Tunable Notch Filter for RF Blocker Coexistence
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Solution Overview
Problem
Low power wireless transceivers face communication challenges when co-located with high power transceivers due to interference, leading to decreased performance and reduced successful communication probabilities due to signal blockers.
Innovation Solution
A wireless transceiver with a tunable notch filter, programmable by a controller, is used to attenuate specific blocker frequencies, comprising a variable capacitor and inductance, such as a bondwire, to mitigate interference between collocated or nearby high power and low power transceivers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a low power wireless transceiver operates near a high power transceiver, then both devices can share the same communication area, but the low power transceiver experiences signal blocking and performance degradation
Solution Approach 1:
The patent applies local quality by making the receiver's frequency response non-uniform across the bandwidth. Specifically, a notch filter is introduced to create a localized attenuation at the aggressor's frequency while maintaining normal gain elsewhere. This allows the receiver to selectively reject interference at specific frequencies while preserving sensitivity to desired signals at other frequencies, thereby enabling coexistence without sacrificing communication reliability
Solution Approach 2:
The patent introduces an intermediary component - the notch filter - that mediates between the aggressor signal and the receiver. This filter acts as a selective barrier that allows desired signals to pass through while blocking the harmful aggressor signal at its specific frequency. The notch filter serves as a mediator that reconciles the presence of both high power and low power transceivers in the same communication environment
2Reliability
If a notch filter is added to attenuate blocker signals, then receiver performance improves in the presence of aggressors, but device complexity increases
Solution Approach 1:
The patent applies dynamics by making the notch filter tunable rather than fixed. The filter's center frequency can be dynamically adjusted to match the aggressor's frequency, allowing the receiver to adapt to different interference conditions. This dynamic capability enables the same hardware to handle multiple frequency scenarios, reducing the need for multiple fixed filters and thereby limiting the increase in device complexity
Solution Approach 2:
The patent achieves universality by designing a notch filter that can be tuned to different frequencies to handle various aggressor signals. Rather than requiring separate fixed filters for each potential interferer, a single tunable notch filter can serve multiple functions across different frequency scenarios. This multi-functionality approach improves signal reception quality while minimizing the increase in device complexity
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 enables effective coexistence of low power and high power transceivers by selectively attenuating blocker signals, improving the reception capabilities of low power transceivers and maintaining the integrity of desired signals.
Implementation Method 1
The tunable notch filter may include a variable capacitor and an inductance coupled in series between the radio frequency transceiver node and ground
Data Source
AI summary
A wireless transceiver including a receiver circuit coupled to an RF transceiver node, a tunable notch filter coupled between the RF transceiver node and a reference node, and a controller that programs the tunable notch filter with a selected blocker frequency and that selectively enables the tunable notch filter to attenuate at least one blocker signal. The tunable notch filter may include a variable capacitor and an inductor coupled in series between the RF transceiver node and ground. The inductor of the tunable notch filter may include a bondwire coupled between a semiconductor die and a semiconductor package. The inductance may include a physical inductor mounted on the package or a printed circuit board. The tunable notch filter may be enabled by a switch selectively coupling the filter to either the RF transceiver node or ground. The variable capacitor may be digitally programmed with digital values stored in a memory.