Oversampled RF Filtering Circuit for 60 GHz Power Confinement

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Solution Overview

Problem

Existing filtering circuits face challenges in efficiently concentrating the power of radio frequency signals within specific frequency bands, particularly in the 60 GHz band, due to inadequate filtering of secondary lobes, leading to power leakage outside the desired range.

Innovation Solution

A radio frequency transmitter is designed with a filtering circuit comprising a series/parallel shift register and a summing circuit, utilizing coefficients determined by an interpolation filter's impulse response to achieve efficient power concentration within the desired frequency band by oversampling the binary data signal and applying coefficients that recalculate the signal outputs to ensure proper filtering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If traditional filtering circuits are used to shape radiofrequency signals, then signal transmission occurs, but secondary lobes are inadequately filtered causing power leakage outside the desired frequency band

Engineering Contradiction:
Improvepower leakageVSAvoidfiltering precision
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The filtering function is segmented into multiple parallel filtering paths, each handling specific frequency components. The shift register outputs are distributed to multiple filtering circuits that process different portions of the signal spectrum simultaneously, improving overall filtering precision and reducing power leakage in secondary lobes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from traditional single-path filtering to a multi-dimensional parallel processing architecture. By oversampling the binary data signal and distributing it across multiple parallel filtering circuits, the system adds temporal and spatial dimensions to the filtering process, achieving superior frequency selectivity and reducing power leakage outside the desired band.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If filtering circuits are designed to concentrate signal power within specific frequency bands, then filtering precision improves, but device complexity and surface area increase

Engineering Contradiction:
Improvefiltering precisionVSAvoidcircuit complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple filtering circuits are merged into a unified parallel architecture where each circuit processes a portion of the oversampled signal. The outputs of these parallel circuits are combined through summing to produce the final filtered output. This merging approach achieves high filtering precision while distributing complexity across modular units that can be efficiently implemented in integrated circuit form.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The parallel filtering circuit architecture is designed to be universally applicable across different frequency bands and signal types. The same structural framework can be configured for various radiofrequency applications by adjusting the filtering parameters and coefficients, reducing overall device complexity through reuse of proven design modules.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If traditional filtering methods are used, then circuit implementation is simpler, but signal power is not adequately concentrated within the desired frequency band

Engineering Contradiction:
Improvecircuit complexityVSAvoidpower concentration
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The binary data signal is oversampled before being distributed to the parallel filtering circuits. This preliminary oversampling action creates multiple temporal copies of each data bit, which are then processed in parallel through the filtering circuits. This preliminary preparation enables the subsequent filtering stage to effectively concentrate signal power within the desired frequency band while maintaining manageable circuit complexity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4383566A1Filtering device and method
Publication Date: 2024.06.12 STMICROELECTRONICS FRANCE
  • EP4383566A1 patent drawingFigure 1~4
  • EP4383566A1 patent drawingFigure 5
  • EP4383566A1 patent drawingFigure 6

AI summary

This description relates to a radio frequency transmitter comprising at least one filtering circuit (400) including: a serial/parallel shift register (402) including a binary input (In) and N binary outputs Oi, with N an integer greater than or equal to OSR, OSR an integer greater than or equal to 2, and i an integer index from 0 to N-1, the register receiving a binary data signal (DATA) at a frequency Fdata on its input (In) and implementing shifts on its outputs Oi at a frequency equal to Fdata*OSR; a circuit (404) defined by N coefficients Ci providing, for each non-zero coefficient Ci, a signal SIGi determined by the coefficient Ci and by the corresponding output Oi; and a summing circuit (408, 502) providing an output (OUT) equal to the sum of the SIGi signals.