked to stable frequency harmonics

Abstract: A signal source and harmonic signal selector for application in frequency-coherent signal generators or synthesizers and in precision radio communication systems features a novel frequency conversion process to obtain pluralities of selectable stable frequency signals from one source. A stable oscillator is employed to excite the desired plurality of signals in a harmonic comb generator. An injection oscillator, controlled by a selected unidirectional voltage level, is used as a filter to select a desired one of the array of harmonically related signals. Means are provided for purifying the spectrum of the selected output signal.

Electric generator control system with radio feedback loop

Abstract: The illustrated embodiments include an exciting generator and a power generator. Each of the generators includes a common tubular rotor. The armature of the exciting generator is maintained within the rotor and is fed through a control rectifier to the field of the power generator, which is also maintained within the rotor. The output voltage of the power generator is sampled for modulation of a radio transmitter which delivers power to a transmitting antenna. A receiving means maintained within the tubular rotor receives and demodulates the signal from the transmitter. The demodulated signal, together with the output of the field generator armature is applied to the control elements of the control rectifier and thus determines the intensity of the power generator field and, correspondingly, the output of the power generator.

Modified time domain comb filters

Abstract: A delay line type comb filter is adapted to produce a response in which a selected portion of the comb characteristic is modified. This is accomplished by attenuating the signal through the delay line in a predetermined manner over a selected frequency range and inversely modifying the nondelayed transmission in that range. These two functions are provided by applying the input signal to a filter element having a transfer function appropriate to the desired modification and combining the filtered output with the input signal in two combiners (one additive and one subtractive). The differential resultant signal is applied to the delay line to produce the prescribed attenuation and the additive resultant signal (enhanced inversely to the differential resultant) is added to the output of the delay line producing the desired modified comb transmission characteristic.