Antenna Port Termination With NMOS Decoupling When Unpowered
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Solution Overview
Problem
Existing electronic circuits face challenges in achieving desired antenna termination impedance in unpowered conditions due to undesired loads generated by native NMOS devices, which affect circuit performance.
Innovation Solution
Using regular NMOS devices with threshold voltages greater than zero for switches in the switching circuit, allowing the antenna to be properly terminated without additional loads by switching between native and regular NMOS devices based on power supply conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If native NMOS devices are used for switches in the switching circuit, then the antenna can be terminated in unpowered conditions, but additional undesired loads are generated that affect termination accuracy
Solution Approach 1:
The patent applies dynamics by making the switching circuit's operational state changeable based on power supply conditions. Regular NMOS devices are used with their on/off states dynamically controlled by power supply voltage: in powered conditions they conduct normally, while in unpowered conditions they are turned off to eliminate undesired loads. This dynamic state change allows the circuit to adapt its behavior to different operating conditions, resolving the contradiction between achieving termination and avoiding load interference.
Solution Approach 2:
The patent changes the electrical parameters of the switching circuit by using regular NMOS devices whose threshold voltage characteristics change with power supply voltage. When power supply voltage drops to zero (unpowered condition), the NMOS devices naturally turn off due to insufficient gate-source voltage to exceed their threshold voltage. This parameter change eliminates the undesired load effect while maintaining the ability to achieve antenna termination through the termination circuit's impedance matching components.
2Manufacturing precision
If regular NMOS devices with threshold voltages greater than zero are used, then undesired loads are eliminated in unpowered conditions, but switching control becomes more complex
Solution Approach 1:
The patent applies self-service by allowing the regular NMOS devices to automatically adjust their conduction state based on the power supply voltage conditions. The devices use their inherent threshold voltage characteristics to self-determine when to conduct or block current, eliminating the need for external control circuits or additional complexity. When power supply voltage is present, the NMOS devices conduct; when power supply voltage is removed, they automatically turn off, providing self-regulating behavior that simplifies overall circuit design.
Data Source
AI summary
Methods and devices to address antenna termination in absence of power supplies within an electronic circuit including a termination circuit and a switching circuit. The devices include regular NMOS devices that decouple the antenna from the switching circuit in absence of power supplies while the antenna is coupled to a terminating impedance having a desired impedance value through a native NMOS device. The antenna is coupled with the switching circuit via the regular NMOS device during powered conditions while the antenna is decoupled from the terminating impedance.