RF Synthesis Device Using Continuous Inverse Fourier Transform

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Solution Overview

Problem

High-bandwidth digital communication systems face challenges in reducing unwanted interference signals due to high circuit complexity and glitch generation from oversampling and filtering processes in RF-DACs, which are inadequate for suppressing interference in high-bandwidth transmissions.

Innovation Solution

A circuit arrangement using a synthesis device for generating high-frequency, analog single-carrier transmission signals through a continuous inverse Fourier transform of a digital baseband signal's discrete frequency spectrum, eliminating the need for oversampling and filtering, and operating at a reduced switching frequency to minimize interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If oversampling and digital filtering are used in RF-DAC to reduce interference, then interference suppression is improved, but circuit complexity increases and glitches are generated

Engineering Contradiction:
Improveinterference suppressionVSAvoidcircuit complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts the interference-generating components (oversampling and digital filtering circuits) from the RF-DAC system. By performing the inverse Fourier transform directly in the analog domain using a continuous-time Fourier transform circuit, the system eliminates the need for discrete-time oversampling and digital filtering, thereby removing the source of glitches and circuit complexity while maintaining interference suppression capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the digital signal processing mechanism (discrete-time Fourier transform with oversampling and filtering) with an analog continuous-time Fourier transform mechanism. This substitution eliminates the switching artifacts and glitches inherent in digital systems while achieving the same spectral shaping and interference suppression function

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Speed

If high switching frequency is used for baseband signal processing to achieve high bandwidth, then transmission bandwidth is improved, but glitch generation increases and interference is promoted

Engineering Contradiction:
Improvetransmission bandwidthVSAvoidglitch generation
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent replaces high-frequency digital switching operations with continuous-time analog signal processing. The inverse Fourier transform is performed continuously in the analog domain, eliminating the need for high-speed digital switching and thereby preventing glitch generation while maintaining high transmission bandwidth capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements continuous-time signal processing throughout the transmission chain, from the continuous inverse Fourier transform to the continuous modulation and amplification. This continuous operation eliminates the discontinuities and abrupt transitions that cause glitches in discrete-time systems, enabling high-bandwidth transmission without interference

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If RF-DAC operates at high clock frequency to achieve high sampling rate, then sampling accuracy is improved, but interference emission increases

Engineering Contradiction:
Improvesampling accuracyVSAvoidinterference emission
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the discrete sampling process with continuous-time signal generation. Instead of capturing discrete samples at high clock frequencies, the system continuously generates the time-domain signal through analog inverse Fourier transform, eliminating the clock-synchronized switching that causes interference while maintaining signal fidelity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent removes the RF-DAC component entirely from the system architecture. By generating the time-domain signal continuously in the analog domain before modulation, the system eliminates the need for high-frequency sampling and conversion operations that are the source of interference emission

Inventive Principle:
Principle #2Taking out (Extraction)

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 reduces the emission of unwanted interference signals and simplifies circuitry, enabling efficient high-bandwidth transmission with reduced glitches and increased reliability.

Implementation Method 1

The synthesis device is a device for performing a continuous inverse Fourier transform

Methodology Applied
Scientific EffectFourier transform:

Data Source

PatentEP3411955B1Circuit arrangement and method for generating a radio-frequency, analogue transmission signal using reduced interference signals
Publication Date: 2022.11.02 INCIRT GMBH
  • EP3411955B1 patent drawingFigure 1
  • EP3411955B1 patent drawingFigure 2~3
  • EP3411955B1 patent drawingFigure 4~5

AI summary

The present invention relates to a circuit arrangement for generating a radio-frequency, analogue transmission signal (109), particularly a radio-frequency, analogue single-carrier transmission signal, wherein the circuit arrangement has a synthesis apparatus (105) for generating the radio-frequency, analogue transmission signal (109) on the basis of a discrete frequency spectrum of a digital, in particular modulated, baseband signal (103). Further, the invention relates to a transmission device for sending a radio-frequency, analogue transmission signal (109), particularly a radio-frequency, analogue single-carrier transmission signal, wherein the transmission device (100) has an antenna (112) for sending the transmission signal (109), the transmission device (100) having a synthesis apparatus (105) for generating the radio-frequency, analogue transmission signal (109) on the basis of a discrete frequency spectrum of a digital, in particular modulated, baseband signal (103). The invention additionally relates to a method for sending a radio-frequency, analogue transmission signal (109) that is particularly a radio-frequency, analogue single-carrier transmission signal, having the following method steps: – provision of a discrete frequency spectrum of an, in particular modulated, digital baseband signal (103); – generation of the radio-frequency, analogue transmission signal (109) on the basis of the discrete frequency spectrum; and – sending the radio-frequency, analogue transmission signal (109) via an antenna (112).