PSK modulation by temporarily increasing frequency to achieve phase change

Claim 1

Short distance, low power phase shift keyed communication apparatus comprising: control circuit means for generating a pair of encoded data binary signals each of recurrent time period p from a data input signal, and for generating a recurrent binary keying signal having selected predetermined active time segments of duration t, between one-half and twenty percent of said period p, in response to one data transition occurrence within said pair of encoded data binary signals and for generating a recurrent binary keying signal having predetermined active time segments of duration 2t, between one and forty percent of said period p, in response to simultaneous data transition occurrences within said pair of encoded data keying signals; multivibrator oscillator radio frequency signal generating means, including a controlled capacitor charge current frequency determining network, operable at first and second predetermined radio frequencies in time segments responsive to said recurrent binary keying signal, each said second radio frequency operation segment being for a selected predetermined time interval of said t and 2t duration binary keying signal and with second frequency operation for said predetermined time segment generating a predetermined phase shift modulation of forty-five degrees for duration t and ninety degrees for duration 2t with respect to said first frequency; radio frequency wave filter means for generating a filtered radio frequency signal of limited spurious frequency content from said first and second frequency time segmented multivibrator oscillator radio frequency signal; radio frequency amplifier means generating from said filtered radio frequency signal an amplified radio frequency signal of power level below ten watts; propagation means for communicating said amplified radio frequency signal to a remote signal reception locus; and phase demodulation means located in said remote reception locus for demodulating the communicated frequency shift modulated radio frequency signal and reconstructing said data input signal therefrom.