Balanced Antipodal Vivaldi Antenna Research Articles

Gain and radiation pattern enhancement of balanced antipodal Vivaldi antenna

Balanced antipodal Vivaldi antennas normally suffer from tilted beams and low axial gains. A simple technique, based on the substrate end shaping, is used to correct both problems. Consequently, the resulting antennas provide high axial gains, within a wide frequency band. Their performance is compared with the conventional Vivaldi antenna, and the improvements are discussed.

Balanced Antipodal Vivaldi Antenna With Dielectric Director for Near-Field Microwave Imaging

A balanced antipodal Vivaldi antenna is designed to be used as a sensor for a microwave breast cancer detection system. The antenna has the ability to send short electromagnetic pulses into the near-field, with low distortion, low loss and in a directional manner. The antenna directivity is further improved by the inclusion of a novel feature in the antenna aperture called a “director” which consists of a profiled piece of higher dielectric constant material. Several simulated results are successfully confirmed with measurements. Reflections of a tumor placed in a breast model are simulated for two cases, namely a balanced antipodal Vivaldi antenna with and without a director. Greater tumor responses are recorded with the director present, demonstrating the potential of this feature for microwave breast imaging.

DESIGN AND OPTIMIZATION OF COMPACT BALANCED ANTIPODAL VIVALDI ANTENNA

In this paper, the conformal finite-difference time-domain (CFDTD) method using PSO optimization is applied to design a compact directive balanced antipodal Vivaldi antenna for ultrawideband (UWB) applications. This paper demonstrates miniaturized antipodal Vivaldi antenna (32 × 35 × 1.6mm3), having low-cross polarization levels and reasonable gain from 3.1 to 10.6 GHz. The antenna peak gain is 5.25 dBi in the specified band. The simulated and experimental results of return loss, far field patterns and gain are presented.

A new design tapered slot antenna for ultra-wideband applications

This paper describes the design and the high performance of a new balanced antipodal Vivaldi antenna for ultra-wideband applications. The return loss, radiation pattern, antenna gain, and level of cross polarization of this antenna are presented for both simulated and experimental results. The antenna is demonstrated to have greater than decade bandwidth (impedance within 10 dB over 1.3–20 GHz) and low cross polarization (<−17 dB in the broadside direction) over the band. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 19: 286–289, 1998.

Balanced antipodal Vivaldi antenna for wide bandwidth phased arrays

The Vivaldi antenna, a form of tapered slot radiator, has been shown to produce good performance over a wide bandwidth, limited only by the traditionally used slotline to microstrip feed transition. The authors present a new antenna, the balanced antipodal Vivaldi, which incorporates an ultrawide bandwidth transition and overcomes the poor polarisation performance of the antipodal form. Good performance over a 1 to 40 frequency range has been obtained. The use of the antenna in a linear phased array has also been investigated using elements constructed on high permittivity substrate. Wideband wide angle scanning with good cross-polarisation levels is obtained.

Novel ultrawide-bandwidth Vivaldi antenna with low crosspolarisation

The conventional Vivaldi antenna typically has a bandwidth of less than 3:1, limited by the feed line to radiating slot transition. The antipodal Vivaldi antenna removes this limitation but gives very high crosspolarisation which is undesirable for phased array applications. The Letter describes a new balanced antipodal Vivaldi antenna that retains the wide bandwidth characteristics while reducing the crosspolarisation by 15dB across an 18:1 band. Measurements are presented that compare the performance of existing antenna structures with this novel antenna element.