Circularly polarized omnidirectional millimeter wave monopole with parasitic strip elements

Abstract

permittivity of 2.65) with its size 70 ϫ 57 mm 2 . Its dimension parameters are listed in Table I. RESULTS AND DISCUSSIONTo examine the performance in terms of impedance bandwidth, the return loss for the fabricated antenna was measured using an HP8510C network analyzer. The simulated and measured return losses of the antenna are shown in Figure 2. It can be seen that the investigated antenna can approach an impedance bandwidth from 2.0 to over 12 GHz for S 11 Յ Ϫ10 dB, and a notch centered at 5.76 GHz (about 260 MHz higher than that of the simulated one) is also observed. The difference between simulations and measurements is mainly due to the substrate errors (including its thickness and relative permittivity) and fabrication tolerances.The measured radiation patterns in the E-plane and H-plane at 3.0, 5.0, 7.0, 9.0, and 10.5 GHz are illustrated in Figure 3. Notice that the proposed antenna has almost bi-directional patterns, especially at lower frequencies, in the E-plane, and omni-directional patterns in the H-plane at the lower or higher frequencies. Meanwhile, the measured antenna gain, given in Figure 4, shows the antenna has a gain of about 3.8 -6.8 dBi across the UWB frequency band. A sharp notch, centered at 5.76 GHz, is also observed with the rejection level approximately 10 dB. CONCLUSIONA planar elliptical slot antenna has been investigated. The proposed antenna has a compact size of 70 ϫ 57 mm 2 because of employing FG-CPW structures. To co-exist with the WLAN systems, a V-shaped slot is introduced. The antenna offers UWB performance with frequency band-rejection characteristic and suitable radiation patterns, which is met for UWB applications.

28 GHz Compact Omnidirectional Circularly Polarized Antenna for Device-to-Device Communications in the Future 5G Systems

“…Only (to the best of our knowledge) two designs, [23] and [24], have been reported to date that realize OCP radiation characteristics in the mm-Wave band at 37 GHz and 38 GHz, respectively. The design in [23] consists of a LP omni-directional monopole radiator and a surrounding sleeve polarizer which transforms the radiated LP wave into a CP wave.…”

Compact, omni-directional, circularly-polarized mm-Wave antenna for device-to-device (D2D) communications in future 5G cellular systems

“…To date, only one reported design [8] realizes CP omnidirectional radiation at 37 GHz in the mm-Wave band. However, its size is quite large (diameter: 38 mm = 4.7 λ 0 ).…”

Dual Linear/Circular Polarized Plannar Antenna With Low Profile Double-Layer Polarizer of 45⺠Tilted Metallic Strips for Wimax Applications

“…Based on [10], authors presented a monopole antenna in millimeter band with a cylindrical double layer polarizer of metallic strips in diagonal orientation [15]. On that occasion, a narrow band polarization was achieved with a high profile structure.…”

“…A narrow band response was obtained in [15] (T = 5.5λ 0 ) with a two layer polarizer as the one shown in Fig. 1.…”

“…In previous author's paper [15], as well as in other publications [10], the air distance T from the radiating element to the polarizer is set to at least λ 0 , in order to achieve an incident plane wave at the polarizer position. A narrow band response was obtained in [15] (T = 5.5λ 0 ) with a two layer polarizer as the one shown in Fig.…”