Integrated Variable Capacitance Diode Resonance Circuit
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Solution Overview
Problem
Conventional variable capacitance diode configurations require additional components and increased substrate area due to the need for external resistances to ground anode terminals, leading to higher costs and complexity in LC resonant circuits.
Innovation Solution
Integration of two variable capacitance diodes and a resistance element on a single chip, where the resistance connects the anode terminals, eliminating the need for external resistances and reducing the number of components and substrate area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external resistances are used to ground anode terminals, then the LC resonant circuit functionality is maintained, but the substrate area and component count increase
Solution Approach 1:
The patent combines multiple components (variable capacitance diodes and resistance elements) onto a single chip substrate. The resistance element is integrated directly on the chip to connect anode terminals to ground, eliminating the need for external resistance components. This merging of components reduces both substrate area and component count while maintaining the required LC resonant circuit functionality.
Solution Approach 2:
The chip substrate serves multiple functions: it hosts the variable capacitance diodes, integrates the resistance elements for grounding anode terminals, and provides the overall circuit structure. This multi-functional integration allows the single chip to replace what would traditionally require multiple separate components, thereby reducing substrate area while maintaining functionality.
2Reliability
If external resistances are used to ground anode terminals, then the circuit can be properly biased, but the number of components and installation costs increase
Solution Approach 1:
The resistance elements are integrated directly onto the chip substrate, combining the biasing function with the main circuit components. This eliminates the need for separate external resistance components, reducing the total number of components and simplifying installation while maintaining proper circuit biasing.
Solution Approach 2:
The chip itself provides the resistance elements needed for biasing, making the system self-sufficient. The integrated resistance elements on the chip perform the biasing function without requiring external components, thereby reducing device complexity and installation costs.
3Area of stationary object
If two variable capacitance diodes are integrated on one chip, then substrate area is reduced, but manufacturing complexity increases
Solution Approach 1:
Two variable capacitance diodes are integrated onto a single chip substrate, reducing the overall substrate area required. The manufacturing process is designed to handle this integration, with resistance elements and diode structures fabricated using compatible semiconductor manufacturing techniques that can be implemented in standard production lines.
Solution Approach 2:
The patent employs specific impurity concentration ranges (p-type: 1×10^16 to 1×10^18 atoms/cm³, n-type: 1×10^14 to 1×10^16 atoms/cm³) and structural parameters (depletion layer width: 1-10 μm) to optimize the integrated diodes' performance. These parameter specifications ensure that the integrated components maintain their electrical characteristics while being manufactured on a compact substrate.
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 integration reduces the substrate mounting area and installation costs by eliminating the need for external resistances, while maintaining the functionality of LC resonant circuits and enabling three-point tracking configurations.
Implementation Method 1
a variable capacitance diode D in which the cathodes of the two variable capacitance diodes D1 and D2 shown in FIGS. 4A and 4B are connected to each other
Implementation Method 2
a parallel LC resonant circuit is configured of a combined capacitance obtained by series connection of the variable capacitance diodes D1 and D2 and the capacitors Cb and C1, and inductance of the coil L1
Data Source
AI summary
A resistance having a high impedance is connected between anode terminals of two variable capacitance diodes sharing a cathode, and the components described above are sealed in one package. The resistance can be formed of a diffusion region between p-regions of the variable capacitance diodes or can be formed of polysilicon and disposed on a chip. Thus, the resistance can be mounted while a chip size of the variable capacitance diode is maintained. Accordingly, it is not required that a bias resistance having a high impedance is additionally provided, whereby achieving reduction in the substrate mounting area and reduction in costs of the set.