Wake-Up Receiver With High-Q Self-Mixing Noise Suppression
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Solution Overview
Problem
Existing wake-up receivers struggle to effectively suppress background noise in crowded frequency bands due to low quality factor resonators and on-off keying modulation, leading to signal overshadowing by noise.
Innovation Solution
A wake-up receiver architecture utilizing a radio frequency filter with high-Q resonators, a self-mixing oscillator, and an intermediate frequency filter to separate and suppress noise signals, followed by a wake-up signal generation module for decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional piezoelectric resonators (off-chip inductors and capacitors or FBARs) are used in the matching network, then the device complexity is reduced, but the quality factor (Q value) is insufficient (Q < 1000), leading to poor background noise suppression
Solution Approach 1:
The patent changes the key parameter of the resonator from traditional piezoelectric materials with Q < 1000 to high-Q resonators with Q > 16000. This parameter change fundamentally improves the background noise suppression capability while maintaining the matching network's functional simplicity, resolving the contradiction between reliability and device complexity.
Solution Approach 2:
The patent employs composite filtering structures combining high-Q resonators with specific filtering topologies (such as π-type or T-type networks) to achieve superior noise suppression. The composite structure leverages the high Q value of the resonator combined with optimized circuit topology to maximize performance while managing complexity.
2Reliability
If the wake-up receiver monitors the channel continuously with low power consumption, then the standby power consumption is reduced, but the system cannot effectively distinguish weak input signals from strong background noise
Solution Approach 1:
The patent applies preliminary filtering action through the high-Q resonator before the signal enters the main receiver. The resonator pre-suppresses background noise at the RF stage, so when the wake-up receiver monitors the channel, the signal-to-noise ratio is already improved, enabling accurate detection of weak signals even at low power consumption levels.
Solution Approach 2:
The high-Q resonator acts as an intermediary element between the antenna and the main receiver. It selectively passes the desired signal frequency while attenuating background noise, thereby mediating the interaction between the weak input signal and strong noise environment, enabling reliable detection without increasing power consumption.
3Reliability
If on-off keying modulation is used for wake-up signals, then the system simplicity is maintained, but the wake-up signal cannot be distinguished when background noise is stronger than the signal
Solution Approach 1:
The patent applies preliminary anti-action by using the high-Q resonator to counteract the background noise before the signal processing stage. The resonator's narrow bandwidth and high selectivity pre-combat the noise interference, creating a cleaner signal environment that enables reliable wake-up signal detection even with simple on-off keying modulation, without requiring complex signal processing.
4Reliability
If a narrow bandwidth filter is used to suppress background noise, then the noise suppression capability is improved, but the signal processing speed decreases
Solution Approach 1:
The patent changes the Q value parameter from traditional values (< 1000) to ultra-high values (> 16000). This parameter change enables the filter to achieve both narrow bandwidth for superior noise suppression and fast transient response for maintaining signal processing speed, effectively resolving the contradiction between reliability and speed.
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
The solution achieves significant noise suppression, enabling faster system wake-up with higher sensitivity and reduced power consumption.
Implementation Method 1
a radio frequency filter configured to filter a composite signal including an input signal and a background noise signal to obtain a first filtered signal
Implementation Method 2
a self-mixing oscillator connected to the radio frequency filter and configured to cause the first filtered signal to self-mix to obtain a mixed signal
Implementation Method 3
an intermediate frequency filter connected to the self-mixing oscillator and configured to filter the mixed signal, so as to filter out the noise self-mixed signal in the mixed signal
Data Source
AI summary
The present disclosure provides a wake-up receiver, including: a radio frequency filter configured to filter a composite signal including an input signal and a background noise signal to obtain a first filtered signal, the first filtered signal includes the input signal and a part of the background noise signal, and the input signal is a product of a modulated signal and a radio frequency carrier; a self-mixing oscillator connected to the radio frequency filter and configured to cause the first filtered signal to self-mix to obtain a mixed signal; an intermediate frequency filter connected to the self-mixing oscillator and configured to filter the mixed signal, so as to filter out the noise self-mixed signal in the mixed signal and obtain a second filtered signal, the second filtered signal includes the modulated signal; and a wake-up signal generation module connected to the intermediate frequency filter and configured to obtain a wake-up signal according to the modulated signal.