High-Frequency Switch Circuit for Tunable Insertion Loss and Isolation
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Solution Overview
Problem
Existing high frequency switches lack the ability to variably adjust switching characteristics such as insertion loss and isolation, which are critical for supporting multiple frequency bands in wireless communications, leading to increased signal loss and interference.
Innovation Solution
A high frequency switch design that includes shunt series switching devices connected between transmitting and receiving ports and a ground, allowing for individual control of signal flow to form bypass paths, using a combination of field effect transistors (FETs) and bipolar junction transistors (BJTs) to adjust switching characteristics through varying gate signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single pole double throw (SPDT) type switch is used to support various frequency bands, then the number of supported frequency bands increases, but insertion loss increases and isolation characteristics deteriorate
Solution Approach 1:
The switch is divided into multiple switching units (first switching unit with first switching device, second switching unit with second switching device, third switching unit with third switching device, fourth switching unit with fourth switching device), each independently controlling signal flow for different frequency bands. This segmentation allows optimized signal paths for each band, reducing overall insertion loss while maintaining multi-band support capability.
Solution Approach 2:
The patent implements dynamic control of switching characteristics by applying different gate signals (first gate signal, second gate signal, third gate signal, fourth gate signal) to different switching units. This enables real-time adjustment of insertion loss and isolation characteristics according to the active frequency band, optimizing performance dynamically rather than using fixed characteristics.
2Adaptability or versatility
If a single pole double throw (SPDT) type switch is used to support various frequency bands, then the number of supported frequency bands increases, but isolation characteristics deteriorate due to interference between frequency bands
Solution Approach 1:
By segmenting the switch into four independent switching units, each unit can be independently controlled to provide signal isolation between different frequency bands. The first and second switching units handle transmit paths while the third and fourth switching units handle receive paths, creating natural isolation barriers that reduce inter-band interference.
Solution Approach 2:
The patent introduces intermediate control elements (gate signals and switching devices) that act as mediators between different frequency bands. These intermediaries enable selective signal routing and isolation, allowing multiple frequency bands to coexist without significant interference while maintaining full dual-band functionality.
3Adaptability or versatility
If switching devices are added to support multiple frequency bands, then frequency band support increases, but device complexity increases
Solution Approach 1:
The patent merges multiple switching functions into a unified switch structure that supports multiple frequency bands. By combining the first switching unit, second switching unit, third switching unit, and fourth switching unit into a single integrated device with common ports (first port, second port, third port, fourth port), the design achieves multi-band support without requiring separate switches for each function, thereby controlling overall complexity.
Solution Approach 2:
Each switching unit is designed with universal functionality to handle different frequency bands through controlled signal routing. The switching devices can operate in multiple modes (transmit, receive, isolation) depending on the applied gate signals, allowing a single device to perform multiple functions across different frequency bands without requiring specialized components for each band.
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 design enables flexible adjustment of insertion loss and isolation characteristics, improving signal transfer efficiency and reducing interference between frequency bands, as demonstrated by simulation data showing improved performance at 2.4 GHz frequencies.
Implementation Method 1
A first signal transferring unit including a plurality of first switching devices connected to each other in series to enable or block signal flow between a common port and a first port according to a first gate signal controlling the plurality of first switching devices
Implementation Method 2
using a combination of field effect transistors (FETs) and bipolar junction transistors (BJTs) to adjust switching characteristics through varying gate signals
Data Source
AI summary
There is provided a high frequency switch including: a first signal transferring unit including a plurality of first switching devices; a second signal transferring unit including a plurality of second switching devices; a first shunting unit including a plurality of third switching devices; and a second shunting unit including a plurality of fourth switching devices.