Adjustable Notch Filter for Uplink Interference Management
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Solution Overview
Problem
Existing radio frequency receivers face challenges in managing uplink signals due to interference, which can activate Automatic Level Control circuits and lead to signal distortion or ADC saturation, necessitating efficient interference cancellation with highly selective filters.
Innovation Solution
An appliance with a receiver device featuring a low noise amplifier and an adjustable notch filter, assisted by a detection unit and spectrum analyzer, adjusts the filter's central frequency and bandwidth to specifically eliminate interference while preserving the useful signal, using either manual or automated software-based monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a strong input signal is present, then the ALC circuit activates to maintain constant signal power, but this causes indiscriminate reduction of the disturbed input signal or saturation of the ADC circuit
Solution Approach 1:
The patent extracts and removes the harmful interference signal from the input signal before it reaches the ALC circuit and ADC. By using a notch filter to eliminate the specific interference frequency component, the system prevents the ALC from incorrectly reacting to the strong interference signal and avoids ADC saturation, thereby resolving the contradiction between maintaining signal power stability and preventing signal distortion
Solution Approach 2:
The patent converts the harmful strong interference signal into a useful detection opportunity. The spectrum analyzer detects the interference frequency, and this information is used to configure the notch filter to target and eliminate the specific harmful frequency. The harmful strong signal becomes the basis for adaptive filter configuration, transforming the problem into a solution
2Object-affected harmful factors
If highly selective filters are used to eliminate interference frequencies, then interference cancellation is improved, but device complexity increases
Solution Approach 1:
The system performs self-configuration through automated detection and control. The spectrum analyzer automatically detects interference frequencies, and the control unit automatically configures the notch filter parameters based on this detection. This self-service mechanism eliminates the need for manual filter tuning and reduces operational complexity while maintaining high interference elimination performance
Solution Approach 2:
The control unit serves multiple functions: it controls the notch filter, manages the spectrum analyzer, processes detection results, and configures filter parameters. By consolidating these functions into a single multi-functional control unit, the patent reduces overall system complexity compared to having separate dedicated components 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
Effectively reduces or eliminates interference frequencies from the input signal without altering the rest of the signal spectrum, improving signal quality and reducing noise figure, depending on the placement of the notch filter within the uplink chain.
Implementation Method 1
an adjustable notch filter operatively connected to the amplification unit LNA
Implementation Method 2
an amplification unit LNA connected to the input port IN and an output port OUT connected to the amplification unit LNA. Preferably, the amplification unit LNA is made up of a low noise amplifier
Implementation Method 3
a detection unit DU of the interference frequency fi of at least a disturbance signal of the input signal SIN
Data Source
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AI summary
The appliance for receiving radio frequency signals, usable in particular for the management of uplink signals, comprises an input port of a radio frequency input signal, an amplification unit connected to the input port an output port connected to the amplification unit, an adjustable notch filter operatively connected to the amplification unit, a detection unit of the interference frequency of a disturbance signal of the input signal, an adjustment unit operatively connected to the adjustable notch filter and to the detection unit and able to adjust the central frequency of the adjustable notch filter on the interference frequency.