Xiao Shaoqiu

Composite metamaterial enabled excellent performance of microstrip antenna array

This paper reports that the split ring resonators and complementary split ring resonators are compounded to construct a novel compact composite metamaterial. The composite metamaterial exhibits a unique property of blocking electromagnetic wave propagating in two directions near the resonant frequency. An example of two-element microstrip antenna array demonstrates that the developed metamaterial enables array performance that is an improvement in comparison with the traditional one, including mutual coupling suppression of 9.07 dB, remarkable side lobe suppression and gain improvement of 2.14 dB. The mechanism of performance enhancement is analysed based on the electric field and Poynting vector distributions in array. The present work not only is a meaningful exploration of new type composite metamaterial design, but also opens up possibilities for extensive metamaterial applications to antenna engineer.

Expanding the bandwidth of planar MNG materials with co-directional split-ring resonators

An effective approach to expand the bandwidth of negative permeability of small-sized planar materials is proposed. Based on qualitative analysis of equivalent circuit models, the fractional bandwidth of an μ-negative (MNG) material is expanded from 3.53% up to 12.87% by adding split-ring resonators (SRRs) and arranging them by proposed steps. Moreover, the experimental results validate the effectiveness of bandwidth-expanding methods, which is promising for the extensive application of metamaterials in the microwave field.

Design of a Broadband, Wide-Beam Hollow Cavity Multilayer Antenna for Phased Array Applications

A broadband and wide-beam antenna with a hollowcavity multilayer H-shaped slot structure is presented and manufactured by microwave multilayers laminate technology (MLT) simultaneously. Numerical investigation and experiment on a 64-element (8×8 ) array has been implemented, which is composed of the proposed antenna elements that have been designed, fabricated, and measured. The measured impedance bandwidth of the proposed antenna embedded in the array is beyond 25% with the reference of S11 <;-10 dB. The phased array composed of the presented antenna is able to cover ±60° wide-angle scanning range with low scanning gain loss.

Development for millimeter-wave PHEMT mixer

The analysis and optimizing design for PHEMT drain mixer circuit in Ka-band is given in this paper. The nonlinear equivalent circuit and its parameters are simulated and obtained from the small signal S-parameter and the DC measurements of the PHEMT device. The drain mixer circuit is designed with optimization, making use of the harmonic balance method and the conversion matrices method. The result shows that the mixer has conversion gain 4 dB at RF 27.4 GHz and LO 33.4 GHz/10 dBm.

Vortex Wave Generation Based on Tensor Holographic Artificial Impedance Surface

In this paper, a holographic vortex wave antenna with a modulated tensor artificial impedance surface is presented for the first time. This antenna consists of an array of sub-wavelength metallic patch with periodically varying gaps printed on a grounded dielectric substrate. The holographic impedance modulation technique is used to design the tensor impedance surface to generate vortex wave in a desired direction. A holographic antenna is designed as an example and simulated results are presented.