Dual-Polarized Corrugated Horns for Advanced Measurement Applications

Abstract

Recent advances in the design of orthomode junctions (OMJs) have created new devices capable of achieving as much as a 1:4 bandwidth, while maintaining the high performance of traditional OMJ designs [1][2][3][4][5][6]. The new OMJ technology is based on an inverted-ridge structure, with four symmetrical feeding points for external balanced feeding, stabilizing the frequency dependence of the OMJ.Probes with one or more corrugations on the aperture can greatly enhance the radiated performance in terms of return loss, pattern symmetry, stability with frequency, and minimizing the cross-polar levels within the main beam of the probe. In the standard corrugated-horn literature [7], the upper limit on achievable bandwidth for corrugated horns is often stated to be somewhere between a ratio of 1: 1.5 to 1: 1.8, depending on the performance requirements. New strategies in corrugated-horn design and optimization are therefore required in order to take advantage of the increased bandwidth of the wide band OMJ technology. This paper discusses the achievable performance and limitations of wideband probes with multiple corrugated apertures. It shows measured and predicted design examples of apertures covering up to 1:2 bandwidth in the L-to Ka-band range.

UTD-PO Radiation Pattern Analysis of Rectangular Horn Antennas With Cylindrical Corrugations

“…which is the term that represents the field of both the contributions and , and is a reflection coefficient for hard/vertical polarization for positive incidence over the cylinders: (4) where is the so-called transition function, which is defined in terms of a Fresnel integral, is the Fock scattering function for hard polarization [18], and (5) where (6) and (7) Moreover, , which is the relative amplitude of the incident plane wave, is the wave number, and and form the first cylinder over which the formulation presented in [17] for the evaluation of the multiple diffraction of a plane wave by a series of cylinders is applied-assuming a positive incidence angle (lit region), which implies the calculation of both and .-Furthermore, the second term of (2) can be calculated as (8) where , is the above-mentioned reflection coefficient for hard/vertical polarization given by (4), where in this case (9) and (10) and and are assumed to be the same point, with (11) where is the diffraction coefficient for an edge given in [19], is the length of the faces of the horn, is the half-angle of the aperture of the horn, and (12) In this case, in order to evaluate , one first diffraction at the edge of the end of the lower arm of the horn is considered, ( and are approximated by the same point, as occurs in the case of a non-corrugated horn), therefore obtaining the field existing over the subsequent cylinder . Then, the remaining multiple-cylinder diffraction is calculated by considering a grazing incidence over the cylinders, since the direct ray was already considered in (3), where the smaller angle of incidence makes the effect of the multiple diffraction much more relevant than that arising at the array of corrugations of the lower arm of the horn, where the angle of incidence is greater (13) with (14) where is the diffraction coefficient for hard/vertical polarization for negative incidence over the cylinders (shadow region): (15) with (16) where (17) and…”

“…But the traditional LPDA antennas are difficult to integrate with planar circuits, and therefore not suitable for mass-production, especially at millimeter-wave frequencies. In order to be compatible with modern planar systems, the LPDA antenna implemented based on the printed circuit board (PCB) technology, called printed log-periodic dipole arrays (PLPDA) antenna was proposed and has already been investigated in the past years [8]- [16].…”

A Miniaturized Fractal Antenna With Sqare Ring Slots for Ultrawideband Applications

“…Since the antenna is a key element in these systems which determine the performance in terms of capacity, data rate, and efficiency, an antenna with good radiation characteristics, low cross polarization, and large bandwidth has become a research hotspot in the applications such as wireless portable devices, radars, and remote sensing [2,3]. Several antennas have been designed and employed for UWB applications, typically Vivaldi antenna [4], horn antenna [5], spiral antenna [6], and log periodic antenna [7]. Though wide bandwidth, high gain, and antenna with good radiation characteristics have been realized, in the recent days, the antenna based on fractal theory has become the centre of attraction due to several advantages including size reduction, multi-band operation, and uniform repeatability.…”

Design of a novel broadband compact dual polarized horn

“…It is increasingly desired demand for many applications, such as satellite co mmunication systems, commercial co mmunicat ions, and radar communicat ions [1][2]. The various dual polarized antenna structures have been researched [3][4][5][6][7][8]. The structure is based on the tapered slot antenna which is embedded in a substrate.…”

“…Although this sort antenna can provides good radiation pattern, its structure is so complex that mechanical processing is difficult [3]. A waveguide or a coaxial feeding horn antenna has been researched [5][6]. A lthough it holds excellent radiation pattern, its cost is high.…”