CMOS Tuner Front-End Filter with External Inductor Integration
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Solution Overview
Problem
Conventional tuners have large volumes and high supply voltage requirements due to varactors, and silicon tuners, while more compact, are costly to produce and compromise on filtering quality due to cost considerations in implementing front-end filter circuits.
Innovation Solution
A tuner design with partial or all components packed in a silicon chip, utilizing a transformer and differential amplifier with a varactor and inductor to achieve high filtering quality while reducing production costs, where the inductor can be either internally or externally connected to the chip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional CAN tuner is used, then the filtering quality can be maintained, but the volume is large and the supply voltage requirement is high
Solution Approach 1:
The patent replaces the conventional CAN (Canopus Analog to Digital Converter) tuner architecture with a silicon-based CMOS implementation. This substitution transitions from a mechanical/electronic hybrid system to a fully integrated semiconductor system, achieving miniaturization while maintaining filtering performance through careful circuit design including differential amplifiers and trace filters.
Solution Approach 2:
The patent integrates multiple discrete components including the differential amplifier, trace filter, varactor, and surrounding circuitry onto a single silicon chip. This merging of previously separate components into one integrated circuit achieves volume reduction while preserving the individual functions necessary for high-quality signal filtering.
2Volume of moving object
If a silicon tuner is manufactured by BJT manufacturing process, then the volume is reduced and supply voltage is lowered, but the production cost increases and area is large
Solution Approach 1:
The patent changes the manufacturing process parameter from BJT (bipolar junction transistor) to CMOS (complementary metal-oxide semiconductor). This parameter change in the fabrication process enables smaller device area, lower production cost, and reduced supply voltage requirements while maintaining the miniaturized form factor of the silicon tuner.
3Ease of manufacture
If three front-end filter circuits are implemented in one single chip by capacitors and inductors, then the cost is reduced, but the filtering quality is sacrificed
Solution Approach 1:
The patent extracts the inductors from the integrated circuit chip and implements them as external discrete components. This extraction allows the use of high-quality external inductors for the front-end filter circuits while keeping the cost-effective CMOS chip for the active circuitry, thereby achieving both cost reduction and high filtering quality.
Solution Approach 2:
The patent segments the filter circuit into two parts: the active components (amplifiers, capacitors, control logic) remain on the integrated CMOS chip, while the passive inductive components are implemented externally. This segmentation allows optimization of each part separately - integrated circuits for cost and active performance, discrete components for filtering quality.
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, low-cost tuner with improved filtering quality by using a CMOS chip to house the differential amplifier and varactor, and externally connecting inductors, thus reducing production costs while maintaining high filtering performance.
Implementation Method 1
The transformer converts a single-end signal into a differential signal
Implementation Method 2
the tuner implements a trace filter with a capacitive/inductive filter as to select a desired frequency, with a capacitor of the trace filter being a varactor
Data Source
AI summary
A tuner includes a plurality of paths, and at least one of the paths includes a front-end filter circuit, an amplifier, and a trace filter. The trace filter includes a varactor and an inductor, which are coupled to an output end of the amplifier. Further, the amplifier and the varactor of the tuner are packed in a complementary metal-oxide semiconductor (CMOS) chip.