RF Receiver Tuning by Identification Code for Fast Low-Power Startup
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Solution Overview
Problem
Existing radiofrequency signal receivers face challenges in achieving precise local frequency generation and high frequency selectivity, especially in ultra-low consumption and sporadically activated devices, due to the need for precise local oscillators and costly inductors, which hinder quick startup and shutdown during short cycles.
Innovation Solution
A radiofrequency signal receiver device that compensates for local oscillator inaccuracy using a predetermined identification code, allowing for quick activation and adjustment without requiring precise local oscillator control, and incorporates a secondary receiver to activate the main receiver upon detection of the code, reducing the need for precise frequency management and costly components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a phase-locked loop with a quartz resonator is used to achieve precise local frequency generation, then frequency precision is improved, but steady-state establishment time increases and power consumption increases
Solution Approach 1:
The patent uses a coarse frequency tuning mechanism activated before fine frequency tuning to preliminarily establish the local oscillator frequency within an acceptable range. This preliminary action reduces the time required for the phase-locked loop to reach steady state by avoiding the need to tune from a completely uncalibrated state.
Solution Approach 2:
The frequency tuning process is segmented into multiple stages: coarse tuning using a first control signal to establish a preliminary frequency range, followed by fine tuning using a second control signal to achieve precise frequency. This segmentation allows the system to quickly establish a usable frequency before applying precise calibration.
2Measurement precision
If a phase-locked loop with a quartz resonator is used to achieve precise local frequency generation, then frequency precision is improved, but power consumption increases
Solution Approach 1:
The patent implements dynamic power management by selectively activating different oscillator modes based on operational requirements. During sporadic activation cycles, the system uses a low-power oscillator mode for quick startup and only engages the high-precision phase-locked loop when absolutely necessary, thereby reducing average power consumption while maintaining required frequency precision.
Solution Approach 2:
The system applies different quality levels of frequency generation to different operational contexts: using a simplified, lower-power oscillator for routine operations and quick startup, and reserving the high-precision quartz resonator-based phase-locked loop for critical operations requiring extreme frequency accuracy.
3Measurement precision
If inductors are added to achieve high frequency selectivity, then frequency selectivity is improved, but device cost and size increase
Solution Approach 1:
The patent extracts the frequency selectivity function from traditional inductor-based filters and implements it through digital signal processing and software-controlled filtering algorithms. This extraction eliminates the need for bulky inductors while maintaining high frequency selectivity through computational methods.
Solution Approach 2:
The patent replaces the mechanical/physical inductor-based filtering system with an electronic/digital filtering system. Instead of using physical inductors to achieve frequency selectivity, the system uses digitally controlled filters and signal processing algorithms that provide equivalent or superior selectivity without the associated size and cost penalties.
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
Enables quick startup and shutdown during short cycles with reduced power consumption and cost, maintaining sensitivity and selectivity by using adjustable filtering and amplification within defined frequency ranges, facilitating efficient sporadic activation.
Implementation Method 1
a local oscillator oscillating at an adjustable local frequency
Implementation Method 2
a mixer receiving the radio frequency signals and the output of the local oscillator for the supply of intermediate frequency signals
Implementation Method 3
a filtering system, low pass or band pass, configured and placed to filtering the intermediate frequency or radio frequency signals according to a bandwidth of adjustable frequency width
Data Source
Figure 1~4
Figure 2~3
Figure 5~6
AI summary
This radiofrequency signal receiver device (14) comprises: a local oscillator (18) oscillating at an adjustable local frequency; a mixer (20) receiving the radio frequency signals and the output of the local oscillator (18) for supplying intermediate frequency signals; a filtering system (22, 24) configured and placed to filter the signals according to a passband of adjustable frequency width; and a data detector (28) in the intermediate frequency signals. It further comprises means (40, 42) for adjusting the local frequency of the local oscillator (18), between minimum and maximum oscillation frequencies, and for adjusting the bandwidth of the filtering system (22, 24), between minimum and maximum frequency widths, adapted to adjust this local frequency and this bandwidth until the detector (28) detects a predetermined identification code in one of the intermediate frequency signals.