Programmable DLL Phase Detector for Accurate HRM Phase Outputs
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Solution Overview
Problem
Existing delay-locked loops (DLLs) in RF transceivers face issues with imprecise phase outputs that affect harmonic rejection mixers (HRMs), leading to degraded performance parameters like 3LOmBB and 4FMODS, due to post-layout mismatches and tight design/manufacturing constraints.
Innovation Solution
A programmable phase detector (PD) in the DLL uses resistors instead of logic gates to adjust output phase differences, allowing precise phase control and reducing power consumption, while achieving a 12.5% duty cycle over a wide angular range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If traditional logic gates are used in the phase detector, then phase detection functionality is achieved, but power consumption increases and manufacturing precision requirements become tighter
Solution Approach 1:
The patent replaces logic gates (electronic/digital system) with resistors (passive electrical components) in the phase detector circuit. This substitution eliminates the high power consumption and tight manufacturing constraints associated with logic gates, as resistors consume minimal power and have more relaxed tolerance requirements.
Solution Approach 2:
The patent uses simple, low-cost resistors instead of complex logic gates. Resistors are inexpensive components with loose tolerance specifications, making them easier to manufacture and less costly than logic gates, thereby reducing both power consumption and manufacturing precision requirements.
2Productivity
If DLL outputs are used to drive HRM, then RF transmission is enabled, but phase inaccuracies degrade HRM performance parameters
Solution Approach 1:
The patent introduces an intermediate circuit stage between the DLL and HRM that uses resistors to condition and stabilize the phase signals. This intermediary circuit compensates for phase inaccuracies and provides clean, accurate phase outputs to the HRM, enabling both RF transmission capability and high phase precision.
3Manufacturing precision
If tight design constraints are employed to ensure precise DLL phases, then phase accuracy improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent uses simple resistors with loose tolerance specifications instead of complex, high-precision components. This approach achieves the required DLL phase precision without imposing tight design constraints, thereby reducing device complexity and manufacturing difficulty while maintaining high phase accuracy.
Data Source
AI summary
A delay-locked loop (DLL) is provided that ensures that the phase outputs that are provided as inputs to the harmonic rejection mixer (HRM) are sufficiently accurate to allow the HRM to effectively cancel out the spurious harmonic frequencies, thereby improving HRM parameters. The phase detector of the DLL can be programmable to provide a “knob” that can be used post layout to adjust the output phase differences of the DLL to make them more precise. This feature overcomes issues with mismatches in silicon that in the past have affected the ability of the DLL to settle precisely to the desired phases. This, in turn, loosens design and manufacturing constraints that are currently employed to ensure that the DLLs settle precisely to the desired phases. Additionally, logic gates are eliminated from the phase detector and replaced with resistors to reduce current consumption and further looser design and manufacturing constraints.