The performance of wireless communication systems is predominantly dependent on propagation environment and respective radiating antennas. Due to the shorter wavelength at Millimeter Wave (MmW) frequencies, the propagation loss through surroundings in indoor environments is typically very high. To improve the channel capacity and to reduce inter-user interference, a high gain directional antenn...

In this paper, a broadband circularly polarized (CP) antenna based on slot-loaded dipole with L-shaped arms and parasitic patches is proposed and investigated. Circular polarization is initially obtained at the lower frequency by bending the dipole arms into L-shape. To extend the axial ratio (AR) bandwidth, two pairs of parasitic patches are introduced along the orthogonal sections of the L-sh...

We describe a new quasi-optical SIS mixer designed for efficient radiation coupling. The mixer uses a twinslot antenna which has the advantages of a good beam pattern and a low impedance. The radiation and impedance characteristics of the antenna were obtained from a moment-method calculation. Tapered superconducting microstrip transmission lines are used to carry the radiation from the slot an...

Progress on the development of the multi-channel, ground penetrating radar imaging system is presented from hardware and software perspectives. A new exponentially tapered slot antenna, with an operating bandwidth from 100 MHz to 1.5 GHz was fabricated and tested using the eight-port vector network analyzer, designed by Rhode and Schwarz Incorporated for this imaging project. An eight element a...

In this paper a wideband dual polarized antenna is designed, manufactured and measured. Slot coupled patch antenna structure is considered in order to achieve the wideband characteristic. Although rectangular shaped slot coupled patch antennas are widely used in most of the applications, their utilization in dual polarized antenna structures is not feasible due to space limitation. For a rectan...

This paper presents a multiband CPW-fed slot antenna with L-slot bowtie tuning stub. The proposed antenna has been designed for PCS 1900, UMTS, WLAN 802.11 a/b/g and bluetooth applications, with a cost-effective FR4 substrate. The proposed antenna still radiate as omni-directional in azimuth plane and sufficient bandwidth for all above mentions. The proposed antenna works as dual-wideband, band...

We analyze spectral efficiency of a dynamic time division duplex system in a fixed wireless cellular network. Conventionally, spectral efficiency has been analyzed under static and fully-loaded conditions. In this paper, we investigate how asymmetric and dynamic traffic affects spectral efficiency of TDD systems. Recently, dynamic TDD (D-TDD) has gained much attention as an efficient duplex sch...

A compact microstrip-fed antenna with dual notched bands is proposed. First, a simple basic configuration is presented for Ultra Wide Band (UWB) applications and then the dual band notched structure is extended from the UWB one. The basic structure of the UWB antenna consists of a simple square radiating patch and a ground plane with a wide square slot on back of the substrate. A semi-circle sh...

<p class="Default">The radiation power in the endfire is decreased while main beam of half substrate integrated waveguide scan from broadside to a forward. The design half-width microstrip leaky-wave antenna (HW-MLWA) has been presented this work increase near by using slots technique element. This slot leads decrease cross-polarization. proposed comprises one element HW-MLWA with repeate...

In this study, a simple and compact ultra-wideband (UWB) patch antenna with rectangular slot is presented. The fabricated antenna consists of a rectangular patch tapered from a microstrip feeding structure and a truncated ground plane. The proposed antenna is etched onto a FR4 printed circuit board (PCB) with an overall size of 28 mm × 29 mm × 1.6 mm. Simulated and experimental results are comp...