Marc Esquius-Morote

A Printed Transition for Matching Improvement of SIW Horn Antennas

The substrate integrated waveguide (SIW) technology allows to construct several types of commonly used antennas in a planar way. However, frequency limitations associated to commercial substrates appear in the implementation of certain types of antennas, e.g., SIW horn antennas are not well matched when the substrate thickness is much smaller than the wavelength. A printed transition is proposed to overcome this problem. Differently from current solutions, no bulky elements are required allowing to maintain the most important features of this technology namely its compactness and ease of manufacturing. In order to quickly analyze and design the transition, both a coupled resonator and a transmission line models are developed, together with design guidelines. The proposed transition is designed to match a H-plane SIW horn antenna built in a thin substrate

Orthomode Transducer and Dual-Polarized Horn Antenna in Substrate Integrated Technology

({\rm thickness}<\lambda_{0}/10)

Dual-polarized directional antenna with application to polarimetric radar

at different frequency bands at the Ku-band. Experimental results for 3 different transitions show that the matching characteristics are efficiently improved compared with the conventional SIW horn antenna and validates the proposed models.

A planar feed for SOTM Ka-band lens antennas

A dual-polarized system fully implemented in substrate integrated technology is presented. It comprises an orthomode transducer (OMT) with planar excitation schemes for both orthogonal TE10- and TE01-modes and a dual-polarized horn antenna. The whole structure requires only two layers of substrate, and it is based on the extended substrate integrated waveguide (ESIW), which allows the propagation of TEm0- and TE0n-modes. A compact OMT design is proposed along with a procedure to optimize it. The matching and radiation characteristics of a dual-polarized horn antenna fed with this OMT are also studied. The complete structure was manufactured exhibiting an 8.6% bandwidth (13.9-15.15 GHz) where both modes are well matched ( <; -10 dB ) and isolated ( > 28 dB). The horn radiation patterns within the frequency range of operation are also similar for both polarizations. The proposed design demonstrates the feasibility of dual-polarized substrate integrated circuits (SICs). This opens the door to new substrate integrated devices as well as to the use of SICs in applications requiring polarization diversity at end-fire. All together, this combined design becomes a promising approach to tackle the increasing demand for capacity in modern communication systems.

Low-profile direction finding system with SIW horn antennas for vehicular applications

We propose a one-dimensional leaky-wave antenna (LWA) fed by two ports which radiates two orthogonally polarized beams corresponding each one to a port. The structure is based on a simple metallic rectangular waveguide whose top surface is drilled with crossed-slots. The waveguide allows the propagation of both the TE10 and the TE01 modes, each one carrying the energy injected by each of the ports. The crossed-shape of the slots has been chosen in order to induce radiation from both modes while preserving their orthogonality. Hence, the antenna cross-polarization levels are kept below -30 dB. This property, together with the inherent frequency scanning capabilities of LWAs, make this one-dimensional antenna a promising candidate to construct two-dimensional arrays suitable for polarimetric radars.

Gain enhanced H-plane gap SIW horn antenna with phase correction

Ka-band satellite technology has been drawing growing interest from public transportation industry to military applications, due to its advantages of higher speed links, smaller terminals and reduced costs. These well-recognized characteristics have also boosted the interest in exploiting the Ka-band devices for personal use in small boats or all-terrain vehicles. This paper presents a simple, low-cost and compact mobile ground terminal antenna useful for satellite communications on-the-move (SOTM) applications. The system operates in the downlink Ka band (19.7 - 20.2 GHz). It consists of a shaped dielectric lens fed by a circularly polarized (CP) patch antenna. The lens system allows a mechanical beam steering from 0° to 57° in relation to the zenith, with a scan loss below of 4.5 dB. A comparison is provided between this system and a previous one using the same lens but fed by a horn antenna, demonstrating the potential of planar structures as low profile feeders for SOTM lens antennas.

A new type of printed Ku-band SIW horn antenna with enhanced performances

A fully operational low-profile direction finding system working in Ku-band is presented. In particular, a circular array of 8 SIW horn antennas is used to provide a full 360° coverage of the azimuthal plane. The antennas are interconnected with commercial MMICs and driven by a microcontroller to estimate the direction of arrival. Thanks to the SIW technology, the antenna array and hence the whole system is low-profile, lightweight and low cost, therefore being suitable to be flush-mounted in airborne or terrestrial vehicles. The proposed concept is not only limited to direction finding operations, but also feasible for more ambitious applications requiring high data rate transmissions.