Design of dual‐band annular slot antenna with strip‐loaded approach

This article investigation develops and experimentally explores the dual-band design for a compact coplanar waveguide (CPW)-fed annular slot antenna loaded with conducting strips.In the proposed strip-loaded design, the arc-like metal strips excite the first resonant mode at the operating frequency, which is lower than that of the annular slot antenna, to achieve miniaturization. The prototype is implemented on a 0.8 mm FR-4 substrate with er = 4.4; the outer and inner radii of the compact annular slot are 9.0 mm and 6.5 mm, respectively. The return loss of the proposed design reveals two operating bands with a VSWR of 2.5: 1 over bandwidths of 3.5% and 9.8%, respectively. Two resonant bands exhibit the broadside radiation patterns with the peak antenna gains of 1.3 dBi and 4.9 dBi, respectively. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1398–1402, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25165