The equiangular spiral antenna

Abstract

List of Symbols I Introduction II Definition of the Antenna 2,1 The Design Principle 2"2 The Equiangular Spiral 2.3 The Antenna 2.4 Physical Construction of the Antenna III The Radiation Pattern 3.1 The General Far Field Pattern 3,1a The Typical Antenna 3"lb The Pattern Bandwidth 3.2 Variation of Antenna Parameters 3.3 Pattern Beamwidth and Pattern Rotation 3,3a Pattern Rotation 3, 3b Pattern Beamwidth 3.4 Polarization of the Field 3.5 Variations in the Basic Antenna 3,5a Designing for a Specific Band of Frequencies 3,5b Effect of Construction with Thick Arms IV The Near Fields 4.1 The Tangential Field in the Slot Arms 4.2 The Normal Field on the Arms 4,2a General Considerations and Theory of Measurement 4,2b Adjustment of Equipment 4,2c Measured Fields 4.3 Estimation of Error V The Input Impedance VI Efficiency of the Basic Antenna 6.1 Method of Measurement 6.2 The Experimental Investigation 6,2a Measurement of Surface Resistivity 6,2b Ratio of Power Inputs 6, 2c A Check on the Current Distribution 6, 2d Measured Efficiency VII The Cavity Backed Antenna 7.1 Efforts toward a Unidirectional Antenna 7.2 Antenna with Absorbing Termination 7.3 The Antenna over .a Conventional Cavity IX

A Wide Band Antenna for Multi-Constellation GNSS and Augmentation Systems

“…The planar cardioid arms antenna has bidirectional radiation patterns perpendicular to the plane of the antenna as expected for such planar antennas [17,18]. This phenomenon has been observed in the simulation studies as well (Fig.…”

“…The maximum size of the antenna along X-axis will be λ/4 which is less than the size of cavity backed Archmedian spiral antenna, i.e., λ/π. As the structure is solely defined by angle this will give frequency independent characteristics [15,17,18].…”

Travelling Wave Mechanism and Novel Analysis of the Planar Archimedean Spiral Antenna in Free Space

“…The backside of fabricated antenna has no conductor plane. The infinite balun design in [40] is adopted as a feed, which requires a wide metal arm to carry the feeding cable along the middle of spiral arm. The dummy cable on the other arm is necessary to remain the symmetry of spiral structure.…”

Potential space applications for body-centric wireless and E-textile antennas

“…An RG-178 coaxial cable was used to feed the antenna with the outer conductor soldered to one spiral arm. The inner conductor of the coaxial cable was soldered to the opposing spiral arm, and a short length of dummy cable was also soldered to this opposing arm to maintain symmetry as demonstrated by Dyson [9]. For comparison, a similar antenna was constructed using etched copper spiral arms on a 1.52 mm thick Rogers RT/Duroid 5880 substrate.…”