US 12278414 B1Patent grantUnited States

Tapered Millimeter-Wave Waveguide Connector

Official patent title

Millimeter wave connection device for rectangular/substrate integrated waveguides

Arabic title: جهاز اتصال بالموجات المليمترية للأدلة الموجية المستطيلة/المدمجة في الركيزة

Invention

Problem

Rectangular waveguides offer high power handling but are expensive and difficult to integrate, while substrate-integrated waveguides are easier to incorporate into circuits. Existing transitions can require case-specific optimization, overlook mode purity, or inadequately address air-filled SIW connections.

Why it matters

Reliable low-loss transitions are enabling components for millimeter-wave communication, radar, sensing, imaging, and test systems that must connect conventional waveguide hardware to planar or multilayer circuits.

Approach

A tapered hollow metallic transition connects RWG apertures to SIW or air-filled SIW apertures. Analytical expressions determine transition length and impedance behavior, while the geometry supports tapered-in or tapered-out configurations, dielectric bridges, and CNC micromachining.

Who may benefit

Potential beneficiaries include millimeter-wave module manufacturers, 5G and WiGig developers, radar and sensor companies, microwave test-equipment suppliers, PCB and waveguide fabricators, and RF research laboratories.

Potential value

One systematic transition concept serves both dielectric-filled and air-filled SIW technologies and specifies impedance, reflection, standing-wave, modal-purity, length, and frequency ranges, reducing reliance on separate case-by-case optimization.

Background

Millimeter-wave systems are expanding in communications, radar, sensors, security imaging, nondestructive testing, and mobile platforms. Rectangular metallic waveguides have strong power handling but can be costly and structurally difficult to integrate. SIW brings waveguide behavior into planar circuit fabrication, while air-filled SIW lowers dielectric loss. These technologies still need interfaces to conventional RWG feeds. Existing transitions are often optimized for a particular geometry and may not explicitly control higher-order modes. The disclosure provides a unified analytical and geometric approach for both SIW variants.

Technology overview

Pairs of tapered hollow metallic structures connect RWG ports to the entrance and exit of an SIW or AFSIW. For 0.2–1.0 mm aperture heights, the claimed transition length is about 1–15 mm. The device operates over roughly 50–75 GHz, with specified impedance, VSWR, reflection coefficient, and dominant versus non-dominant modal levels. An analytical calculation uses waveguide dimensions, characteristic impedances, resonant frequency, and effective dielectric constant to determine a short matching length, after which the part may be CNC micromachined.

Potential applications

5G, WiGig, and other millimeter-wave communication modules.
Automotive and industrial radar front ends.
Millimeter-wave sensing, security imaging, and nondestructive testing.
Waveguide-fed antenna and transceiver assemblies.
High-frequency laboratory and production test fixtures.

Evidence-supported advantages

Uses a unified transition concept for both SIW and air-filled SIW.
Provides an analytical length-selection method instead of only geometry-specific optimization.
Explicitly addresses impedance matching, reflection, standing-wave ratio, and modal purity.
Supports tapered-in and tapered-out geometries and optional dielectric bridges.
Is compatible with CNC micromachining of the metallic transition.

Development stage

Analytical design, full-wave design examples, and simulated performance are described, together with a CNC fabrication route; repeatable measured hardware validation in packaged systems was not clearly established in the supplied evidence. The development stage was not independently verified.

Commercial opportunity

The design may support component licensing, RF-design software integration, or joint development with radar, communications, and test-equipment suppliers. Adoption requires measured prototype data across tolerances and temperature, repeatable fabrication, connector and package integration, reliability testing, and cost comparison with commercial transition technologies.

Patent classifications

WIPO IPC

H01P5/08Waveguides; resonators, lines or other devices of the waveguide type
H01P1/208Waveguides; resonators, lines or other devices of the waveguide type

CPC

H01P5/082Waveguides; resonators, lines or other devices of the waveguide type
H01P1/2088Waveguides; resonators, lines or other devices of the waveguide type
H01P5/024Waveguides; resonators, lines or other devices of the waveguide type

Inventors

First inventorMuhammad Shah Alam
InventorAsif Alam
InventorKhalid Almuhanna

Keywords

rectangular waveguide
substrate integrated waveguide
air-filled SIW
millimeter wave
waveguide transition
impedance matching
modal purity
CNC micromachining

Patent document and drawings

The patent publication is mapped to this record. Patent drawings remain within that publication; no separately cleared public media package has been supplied.