Abstract: A periodic function wave generator is provided in a digital phase synchronizing circuit which comprises a memory circuit for storing the values of n phases obtained by equally dividing one period of a sine wave by 4n and each having a phase .theta.=90.degree./n(i+0.5), where n represents an integer and i is an integer of from 0 to n-1, a circuit for designating a predetermined one of these phases in one period, a circuit for converting an address read out of the memory circuit into one of the n phases in accordance with one of the ranges of 0.degree. to 90.degree., 90.degree. to 180.degree., 180.degree. to 270.degree. and 270.degree. to 360.degree. and a circuit for inverting the sign of the output of the memory circuit in accordance with the particular range in which the designated phase falls.

Abstract: A digital filter system comprising a plurality of digital filters having respective counters operated by the same clock signal, at least one of these digital filters including an operation control section having a counter to count the clock signal and be cleared with a clear signal and a circuit to produce a control signal according to the content of the aforesaid counter, an ROM to provide predetermined coefficients according to the output of the arithmetic control section, an arithmetic section to carry out predetermined arithmetic operations with the above predetermined coefficients under the control of the control signal received from the arithmetic control section, a delay memory section, a switching device controlled for switching to execute the arithmetic operations under the control of the control signal received at the time of execution of the operations, and a circuit to produce a synchronizing signal at the time of the end of the operations in the aforesaid filter, said synchronizing signal being s

Abstract: The detector is provided with an input control circuit supplied with a first input for extracting a carrier wave from a modulated wave and a second input for demodulating the modulated wave and controlled to produce the first and second inputs on the time division basis, a reference wave generating circuit which produces a sine wave or a cosine wave as a reference wave and produces amplitude values corresponding to designated phases, and a time division multiplying circuit which multiplies the outputs of the input control circuit with the amplitude values on the time division basis for producing the demodulated signal.