Continuously Tunable Capacitor Bank for Wide-Range RF Front Ends
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current RF front-end modules, particularly those for advanced ground mobile radios, face challenges in achieving multiple frequency band coverage, continuous tuning, and low insertion loss while maintaining a small form factor, due to limitations in tuning range and resolution of existing capacitor banks.
Innovation Solution
A wide range continuously tunable capacitor bank is developed, comprising a variable capacitor with high quality factor and switched capacitors, allowing for continuous tuning over a large capacitance range by adjusting the bias voltage and actuating switched capacitors, thereby enabling flexible frequency tuning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a capacitor bank uses fixed capacitance values with manual switching between discrete capacitors, then it can achieve basic frequency control, but it cannot provide continuous frequency modulation and requires large physical size for wide frequency ranges
Solution Approach 1:
The patent replaces the mechanical switching system (manual switches and discrete capacitors) with an electronic system using voltage-controlled variable capacitors. This substitution enables continuous frequency modulation through electrical control signals while dramatically reducing the physical size and component count of the capacitor bank.
Solution Approach 2:
The patent transforms the static, fixed capacitance values into dynamic, continuously adjustable capacitance values. By using voltage-controlled variable capacitors, the system can dynamically change its capacitance in real-time based on control voltages, enabling continuous frequency modulation across a wide range without requiring multiple discrete capacitor components.
2Adaptability or versatility
If a capacitor bank is designed for wide frequency range coverage using multiple discrete capacitors, then it can achieve frequency versatility, but it increases the physical size and reduces tuning continuity
Solution Approach 1:
The patent changes the fundamental parameter of capacitance from discrete fixed values to continuously variable values through voltage control. By applying different control voltages to the variable capacitors, the capacitance can be smoothly adjusted across a wide range, providing both extensive frequency coverage and continuous tuning capability without the need for multiple discrete capacitor components.
3Adaptability or versatility
If a capacitor bank uses discrete capacitor switching for frequency control, then it can achieve frequency selection, but it creates impedance mismatches and standing waves that reduce power transfer efficiency
Solution Approach 1:
The patent replaces the discrete capacitor switching mechanism with voltage-controlled variable capacitors that can continuously adjust their capacitance values. This electronic control method eliminates the abrupt impedance changes caused by discrete switching, thereby reducing standing waves and improving power transfer efficiency while maintaining frequency selection capability through smooth impedance matching.
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 solution provides a compact RF front-end module capable of continuous wide-range tuning, enhancing frequency band coverage and reducing insertion loss, while maintaining a small form factor, thus addressing the limitations of existing technologies.
Implementation Method 1
Each of the plurality of voltage controlled variable capacitors may change capacitance in response to a control voltage signal
Data Source
Figure 1~5
Figure 2a~2b
Figure 4a~4b
AI summary
A wide range tunable capacitor bank is provided. The capacitor bank comprises a variable capacitor, the capacitance value of which is adjustable within a predetermined capacitance range defined by a minimum capacitance value and a maximum capacitance value, The capacitor bank further comprises one or more switched capacitors each electrically connected in circuit to the variable capacitor. The variable capacitor is configured to allow the capacitance value thereof to be adjusted within the predetermined capacitance range and the one or more switched capacitors are configured to be selectively actuated to permit continuous tuning of the capacitor bank over a second capacitance range that is greater than the predetermined capacitance range. Applications in which the capacitor bank may be implemented, and a method of fabricating an integrated system comprising a plurality of passive components, such as, for example, those of the capacitor bank and high quality factor inductors, are also provided.