Input Impedance and Performance Analysis of Series-Fed Microstrip Patch Array Antenna

Abstract

This paper presents input impedance and performance analysis of a series-fed 2×1 patch array antenna operating at 9.55 GHz. Effects of substrate's dielectric constant and height are discussed. Input impedance is optimized step by step from a single patch to a 2×1 array. Low impedance patches provide higher gain at the cost of increased capacitive coupling between the elements. Consequently, input impedance at the operating frequency is affected by the higher resonant mode. Finally, a technique to mitigate the coupling between the patches is proposed. With the proposed technique, the higher resonant mode can be eliminated so that the 2×1 array can easily be matched and operates with the correct patch array mode.