DC Bias Resistor Point Connection for RF Transmission Line
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Solution Overview
Problem
Existing RF systems face challenges in efficiently injecting DC bias current into transmission lines over a wide frequency range without significantly impacting performance parameters such as insertion loss.
Innovation Solution
The implementation of DC bias resistors coupled to transmission lines via small point connections, which are less than 5% of the transmission line length, allowing for effective DC bias current injection across a wide frequency range (500 MHz to 40 GHz) with minimal impact on performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If DC bias resistors are coupled to transmission lines via large connections, then DC current injection is effective, but insertion loss increases significantly
Solution Approach 1:
The patent applies local quality by creating a point connection with highly localized electrical contact between the DC bias resistor and transmission line. This concentrated local connection minimizes the affected area on the transmission line, thereby reducing insertion loss while maintaining effective DC bias current injection at the specific connection point.
Solution Approach 2:
The patent employs asymmetry by designing a connection structure where the DC bias resistor connects to the transmission line through a single point contact rather than a symmetric distributed connection. This asymmetric point connection (with length less than 5% of transmission line length) creates minimal disruption to the transmission line's electromagnetic field distribution, reducing insertion loss while effectively injecting DC bias current.
2Loss of energy
If DC bias resistors are coupled via point connections less than 5% of transmission line length, then insertion loss is reduced, but DC current injection effectiveness may be compromised
Solution Approach 1:
The patent applies parameter changes by optimizing the connection length parameter to be less than 5% of the transmission line length. This parameter optimization balances the trade-off between minimizing insertion loss (by keeping connection short) and maintaining sufficient DC bias current injection effectiveness (by ensuring adequate electrical contact). The specific parameter range resolves the contradiction between these two competing requirements.
3Reliability
If conventional bias-T systems are used for DC bias injection, then DC current can be injected into transmission lines, but performance parameters such as insertion loss are significantly impacted
Solution Approach 1:
The patent extracts the essential function of DC bias injection from the conventional bias-T system and implements it through a simplified point connection structure. By taking out only the necessary DC current injection capability and removing the complex bias-T topology, the patent achieves DC bias injection while minimizing insertion loss, as the simple point connection introduces minimal disruption to the transmission line.
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 enables the provision of DC bias current to RF signals in RF systems, including high-frequency devices, with reduced insertion loss, ensuring efficient communication across a broad frequency spectrum.
Implementation Method 1
Each DC bias resistor provides a path for injecting DC current to the transmission line to provide DC bias for the RF signal
Data Source
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AI summary
Systems and methods for introducing DC bias in a radio frequency (RF) signal communicated over a transmission line are provided. In one example implementation, the RF system can include a transmission line having a first port and a second port. The transmission line can be configured to communicate an RF signal between a first port and a second port. One or more DC bias resistors can be coupled to the transmission line at a location between the first port and the second port. Each DC bias resistor can provide a path for injecting DC current to the transmission line to provide DC bias for the RF signal. Each DC bias resistor can be coupled to the transmission line via a point connection.