Figure 1 Four sample Quadrifilar Antennas T he Quadrifilar Helix Antenna as shown in Figure 1 has already been described in detail and discussed in references [1], [2], [3], [4]. That discussion will not be repeated here. Unfortunately, very little has been written on how to built a Quadrifilar Helix Antenna to radiate with RHCP (Right Hand Circular Polarization) or with LHCP (Left Hand Circula...

Frequency Reconfigurable antennas have received significant attention for their applications in communications, electronic surveillance and countermeasures, by adapting their properties to achieve selectivity in frequency, bandwidth, polarization and gain. This paper presents the design of reconfigurable conformal antenna for wireless LAN networks. The proposed antenna is suitable for Wireless ...

A single-layer wideband printed antenna for dual-polarized applications is proposed in this paper. Two orthogonal linear polarizations are achieved by adopting a hybrid feeding technique. The horizontal polarization is excited by an aperture-coupled microstrip feed line while the coplanar waveguide (CPW) feed line is responsible for the vertical polarization. Measurements demonstrate a fairly w...

A novel concept of a differential feeding network for four-node antenna/antenna arrays is proposed. The constructed out four-strip coupled-line directional coupler operating in mixed differential-nodal mode enabling direct interfacing front-ends with single-ended antennas. It shown, that such configuration provides at the outputs proposed four signals, which are equal amplitude and phase progre...

In this paper, stainless steel core yarn was selected as a conductive yarn to produce conductive fabrics. The electromagnetic shielding effectiveness of twill and some diced woven fabrics with different metal densities were measured by free space measurement technique at horizontal polarization of the antenna. It was found that woven fabric samples shielded well in high frequency band, namely i...

In this paper, antenna isolations for MIMO repeater system using orthogonal polarization is evaluated by the computer simulation. From the results, the isolation of the orthogonal polarization is higher than that of the co-polarization. Therefore, the MIMO repeater using orthogonal polarization technique expects to have cost effective and high performance.

Abstract We present recent 2-port vector network analyzer (VNA) measurements of the complete set scattering parameters for antenna used within Long Wavelength Array (LWA) and associated front end electronics (FEEs). Full parameter yield not only reflection coefficient each polarization, S11 S22, but also coupling between polarizations, S12 S21. These had been previously modeled using simulation...

I discuss the physics of polarization in models with early reionization. For sufficiently high optical depth to recombination the polarization is boosted on large scales while it is suppressed on smaller scales. New peaks appear in the polarization power spectrum, their position is proportional to the square root of the redshift at which the reionization occurs while their amplitude is proporti...

To optimize communication with the Generic Modular Aircraft T-Tail (GMA-TT) unmanned aerial vehicle (UAV), electromagnetic (EM) simulations have been performed to predict the performance of two antenna types on the aircraft. Simulated far-field radiation patterns tell the amount of power radiated by the antennas and the aircraft together, taking into account blockage by the aircraft as well as ...

We describe a new dual-polarized slot antenna to be used with quasi-optical devices such as superconductor-insulatorsuperconductor (SIS) mixers at millimeter and submillimeter wavelengths. The radiation and impedance characteristics of the antenna were obtained from a moment-method calculation. The antenna has an excellent radiation pattern, a low impedance, wide bandwidth, and low cross polari...