A new type of directional dual-band antenna is developed for 2.4/5 GHz wireless applications. The dual-band antenna consists of a longer dipole for the lower band and a pair of shorter dipoles for the upper band. A simple coupling microstrip line is employed to excite the dipoles. Both the dual-band antenna and the feeding microstrip line are printed on the same substrate, leading to a fully pl...

The microstrip antennas have been one of the most innovative fields of antenna techniques for the last three decades. Microstrip antennas have several advantages such as lightweight, smallvolume, and that they can be made conformal to the host surface. In addition, these antennas are manufactured using printed-circuit technology, so that mass production can be achieved at a low cost. Microstrip...

Minimization of power loss in the tuning circuits of frequency-tunable small resonant antennas, such as microstrip patches, is studied. First, the frequency shift and the associated power loss in certain tuning circuits are theoretically calculated based on approximate circuit models of fairly narrow-band resonant antennas. By investigating the ratio of frequency shift and loss, an optimal conf...

A new design and experimental results of a microstripfed ultra-wideband Fermi antenna at millimeter-wave frequencies are presented. By utilizing a new microstrip-to-CPS balun (or transition), which provides wider bandwidth than conventional planar balun, the design of microstrip-fed Fermi antenna is greatly simplified. The proposed Fermi antenna demonstrates ultra-wideband performance for the f...

A new planar bow-tie antenna is proposed here for UWB applications. The self-complementary principle has been applied to a planar triangular monopole antenna along with bending the microstrip feed line. The antenna has a wider frequency band compared to the traditional bow-tie antenna, complies with the UWB requirements and it is directly matched to the (SMA) connector via 50Ω microstrip feed l...

The paper describes a theoretical investigation into a limited bandwidth operation of a microstrip reflectarray. Two main factors limiting the bandwidth are considered. One is related to the requirement of phase compensation to convert a spherical wavefront launched by a feed into a planar wavefront. The other one is linked to the limited phasing range of microstrip antenna elements. The two fa...

This paper presents a novel microstrip low-pass filter with good performance. A complete detailed theoretical analysis for the proposed filter is given using equivalent circuit models. The proposed filter applying multiple cascaded modified radial stubs resonators provides a sharp cut off frequency response that has a 185 dB/GHz roll off rate. Also, U-shaped attenuators provide a wide stop-band...

A microstrip power splitter with band-pass responses is presented in this paper. The design is based on square open loop resonator topology. This filtered power splitter does not require quarter wavelength transformers and will result in a smaller size than a conventional Wilkinson power divider with integrated band-pass filter. It is a two-way equal power splitter with fifth order band-pass fi...