GaAs MMIC Interconnection Selection for Yield Optimization

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Solution Overview

Problem

The high cost and lower yield of GaAs fabrication for integrated MMIC circuits, particularly in microwave wireless communication systems, lead to increased production costs and reduced efficiency due to the inherent expense and yield issues of GaAs-based fabrication processes.

Innovation Solution

A method for forming an integrated circuit where the interconnection between a mixer and an amplifier is selected based on the characteristics determined during the fabrication process, allowing the circuit to function either as a transmitter or receiver, thereby optimizing the use of suitable amplifier/mixer combinations and increasing the yield of usable dies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If GaAs fabrication process is used to form integrated MMIC circuits, then gain and noise figure performance is improved, but manufacturing cost increases and yield decreases

Engineering Contradiction:

ImproveperformanceVSAvoidyield

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent changes the functional parameter of the amplifier/mixer combination by selecting different interconnection configurations (transmitter vs receiver mode) based on fabrication outcomes. This allows the same physical structure to serve different functions, effectively converting potential defects into acceptable variations and improving yield without compromising performance requirements.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If GaAs fabrication process is used to form integrated MMIC circuits, then gain and noise figure performance is improved, but manufacturing cost increases

Engineering Contradiction:

ImproveperformanceVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If interconnection is predetermined before fabrication, then circuit function is determined, but yield of usable dies decreases due to process variations

Engineering Contradiction:

Improvecircuit functionVSAvoidyield

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The patent introduces dynamic selection of circuit function after fabrication by providing multiple interconnection paths that can be selectively activated. The circuit transitions from a static predetermined function to a dynamic configurable function based on measured characteristics, allowing adaptation to process variations and improving die yield.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Inventive Principle:

Principle #35Parameter changes

4Ease of manufacture

If amplifier and mixer are integrated on single chip, then production is simplified and costs reduced, but interconnection flexibility is limited

Engineering Contradiction:

Improveproduction simplicityVSAvoidinterconnection flexibility

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent makes the integrated circuit universal by enabling the same amplifier/mixer combination to function as either a transmitter or receiver based on interconnection selection. Multiple functional modes are integrated into a single chip design, providing versatility without compromising manufacturing simplicity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS7787838B2Integrated circuit, and an arrangement and method for interconnecting components of an integrated circuit

Publication Date: 2010.08.31 COMS IP HOLDINGS LLC

AI summary

A monolithic substrate contains an integrated circuit comprising an amplifier having input and output, a mixer and a hybrid coupler for coupling the amplifier to the mixer. Metallic pads on the substrate are connected to each of two ports of the coupler and separate metallic pads are also connected to each of the input and output of the amplifier. The metallic pads allow the amplifier and mixer to be separately tested by a probe and the input or the output of the amplifier to be selectively connected to the mixer to enable the circuit to operate either as a receiver or transmitter. Alternatively, connections between the mixer and both input and output of the amplifier may be preformed and one of the connections subsequently severed depending on whether the circuit is to operate in receive or transmit mode.