Abstract: A frequency modulated signal is converted into a pair of baseband signals by mixing the signal with a pair of phase-quadrature reference signals of substantially carrier center frequency. The double reference frequency component of each of the baseband signals is filtered to obtain I and Q signals. The I and Q signals constitute in rectangular coordinates the components of a vector represented in polar coordinates by R and .theta. where R is the maximum amplitude of the I and Q signals and .theta. is the instantaneous angle represented by the arctangent of the I signal divided by the Q signal. The I and Q signals are sampled to provide a sequence of sets of signal samples. For each set of signal samples the angle .theta. is obtained. A sequence of changes in the values of the angle .theta. over successive sampling periods is obtained and represents the deviation in frequency of the FM carrier corresponding to changes in amplitude of the modulating signal.

Abstract: A frequency modulated signal is converted into a pair of baseband signals by mixing the signal with a pair of phase-quadrature reference signals of substantially carrier center frequency. The double reference frequency component of each of the baseband signals is filtered to obtain I and Q signals. The I and Q signals constitute in rectangular coordinates the components of a vector represented in polar coordinates by R and .theta. where R is the maximum amplitude of the I and Q signals and .theta. is the instantaneous angle represented by the arctangent of the I signal divided by the Q signal. The I and Q signals are inverted to provide respective -I and -Q signals. The I, -I, Q, -Q signals are sampled to provide a sequence of sets of signal samples. For each set of signal samples the angle .theta. is obtained. A sequence of changes in the values of the angle .theta.

Abstract: A system is described which makes use of the fact that in a raster scanned television system a high degree of correlation exists both in the luminance and in the chrominance signals of a pair of adjacent lines. Because of this correlation, the difference between the luminance signals of the two lines is usually much smaller than luminance signal of either line alone, and requires less bandwidth. The present invention takes advantage of the natural correlation in a television picture in the horizontal and vertical directions for bandwidth reduction without significant impairment of the reproduced picture. This is accomplished by processing the television signal for bandwidth reduction in particular ways and transmitting it entirely in the analog domain. The bandwidth requirement is reduced for the transmission of the video signals over a transmission channel such as a cable television channel, a broadcast channel or a storage medium.

Abstract: A capacitive commutating filter provides a D. C. output voltage of amplitude responsive to the amplitude of an input waveform having a frequency substantially equal to the operating frequency of the filter. The filter operating frequency is established by a digital signal. The filter input is selectively and cyclically connected through N input resistances, wherein N is an integer greater than zero, to adjacently progressive N ones of (2N+1) nodes, each having one of (2N+1) capacitive filter elements connected to ground potential.