Current-Mode RF Frequency Translation with Shared Bias Current

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Solution Overview

Problem

The integration of room temperature electronics with cryogenic quantum circuitry faces challenges such as power dissipation and noise interference, limiting the efficiency and reliability of quantum computing systems.

Innovation Solution

A radio frequency (RF) transmission circuit with a series stack configuration, including a current-mode mixer, attenuator, and matching network, which shares a bias current to reduce power consumption and enhance efficiency, while operating transistors in specific regions for improved performance and linearity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If room temperature electronics are integrated with cryogenic quantum circuitry, then control and readout functionality is provided, but power dissipation and noise interference increase

Engineering Contradiction:

Improvecontrol and readout functionalityVSAvoidpower dissipation

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The patent transitions from voltage-mode operation to current-mode operation, fundamentally changing the dimensional approach to signal processing. This current-mode architecture enables direct coupling between room temperature control electronics and cryogenic quantum circuits, providing control and readout functionality while minimizing power dissipation and noise interference through the inherent properties of current-mode signaling at cryogenic temperatures

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If multiple circuit blocks are powered by separate bias currents, then each block can be independently optimized, but total power consumption increases

Engineering Contradiction:

Improveindependent optimization capabilityVSAvoidtotal power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent merges multiple separate bias current sources into a single shared bias current that powers the input stage, mixer, and output stage simultaneously. This unified current-mode architecture maintains the ability to independently optimize each circuit block's performance while dramatically reducing total power consumption by eliminating redundant bias current paths and leveraging the shared current resource across all stages

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single bias current serves multiple functions simultaneously, powering the input stage, the mixer, and the output stage. This universal current source approach enables one current to fulfill multiple roles, reducing the total number of power sources needed while maintaining independent optimization capability for each functional block through current-mode signaling advantages

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If transistors operate in non-optimal regions, then circuit design is simplified, but performance metrics such as gain, linearity, and noise deteriorate

Engineering Contradiction:

Improvecircuit design simplicityVSAvoidperformance metrics

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent systematically changes the operating parameters of transistors across different stages to optimize performance. The input stage transistors operate in saturation region for high gain and low noise, mixer transistors switch between cutoff and triode regions for efficient frequency conversion, and output stage transistors operate in saturation for high linearity. These parameter changes enable each block to achieve optimal performance metrics while maintaining current-mode architecture benefits

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11539347B1Current-mode frequency translation circuit with programmable gain

Publication Date: 2022.12.27 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

A radio frequency (RF) transmission circuit includes an input stage, a current-mode mixer coupled to an output of the input stage, an attenuator coupled to an output of the current-mode mixer, and a matching network coupled to an output of the attenuator. The input stage, current-mode mixer, attenuator, and the matching network are configured in a series stack.