Radar Gain Control Timing for Pulse Signal Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional radar apparatuses experience significant signal distortion and accuracy degradation due to the response time of gain adjustment in amplifiers or attenuators, particularly when using wideband pulse signals for high-resolution applications, where the pulse width is shorter than the response time, leading to reduced detection accuracy.
Innovation Solution
The radar apparatus incorporates a transmission signal producing section, a reception signal adjusting section with a variable gain, a gain adjusting section that produces a gain control signal increasing the signal level over time, and a timing adjusting section that controls the gain adjustment timing, dispersing the degraded signal portions across different transmission zones to prevent accuracy loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pulse width is reduced to increase resolution, then measurement precision is improved, but the response time of gain adjustment becomes longer than the pulse width, causing signal distortion
Solution Approach 1:
The gain adjustment is performed in advance during the signal interval before the next pulse arrives, so that the amplifier is already at the correct gain level when the pulse is received, avoiding distortion during the pulse width
Solution Approach 2:
The gain adjustment is performed periodically during the signal interval between pulses, allowing the system to reset and prepare for the next pulse cycle without interfering with the pulse itself
2Power
If the gain adjustment is performed during the pulse width, then signal level can be optimized, but signal distortion occurs due to the response time of the amplifier
Solution Approach 1:
The gain adjustment is completed before the pulse arrives, so the amplifier is already at the optimal gain level when processing the signal, ensuring both optimal signal level and minimal distortion
3Measurement precision
If the pulse width is made very narrow to achieve high resolution, then measurement precision is improved, but the response time of the amplifier becomes significant compared to the pulse width, leading to accuracy degradation
Solution Approach 1:
The amplifier gain is adjusted in advance during the signal interval before the narrow pulse arrives, eliminating the response time delay from the critical pulse processing period and preserving detection accuracy
Data Source
AI summary
A pulse signal is produced in a pulse generating section, and repetitively transmitted from an antenna at constant time intervals. A reception signal, received through an antenna and including a reflective wave from an object, is amplified and gain-adjusted. Thereafter, a distance detecting section detects a reception pulse of the reflected wave, and calculates the distance to the object. The variable attenuator attenuates the reception signal by a gain adjusted in accordance with a gain control signal. The gain of the variable attenuator is controlled so as to be maximum immediately after the pulse signal is transmitted, and to be reduced with elapse of time. Based on a gain adjustment timing signal, a gain adjustment timing when the attenuation amount is changed is made different for each transmission of the pulse signal.