Ultra-Wideband Phased Array Antenna with Integrated Marchand Balun

Solution Overview

Problem

Existing compact scanning phased array antenna designs face challenges in achieving wide bandwidths while maintaining a low profile, as traditional baluns are bulky and increase the size, weight, and cost of the array, and existing solutions that mitigate common mode resonances result in reduced bandwidth.

Innovation Solution

Incorporating a compact Marchand balun as an impedance matching network within the array substrate, eliminating the need for external baluns and providing a standard 50 ohm unbalanced feed, which enhances bandwidth and reduces size and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional external baluns are used to feed dipole elements in TCDAs, then the array can achieve good scan performance and low cross polarization, but the size, weight, and cost of the array significantly increase

Engineering Contradiction:

Improvescan performanceVSAvoidarray weight

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent combines the balun and impedance matching network into a single integrated structure that is printed directly on the substrate beneath each dipole element. This merging eliminates the need for separate external baluns and matching networks, significantly reducing the overall size and weight of the array while maintaining the required scan performance and low cross-polarization characteristics

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated balun structure serves multiple functions simultaneously: it acts as a balun to convert between balanced and unbalanced signals, provides impedance matching between the 50-ohm feed line and the dipole elements, and serves as part of the ground plane structure. This multi-functionality reduces the number of separate components needed, thereby reducing weight and complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Volume of stationary object

If passive baluns are designed to fit within the limited unit cell volume, then the array size is reduced, but the bandwidth decreases to less than 2:1

Engineering Contradiction:

Improveunit cell volumeVSAvoidbandwidth

Core Design Contradiction:

Volume of stationary objectVSDuration of action of stationary object

Solution Approach 1:

The patent merges the balun and impedance matching network into a single integrated structure printed on the substrate. This combination allows the design to achieve both compact size and wide bandwidth by optimizing the interaction between the balun arms and the matching network components, eliminating the trade-off that exists when these functions are separated

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent employs parameter optimization in the design of the integrated balun and matching network, including adjusting the dimensions, positions, and geometries of the conductive traces on the substrate. By carefully tuning these parameters, the design achieves both compact footprint and wide bandwidth operation

Inventive Principle:

Principle #35Parameter changes

3Volume of stationary object

If vias are used to mitigate common mode resonances instead of baluns, then the array size is reduced, but the bandwidth is limited to 3:1 or 5:1 with additional external baluns

Engineering Contradiction:

Improvearray volumeVSAvoidbandwidth

Core Design Contradiction:

Volume of stationary objectVSDuration of action of stationary object

Solution Approach 1:

The patent combines the balun and impedance matching network into a single integrated structure that is printed directly on the substrate beneath each dipole element. This merging eliminates the need for separate external baluns and matching networks, significantly reducing the overall size and weight of the array while maintaining the required scan performance and low cross-polarization characteristics

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated balun structure serves multiple functions simultaneously: it acts as a balun to convert between balanced and unbalanced signals, provides impedance matching between the 50-ohm feed line and the dipole elements, and serves as part of the ground plane structure. This multi-functionality reduces the number of separate components needed, thereby reducing weight and complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9865934B2Ultra-wideband extremely low profile wide angle scanning phased array with compact balun and feed structure

Publication Date: 2018.01.09 THE OHIO STATES UNIV

AI summary

A phased array antenna comprising a dielectric superstrate material, a ground plane material, a plurality of dipole structures located between the superstrate and ground plane materials, and a plurality of balun and matching networks in electrical communication with the plurality of dipole structures, wherein the phased array antenna is adapted to achieve a bandwidth of at least about 7:1.