Directional Coupler Diplexer Layout to Suppress Signal Reflection
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Solution Overview
Problem
Conventional directional couplers face challenges in accurately extracting desired signals due to unwanted signals being reflected by filters and returning to the sub line, which then couple back to the main line, causing errors in signal power and reducing extraction accuracy.
Innovation Solution
The directional coupler incorporates a diplexer with two filters having different pass bands, where the first filter is terminated to absorb unwanted signals, preventing them from reflecting back to the sub line and ensuring high accuracy in extracting desired signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a filter is used to extract desired signals, then signal extraction accuracy is improved, but unwanted signals are reflected back to the sub line causing measurement errors
Solution Approach 1:
A termination circuit is introduced as an intermediary component connected to the output terminal of the first filter. This termination circuit absorbs unwanted reflected signals before they can return to the sub line, thereby eliminating the harmful reflection effect while preserving the signal filtering function
Solution Approach 2:
The invention converts the harmful reflected signals into beneficial absorbed energy by using the termination circuit. The termination circuit is designed to match the impedance of the filter output, transforming the reflected signals into useful termination that prevents them from causing measurement errors
2Reliability
If unwanted signals are reflected by the filter, then desired signals can be separated, but the reflected unwanted signals return to the main line causing power measurement errors
Solution Approach 1:
The invention extracts the problematic reflected signals from the signal path by providing them with a dedicated termination path through the termination circuit. This separates the unwanted signal handling from the main signal measurement path, preventing measurement errors while maintaining signal separation capability
Solution Approach 2:
The termination circuit acts as an intermediary that intercepts reflected unwanted signals before they can re-enter the main line. This mediator component ensures that signal separation is maintained without compromising power measurement accuracy
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 configuration effectively suppresses the reflection of unwanted signals, improving the accuracy of desired signal extraction and reducing errors in signal power, thereby enhancing the overall performance of the directional coupler.
Implementation Method 1
a first filter and a second filter having a pass band different from a pass band of the first filter, in which the first filter and the second filter are constituent elements of a multiplexer
Implementation Method 2
the first filter is terminated
Implementation Method 3
a sub line electromagnetically coupled to the main line
Data Source
AI summary
A directional coupler includes a main line, a sub line electromagnetically coupled to the main line, a coupling output terminal, a first filter connected to one end of the sub line, and a second filter connected to the one end of the sub line and the coupling output terminal and having a pass band different from that of the first filter. The first filter and the second filter are constituent elements of a multiplexer. The first filter is terminated.