Compact Tunable Filter Using Bond Wire Inductors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tunable filters face challenges in achieving compact size, high performance, and low production cost, with limitations in tunability, size, Q-factor, and cost associated with previous technologies such as fixed capacitors, bulk acoustic wave resonators, discrete air coils, and dielectric block resonators.
Innovation Solution
A tunable filter design utilizing voltage tunable dielectric capacitors integrated onto a single MgO chip with bond wires serving as inductors, providing inductive coupling between resonators, and using microstrip traces as coupled inductors for a compact, high-performance package with enhanced IP3 performance and noise rejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If discrete air coils are used as inductors, then inductance can be achieved, but the device size becomes large and Q-factor decreases
Solution Approach 1:
The patent merges the inductor function into the bond wires that connect the capacitors, eliminating the need for separate discrete air coil inductors. The bond wires serve dual purposes: mechanical connection and inductive coupling, thereby reducing device size while maintaining acceptable Q-factor through optimized wire geometry and positioning.
Solution Approach 2:
The bond wires perform multiple functions: they provide mechanical support for mounting the capacitors and simultaneously serve as inductors for the filter circuit. This multi-functionality eliminates the need for separate inductor components, reducing overall device size and component count.
2Volume of moving object
If voltage tunable dielectric capacitors are integrated onto a single chip, then device size is reduced and cost is lowered, but manufacturing precision requirements increase
Solution Approach 1:
Multiple voltage tunable dielectric capacitors are integrated onto a single substrate, reducing the overall device size and component count. The integration process uses standardized mounting techniques that balance precision requirements with manufacturing feasibility.
Solution Approach 2:
The capacitor values and geometric parameters are optimized during design to achieve the desired filter characteristics while accommodating manufacturing tolerances. By carefully selecting capacitor dimensions and spacing, the design achieves robust performance that is tolerant to typical manufacturing variations.
3Device complexity
If bond wires are used as inductors, then device complexity is reduced, but inductive coupling control becomes more challenging
Solution Approach 1:
The inductive coupling characteristics are optimized by controlling the local geometry and positioning of the bond wires. By adjusting wire length, diameter, and spacing between capacitors, the coupling strength can be tailored for each specific filter application, providing adequate control despite the simplified structure.
Solution Approach 2:
The inductive coupling between bond wires is made tunable through the voltage-tunable dielectric capacitors. By changing the capacitance values electrically, the resonant frequencies and coupling characteristics of the filter can be adjusted dynamically, providing operational flexibility.
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 enables a compact, high-performance tunable filter with improved noise rejection and intermodulation performance, achieving a high Q-factor and low component count while reducing production costs.
Implementation Method 1
bond wires connecting voltage tunable dielectric capacitors to an RF ground and serving as inductors, wherein inductive coupling between the plurality of bond wires serve as coupling between resonators
Implementation Method 2
voltage tunable dielectric capacitors may be integrated onto a single MgO chip
Data Source
AI summary
An embodiment of the present invention provides an apparatus, comprising a tunable filter with a plurality of bond wires connecting voltage tunable dielectric capacitors to an RF ground and serving as inductors, wherein inductive coupling between the plurality of bond wires serve as coupling between resonators within the tunable filter. The voltage tunable dielectric capacitors may be integrated onto a single MgO chip thereby providing a complete set of tunable capacitors for a filter circuit in a low cost, compact package.