Radio Receiver IF Mixing for Low-Noise Signal Filtering
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Solution Overview
Problem
Radio receivers face challenges in filtering out unwanted frequencies, noise, and interference from received RF signals, which can be exacerbated by the type of integrated circuits used and power consumption issues due to multiple mixers, leading to suboptimal signal quality and increased power usage.
Innovation Solution
The solution involves separating received RF signals into low-frequency components with different phases, up-converting and amplifying these components into intermediate frequencies, and then down-converting them back to low-frequency signals, while using balanced mixers and low-pass filters to attenuate noise and interference, thereby reducing the number of components and improving signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple mixers are used to process RF signals, then signal quality and filtering capability are improved, but power consumption increases
Solution Approach 1:
The patent combines multiple mixing operations into a single mixer by using a composite local oscillator signal that contains multiple frequency components. Instead of using separate mixers for different frequency conversions, the invention merges these functions into one mixer that processes all frequency conversions simultaneously, thereby reducing power consumption while maintaining signal quality.
Solution Approach 2:
The single mixer in the invention performs multiple functions that would traditionally require separate mixers. By designing the local oscillator to provide multiple frequency components, the mixer becomes a multi-functional device that can handle different frequency conversions and signal processing tasks, reducing the overall component count and power usage.
2Stability of the object's composition
If multiple mixers are interconnected with low pulse ratios, then phase overlap is avoided, but device complexity increases
Solution Approach 1:
The patent merges multiple mixer components into a single mixer, thereby reducing device complexity. The phase stability requirement is met by carefully designing the local oscillator signal to provide properly phased frequency components, eliminating the need for multiple interconnected mixers while maintaining stable phase relationships.
Solution Approach 2:
The single mixer performs multiple mixing functions that would traditionally require separate components. The local oscillator is designed to provide multiple frequency components with appropriate phase relationships, allowing one mixer to replace multiple mixers and reduce overall system complexity while maintaining phase stability.
3Use of energy by moving object
If integrated circuits operate at low voltage, then power consumption is reduced, but noise is introduced to the RF signal
Solution Approach 1:
The patent applies filtering actions at multiple stages in the signal processing chain, particularly after mixing and frequency conversion. By performing preliminary filtering to remove unwanted frequency components and noise before subsequent processing stages, the system can operate at lower voltages without amplifying noise, as the noise has already been attenuated by the filtering operations.
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 approach effectively separates and filters unwanted frequencies, reduces noise and interference, and minimizes power consumption by optimizing the number of mixers and local oscillator signals, resulting in improved signal quality and reduced power usage in radio receivers.
Implementation Method 1
a mixer configured to mix the received signal with a local oscillator signal to produce an intermediate frequency signal
Implementation Method 2
a local oscillator configured to generate first and second local oscillator signals at different frequencies
Implementation Method 3
a filter configured to filter the intermediate frequency signal
Data Source
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AI summary
An apparatus configured to separate from a received radio frequency (RF) signal a first low-frequency signal and a second low-frequency signal having different phases, up- convert the first low-frequency signal and the second low-frequency signal into a first intermediate frequency signal and a second intermediate frequency signal, respectively, and amplify the first and the second intermediate-frequency signals.