This paper is to demonstrate the potential and realizability of a high-performance waveguide slot antenna. A double-layer slotted waveguide array with a partially corporate feed circuit installed in the bottom layer is proposed and designed in 38GHz band to realize broadband characteristics. For the antenna realization, a diffusion bonding of laminated thin plates is introduced as the fabricati...

Circularly-polarized antenna is built based on a new SIW (substrate integrated waveguide)structure which contains cavity-backed resonator and a conventional polarized ring with twosquare slits in inner and outer ring that differ 90° at position and is proposed for right-handedcircular polarization (RHCP) and fabricated in two separate layers. A broadband impedancebandwidth of 13.9% and a RHCP a...

Microwave-frequency signals are conveyed by using the Microstrip antennas. It is capable of dual and triple frequency operations and has light weight and low cost. Similarly, larger bandwidth can be achieved by Coplanar Waveguide (CPW) structure. Gain can be enhanced using the Defected Ground Structure (DGS). This paper presents the performance comparison of the design of a microstrip antenna a...

question I am frequently asked is, “Why do the antenna dimensions in the W1GHZ Microwave Antenna Book — Online not include the probe dimensions (for the transition from waveguide to coaxial transmission line)?” The answer is that the transition is part of the transmission line, not the antenna, and does not directly affect the performance of an antenna. The transition may be right at the antenn...

The plate-laminated waveguide slot array antenna is a high-efficiency and wide-band antenna in the millimeterwave band. However, in the conventional corporate-feed circuit, the number of radiating elements is limited to be a power of two by using a cascade of T-junctions. In this paper, we propose the corporate-feed with a cross junction and an asymmetric Tjunction for 12×16 elements. The bandw...

It has been demonstrated recently that it is possible to guide broadband terahertz pulses utilising a novel coaxial waveguide. This technique is hindered by the difficulty in exciting the radially polarised fundamental mode of the waveguide. To optimise mode matching, a novel radially symmetric photoconductive terahertz antenna is proposed. Using finite element method simulations and analytical...

Possibilities for the extension of the operational frequency band of slotted waveguide antennas are studied. It is shown that by using both conventional longitudinal slots and subarraying techniques it is possible to reach the relative bandwidth of about 15%. This result is illustrated by the development of a novel slotted waveguide antenna for high-resolution SAR applications. The antenna oper...

This dissertation focuses on designing, fabricating and testing antennas that are suitable for operation within the V/W bands. In particular, this work focuses on the design of slotted rectangular waveguide antenna arrays and cross slotted waveguide fed horn antennas. These structures are known for their high efficiency and high circularly polarized gain that can be implemented in satellite and...

The TM0 surface mode in an infinitely long parallel-plate waveguide filled with a double-positive (DPS) and epsilon-negative (ENG) metamaterial bi-layer is studied. With proper constitutive parameters and thicknesses of the two layers, the slow-wave factor (SWF) for such a parallel-plate waveguide can tend to infinity as the frequency decreases. A 2-D cavity based on the DPS-ENG bilayer wavegui...

A low-cost short-range K-band Doppler radar sensor for traffic control applications has been developed. The compact sensor, including a waveguide front-end module and a planar patch antenna, weighs only 0.1 lb. The module incorporates a Gunn oscillator, a mixer and a simple coupling/duplex configuration; the antenna is realized on a 0.031” thick Rogers 4003 laminate to allow its stand alone ope...