Abstract: A highly stable variable frequency oscillator is disclosed which employs a ultitap surface acoustic wave device as a frequency standard. A feedback path which includes a voltage controlled switch for selecting a desired output tap drives a differential amplifier, phase detector, low pass filter, voltage controlled oscillator and phase splitter for driving the input tap of the surface acoustic wave device. Various additional feedback paths are also employed. The variable frequency signal is taken from the output of the voltage controlled oscillator.

Abstract: For reducing or preventing unwanted variations at adjacent storage electrodes upon polarization or depolarization of one of the storage electrodes on a PXE body a storage electrode terminating impedance is proposed of a special value.

Abstract: A surface acoustic wave delay line for use with an amplifier to form an oscillator has the spacing of its two transducers arranged to provide the desired mode of oscillation and the frequency responses of one or both transducers arranged to suppress unwanted moles of oscillation. Various transducers configuration are provided to reduce reflection problems between and within the transducers. The oscillator may be frequency modulated.

Abstract: A system for generating angular modulation comprising a balanced modulator and an adding circuit to which a surface wave device quadrature oscillator applies two signals at the carrier frequency differing 90.degree. in phase, such phase difference being accurately maintained independent of aging and variations in operating temperatures. More particularly, an information signal is applied to one input of the balanced modulator, the output of which is applied to the adding circuit. The surface wave device oscillator completes the system by applying an in-phase carrier frequency to a second input of the balanced modulator and a carrier frequency shifted 90.degree. in phase to a second input of the adding circuit. Angular modulation is thus produced at the output of the adding circuit.

Abstract: A surface acoustic wave oscillator comprises a surface acoustic wave delay line and amplifier. The phase difference between signals received from two transducers on the surface acoustic wave delay line is measured by a phase sensitive detector whose output is used to control a phase correction circuit. The oscillator may oscillate at a steady frequency or be frequency modulated.