Perfect Electric Conductor Reflector Research Articles

Gain-enhanced PEC reflector backed slot-loop antenna

This paper proposes a low-cost, gain-enhanced, wideband, perfect electric conductor (PEC) reflector backed antenna. The proposed antenna consists of a rectangular loop with an internal inset-fed rectangular patch, a pair of symmetrical L-shaped interdigitated radiating branches, and a PEC reflector. The antenna has compact dimensions of 36 mm × 17.5 mm × 7.2 mm. The proposed antenna satisfies a −10 dB reflection coefficient bandwidth from 7.94 GHz to 14.45 GHz. To understand the operating principle of the proposed antenna, this paper presents a modal analysis. The gain performance is improved by using the constructive superposition of in-phase electromagnetic energy from the side edges of the rectangular loop and the two vertical edges of the radiating branches. In addition, the experimental and simulated results of the proposed antenna are in good agreement.

A Low-Profile Dual-Polarized Dipole Antenna Using Wideband AMC Reflector

A low-profile dual-polarized dipole antenna using wideband artificial magnetic conductor (AMC) reflector with stable radiation pattern for use in 2G/3G/4G base stations operating from 1.7 to 2.7 GHz is presented. The antenna consists of a pair of crossed-dipoles and a wideband AMC reflector which consists of an AMC surface, a metallic ground plane, and the air substrate between them. The AMC is designed to operate with 90° reflection-phase bandwidth of 1.64–2.88 GHz (54.8%). Compared with using perfect electric conductor reflector, the profile height of the dual-polarized dipole antenna using AMC reflector is reduced by half from 36 to 18 mm, resulting in the lowest-profile 2G/3G/4G base station antenna. Six metallic ground walls are used to stabilize the radiation pattern, and the resulted half-power beamwidths are around 68±3° and 81±3° in the H- and V-planes, respectively, across the operating band. More measured results show that wide impedance bandwidths of 1.67–2.98 and 1.64–3.05 GHz for the two input ports, isolation of more than 25 dB, and cross-polarization of less than −20 dB are achieved.

Analysis and Design for High-gain Antenna with Periodic Structures

Unlike metal as conventional Perfect Electric Conductor (PEC) for unidirectional beam reflector, the periodic structures are now attracting more attention form academia and industrial as High Impedance Surface (HIS) or Artificial Magnetic Conductor (AMC) reflector. Because quarter wavelength (λ/4) separation between antenna and PEC reflector is needed for unidirectional beam applications, it inevitably increases the profile and stringently limits the operation bandwidth of the antenna system. However, the utilization of AMC of periodic structures as reflector not only significantly reduces the antenna profile with phase enhancement, but it will also enhance its gain and directivity performance. In this paper, we use monopole antenna with center frequency at 2.45GHz and design periodic structure operated in frequency range between 2.4GHz and 2.483 GHz to investigate the applications of EBG structure on antenna. We will finally compare the simulated result and measured result to further predict the optimization of the antenna-EBG system design parameters.

A Double-sided Printed Dipole Array with an Electromagnetic Band-Gap Reflector

Electromagnetic band-gap (EBG) structures have unique properties in controlling the propagation of electromagnetic wave and have been applied to a wide range of electromagnetic devices design. In this paper, a double-sided printed dipole (DSPD) array backed by an EBG reflector is proposed for achieving a low-profile design as well as gain enhancement. Simulation results show that a reduction of more than 55% in antenna height can be obtained by placing the DSPD array over an EBG reflector rather than a perfect electric conductor (PEC) reflector. And the obtained gain of the antenna with an EBG reflector is about 1.9 dB higher than that with a PEC reflector at the operating frequency 2.77 GHz. The EBG reflector can be utilized to reduce a cavity-backed antenna height and enhance the antenna radiation efficiency. The design has a good potential application to antenna arrays with more elements in wireless communication.

Switched-Beam Slot Antenna over Electromagnetic Band-Gap Reflector

This paper presents the switched-beam slot antenna over the electromagnetic band-gap (EBG) reflector. This antenna is composed of two slot elements fed with a phase difference and the EBG reflector, which is used in order to realize a low profile structure. The radiation characteristics of this antenna are calculated using the FDTD method. Calculations show that the height of the antenna using the EBG reflector is 60 % lower than that of the antenna using a perfect electric conductor (PEC) reflector. The radiation characteristics at the center of the operating frequency band in the EBG reflector are equivalent to that in the PEC reflector. It is shown that the tilt angle of the main beam in the elevation plane varies with the operating frequency, and the variation in the case of the EBG reflector is caused by its frequency-dependent reflection phase. Moreover, the radiation pattern of the fabricated antenna is measured. The results demonstrate that the low profile design can be achieved by using the EBG reflector, and reveal the influence of the EBG reflector on the antenna efficiency.

Analysis and characterization of multilayered reflector antennas: rain/snow accumulation and deployable membrane

There are important engineering issues in designing reflector antennas that cannot be addressed by simply assuming a perfect electric conductor (PEC) reflector surface. For example, coatings may exist on antenna surfaces for protection, rain or snow can accumulate on outdoor reflectors, and the deployable mesh or inflatable membrane antennas usually do not have solid PEC reflector surfaces. Physical optics (PO) analysis remains the most popular method of reflector analysis owing to its inherent simplicity, accuracy, and efficiency. The conventional PO analysis is performed under the assumption of perfectly conducting reflector surface. To generalize the PO analysis to arbitrary reflector surfaces, a modified PO analysis is presented. Under the assumptions of locally planar reflector surface and locally planewave characteristic of the waves incident upon the reflector surface, the reflection and transmission coefficients at every point of the reflector surface are determined by the transmission-line analogy to the multilayered surface structure. The modified PO currents, taking into account by the finite transmissions of the incident waves, are derived from the reflection and transmission coefficients. Applications on the analyses of the rain and snow accumulation effects on the direct-broadcast TV antennas and the effects of finite thickness and finite conductivity of the metal coating on a 15-m inflatable antenna are described and results are presented.