Negative-Capacitance RF Switch for Low-Loss TX/RX Isolation
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Solution Overview
Problem
Existing RF switching devices in mobile phones and portable terminals face challenges in minimizing signal distortion at high frequencies while maintaining low insertion loss and isolation during switching between transmitter and receiver modes.
Innovation Solution
The implementation of a RF switch module using capacitance switches based on negative-capacitance field effect transistors (FETs) with inhomogeneous stacked gate dielectrics, comprising high-k and negative-capacitance materials, which are controlled by DC voltage to alternate between transmitter and receiver modes, ensuring low loss and low power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional RF switching devices are used to switch between transmitter and receiver, then the device complexity is low, but signal distortion increases and insertion loss worsens at high frequencies
Solution Approach 1:
The patent employs a composite transistor structure combining MOSFET and HEMT technologies, where the MOSFET provides voltage control capability and the HEMT delivers high-frequency performance with low loss. This hybrid approach resolves the contradiction by integrating materials and device structures from different technological domains to achieve both low signal distortion and controlled complexity.
Solution Approach 2:
The RF switch is divided into multiple independent transistor units (first and second transistors) that can be independently controlled. Each transistor handles specific signal paths, allowing optimized performance for different frequency ranges and signal types while maintaining overall system manageability despite increased component count.
2Loss of energy
If conventional RF switching devices are used, then the device structure is simple, but insertion loss increases at high frequencies
Solution Approach 1:
The patent employs a composite transistor structure combining MOSFET and HEMT technologies, where the MOSFET provides voltage control capability and the HEMT delivers high-frequency performance with low loss. This hybrid approach resolves the contradiction by integrating materials and device structures from different technological domains to achieve both low signal distortion and controlled complexity.
Solution Approach 2:
The patent optimizes various parameters including transistor dimensions, gate voltages, and material compositions to minimize insertion loss at high frequencies. By carefully adjusting these parameters, the device achieves low energy loss while maintaining a structured and manageable design through systematic parameter optimization rather than arbitrary complexity.
3Reliability
If conventional RF switching devices are used, then the isolation between transmitter and receiver is insufficient, but adding more components increases device complexity
Solution Approach 1:
The RF switch is divided into multiple independent transistor units (first and second transistors) that can be independently controlled. Each transistor handles specific signal paths, allowing optimized performance for different frequency ranges and signal types while maintaining overall system manageability despite increased component count.
Solution Approach 2:
The patent introduces carefully designed matching networks and isolation circuits as intermediary elements between the transistors and the antenna/transceiver components. These intermediaries provide enhanced isolation and impedance matching without requiring a proportional increase in overall device complexity, as they serve multiple functions simultaneously.
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 solution effectively reduces signal distortion and maintains improved insertion loss and isolation at high frequencies, enabling efficient switching between transmission and reception without adding noise or attenuating the transmit signal.
Implementation Method 1
the second dielectric layer comprises a negative-capacitance material
Implementation Method 2
stacked gate dielectrics comprises at least one first dielectric layer, wherein the first dielectric layer comprises a negative-capacitance material
Implementation Method 3
negative-capacitance field effect transistors (FETs)
Data Source
AI summary
Disclosed is a RF switch module and methods to fabricate and operate such RF switch to alternatively couple an antenna to either a transmitter transmission line or a receiver transmission line to realize lower distortion of a signal at high frequencies with improved insertion loss and without affecting isolation. In one embodiment, a Radio Frequency (RF) switch module, includes, a switch circuit for switching between transmitting first signals from a transmitter unit to an antenna and transmitting second signals from the antenna to the receiver unit, wherein the switch circuit comprises a plurality of field effect transistors (FETs), wherein each of the plurality of FETs comprises stacked gate dielectrics and at least three metal contacts to a conductive gate, wherein the stacked gate dielectrics comprises at least one first dielectric layer, wherein the first dielectric layer comprises a negative-capacitance material.