Design of multioctave spiral-mode microstrip antennas

Abstract

Existing broad-band planar spiral antennas have a cavity loaded with absorbing material. AS a result, they are bulky and lossy. Existing microstrip antennas are narrow-banded aess than 10%). In this paper, the design of spiral-mode microstrip antennas with a bandwidth of 6:l is demonstrated. This new antenna has a small dissipative loss due to a resistive loading outside its active region.

Wireless Systems and Printed Antennas

“…A consequence of such a loading was that the volume of the antenna increased dramatically as the cavity depth had to be greater than the radius of the spiral, and therefore it was more challenging to integrate these radiators into the surfaces of potential platforms. In the early 1990s, a low-profile spiral was developed that significantly reduced the depth of the antenna [30]. Here a wideband printed spiral antenna was developed using a grounded laminate of thickness comparable to that used for microstrip patch antennas over the same frequency range.…”

Characterization of a Tranceiving Antenna Concept for Microwave Heating and Thermometry of Superficial Tumors

“…A simple and efficient technique to remove residual power not radiated in the resonance zone along the spiral, is to place a ring of absorbing material at the truncated edge [27] or terminate the spiral with a 50 Ω load. Here the latter variant is used and allows absorption of residual power, which otherwise has a tendency to reflect back along the spiral and radiate in unwanted modes, resulting in deteriorated (asymmetric) radiation patterns.…”

A New Method for Reducing the Input Impedance of the Archimedean Spiral Antenna

“…The Archimedean spiral antenna (ASA) is a classical frequency-independent antenna [1]. Several papers have been published on the topic of spiral antennas [2][3][4][5]. For its prominent features like consistent input impedance and invariable circularly polarized radiation, it is widely used in high-speed wireless communication, high-resolution radar and airborne applications [6,7].…”