UWB Radar Pulse Circuit Without Local Oscillator for Low-Power Sensing

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Solution Overview

Problem

Existing UWB devices require high energy for signal generation and processing, making them unsuitable for autonomous applications, and they often rely on expensive amplifier circuits and complex components.

Innovation Solution

The method generates UWB transmission pulses using a combination of individual pulses of different polarities and amplitudes, implemented with resistors formed by connecting electronic switches in parallel, and employs Gilbert multipliers with differential stages and weighted current sources to achieve low-energy signal processing and modulation, allowing the device to operate as both a radar and communication device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional amplifier circuits and complex components are used for signal generation and processing, then signal transmission and reception can be achieved, but power consumption is high and device complexity increases

Engineering Contradiction:
Improvesignal transmission reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The transmission pulse is segmented into a sequence of individual sub-pulses with alternating polarities. Instead of using a traditional high-power amplifier to generate a continuous wave, the system transmits multiple lower-power sub-pulses that are modulated with spreading codes. This segmentation allows the signal to maintain reliability through diversity while reducing peak power requirements and average power consumption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces traditional voltage-controlled amplifiers and local oscillators with current-mode logic circuits and direct current switching. The signal generation is achieved through controlled current sources that switch between positive and negative current levels, eliminating the need for complex voltage amplification stages and reducing power consumption significantly.

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

2Reliability

If traditional amplifier circuits and complex components are used for signal generation and processing, then signal transmission and reception can be achieved, but device complexity and cost increase

Engineering Contradiction:
Improvesignal processing reliabilityVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the functions of the local oscillator, signal generator, and modulator into a single integrated current-mode circuit. The same circuit structure is used for both transmission signal generation and received signal demodulation, eliminating the need for separate local oscillators and reducing overall device complexity. The spreading code sequence is generated and applied in a unified manner across both transmit and receive paths.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The current-mode circuit is designed to perform multiple functions: it generates transmission pulses with alternating polarities, modulates spreading codes onto the signal, and demodulates received signals. This universal circuit replaces multiple specialized components (amplifiers, oscillators, modulators) with a single multi-functional block, reducing complexity and cost.

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

3Use of energy by moving object

If individual pulses with different polarities and amplitudes are used for transmission, then power consumption is reduced, but signal generation complexity increases

Engineering Contradiction:
Improvepower consumptionVSAvoidsignal generation complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The system uses periodic switching of current sources at the chip level to generate individual pulses with alternating polarities. The current switches between positive and negative levels in a regular pattern determined by the spreading code sequence. This periodic action simplifies the generation of multi-polarity pulses compared to traditional methods, as it relies on simple switching rather than complex amplitude modulation.

Inventive Principle:
Principle #19Periodic action

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 power consumption, simplifies signal generation and processing, and enables robust signal transmission and reception with minimal energy usage, suitable for autonomous applications and efficient in both radar and communication functions.

Implementation Method 1

resistors of different sizes, with which pulses of different heights can be generated, are implemented by connecting in parallel a number of electronic switches (switching transistors) resulting in the total resistance value of the relevant resistor

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

a correlation signal is generated just like the transmission signal and by means of the second switch units similar to the first switch units, which are sequentially driven in the same way as the first switch units according to the timing scheme

Methodology Applied
Scientific EffectGilbert multiplication:

Data Source

PatentEP2737333B1Ultra wide band radar without local oscillator
Publication Date: 2017.06.14 ELMOS SEMICON AG
  • EP2737333B1 patent drawingFigure 1~2
  • EP2737333B1 patent drawingFigure 3
  • EP2737333B1 patent drawingFigure 4

AI summary

The method for operating a UWB device having at least one transmitting antenna and/or at least one receiving antenna comprises the following steps: - triggering the transmitting antenna (12) or the receiving antenna (12') with a triggering pulse signal (13, 13') having a sequence of substantially sinusoidal pulses of alternating polarity and differing amplitudes and particularly having the waveform of a fifth-order Gaussian pulse signal, - wherein the transmitting antenna (12) can be alternately supplied with current pulses of differing polarity and differing magnitude by switching on and off first electronic switch units (16) that are coupled to the transmitting antenna (12) and have resistances associated with the amplitudes of the pulses to be generated, - wherein each first switch unit (16) has a specifiable, particularly equal, number of first switching transistors(18,19), each having substantially identical on-state resistance values (R), - wherein the resistance of a first switch unit is adjusted either by using only one of the first switching transistors (18,19) or by using a plurality of first switching transistors (18,19) connected in parallel, and - wherein the first switch units (16) are triggered sequentially according to a first specifiable temporal schema and each for a triggering time interval of a predetermined length.