Chao-Ming Luo

A bowtie-shaped MIMO dielectric resonator antenna for WLAN applications

A simple bowtie-shaped MIMO dielectric resonator antenna (DRA) resonating at 2.45GHz with 75MHz measured common bandwidth for both ports is presented in this paper for 2.40–2.48GHz WIFI band applications. The MIMO characteristics are obtained by simultaneously exciting the TEδ21 modes by coaxial probe and TM22δ modes by coupled aperture feed in the DRA. Omni-directional radiation patterns are obtained in both principle planes, simulated and measured radiation patterns are found to be close to each other. Moreover, the proposed bowtie-shaped DRA is compact, exhibits high isolation (25 dB) and relatively low correlation (0.0156) suggesting its suitability for the MIMO applications.

A decoupling method between two tri-band antennas for WLAN/WiMAX applications

A decoupling method between two tri-band antennas for WLAN/WiMAX applications is presented. A monopole is first designed with tri-band characteristic; three resonating frequencies are generated by three separate resonators. Then, two tri-band monopoles are employed to develop a MIMO antenna system. The resonators of low band can reduce the mutual coupling for two higher bands by suppressing surface wave propagation. Finally, coupling reduction at low band is achieved by a Ω-shaped metal line to neutralize original coupling. The proposed MIMO antenna covers the 2.4/5.8GHz WLAN and 3.5GHz WiMAX bands, with the measured mutual coupling lower than −18 dB.

Higher order modes in cubic Dielectric Resonator antenna for directivity enhancement

In this paper, a modified slot aperture feed is presented. This new feed is applied to a cubic-shaped Dielectric Resonator as a result it resonates antenna in higher order TEσ13 modes at 5.59 GHz to achieve enhanced directivity (11.6dBi). This new feed is engineered by replacing the rectangular stub of conventional slot aperture feed with a circular metallic strip of radius 3mm. Which enhances the directivity of antenna by resonating it in TEσ13 modes. This antenna can be used for 5.59 GHz (5.470–5.725 GHz) WIFI-band applications.

Gain enhancement in cubic DRA with modified microstrip feed for WLAN applications

In this paper, a modified microstrip slot aperture feed is introduced which generates TEσ13 modes in a cubic dielectric resonator antenna resulting in a high gain (simulated = 10.5 dB and measured = 9 dB). The proposed feed can be realized by replacing the rectangular stub of microstrip slot aperture feed with a circular metallic stub of radius 3mm. The proposed feed excites the dielectric resonator antenna around a resonant frequency of 5.78GHz covering 5.725–5.850GHz WIFI band. The antenna exhibits an impedance bandwidth of 130.2MHz, and 135MHz in simulations and measurements respectively, and a stable gain throughout the 5.78GHz WIFI band with a maximum of 9 dB in measurements.

A tri-band dual-polarized cylindrical dielectric resonator antenna with high isolation

This paper presents a tri-band dual-polarized cylindrical dielectric resonator antenna (DRA). To obtain dual linear polarization, the probe- and slot-fed excitation methods are used for Ports 1 and 2 of the antenna, respectively. The antenna makes use of two fundamental modes and three higher-order modes of cylindrical dielectric resonator to achieve tri-band. Also, the antenna has high input isolation (exceeding 45 dB) and low cross polarization, which can be widely applied in communication and radar systems.

Compact UWB antenna with triple notched bands reconfigurable

A compact ultra-wideband (UWB) antenna with reconfigurable notch function is presented. The proposed antenna, with a compact size of 25×29 mm2, can be able to switch among eight operative modes,including a UWB mode, three single band notched modes, three dual band notched modes, and a triple band notched modes. Three different types of slots are introduced to generate three notched bands with central frequencies of 3.5, 5.5, and 7.5 GHz, respectively. In order to achieve reconfigurable function, three switches utilized across the slots are used to activate and deactivate the band-notched structures.