Triangular grid interconnected crossed rings antenna for large‐scale ultra‐wideband dual‐polarised arrays

Ultrawideband Antenna Arrays and Directional Propagation Channels

The large spectral occupancy of ultrawideband (UWB) wireless signals significantly complicates the design of multi-antenna arrays and the characterization of propagation channels determining the performance of such arrays. This survey paper develops generic techniques for double-directional UWB channel characterization, and surveys methods for the extraction of the parameters of multipath compo...

A Compact Printed Triangular Monopole Antenna for Ultrawideband Applications

In this article, a printed triangular-shaped monopole antenna is proposed for emerging ultrawideband application. The proposed antenna uses a triangular radiating patch which is directly fed by a 50-X microstrip feed line. To improve the impedance bandwidth, a round-corner ground plane has been used. To further improve the impedance bandwidth for the entire band, a microstrip transition (near t...

Compact Ultrawideband Mimo Antenna for Mobile Applications

A new broadband multiple-input multiple-output (MIMO) antenna with good isolation and compact size is proposed. The proposed antenna consists of two G-shaped elements in the upper layer and two inverted L protrude branches and a T slot etched in ground which is used to reduce the mutual coupling. This planar antenna has a bandwidth of 100% with |S11| ≤ -10 dB from 2.26GHz to 6.78 GHz. The value...

Differential Polynomial Rings of Triangular Matrix Rings

Duality Theorems for Crossed Products over Rings

In this note we extend duality theorems for crossed products obtained by M. Koppinen and C. Chen from the case of a base field or a Dedekind domain to the case of an arbitrary noetherian commutative ground ring under fairly weak conditions. In particular we extend an improved version of the celebrated Blattner-Montgomery duality theorem to the case of arbitrary noetherian ground rings.