Low-profile Ultra Wideband Research Articles

Recent Patents Review on Low-profile Ultrawideband Antennas for Future Broadband Communications (Invited Paper)

This paper provides a review on patents linked with low-profile Ultrawideband (UWB) antennas in the last decade for broadband communications. Six selected patents on this topic including tapered slot antennas with reduced profile, planar dipole antennas with flat reflector and planar slot antennas with flat reflector are highlighted and discussed in detail. The trend of using structural compensation instead of using absorbing loads at the end of feeding lines or at the body of antennas is rather obvious for improved antenna efficiencies as well as reduced fabrication costs. At the same time, difficulties of impedance matching encountered for structural compensation and reduced profile are partly overcome by using new structural mechanisms, such as the coupled feeding schemes, inductance loaded structures and compact baluns. These noticeable progresses on this topic could play an important role in the development of various broadband communications and other broadband applications. Keywords: Low-profile, Ultrawideband antennas, radiation patterns, monopole antennas, MMIC, half-ellipsoids, VSWR, broadband communications, FCC, planar dipole antennas, planar slot antennas, auxiliary elements, structural compensation, flat reflector, single lobe radiation

A Novel Low-Profile Compact Directional Ultra-Wideband Antenna: The Self-Grounded Bow-Tie Antenna

Low-profile directional ultra-wideband (UWB) antennas are strongly demanded in many UWB applications. However, few such UWB antennas have been reported. To meet the demands, an original novel low-profile directional UWB antenna-the self-grounded Bow-Tie is developed and presented here. This new UWB antenna has a compact and simple geometry, and ultra-wideband performance, such as presented here over a frequency range of 2-15 GHz with about -10 dB reflection coefficient, stable radiation patterns, and good time-domain impulse response. Measurements of a prototype of the antenna have verified the design and the simulation. It can be foreseen that this new antenna will find many applications in the different areas in UWB technology.

Nonplanar Dipole Antennas for Low-Profile Ultrawideband Applications: Design, Modeling, and Implementation

This letter presents a printed circuit board (PCB)-based nonplanar dipole antenna with a flat reflector for low-profile ultrawideband applications. Physical fundamentals of the proposed antennas are summarized and discussed. Design considerations, modeling, and implementation methods are introduced in detail. A prototype antenna was fabricated and tested to verify the presented results. The prototype antenna has a measured impedance bandwidth of 7.2 GHz from 2.8 to 10 GHz, and it also possesses stable unidirectional radiation patterns up to 6.0 GHz, which is suitable for many broadband applications.

On the Performance of Printed Dipole Antenna With Novel Composite Corrugated-Reflectors for Low-Profile Ultrawideband Applications

An investigation of the performance of printed dipole antenna with finite periodically corrugated-reflectors for low-profile ultrawideband (UWB) applications is presented. According to the relative orientations of the linear-polarized source antenna and the corrugated-reflectors, the problem could be divided into H and E cases. Their fundamental differences and design guidelines are discussed in detail. A novel composite corrugated-reflector based on the combinations of H-type and E-type ones is proposed for the first time, and fully characterized with a UWB source dipole which was optimized in the free space for better comparisons. An example antenna with only 21 mm core profile, composed of a printed UWB dipole, a microstrip balun and a composite corrugated-reflector, has an impedance bandwidth of 2.75 GHz to 8.35 GHz. Both numerical and experimental results show that the example antenna also has stable uni-directional radiation patterns and a realized gain of over 6 dB within the frequency band from 2.3 to 6.0 GHz, which could be a decent alternative to the EBG antennas due to significant improvements on pattern and gain bandwidth.

Low profile and compact size coplanar UWB antenna working from 2.8 GHz to over 40 GHz

AbstractA square monopole coplanar antenna with a circular base is proposed for ultra wideband (UWB) communications. The design parameters are analyzed and optimized to obtain a good performance and the measured return loss below −10 dB is from 2.8 to over 40 GHz. The proposed antenna has advantages of low profile, small size, UWB, and omni‐directional pattern. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 408–411, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24062

Size Reduction of a Low-Profile Spiral Antenna Using Inductive and Dielectric Loading

This letter discusses a miniature low profile ultrawideband (UWB) spiral. The antenna is miniaturized using a combination of dielectric and inductive loading. In addition, a ferrite coated ground plane is adopted in place of the traditional metallic ground plane for profile reduction. Using full-wave simulations and measurements, it is shown that the miniaturized spiral can achieve similar performance to a traditional planar spiral twice its size.