Dielectric Loaded Horn Antenna Research Articles

Smooth-Walled Light-Weight Ka-Band Shaped Horn Antennas in Metallized Foam

Several smooth-walled axis-symmetrical dielectric-loaded horn antennas with large flare angles have been designed and characterized in Ka-band. They have been optimized using an in-house CAD tool based on the BoR-FDTD technique and genetic algorithms. Two antenna configurations have been compared: in the first case, only the metallic profile of the horn is shaped and the radiating aperture remains flat, whereas in the second one, the shapes of the horn profile and the aperture are simultaneously optimized. The impact of both techniques in terms of antenna size and performance is discussed. An original fabrication process (metallized foam) has been developed to produce monolithic prototypes. Two prototypes with optimized shapes have been fabricated, and their main characteristics (radiation characteristics, bandwidth, compactness, weight) are compared to those of a standard conical horn used as a reference (same flare angle, same diameter, but without shaped profile). Our results show that the proposed design and fabrication procedures enable us to produce reduced-size horns with high radiation efficiency; the total loss, including the transition loss, is lower than 1 dB in average around 29.5 GHz.

Lens-Corrected Axis-Symmetrical Shaped Horn Antenna in Metallized Foam With Improved Bandwidth

A lens-corrected smooth-walled axis-symmetrical dielectric-loaded horn antenna is designed and characterized in Ka-band using the bodies of revolution finite-difference time domain (BoR-FDTD) technique and genetic algorithm. The joint optimization of the horn and dielectric loading profiles enables us to develop a horn with a very good gain performance achieved in a frequency range of about 18%. Compared to earlier results, the bandwidth improvement exceeds a factor two. A lightweight prototype is fabricated in metallized foam. A very good agreement between the numerical and measured data is obtained.

8 mm Passive Focal Plane Image System

Abstract A 8 mm passive focal plane image system which could be applied for airplane ils was introduced in this paper. System parameters were designed for this special purpose. Since high gain must be obtained based on limited feed antenna's aperture, dielectric-loaded horn antenna was designed as the feed of parabolic reflector antenna to receive the power radiated from the object. 8 mm direct detector receivers were connected directly to the feed horn antennas to avoid undesirable blockage. From the imaging results, the concrete buiding could be distinguished easily from the sky in the passive millimeter wave image.

8 mm Passive Focal Plane Image System

A 8mm passive focal plane image system which could be applied for airplane ils was introduced in this paper. System parameters were designed for this special purpose. Since high gain must be obtained based on limited feed antenna's aperture, dielectric-loaded horn antenna was designed as the feed of parabolic reflector antenna to receive the power radiated from the object. 8mm direct detector receivers were connected directly to the feed horn antennas to avoid undesirable blockage. From the imaging results, the concrete buiding could be distinguished easily from the sky in the passive millimeter wave image.

Integrated lens with dielectric horn antenna

A dielectric lens is integrated into a dielectric loaded horn antenna to produce a high efficiency feed for reflectors. The lens is designed using simple ray theory and analysed using modal matching techniques. Aperture efficiencies of up to 78% are achieved while retaining good crosspolar performance.

New types of dielectric-loaded horn antennas

This paper presents low-loss dielectric loading techniques for improving some of the radiation characteristics of H-plane horn antennas. Specifically, the paper reports experimental results over new horns loaded with dielectric in the transverse and longitudinal planes with and without air gaps between the dielectric layers or between the dielectric and metallic walls. Sample results are presented showing improvements in the beam width, axial gain, input voltage standing wave ratio (VSWR) at the expense of new or increased side lobe level at some frequencies within the passband. Results are also presented to show that the main beam of a novel dielectric-loaded horn can almost be scanned from one wall of the horn to the other in synchronism with frequency sweep within the passband. Finally, a line-of-sight portable communication device employing the characteristics of dielectric-loaded horn antennas is proposed for further research and development.

Radiation characteristics of dielectric-loaded horn antennas

The radiation characteristics of electromagnetic horns loaded with curved transverse dielectric slabs and radial dielectric strips are investigated experimentally. It is shown that the axial directivity and halfpower beamwidth of horn antennas may be significantly improved with such schemes of dielectric loading.