This paper explores the use of quasi-static frequency-domain antenna combining weights for multi-user (e.g., SDMA) or multi-stream (e.g., MIMO) communication systems operating in rapidly time-varying frequency-selective channels. By implementing combining weights that are constant across a time slot but are updated from slot-to-slot (i.e., “quasi-static”), great computational complexity savings...

─ A simple and compact microstrip-fed ultra wideband (UWB) slot antenna with dual band-notch characteristic for UWB applications has been presented. In order to increase the impedance bandwidth of the square slot antenna, we insert a T-shaped slot in the ground plane that with this structure UWB frequency range can be achieved. Additionally, by using a pair of Lshaped slits at the square radiat...

Objective Parallel transmission is receiving more and more attention in MRI, and multi-element transmit MRI systems become commercially available. A number of different Tx/Rx antenna types have been presented for usage in parallel transmit configurations: degenerate birdcage coils, decoupled TEM or stripline coils [1,2,3]. All of these ‘traditional’ coil-types have their pro’s and con’s. We pro...

I have designed a folded-shot fractal antenna with single iteration with help of Koch iteration technique to achieve multiband properties. Antenna simulation tool Ansoft HFSS is used to design and simulate. Antenna proposed by me work with six frequency bands with acceptable return loss. Implementation of Folded slot antenna is done over a single slot antenna. Proposed design of antenna offers ...

In this paper a CPW-fed annular slot antenna is miniaturized with enhanced impedance bandwidth using a reactive impedance surface (RIS) substrate. The RIS is realized by patterning 3× 3 array of circular elements over an inexpensive FR-4 substrate which is backed by a circular metallic plane. Due to the compensation of electric and magnetic energy stored by antenna and RIS substrate respectivel...

Beam-scanning antennas are attractive for high-bit-rate data communication systems and high resolution sensing systems in millimeter-wave band. Waveguide antenna is one of the most attractive antennas for such millimeter-wave systems because of its low loss and high efficiency characteristics in high frequency band. Horizontally-beam-scanning antennas such as phased arrays and DBF (Digital Beam...