Phase Rotator Control Circuit With Filtered DAC Noise Shaping

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Solution Overview

Problem

Integrated circuit and system-on-a-chip devices for advanced automotive radar systems face challenges in balancing high-speed and high-accuracy operations while managing product costs, with existing control circuits failing to meet performance targets effectively.

Innovation Solution

A phase rotator control system incorporating a phase rotator core and a phase control block, utilizing a digital-to-analog converter with embedded filter circuitry and multi-stage noise shaping, enables low noise and power-efficient operation by allowing sample-and-hold circuit arrangements during chirp time periods and seamless updates during inter-chirp periods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional control circuits are used in radar systems, then product costs are reduced, but high-speed and high-accuracy operation requirements cannot be met

Engineering Contradiction:
Improveperformance target achievementVSAvoidcontrol circuit sophistication
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control circuit is divided into modular components: phase rotator core, phase control block, digital-to-analog converter, and filter circuit. Each module performs a specific function, allowing independent optimization and reducing overall system complexity while maintaining high performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The filter circuit is embedded within the digital-to-analog converter structure, and the phase control block integrates multiple control signals. This nested architecture reduces the number of discrete components and interconnections, lowering complexity while achieving high-speed operation.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Productivity

If sophisticated control circuitry is implemented to meet performance targets, then high-speed and high-accuracy operation is achieved, but product costs increase

Engineering Contradiction:
Improveradar system speed and accuracyVSAvoidcontrol circuit sophistication
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Multiple control functions are merged into the phase control block, which simultaneously processes multiple control signals and generates phase-adjusted outputs. This consolidation achieves high productivity through integrated operation while reducing the overall device complexity compared to separate control circuits.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The phase rotator core serves multiple functions: it receives RF signals, processes phase control signals, and generates phase-adjusted outputs. This multi-functionality allows a single component to achieve high-speed and high-accuracy operation across different operating conditions without requiring multiple specialized circuits.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If standard digital-to-analog converter circuits are used, then device complexity is reduced, but noise performance deteriorates

Engineering Contradiction:
Improvenoise levelVSAvoidconverter circuit structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

A filter circuit is introduced as an intermediary between the digital-to-analog converter and the phase rotator core. This filter removes quantization noise and signal artifacts, significantly improving noise performance while adding minimal complexity to the overall system.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The filter circuit modifies signal parameters by adjusting frequency response characteristics and attenuating noise components. This parameter transformation achieves low noise performance through controlled signal processing rather than complex converter architecture.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3886322B1Phase rotator control apparatus and method therefor
Publication Date: 2025.07.16 NXP USA INC
  • EP3886322B1 patent drawingFigure 1
  • EP3886322B1 patent drawingFigure 2A
  • EP3886322B1 patent drawingFigure 2B

AI summary

A phase rotator control circuit is provided. The phase rotator control circuit is coupled to a phase rotator core and includes a first set of transistors coupled to receive digital control signals. The first set of transistors is coupled to a second set of transistors configured and arranged to form a filtered current mirror. An output of the filtered current mirror is coupled to provide an analog phase control signal to the phase rotator core.