Amplifier Termination Circuit With Heat-Stable Resistor Substrate
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Solution Overview
Problem
Existing baseband termination circuits in high-power amplifier circuits face challenges in suppressing changes or deterioration in resistor characteristics due to temperature rises and high voltage applications, which can lead to deviations from desired circuit characteristics.
Innovation Solution
The amplifying circuit incorporates a resistor component with an insulated substrate having high thermal conductivity (20 W/m·K or more) and bandgap energy (1.5 eV or more), along with a first inductor and a first capacitor, where the absolute value of the inductor's impedance at the center frequency is greater than the capacitor's impedance at the corresponding bandwidth frequency, thereby minimizing resistor deterioration and maintaining circuit characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a resistor is used in a baseband termination circuit for high-power amplifier circuits, then the circuit can provide baseband termination function, but the resistor characteristics change or deteriorate due to temperature rise and high voltage application
Solution Approach 1:
The patent changes the material parameters of the substrate by specifying a minimum thermal conductivity of 20 W/m·K and minimum bandgap energy of 1.5 eV. This parameter change ensures the substrate can handle high temperature and high voltage conditions without causing resistor characteristic deterioration, directly resolving the contradiction between maintaining reliability and dealing with temperature rise.
Solution Approach 2:
The patent employs a composite structure consisting of a substrate with specific thermal and electrical properties (high thermal conductivity and high bandgap energy materials like aluminum nitride, silicon carbide, or gallium nitride) combined with a resistance film. This composite material approach allows the baseband termination circuit to maintain resistor stability under high power conditions while providing the necessary termination function.
2Reliability
If a resistor is used in a baseband termination circuit for high-power amplifier circuits, then the circuit can provide baseband termination function, but the resistor characteristics change or deteriorate due to high voltage application
Solution Approach 1:
The patent changes the material parameters by specifying a minimum bandgap energy of 1.5 eV for the substrate material. This high bandgap energy parameter enables the substrate to withstand high voltage application without breaking down or causing resistor characteristic changes, directly addressing the contradiction between reliability and high voltage exposure.
Solution Approach 2:
The patent uses a composite structure with a high bandgap energy substrate (such as aluminum nitride, silicon carbide, or gallium nitride) combined with a resistance film. This composite material configuration provides both the necessary electrical insulation to handle high voltage and the thermal management capabilities to maintain resistor stability under high power conditions.
3Reliability
If an insulated substrate with high thermal conductivity and bandgap energy is used, then resistor characteristic stability is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent establishes clear quantitative parameters (thermal conductivity ≥ 20 W/m·K, bandgap energy ≥ 1.5 eV) that guide material selection. While this ensures reliability, it does limit material choices to specific high-performance ceramics and semiconductors, increasing manufacturing complexity compared to using conventional substrates.
Solution Approach 2:
The patent specifies a composite structure requiring both a high-performance substrate and a resistance film deposition process. This composite approach improves reliability but adds manufacturing steps and material compatibility requirements, making the fabrication process more complex than simple resistor fabrication on conventional substrates.
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 configuration effectively suppresses changes or deterioration in resistor characteristics, maintains desired circuit characteristics, and ensures reliable operation under high power and temperature conditions.
Implementation Method 1
an insulated substrate mounted on or over an upper surface of a base substrate and having a thermal conductivity of 20 W/m·K or more
Implementation Method 2
a bandgap energy of 1.5 eV or more
Data Source
AI summary
An amplifying circuit includes an amplifier that outputs an amplified high frequency signal to an output terminal, a first inductor connected to a line between the amplifier and the output terminal, a resistor component connected to the first inductor, the resistor component including an insulated substrate mounted on or over an upper surface of a base substrate and having a thermal conductivity of 20 W/m·K or more and a bandgap energy of 1.5 eV or more, and a resistance film disposed on an upper surface of the insulated substrate, and a first capacitor connected to the resistor component and a reference potential. An absolute value of an impedance of the first inductor at a center frequency of an operating band of the amplifier is larger than an absolute value of an impedance of the first capacitor at a frequency corresponding to a bandwidth of the operating band.