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A micro-strip quasi-Yagi antenna is improved in this paper. The antenna unit for X band is designed. The number of the directors is increased in order to improve the gain of the antenna. The length of the directors, the width of the directors and the space of each directors are simulated and analyzed by the simulation software HFSS. The results show that: the bandwidth of the antenna is greater than...
The design of a small printed-log-periodic antenna, loaded with an active matching network, for multiband applications is presented. A well-known, low-cost and low-profile antenna is re-engineered for including an additional impedance bandwidth in the lower UHF-band. The design method includes the use of the recently introduced sensitivity parameter Sens in order to find a suitable location for a...
This paper presents a wideband high efficiency slot antenna array based on ridge gap waveguide technology at 60 GHz for millimeter-wave applications. The antenna sub-array consists of four radiating slots that are excited by a cavity. Some tuning pins are placed inside the cavity to achieve wideband performance. A 4×4 slots array antenna is designed using 4-ways power divider. The proposed structure...
In the present paper we evaluate the performance of a hybrid digital/analog multi-beam beam-forming architecture with polarization and delay compensation using time reversal (TR). Double-directional, ultra wideband dual-polarized channel measurements at 70 GHz in a conference room have been used to emulate the channel. The use of multiple beams to mitigate human shadowing has been evaluated and the...
A simple and wideband subarray for D-band applications is presented in this paper. The proposed multilayer subarray consists of 2 × 2 cavity-backed slot subarray fed by a ridge gap waveguide transmission line. The simulated results show that the proposed subarray has a relative impedance bandwidth of 22.5% with input reflection coefficient better than −10 dB over the 126–158 GHz frequency band. An...
This paper describes a wide-band dual-polarized slotted-waveguide antenna working at V-band (57–66 GHz) based on Gap Waveguide concept. The antenna has three layers. The first one (feeding-layer 1) is practically identical to the second one (feeding-layer 2). This optimizes the design and facilitates manufacturing. The corporate-feeding networks on the two layers are rotated 90 degrees to each other...
This paper investigates a planar monopole antenna for fifth generation (5G) wireless communication networks. The proposed antenna has an ultra-wide band impedance response in millimeter wave (mmW) spectrum, 25–39 GHz covering Ka band. The antenna has unique structural layout resembling hexagonal honeycomb and has low profile (8×7 mm2) on 0.254 mm thick Rogers substrate, enabling the design for incorporation...
This paper presents an overview of the advances in single layer reflectarrays. In particular, it reports the progress in wideband reflectarrays and reconfigurable reflectarrays.
This paper investigates the impact of phase errors of beamforming networks on the performance of distributed transmit beamforming systems. Through multi-tone signal, wider band, models and the defined phase error percentage (PEP) of the beamforming networks, the distorted signal waveforms for different wider band occupying beamforming systems are presented. Furthermore, simulated bit error rates (BERs)...
In this paper, a multilayer substrate integrated waveguide (SIW) cavity-backed slot antenna array with wideband performance is proposed. In order to broaden the operating bandwidth of SIW slot antenna, multilayer cavities with gradually decreased permittivity and expanded aperture sizes are loaded above the slot, which realizes a smooth transition between SIW slot and free space. A wideband feeding...
An investigation of curved contoured beam reflectarrays with reusable surface for multiple coverages is presented. The main advantage of curved reflectarrays over shaped reflectors is that they allow the possibility of reusing a standard parabolic mold for multiple missions. To demonstrate this, two curved reflectarrays are designed using the direct optimization technique to fulfill the requirements...
A suspended plate antenna (SPA) array for a high power application is presented. The application required a compact and light weight antenna with at least 20 percent of impedance bandwidth and 14 dBi of gain as well as a low backlobe over a frequency range of 750 to 850 MHz. A single SPA has a little more than 36 percent impedance bandwidth and 8 to 9 dBi of gain. Forming a 2-dimensional array of...
The SKA1-LOW radio telescope will be a low-frequency (50–350 MHz) aperture array composed by ∼130,000 antenna elements spread over tens of kilometers and located in Western Australia. Its scientific objectives will prioritize studies of the Epoch of Reionization and pulsar physics. This paper will focus on the key performance parameters and constraints driving the architectural design of the World's...
We present a novel tightly coupled dipole array (TCDA) that achieves 67:1 bandwidth over the 30 MHz to 2 GHz frequency range. The design is extremely simple, and consists of 3 overlapping dipoles that are fed at 3 different locations to ensure uniform current flow. The overlapping dipoles are “printed” on a 0.3 mm-thick polymer substrate (εr=3), and “sandwiched” between two layers of flexible polymer...
This work presents a spiral antenna array, which can be used in the V- and W-Band. An array equipped with Dolph-Chebychev coefficients is investigated to address issues related to the low gain and side lobe level of the radiating structure. The challenges encountered in this achievement are to provide an antenna that is not only good matched but also presents an appreciable effective bandwidth at...
Retrodirective antennas used for radiative wireless power transfer (WPT) are typically resonant and exhibit strong backscatter, a limited field of view and small bandwidth. These limitations are here overcome by using an array of long slots fed by parallel plate waveguides (PPWs). It is shown that the array can collect the total power impinging from a remote source over a large field of view and bandwidth...
Nowadays numerous standards in mobile phones and short range links are emerging. The development of antennas covering all those allowed frequencies with only one element and one feeding appears to be an important goal [1]. For example, base stations for mobiles are mostly composed of different arrays of antennas, each array working for only one band. The purpose of the presented study is to develop...
A reflectarray antenna composed of double cross loop elements of varying arm length printed on a conductor-backed substrate is introduced. Two different realizations are presented: in the first design, the lengths of both constituent arms of the cell elements are varied whereas the length of only one of the two arms is varied in the second design. Prototype reflectarrays were fabricated and measured...
MICROWAVE beamforming (MBF) is advantageous over digital beamforming (DBF) in several regards [1]. First, due to a lower number of RF down-converters and analog to digital converters (ADC), MBF structures have lower size, weight and battery power consumption. Second, due to weighting and combining of signals in the analog domain and avoiding quantization errors, MBFs have higher dynamic and suppression...
An 8×8 element array antenna is composed of the E-plane waveguide parallel-feeding circuit in the lower layer and the 2×2 slotted cavities in the upper layer. The E-plane waveguide parallel-feeding circuit consists of two plates and assembled at the center of the broad wall of the waveguide to achieve low-loss property and wide bandwidth simultaneously. The 2×2 slotted cavities are designed to obtain...
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