Variable Gain Feedback Circuit for Fast Settling Interference Handling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Automotive radar systems face interference from nearby vehicles, leading to receiver overload and a decrease in Signal-to-Noise ratio (SNR), which is typically addressed by reducing receiver gain, but this approach increases power consumption and disrupts DC equilibrium, causing undesirable settling effects.
Innovation Solution
A variable gain arrangement using capacitive feedback with transient compensation capacitors to adjust gain quickly, minimizing transient settling effects by dynamically reconfiguring capacitor interconnections and injecting charge to maintain charge balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If receiver gain is reduced to handle interference bursts, then interference robustness is improved, but power consumption increases and DC equilibrium is disrupted causing settling effects
Solution Approach 1:
The patent implements dynamic gain adjustment by switching between different gain states (first gain state and second gain state) based on interference detection. The gain switching apparatus changes the ratio of feedback capacitor to input capacitor dynamically, allowing the receiver to adapt to interference conditions without permanent high-power consumption configuration.
Solution Approach 2:
The transient compensation capacitor arrangement is pre-configured to counteract the settling effects that would result from gain changes. By anticipating the DC equilibrium disruption, the compensation capacitors are arranged to automatically counterbalance the transient effects when gain switching occurs, preventing the harmful settling effects before they fully manifest.
2Speed
If gain is adjusted quickly to handle interference, then interference handling speed is improved, but transient settling effects increase
Solution Approach 1:
The transient compensation capacitor arrangement acts as an intermediary element between the gain switching apparatus and the amplifier. When gain switching occurs, the compensation capacitors mediate the transition by providing charge compensation, thereby enabling fast gain adjustment while minimizing the transient settling effects that would otherwise occur.
Solution Approach 2:
The patent changes the capacitance ratio parameter dynamically by switching different capacitor configurations. The gain switching apparatus alters the ratio of feedback capacitor to input capacitor to achieve different gain states, while the transient compensation capacitors adjust their configuration to maintain stability during these parameter changes.
3Adaptability or versatility
If capacitor ratio is changed to adjust gain, then gain flexibility is improved, but charge balance is disrupted causing settling effects
Solution Approach 1:
The patent employs feedback through the feedback capacitor arrangement to maintain charge balance during gain adjustments. The feedback mechanism monitors the charge state and the transient compensation capacitors provide corrective charge injection based on the gain switching state, ensuring that charge balance is maintained even as the capacitor ratio changes for gain flexibility.
Solution Approach 2:
The transient compensation capacitors function as counterweights to the charge imbalance caused by gain switching. When the capacitor ratio changes to adjust gain, the compensation capacitors provide an equal and opposite charge effect that counterbalances the disruption, maintaining overall charge equilibrium in the circuit.
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
The solution maintains SNR by reducing gain during interference without significant power increase, effectively handling interference bursts while reducing transient disturbances.
Implementation Method 1
a feedback capacitor arranged in series with the input capacitor arrangement, wherein the gain applied by the variable gain arrangement is based on a ratio of the first input capacitor and the capacitance of the feedback capacitor
Implementation Method 2
the at least one transient compensation capacitor is configured to be coupled to or decoupled from the feedback capacitor such that transient settling effects caused by the gain change are compensated
Data Source
Figure 1A~1B
Figure 2~3
Figure 4~5
AI summary
A variable gain arrangement of a receiver path configured to receive an input signal and apply a gain to the input signal to provide an output signal, comprising: an input capacitor arrangement comprising a first input capacitor; a feedback capacitor arranged in series with the input capacitor arrangement, wherein the gain is based on a ratio of the first input capacitor and the feedback capacitor; and a gain switching apparatus configured to provide for adjustment of the gain applied to the input signal by changing the ratio; an amplifier in series with the input capacitor arrangement, the amplifier arranged in parallel with the feedback capacitor, the amplifier configured to provide the output signal; and a transient compensation capacitor arrangement comprising a first transient compensation capacitor, wherein, upon a change in the gain, the at least one transient compensation capacitor is configured to be coupled to or decoupled from the feedback capacitor such that transient settling effects caused by the gain change are compensated.