Broadband Gain Equalizer for Flat Delay Line Response

Solution Overview

Problem

Electronic circuits used in microwave frequency ranges face challenges such as varying insertion loss and impedance mismatch across a wide frequency range, leading to pulse distortion and instability in broadband applications.

Innovation Solution

Incorporating a gain adjustment circuit with a negative-slope or positive-slope gain equalizer to compensate for insertion loss variations between selectable delay paths, ensuring a relatively constant time-domain delay and reduced dispersion across a specified frequency range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a wide frequency range (broadband) is used, then the operating bandwidth is improved, but insertion loss varies substantially across the frequency range

Engineering Contradiction:

Improveoperating bandwidthVSAvoidinsertion loss variation

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by introducing a gain equalization circuit that dynamically adjusts the gain parameter across different frequencies. The circuit modifies the insertion loss characteristic by applying frequency-dependent gain compensation, transforming the substantially varying insertion loss into a flattened response across the broadband frequency range. This allows the system to maintain consistent signal levels while operating over a wide bandwidth.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If delay lines are used for phase shifting, then the phase control function is improved, but pulse distortion increases due to dispersion

Engineering Contradiction:

Improvephase control functionVSAvoidpulse distortion

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful effect of dispersion into a benefit by using the gain equalization circuit to compensate for the frequency-dependent loss introduced by delay lines. The circuit measures or calculates the dispersion characteristics and applies inverse gain compensation, transforming the pulse distortion problem into a solved condition. The delay lines continue to provide phase control while the gain equalization neutralizes their dispersive effects.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Stability of the object's composition

If impedance matching is improved, then signal stability is improved, but frequency-dependent losses increase

Engineering Contradiction:

Improvesignal stabilityVSAvoidfrequency-dependent losses

Core Design Contradiction:

Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by introducing a gain equalization circuit that dynamically adjusts the gain parameter across different frequencies. The circuit modifies the insertion loss characteristic by applying frequency-dependent gain compensation, transforming the substantially varying insertion loss into a flattened response across the broadband frequency range. This allows the system to maintain consistent signal levels while operating over a wide bandwidth.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10715361B1Delay compensation using broadband gain equalizer

Publication Date: 2020.07.14 ANALOG DEVICES INT UNLTD CO

AI summary

An electronic circuit can include a gain adjustment circuit (e.g., a gain “equalizer” circuit), such as to compensate for a variation in insertion loss over a specified range of frequencies. For example, such a gain adjustment circuit can provide an insertion loss characteristic having a specified slope. Such a slope can include a positive slope where insertion loss increases with respect to frequency, or a negative slope where insertion loss decreases with respect to frequency, as illustrative examples. A gain equalization technique can be used to compensate for variation in insertion loss versus frequency between different circuit paths, such as in relation to a switchable delay line having two or more selectable paths, such as for phase shifting applications. A gain adjustment circuit can be configured to provide relatively flat or constant time-domain delay versus frequency, such as inhibiting or reducing dispersion.