International Journal

This paper shows that the two most common impedance transformation networks for power amplifiers (PAs) can be designed to achieve optimum transformation at two frequencies. Hence, a larger bandwidth for the required impedance transformation ratio is achieved. A design procedure is proposed, which takes imperfections like losses into account. Furthermore, an analysis method is presented to estimate

An N-band resonator, particularly well-suited for reconfigurability, is presented in this paper together with its synthesis. The resonator is based on the association of an N-band dual-behavior resonator and tunable capacitors. Its topology consists of a parallel association of N + different bandstop structures, each one composed of a stub terminated by a capacitor. N pass bands, separated from e

A compact asymmetric coplanar strip (ACS)-fed monopole antenna for dual-band application is presented. The single-layer antenna composed of inverted L-shaped exciting strip and an L-shaped lateral ground plane. The antenna resonating at two different frequencies, 2.4 and 5.8 GHz is covering the wireless local area network/radio frequency identification bands. The antenna has an overall dimension o

A planar circularly polarized (CP) monopole antenna (MA) with dual-band operation for the IEEE 802.11a/b/g wireless local area network (WLAN) is proposed. By introducing dual strip-sleeves shorted at the ground plane, the excitation of dual-resonant modes can resemble the 2.4/5.2 GHz bands required for WLAN operations. The obtained impedance bandwidths (RL ?10 dB) across the operating bands approa

In this paper, a switchable antenna with capability to operate in ultrawideband (UWB) frequency from 3 to 10.7 GHz with two switchable notch bands of 3.3?3.7 and 3.7?4.2 GHz, is presented for cognitive radio (CR) and multiband orthogonal frequency-division multiplexing (MB-OFDM) applications. The proposed antenna has a simple structure and compact size of 17 × 24 mm. The antenna in the UWB charact

A simple and compact microstrip antenna of circular geometry with circular cut defected patch surface has been proposed for significant suppression of cross-polarized (XP) radiation compared with maximum co-polarized gain without affecting the co-polarized radiation pattern at its dominant mode. This will enhance the polarization purity in the radiation performance of the proposed antenna. About 2

This paper proposes a compact, low-loss, and low-cost phase shifter for millimeter-wave/sub-THz applications. The basic idea is to perturb the propagation constant of a high resistivity silicon image guide by high-dielectric constant barium lanthanide tetratitanates (BLT) ceramic loading. Three different BLT ceramic samples have been tested. The measured maximum phase-shift variation reaches 150°

A novel compact multiple-input?multiple-output (MIMO) antenna system operating from 5 to 7.3 GHz is proposed for wireless applications. It comprises of two similar antennas with microstrip feeding and radiating patches developed on a reduced ground plane. The developed antenna system resonates at a dual-band of 5.4 and 6.8 GHz frequencies, giving an impedance bandwidth of 38% (based on S11 < ?10 d