RF Filter Switch Stack Layout for Low-Loss Power Durability
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Solution Overview
Problem
Conventional high-frequency filters face challenges in achieving power durability while reducing switch size and loss when conducting, particularly in multiband systems, due to the trade-off between power durability and switch size and loss.
Innovation Solution
A high-frequency filter configuration with a series-arm circuit and two parallel-arm circuits, where the first switch element has a lower stack count and lower voltage than the second switch element, allowing for reduced size and passband insertion loss, and the voltage across switch elements is dependent on the high-frequency power application direction and resonant frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the stack count of switch elements is increased to improve power durability, then power durability is improved, but the size of the switch and loss when conducting increase
Solution Approach 1:
The patent applies different stack counts to different switch elements based on their local voltage requirements. The first switch element has a first stack count while the second switch element has a second stack count that is greater than the first stack count. This local differentiation allows each switch to have just enough durability for its specific voltage load, minimizing overall size and conducting loss while ensuring power durability where needed.
2Reliability
If the stack count of switch elements is increased to improve power durability, then power durability is improved, but the size of the switch increases
Solution Approach 1:
The patent implements local quality by assigning different stack counts to different switch elements according to their specific voltage requirements. The first switch element uses a first stack count while the second switch element uses a greater second stack count. This approach ensures that only the switch elements that require higher voltage tolerance have larger sizes, while others remain compact, thus improving power durability without unnecessarily increasing overall switch size.
3Ease of manufacture
If uniform stack count is used for all switch elements, then manufacturing is simplified, but power durability cannot be optimized for different voltage positions
Solution Approach 1:
The patent implements local quality by assigning different stack counts to different switch elements according to their specific voltage requirements. The first switch element uses a first stack count while the second switch element uses a greater second stack count. This approach ensures that only the switch elements that require higher voltage tolerance have larger sizes, while others remain compact, thus improving power durability without unnecessarily increasing overall switch size.
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 configuration ensures power durability while minimizing the size and loss of the filter when switches are conducting, and allows for flexible frequency tuning of the attenuation pole without increasing insertion loss.
Implementation Method 1
The first switch circuit includes a first switch element that includes one or more semiconductor elements connected in series. The second switch circuit includes a second switch element that includes one or more semiconductor elements connected in series.
Implementation Method 2
A resonant frequency that is a singular point at which impedance of the parallel-arm circuit has a local minimum value, and thus the frequency of the attenuation pole according to the resonant frequency can be changed.
Data Source
AI summary
A filter includes: a series-arm circuit; a first parallel-arm circuit connected to a ground and a node; and a second parallel-arm circuit connected to the ground and a node. The first parallel-arm circuit includes a parallel-arm resonator, and a first switch circuit. The second parallel-arm circuit includes a parallel-arm resonator, and a second switch circuit. The first switch circuit includes a first switch. The second switch circuit includes a second switch. A voltage across the first switch is lower than a voltage across the second switch. A stack count of the first switch is lower than a stack count of the second switch.