DIGITAL FREQUENCY METER Russian patent published in 2020 - IPC G01R23/02 

FIELD: measurement.

SUBSTANCE: invention relates to measurement equipment and can be used in gyroscopes - magnetrons, radio engineering, in microcontrollers and other devices, where high-frequency precision measurement of signals to tens of gigahertz and their small deviations from nominal values, as well as very short time intervals is required. Digital frequency meter, which includes an input signal receiving port, a high-stable count pulse reception port, three groups of counters with a meter output register, triggers connected to the synchronization and control circuit, in the form of an additional flip-flop for determining a measurement interval and a flip flop of two channels, made in the form of two groups of reversible counters from the high-order and low-order bits, also two multiplexers of high and low order, designed to change display of output information from channels, logic elements unit designed to control generation of counting interval, determination of frequency difference of input and reference signals and switching channels and counting symbols of difference of these frequencies, memory register of whole part of input signal, as well as a fractional part corrector in the form of its divider into a measured frequency mantissa, made on the basis of a programmable integral logic structure chip, characterized by that the digital frequency meter includes a generator of an expanded window for counting frequency pulses of the order ~ ƒ_c…ƒ₀ with ADC with output of number-pulse or frequency-pulse type (FPT), which input is voltage level integrator-integrator proportional to duration of accumulated difference phase between reference and measured frequencies, also comprising stretching pulse generator with time-setting capacitance, inverter with ADC control input and to control device, analogue key in integrator feedback circuit for control thereof, operating capacitance and resistor, dividers at inputs of operational resistor and non-inverting input with diodes in lower arms, separating capacitance between input of former and integrator input, at that, outputs of the first multi-input circuit "and - not" are connected to the corresponding inputs of the logical elements unit, outputs of flip-flop switching of the first channel to the second, outputs of the generator of the expanded window of counting pulses, with outputs of the block of logic elements are connected control inputs of n input counters, register control inputs for storing the integer value of the input signal, inputs of the low-order counters of the first and second channels, wherein outputs of the two high-bit counters are connected to inputs of the high-output switching multiplexer, and outputs of two low-rank digits are connected to low-output switch switching multiplexer inputs, register outputs and multiplexer unit are connected to corresponding chips of programmable logic integral structure microcircuit, first output of which is difference frequency between input and reference signals, and second output thereof and digital frequency meter as a whole - an integer number of input pulses of input signal over measurement period.

EFFECT: invention is expected to be used in orientation and navigation systems on mobile objects - aircrafts, ships and others, in the form of sensors, which require continuous operation and sufficient frequency of information output.

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