Modal Resistance of Spiral Antenna

Abstract

<p class="MsoNormal" style="text-align:justify;"> <span lang="EN-US">This paper proposes a quasi-static conformal mapping analysis to analytically evaluate the input resistance of Archi</span><span lang="EN-US">medean spiral antenna at its radiation region. The deviation from the original constructs of band theory for two-wire spiral antennas leads to the concept of common slot-line mode radiation. The per-unit-length capacitance and the char</span><span lang="EN-US">acteristic impedance of the quasi-TEM fundamental propagating mode in periodic coplanar waveguide (PCPW) struc</span><span lang="EN-US">ture are obtained in terms of spiral parameters including substrate properties. This formula enables little computational effort on the computation of input resistance at the radiation mode of balanced-excited two-arm Archimedean spiral antennas. The numerical simulation demonstrates the accuracy of derived formulas both in free space and when a dielectric layer is presented.</span><span lang="EN-US"><o:p></o:p></span> </p

Cross-Dielectric-Slab-Loaded Archimedean Spiral Antenna

“…However, in the present design, since the ASA is fabricated on a dielectric sheet (RO4725JXR) of thickness 0.7 mm its input impedance is found to be Z 0 = 142.2 Ω (at ASA end) using the conformal mapping analysis from (1), (2), (3) and (4) [11].…”

“…Where, r in1 and r in2 are the inner and outer radii of the spiral curves respectively. a AR is the spiral constant, the range of Ø varies from Ø st to Ø end representing the starting and ending angle of the spiral respectively [11].…”

Miniaturization of Archimedean spiral antenna for wideband beamforming arrays

“…As shown in Figure , however, there are some mismatch points in the impedance matching. This is because the rate‐of‐change for the impedance over the entire range of frequencies increases with the permittivity . From this, it could be determined that the growth of the relative permittivity produced an increase in the dynamic ranges of the inductance and capacitance with the spiral line.…”

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

“…The pioneered work in [26] applied the concept of the band theory and developed the coplanar strip (CPS) model. Our previous work proposed a model based on a conjectured field distribution of the radiation region similar to what the band theory stated due to the in-phase currents [27]. This work proposes an alternative quasi-static model based on a novel analysis on the planar spiral structure (disregarding the band theory) and provides a rigorous conformal mapping analysis.…”