Single-Transistor RF Mixing for LO Leakage and Image Rejection

Solution Overview

Problem

Current wireless communication systems in the 60 GHz frequency range face challenges with LO leakage and image rejection due to mismatch conditions, requiring complex circuit components that occupy significant area and dissipate high power, making them unsuitable for mobile applications.

Innovation Solution

A single transistor is used to mix RF spectra and down-convert signals to detect LO leakage and image rejection, simplifying the design and reducing area and power dissipation by nearly two orders of magnitude, and allowing for the detection of LO leakage and image rejection signals in the desired RF spectrum.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex circuit components (mixer, feedback VCO, filter) are used to detect LO leakage and image rejection, then detection accuracy is improved, but chip area and power dissipation increase significantly

Engineering Contradiction:

Improvedetection accuracyVSAvoidchip area

Core Design Contradiction:

Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent combines the functions of mixer, feedback VCO, and filter into a single transistor device. This merging of multiple circuit components into one element achieves the same detection function while dramatically reducing chip area occupancy and power dissipation by nearly two orders of magnitude

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single transistor is designed to perform multiple functions simultaneously: mixing, frequency conversion, and detection of LO leakage and image rejection signals. This multi-functional approach eliminates the need for separate dedicated components for each function

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If complex circuit components (mixer, feedback VCO, filter) are used to detect LO leakage and image rejection, then detection accuracy is improved, but power dissipation increases significantly

Engineering Contradiction:

Improvedetection accuracyVSAvoidpower dissipation

Core Design Contradiction:

Measurement precisionVSUse of energy by stationary object

Solution Approach 1:

The patent combines the functions of mixer, feedback VCO, and filter into a single transistor device. This merging of multiple circuit components into one element achieves the same detection function while dramatically reducing chip area occupancy and power dissipation by nearly two orders of magnitude

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single transistor circuit is designed to be self-sufficient, performing all necessary detection functions internally without requiring external complex components. The transistor itself provides the mixing, frequency conversion, and detection capabilities needed

Inventive Principle:

Principle #25Self-service

3Difficulty of detecting and measuring

If complex circuit components are used, then detection capability is improved, but device complexity increases

Engineering Contradiction:

Improvedetection capabilityVSAvoidcircuit complexity

Core Design Contradiction:

Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The patent combines the functions of mixer, feedback VCO, and filter into a single transistor device. This merging of multiple circuit components into one element achieves the same detection function while dramatically reducing chip area occupancy and power dissipation by nearly two orders of magnitude

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The detection function is segmented into discrete signal processing steps (mixing, frequency conversion, filtering) that are all performed within the single transistor, allowing for modular analysis and simplified design verification

Inventive Principle:

Principle #1Segmentation

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

This approach significantly reduces chip area and power consumption, enabling more efficient compensation for LO leakage and image rejection, thereby improving signal quality and extending battery life in mobile devices.

Implementation Method 1

the transistor mixes the first signal at the input node with the second signal at the output node generating a mixed signal between the first signal and the second signal at the resultant node

Methodology Applied

Scientific EffectMixing:

Implementation Method 2

A single transistor is used to mix RF spectra and down-convert signals to detect LO leakage and image rejection

Methodology Applied

Scientific EffectDown-conversion:

Data Source

PatentUS9450537B2Method and apparatus to detect LO leakage and image rejection using a single transistor

Publication Date: 2016.09.20 TENSORCOM INC

AI summary

LO leakage and Image are common and undesirable effects in typical transmitters. Typically, thirty complex hardware and algorithms are used to calibrate and reduce these two impairments. A single transistor that draws essentially no de current and occupies a very small area, is used to detect the LO leakage and Image Rejection signals. The single transistor operating as a square law device, is used to mix the signals at the input and output ports of the power amplifier (PA). The mixed signal generated by the single transistor enables the simultaneous calibration of the LO leakage and Image Rejection.