Transmitarray Using Perforated Dielectric Material for Wideband Applications

Abstract

In this paper, linearly polarized transmitarray is investigated as to avoid the usage of multi-layers for improving the bandwidth of transmitarray. The transmitarray is formed from a single dielectric sheet by perforating selected areas of the material. A perforated dielectric layer is divided into square cell elements. Each cell has four holes with the same diameters. Holes with different diameters in the cell elements are used to allow continuous tuning of the transmitted signal's phase over 360 • range with a maximum loss of 3.6 dB at 10 GHz. The transmission coefficient versus the diameter of the holes is calculated by using the finite integration technique. The results are compared with those calculated with transmission line method for verification. The focal-to-diameter ratio of the transmitarray is optimized for lower side lobe level and highest transmitarray gain. A comparison between the transmitarray and the reflectarray with the same aperture area is illustrated.

Compact size high gain lens corrected pyramidal horn antenna for 71–76GHz band

“…As shown in Fig.3 the unit cell have a very low dielectric loss ≤1dB at E-band. The loss of this unit cell is lower than the dielectric loss ≈3.6dB of the perforated unit cells reported in [8]. This low dielectric loss and the absence of the metallic layer (neglected conductor loss) would results in higher aperture efficiency.…”

“…A floquet ports and masterslave boundary condition in HFSS are used to form the waveguide simulator and to calculate the response of the unit cell under oblique incidence of plane wave for 0 o ≤ θ inc ≤30 o . The dielectric loss is less than 1dB except for θ inc =30 o where the loss reaches ≈1.2dB as shown in Fig.5 which is still less than the loss in [8] and the phase response is stable as the angle of incidence varying between 0 o ≤ θ inc ≤30 o and so the phase curve of θ inc =0 o will be used to design lens as will be explained later in this paper [9]. …”

Compact size pyramidal horn lens antenna for E-band gigabit point-to-point communications

“…The amount of the required phase correction at each unit cell is function of the phase delay of the incoming EM wave that travels between the feeder phase center and the closest interface of the lens. A square unit cell of four air filled drilled holes is selected [15,16]. Drilling holes that having different radiuses through a dielectric layer will alter the constitutive parameters of the dielectric material particularly the effective permittivity, index of refraction, phase velocity and the characteristic impedance.…”

Dual-Mode Plasma Reflectarray/ Transmitarray Antennas

“…The most important advantages of reflectarrays relative to the phased arrays are the higher efficiency, simple feed arrangement, and in comparison with parabolic reflectors having low profile, less weight, and flat surface. Reflectarrays provide a promising solution for the design of light weight, Manuscript low cost, and low cross polarization [4]- [6]. Transmitarray antennas have overcome the reflectarray feeder blockage problem by combining the features of lenses and phased array antennas.…”

“…Transmitarray antennas have overcome the reflectarray feeder blockage problem by combining the features of lenses and phased array antennas. Transmitarray is similar to the reflectarray, but the incident wave is not reflected but passes through the antenna structure as it is collimated into almost a plane wave on the opposite side of the array [6], [7]. Plasma antenna is a universal term that represents the ionized gas as a conducting medium instead of a metal to either send or receive a signal to achieve any of the communication purposes [8].…”