Multi-Antenna Receiver Linearization via Phase Predistortion
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Solution Overview
Problem
Conventional RF receivers face signal-to-noise ratio degradation due to intermodulation and harmonic distortion, which is exacerbated in wideband receivers, and existing solutions either increase the size and cost of duplex filters or require significant digital signal processing and additional components.
Innovation Solution
The implementation of phase predistorters in multiple receiver chains to induce specific phase shifts in input signals, causing undesired signal components to combine destructively, thereby reducing intermodulation distortion without increasing filter size or DSP requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the performance of the input bandpass filter is increased to attenuate undesired signal components, then intermodulation distortion is reduced, but the filter size and cost increase significantly
Solution Approach 1:
The receiver is divided into multiple independent receiver chains, each with its own bandpass filter. This segmentation allows each filter to be smaller and less expensive while collectively providing the necessary interference rejection through coordinated operation of multiple chains.
Solution Approach 2:
A combiner is introduced as an intermediary component that combines the outputs of multiple receiver chains. The combiner, along with phase predistorters, provides additional interference suppression functionality without requiring each individual filter to be oversized.
2Object-affected harmful factors
If the performance of the input bandpass filter is increased to attenuate undesired signal components, then intermodulation distortion is reduced, but the cost increases significantly
Solution Approach 1:
The receiver is divided into multiple independent receiver chains, each with its own bandpass filter. This segmentation allows each filter to be smaller and less expensive while collectively providing the necessary interference rejection through coordinated operation of multiple chains.
Solution Approach 2:
A combiner is introduced as an intermediary component that combines the outputs of multiple receiver chains. The combiner, along with phase predistorters, provides additional interference suppression functionality without requiring each individual filter to be oversized.
3Object-affected harmful factors
If tunable notch filters are added to supplement the bandpass filter, then intermodulation distortion is reduced, but insertion loss increases
Solution Approach 1:
The receiver is divided into multiple independent receiver chains, each with its own bandpass filter. This segmentation allows each filter to be smaller and less expensive while collectively providing the necessary interference rejection through coordinated operation of multiple chains.
Solution Approach 2:
A combiner is introduced as an intermediary component that combines the outputs of multiple receiver chains. The combiner, along with phase predistorters, provides additional interference suppression functionality without requiring each individual filter to be oversized.
4Reliability
If the dynamic range of all receiver components is increased to handle larger power levels, then linearity is improved, but power consumption and size increase
Solution Approach 1:
The receiver is divided into multiple independent receiver chains, each with its own bandpass filter. This segmentation allows each filter to be smaller and less expensive while collectively providing the necessary interference rejection through coordinated operation of multiple chains.
Solution Approach 2:
A combiner is introduced as an intermediary component that combines the outputs of multiple receiver chains. The combiner, along with phase predistorters, provides additional interference suppression functionality without requiring each individual filter to be oversized.
5Object-affected harmful factors
If digital signal processing techniques are used to estimate and subtract IMD and HD, then distortion compensation is improved, but DSP requirements and component count increase
Solution Approach 1:
The receiver is divided into multiple independent receiver chains, each with its own bandpass filter. This segmentation allows each filter to be smaller and less expensive while collectively providing the necessary interference rejection through coordinated operation of multiple chains.
Solution Approach 2:
A combiner is introduced as an intermediary component that combines the outputs of multiple receiver chains. The combiner, along with phase predistorters, provides additional interference suppression functionality without requiring each individual filter to be oversized.
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 suppresses intermodulation distortion while maintaining receiver performance and reducing the need for large duplex filters and complex digital processing, thus improving signal quality without increasing power consumption or size.
Implementation Method 1
a first phase predistorter in the first receiver chain configured to shift a phase of the first input signal by a first phase shift φ′A(f)
Data Source
AI summary
A receiver includes a first receiver chain configured to receive a first input signal and a second receiver chain configured to receive a second input signal. A first phase predistorter is provided in the first receiver chain and is configured to shift a phase of the first input signal by a first phase shift φ′A(f). A combiner is coupled to the first receiver chain and the second receiver chain and combines the first and second input signals. The first phase shift is selected to cause undesired signal components received in the first and second input signals to combine destructively.