Radar Receiver Leakage Cancellation via Phase Adjustment
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Solution Overview
Problem
Automotive radar systems face significant challenges due to signal leakages and parasitic couplings, which degrade detection levels and impact driver safety, with existing leakage cancellation techniques failing to adequately improve detection rates.
Innovation Solution
A leakage cancellation technique that adjusts the relative phase between the local oscillator and radio frequency ports of the radar device to maximize uncorrelated phase noise rejection and DC offset cancellation by sweeping the phase using phase shifters and measuring DC voltage, maintaining optimal phase settings to reduce noise and offset.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional leakage cancellation techniques (adding delay on LO signal or complementary signal at RF input) are used, then some noise reduction is achieved, but the parasitic coupling and signal leakages are not reduced enough to significantly improve the detection rate
Solution Approach 1:
The patent changes the phase parameter of the local oscillator signal dynamically. By adjusting the phase of the LO signal to be substantially in phase with the leakage signal, the cancellation technique achieves significant reduction in parasitic coupling and signal leakage, thereby improving detection rate beyond conventional methods.
Solution Approach 2:
The patent implements a feedback mechanism where the phase of the local oscillator signal is continuously adjusted based on the detected leakage signal characteristics. The controller monitors the leakage and dynamically modifies the LO phase to maintain optimal cancellation, ensuring sustained improvement in detection rate.
2Object-affected harmful factors
If the phase of the local oscillator signal is adjusted to cancel leakage, then uncorrelated phase noise and DC offset are reduced, but the system complexity increases due to phase shifter and DC voltage measurement requirements
Solution Approach 1:
The patent introduces a DC voltage measurement as an intermediary parameter to control the phase adjustment. By measuring the DC voltage component of the intermediate frequency signal and using it to control the phase shifter, the system achieves effective noise and offset cancellation through a manageable control mechanism.
Solution Approach 2:
The patent replaces complex mechanical or hardware-based phase adjustment mechanisms with an electronic control system. The controller electronically adjusts the phase of the local oscillator signal based on DC voltage measurements, simplifying the overall system architecture while achieving effective leakage cancellation.
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 effectively reduces uncorrelated phase noise and DC offset, enhancing the detection capabilities of automotive radar systems and improving driver safety by maintaining optimal phase settings for noise reduction and DC offset cancellation.
Implementation Method 1
adjusting a phase associated with a local oscillator (LO) signal of the receiver circuitry using a phase shifter
Implementation Method 2
a signal leakage from the transmit circuitry to a radio frequency (RF) port of the receiver circuitry is reduced by adjusting a phase associated with a local oscillator (LO) signal of the receiver circuitry
Implementation Method 3
DC voltages of an intermediate frequency (IF) signal versus a relative phase from a radio frequency (RF) mixer of the receiver circuitry are measured using a voltage sensor
Data Source
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AI summary
A transceiver includes a transmitter (240), a frequency synthesizer (230) coupled to the transmitter (240), a receiver (220) coupled to the frequency synthesizer and a voltage sensor (270); and a digital controller (262) coupled to the voltage sensor, the receiver, and the transmitter, wherein based on a DC voltage measurement of an IF signal made by the voltage sensor (270), a relative phase adjustment occurs of a relative phase associated with a local oscillator, LO, port and a radio frequency, RF, port of the receiver.