Frequency Measuring Apparatus Using Segmented High and Low Order Digit Calculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing frequency measuring apparatus using the short gate time count method can only provide relative frequency values, lacking the capability to measure absolute frequency values accurately, and struggles with determining the correct output pattern of 1-bit counters for binary signals.
Innovation Solution
A frequency measuring apparatus is designed with a high-order digit calculation section and a low-order digit calculation section, where the high-order digit section uses a frequency counter to measure unit time frequency and an offset calculation section to remove low-order digit components, while the low-order digit section employs a short gate time counter and low-pass filter to measure frequency variations, allowing for the combination of outputs to achieve absolute frequency measurement. Additionally, a complement determination section determines the correctness of 1-bit counter outputs and inverts them if necessary to avoid errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a short gate time count method is used to improve time resolution and frequency resolution, then the circuit scale is suppressed and multi-channel configuration is achieved, but the absolute frequency value information is lost and only relative frequency variation can be observed
Solution Approach 1:
The frequency measurement is segmented into two parts: a high-order digit calculation section that captures the absolute frequency value using a frequency counter, and a low-order digit calculation section that captures frequency variations using the short gate time count method. This segmentation allows both absolute frequency information and high-resolution frequency variation information to be obtained simultaneously without losing either type of data.
2Device complexity
If only the least significant bit of the counter is used as the short gate time count value to simplify the counter circuit, then the circuit complexity is reduced, but it becomes impossible to determine whether the output train corresponds to the magnitude of the count value or has a complementary relationship
Solution Approach 1:
A complement determination section is introduced as an intermediary component that analyzes the output pattern of the 1-bit counter and determines whether it corresponds to the magnitude of the count value or has a complementary relationship. This intermediary section resolves the ambiguity by providing logic that interprets the 1-bit output correctly, maintaining circuit simplicity while enabling accurate measurement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enables accurate measurement of absolute frequencies, improves circuit simplicity, and prevents errors in 1-bit counter outputs, allowing for precise frequency measurement with reduced circuit complexity and power consumption.
Implementation Method 1
a low pass filter section having a count value train of the short gate time counter as an input, and a scaling section adapted to reduce an output value of the low pass filter section into a value per unit time period
Data Source
AI summary
A frequency measuring apparatus includes: a high-order digit calculation section adapted to measure an input signal and output a high-order digit value of a frequency value of the input signal; a low-order digit calculation section adapted to measure the input signal and output a low-order digit value of the frequency value of the input signal; and an adding section adapted to add the high-order digit value and the low-order digit value to each other to output the frequency value of the input signal.