In this paper, the design and implementation of plasma antenna array with beam forming is discussed. The structure consists of a circular array of plasma tube enclosed in a unipolar UHF band monopole antenna. Beam forming is possible by stimulated plasma tubes. The combination of the above antenna with plasma excitation controller makes a beam forming smart antenna. An experimental model in UHF...

-A slotted waveguide providing a two dimensional near-field focused beam is presented in this paper. This antenna focuses the beam in the E-plane and provides a wide beam in the H-plane in order to illuminate a linear array, as reflector transmit-array antenna with a small width (100mm) and a very large length (1530mm) located in the near-field region. The simulated field distribution on the ar...

In the millimeter-wave band, the series-fed array antenna is facing a problem of large transmission loss and narrow bandwidth by using a high-permittivity and large-loss-tangent material. In this paper, an air region is inserted in the half of the height in the LTCC waveguide of εr =6.6 and tanδ =0.013 to reduce the transmission loss. The reduction of the equivalent dielectric constant by the a...

We describe and analyze adaptive antenna array technology to improve naval communications systems to beyond line-of-sight at microwave frequencies by using the ducting layer as a leaky waveguide and the adaptive array to resolve and coherently combine multipath in this layer.

1. Introduction Leaky-wave antennas based on an open-waveguide structure can become a candidate of millimeter-wave antennas. Since such a structure is already open, leakage is produced by introducing not a physical cut, but asymmetry of the structure. As a result, it supports a leaky mode (instead of a bound mode) and therefore radiates all along its length, possess flexibility in beamwidth and...

Series feeds are commonly used in antenna arrays because of their compact size and low loss compared to corporate but typically feature beam squint over wide bandwidths. This work proposes a series-fed waveguide horn array with reduced by introducing synthesized time delay sections between the horns feed line. The array, implemented WR42 waveguide, achieves 1.53° 4 GHz operating band, 10.52° fo...

In this paper, a radial line microstrip antenna array (RL-MSAA) for linear polarization is designed. Stacked microstrip antennas (MSAs) with a stub element in the upper parasitic element are arrayed on a radial waveguide as a phase-controllable radiation element. A prototype array with three concentric rows of the stacked MSAs is tested in 12 GHz.

In this paper, a new configuration of Tapered Slot Antenna (TSA) with improved radiation pattern is proposed and studied. This antenna is designed in the form of a substrate integrated waveguide (SIW) array with respect to side lobe level constraints. For side lobe reduction, a simple quasi-triangular distribution is proposed and is accomplished uniquely by means of 3 dB power dividers. A 12-wa...

A broadband circularly polarized (CP) slot antenna array fed by an asymmetric coplanar waveguide (CPW) with stepped and inverted T-shaped strips is proposed. Using four square slot antenna elements with sequential rotation oblique feed and a modified sequential-phase (SP) feeding network, broadband CP can be achieved. The measured −10 dB reflection coefficient bandwidth and 3 dB axial ratio (AR...