Inkjet printed ultra wideband spiral antenna using integrated balun on liquid crystal polymer (LCP)

In this paper, an ultra wideband spiral antenna with a planar, integrated balun is inkjet printed on liquid crystal polymer (LCP) substrate and operates successfully from 1 GHz up to 8 GHz. An exponentially tapered spiral microstrip balun is used for, the matching of the 130 Ω input impedance, the characteristic impedance (Z
₀
) of 50 Ω, at the feed point. The equiangular spiral antenna is planar and low profile since a bulky balun is not required. Both the microstrip balun and the spiral arms are inkjet printed on LCP. The fabricated antenna covers a wideband frequency range (1~8GHz) that corresponds to L, S, and C bands.