Simple configuration and broadband characteristic are required for RF module in passive millimeter-wave imaging. We propose a layer-structured imaging module for simple structure, low profile and easy manufacturing [1]. This module is composed of lens antenna and detector module as shown in Fig.1. Lens and feeding horn antenna are designed to realize high-gain lens-antenna which operates over b...

High-gain and low-profile antennas are required for high-speed wireless communication systems and mechanically-scanning automotive radars in the millimeter-wave band. Waveguide antenna is one of the most attractive planar antennas for such millimeter-wave systems because of its low loss and high efficiency characteristics in high frequency band. Travelling-wave excitation is more effective for ...

Millimeter-wave technologies are expected to realize broadband high-speed wireless communication systems for home server and HD video transmission. Multi-layer substrate such as LTCC configuration is well-known to integrate many RF-circuits into small area of the substrate [1]. We have already been developed broadband microstrip-to-waveguide transitions composed of a substrate and metal parts [...

In this paper, we propose low-loss and broadband terahertz (THz) waveguide-to-coupled microstrip transitions using dipole antenna with directors. The simulation and measurement show that insertion/return loss and bandwidth of the waveguide transition can be improved by adding two directors to the basic dipole antenna. The fabricated transition with two directors on a 50 μm-thick quartz substrat...

INTRODUCTION A SAR-probe is usually calibrated using a rectangular waveguide with a matching dielectric spacer below 3 GHz [1, 2]. However, the probe diameter is comparable with the aperture size of the waveguide above 3 GHz, and it can deteriorate the accuracy of the calibration. Therefore, an alternative calibration method using a reference antenna in the phantom liquid has been examined [3]....

A planar magnetoinductive (MI) waveguide loaded rectangular microstrip patch antenna is presented and discussed. The MI waveguide consists of two planar metamaterial split squared ring resonators (SSRRs) placed in between two microstrip lines. The backward wave propagation takes place through this structure. The rectangular microstrip patch antenna is magnetically coupled to the MI waveguide. T...

Matching circuits for waveguide-nanoantenna connections are difficult to implement. However, if the waveguide permits only one-way propagation, the matching issue disappears since back-reflections cannot take place; the feed signal is converted to radiation at high efficiency. Hence, a terminated one-way waveguide may serve as an assembly consisting of a waveguide, a matching mechanism, and an ...

Effective propagation of electromagnetic (EM) waves has a wide variety of applications. Here we study the practical requirements necessary for maximizing the bandwidth of frequencies in general Co-axial waveguide structures and also maintain mode purity. In this regard, well known antenna array design is verified using Numerical Simulations. Further these antenna designs were optimized for effi...

A single-layer waveguide slot array antenna of low cost and high performance for a millimetre-wave wireless communication system at 38 GHz frequency band is presented. The waveguide slots and diaphragms are located together on the cover plate of the antenna, which makes the antenna cost effective and highly efficient. Measurements show a cross-polarisation level below 26 dB and an efficiency le...

1. Introduction Leaky-wave antennas based on an open-waveguide structure can become a candidate of millimeter-wave antennas. Since such a structure is already open, leakage is produced by introducing not a physical cut, but asymmetry of the structure. As a result, it supports a leaky mode (instead of a bound mode) and therefore radiates all along its length, possess flexibility in beamwidth and...