A wideband printed dipole antenna with optimized tapered feeding balun for ISM and FWA bands

Abstract

GHz. The poor match, excess losses, and frequency shift of ϳ0.4 GHz can be attributed to losses due to coaxial connectors, conductor and dielectric losses, impedance mismatch, and fabrication errors, respectively, which were not considered in the simulation. No attempt for circuit tuning and iterations in the simulation were made in the proof-of-concept phase. CONCLUSIONA novel compact BPF using Chebyshev multisection transformer has been presented. The filter has dimensions similar to those of the hairpin filter. The filter resonates at 5.28 GHz with a 3-dB cutoff bandwidth of 0.32 GHz (6%). The filter is promising for modern RF and microwave applications.

Wideband printed dipole antenna parasitically enhanced with over-an-octave bandwidth. Dual-band variant for WLAN applications

“…A single-element antenna without any bandwidth enhancements has been previously reported by the authors in [9], in which 58% impedance bandwidth was demonstrated by simply matching the feeding network (that is, a microstrip tapered balun) to the radiating element. In this paper, we present an enhancement to this antenna, using only an additional coplanar parasitic element, and optimizing the main geometry parameters for over-an-octave bandwidth.…”

“…However, we proposed in [9] that adequate performance is achieved even for greater opening angles a (in this case, a ϭ 4Њ), yielding a taper length of approximately 14.75 mm, which is much smaller than a wavelength. Hence minimal size is maintained, which is important for the compactness of the radiator.…”

“…The tapered balun does not match the actual parallel-strips' impedance to the 50⍀ coax input, but instead is designed separately in order to optimize the overall antenna performance [9]. Therefore, a discontinuity between the balun and the parallel strips is apparent (in general, W 3 is different than W 2 ).…”

“…In order to approximate an ideal microstrip line, the groundplane must be much wider than the metallic strip. Our previous work on the optimization of this balun geometry suggests a ratio of W gp /W 4 ϭ 7, and W 4 ϭ 4.9 mm for a 50⍀ microstrip-approximated input line [9].…”

Design of multiband printed dipole antennas using parasitic elements

“…To comply with this requirement, compact and high-performance broadband/multiband planar antennas with good radiation characteristics are needed. Recently, various types of printed dipole antennas (PDAs) have been studied, as they provide easy fabrication, a simple structure, and easy integration of solid-state devices [1][2][3]. In particular, the double-sided printed dipole-antenna is one of the techniques concerning the enhancement of the impedance bandwidth, and the antenna-size reduction in case of multiband operation [4 -6].…”