Feeder Circuit Simplification Using Inverted Coupler Connections

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Solution Overview

Problem

The existing feed circuit for multibeam antennas is complicated due to crossing connecting lines, which are necessary to input signals to different input terminals of septum polarizers, leading to a complex circuit configuration when circularly polarized beams with different rotation directions are used in overlapping multibeams.

Innovation Solution

A feed circuit configuration using a first and second polarizer, a first and second two-way distributor, and a third coupler, where the third coupler outputs signals from the two-way distributors to the polarizers' input terminals, avoiding the need for crossing connecting lines and simplifying the circuit arrangement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If connecting lines are arranged to input signals to different input terminals of septum polarizers for adjacent multibeams, then circularly polarized beams with different rotation directions can be radiated, but the connecting lines cross each other requiring detour arrangements

Engineering Contradiction:
Improvecapability to radiate circularly polarized beams with different rotation directionsVSAvoidcomplexity of connecting line arrangement
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies inversion by swapping the connection assignments: instead of connecting coupler outputs directly to septum polarizer inputs in the conventional manner, the patent connects the output of the first coupler to the second input terminal of the second septum polarizer, and the output of the second coupler to the first input terminal of the first septum polarizer. This inverted connection scheme eliminates the crossing of connecting lines while maintaining the capability to radiate circularly polarized beams with different rotation directions from adjacent multibeams.

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of operation

If conventional feed circuit configuration is used with crossing connecting lines, then signal distribution to radiating elements is achieved, but the circuit configuration becomes complicated

Engineering Contradiction:
Improvesignal distribution capabilityVSAvoidcircuit configuration complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent simplifies the circuit configuration by inverting the conventional connection topology. Specifically, it establishes direct connections between coupler outputs and the cross-assigned septum polarizer input terminals without requiring detour paths. This inverted arrangement maintains full signal distribution capability to all radiating elements while eliminating the complexity of crossing connecting lines and their associated detour arrangements.

Inventive Principle:
Principle #13The other way round (Inversion)

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 configuration allows for a simple circuit configuration and enables the use of polarized beams with different directions in overlapping multibeams without the need for detouring connecting lines, improving the antenna's design and functionality.

Implementation Method 1

Septum polarizers output a circularly polarized signal with a rotation direction which differs between when a signal is inputted to the first input terminal and when a signal is inputted to the second input terminal

Methodology Applied
Scientific EffectCircular polarization: Polarisation

Implementation Method 2

Each coupler has four terminals, and two of these terminals are connected to the two input terminals of a septum polarizer disposed for each radiating element, respectively. Further, in each coupler, a signal inputted from one terminal is outputted from two terminals, and the ratio of amplitudes of output signals is determined by a designed degree of coupling. The phase difference between the output signals is 90 degrees.

Methodology Applied
Scientific EffectSignal coupling: Waveguide

Data Source

PatentEP3379640B1Feeder circuit and antenna device
Publication Date: 2020.02.19 MITSUBISHI ELECTRIC CORP
  • EP3379640B1 patent drawingFigure 1A~1B
  • EP3379640B1 patent drawingFigure 2A~2B
  • EP3379640B1 patent drawingFigure 3A~5B

AI summary

A third coupler (3c) outputs a signal outputted from a first coupler (3a) to an input terminal (8-1) of a second septum polarizer (8b), and outputs a signal outputted from a second coupler (3b) to an input terminal (8-2) of a first septum polarizer (8a).