Filter Adjustment Circuit Using 90° Phase Integration
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Solution Overview
Problem
Existing automatic adjustment circuits for filter circuits in radio devices face challenges in achieving high accuracy and high-speed operation while occupying a small chip area and having low power consumption, due to limitations in phase comparator symmetry and parasitic phase delay.
Innovation Solution
An automatic adjustment circuit that incorporates an integrating circuit with a 90-degree phase difference between its clock and input signals, allowing for high symmetry in signal paths and minimizing parasitic phase delay, thereby enabling accurate and high-speed frequency characteristic adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the phase comparator is configured fully symmetrically to increase accuracy, then measurement precision is improved, but device complexity increases and parasitic phase delay increases making high-speed operation difficult
Solution Approach 1:
The patent introduces an integrating circuit as an intermediary between the replica output and the phase comparator. This integrating circuit processes the phase difference signal and outputs an adjusted signal that compensates for asymmetry effects, allowing the phase comparator to operate with reduced complexity while maintaining high measurement precision. The intermediary circuit absorbs the complexity of achieving symmetry, freeing the phase comparator from requiring full symmetric configuration.
2Measurement precision
If the phase comparator is made larger in scale to achieve full symmetry, then measurement precision is improved, but parasitic phase delay increases reducing operating speed
Solution Approach 1:
The integrating circuit serves as a mediator that processes phase difference signals without requiring a large-scale phase comparator. By performing integration and adjustment functions in this intermediary circuit, the system achieves accurate phase comparison with a compact phase comparator design, thereby maintaining high operating speed while avoiding excessive parasitic phase delay.
Solution Approach 2:
The patent replaces the mechanical approach of achieving symmetry through physical circuit symmetry with a signal-processing approach. Instead of making the phase comparator physically symmetric (which increases size and delay), the system uses the integrating circuit to electronically compensate for asymmetry effects, substituting physical symmetry with computational correction.
3Measurement precision
If the phase comparator is made larger in scale to achieve full symmetry, then measurement precision is improved, but chip area increases
Solution Approach 1:
The integrating circuit acts as an intermediary that performs the complex signal processing functions externally, allowing the phase comparator itself to remain compact. This division of functionality keeps the overall chip area small while achieving high measurement precision through the coordinated operation of the compact phase comparator and the integrating circuit.
Solution Approach 2:
The patent segments the phase comparison function into two parts: a compact phase comparator that performs basic phase detection, and an integrating circuit that performs the complex adjustment and compensation functions. This segmentation allows each component to be optimized independently, keeping the phase comparator small for low chip area while achieving high precision through the integrated circuit's processing capabilities.
4Measurement precision
If the phase comparator is made larger in scale to achieve full symmetry, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The integrating circuit serves as an energy-efficient intermediary that handles the computationally intensive compensation functions. By offloading these functions from a large phase comparator to a dedicated integrating circuit, the system achieves high measurement precision with lower overall power consumption, as the integrating circuit can perform its functions more efficiently than a scaled-up phase comparator.
Data Source
AI summary
An automatic adjustment circuit comprises a replica (1) constituted of either a circuit block of a portion of a filter body (3) or a combination of the circuit block, and fed with a reference signal (2) from the outside, for outputting signals having a phase delays of 90 degrees and 180 degrees with respect to the reference signal (2), and an integrating comparator (4) fed at its input terminal with an output signal, as having a phase delay of 180 degrees, of the replica (1) and the reference signal (2), and at its clock terminal with an output signal, as having a phase delay of 90 degrees, of the replica (1), and having an output terminal connected with a capacity (C1) and a frequency characteristic adjusting terminal of the replica (1). The automatic adjusting circuit is characterized in that the integrating action of the integrating comparator (4) is performed across the two high/low states of the input signal.