DC/DC Converter Frequency Locking for VCO Crosstalk Reduction
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Solution Overview
Problem
Existing radio transmitter and receiver circuits face challenges in efficiently managing supply voltage for frequency synthesizers and switch-mode DC/DC converters, particularly in preventing crosstalk between voltage-controlled oscillators (VCOs) and DC/DC converters, and ensuring optimal switching frequencies that do not overlap with VCO frequencies or their harmonics.
Innovation Solution
The integration of a frequency converter that locks the switching frequency of the DC/DC converter to the oscillator frequency, using a phase locked loop or multiplying/dividing the oscillator frequency by a constant ratio, and the use of self-oscillating DC/DC converters that can operate independently of active oscillators, to generate a supply voltage and prevent frequency overlap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a switch-mode DC/DC converter is used to provide supply voltage, then voltage conversion efficiency is improved, but frequency overlap between DC/DC converter switching frequency and VCO frequency occurs causing crosstalk
Solution Approach 1:
The patent applies preliminary action by pre-determining the switching frequency of the DC/DC converter to be different from the VCO frequency and its harmonics before operation begins. This is achieved by carefully selecting the switching frequency in the design phase to avoid overlap with VCO operating frequencies, thereby preventing crosstalk from occurring in the first place while maintaining efficient voltage conversion.
2Stability of the object's composition
If the DC/DC converter switching frequency is locked to VCO frequency using phase locked loop, then frequency stability is improved, but device complexity increases
Solution Approach 1:
The patent merges the frequency control function into the existing phase-locked loop (PLL) circuitry that is already present in the frequency synthesizer. By utilizing the existing PLL infrastructure to also control the DC/DC converter switching frequency, the patent achieves frequency stability without adding significant complexity, as the same PLL circuit serves dual purposes.
3Object-affected harmful factors
If frequency converter is integrated to lock DC/DC converter switching frequency to oscillator frequency, then crosstalk is reduced, but device complexity increases
Solution Approach 1:
The patent implements a frequency converter circuit that serves multiple functions: it converts the VCO frequency to a suitable switching frequency for the DC/DC converter, ensures frequency stability through PLL control, and prevents crosstalk by maintaining frequency separation. This multi-functional approach reduces overall system complexity compared to having separate circuits for each function.
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 solution ensures efficient voltage conversion, reduces crosstalk, and allows for compact design of DC/DC converters by ensuring the switching frequency does not overlap with VCO frequencies, thereby enhancing the performance of transmitter and receiver circuits.
Implementation Method 1
The DC/DC converter may be a switch-mode DC/DC converter which performs the voltage conversion by applying a DC voltage across an inductor or capacitor for a period of time which causes current to flow and store energy magnetically or electrically
Implementation Method 2
The integration of a frequency converter that locks the switching frequency of the DC/DC converter to the oscillator frequency, using a phase locked loop or multiplying/dividing the oscillator frequency by a constant ratio
Data Source
AI summary
Implementations related to circuits including an oscillator and a switch-mode DC/DC converter are presented herein.