BOTTOM FED PLANAR ELLIPTICAL UWB ANTENNAS

ABSTRACT This paper describes “bottom fed” planar elliptical dipoles. These antennas are electrically small ultra-wideband (UWB) dipoles with bandwidths on the order of 3:1 or better. Return loss is typically –14 dB, and boresight gain is nominally 3 dBi. Bottom fed planar elliptical dipole antennas are well suited for commercial applications. 1. INTRODUCTION Antennas for ultra-wideband (UWB) use must meet demanding performance specifications. They must be well-matched and efficient to take best advantage of parsimonious spectral limits. Ideally, UWB antennas should be non-dispersive or dispersive in a controlled fashion that is amenable to compensation. For a wide variety of applications, an omni-directional response is highly desirable. Commercial operation imposes additional constraints. A mass market UWB antenna must be small and inexpensive, yet must not compromise on performance. Figure 1: Prototype “bottom-fed” planar elliptical dipole antenna, front (to the left) and back (to the right).