A miniaturized dual‐mode band‐pass filter (BPF) using Minkowski‐island‐based (MIB) fractal patch resonator is presented in this article. The BPF is mainly formed by a λg/4 square patch resonator, which is a MIB fractal configuration with second order iteration is embedded in the patch. By tuning the perturbation, which resulted from the fractal patch, two resonant modes are excited and a pair of transmission zeros are generated to improve the BPF performance. The proposed filter at center frequency (f0) of 630 MHz has very good measured characteristics including the bandwidth of 552–708 MHz (3‐dB fractional bandwidth of 24.8%), low insertion loss of –1.38 dB and size reduction with 76.4%. The filter performance is characterized to verify the design concept. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:594–597, 2011; View this article at wileyonlinelibrary.com. DOI 10.1002/mop.25796

A new circularly-polarized (CP) sleeve antenna fed by a CPW for DTV signal reception applications is presented in this paper. The CPW-fed sleeve monopole antenna consists of square loop sleeve, CPW-fed and complementary SIR radiators. The lower and upper resonance frequencies of the desired band are controlled by the complementary SIR arms, making designs of the wide-band antenna very easy. To demonstrate the idea, the proposed antenna was designed at the band with 470-863 GHz (BW = 393 MHz, 58.9%) for DTV UHF-bands. The antenna gains are varied about 2.2 to 4.0 dBi. An omnidirectional radiation property is also shown. The CP operation for the proposed design can be achieved by properly adjusting the asymmetrical radiators. The reflection coefficient, axial ratio, radiation pattern and gain of the proposed antenna were studied, and reasonable agreement between the simulated and measured results was obtained.