Echo-Cancelling Acoustic Delay Circuit for UWB Object Detection
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Solution Overview
Problem
Existing wireless devices face difficulty in detecting nearby objects due to instantaneous echo reflections that overlap with emitted pulses, leading to receiver saturation and requiring multiple antennas, which increases footprint and cost.
Innovation Solution
An echo-cancelling acoustic delay circuit is introduced, adding temporal delays to both emitted and reflected pulses to prevent overlap and cancel undesired echoes, allowing detection with a single antenna.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple antennas are used to avoid echo overlap, then detection accuracy is improved, but device footprint and cost increase
Solution Approach 1:
An acoustic delay circuit is introduced as an intermediary component between the transmitter and receiver circuits. This circuit delays the transmit signal to match the round-trip propagation time of the UWB pulse, allowing the reflected signal to be received and processed without overlapping with the transmitted signal, thereby enabling accurate detection with a single antenna
Solution Approach 2:
The patent replaces the mechanical/physical solution of using multiple antennas with an electronic/acoustic solution using a delay circuit. Instead of physically separating transmit and receive paths with multiple antennas, the system uses signal processing through the acoustic delay circuit to achieve the same effect, reducing device footprint
2Reliability
If multiple antennas are used to detect nearby objects, then detection reliability is improved, but device cost increases
Solution Approach 1:
The acoustic delay circuit serves as a cost-effective intermediary that enables reliable detection by preventing signal overlap. This electronic component is more economical than implementing multiple antenna systems, achieving the same reliability improvement at lower manufacturing cost
Solution Approach 2:
The delay circuit creates a time-copied version of the transmit signal that aligns with the reflected signal arrival, allowing the system to process the reflected signal without interference from the ongoing transmit signal, thereby improving detection reliability
3Speed
If no delay is applied to emitted pulses, then signal transmission speed is maintained, but echo overlap causes detection failure
Solution Approach 1:
The system performs preliminary action by pre-delaying the transmit signal through the acoustic delay circuit before transmission. This preliminary delay ensures that when the reflected signal returns, it does not overlap with the transmit signal, enabling successful detection while maintaining the inherent speed of UWB signal propagation
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
Enables accurate detection of nearby objects by avoiding pulse overlap and reducing device size and cost, while maintaining precise UWB signal integrity across a wide bandwidth.
Implementation Method 1
The acoustic delay device is inserted between the hybrid circuit and the antenna. The acoustic delay device is configured to delay the transmit signal by a delay time equal to a roundtrip propagation time of the UWB pulse
Implementation Method 2
A transmit path of the acoustic delay circuit is coupled to a transmit circuit. A receive path of the acoustic delay circuit is coupled to a receive circuit
Data Source
AI summary
An echo-cancelling acoustic delay circuit, which can be provided in a wireless device operable to detect a nearby object, is disclosed. Given the close proximity of the object, an echo of the emitted pulse(s) may be reflected instantaneously toward the antenna to potentially overlap with the emitted pulse(s), thus causing difficulty in detecting the reflected pulse(s). In this regard, the echo-cancelling acoustic delay circuit is provided in the wireless device to add a temporal delay in the emitted pulse(s) and the reflected pulse(s) to prevent the reflected pulse(s) from overlapping with the emitted pulse(s). In addition, the echo-cancelling acoustic delay circuit is further configured to cancel a reflection echo(s) in the emitted pulse(s) and the reflected pulse(s), thus allowing the wireless device to accurately receive the reflected pulse(s) to thereby detect the nearby object.