A wideband dual-element planar folded dipole antenna is proposed in this letter. It is composed of a pair of asymmetric coplanar strip folded dipoles. The dual-element folded dipole antenna is fed by a microstrip feedline. With suitable design of the asymmetric coplanar strip folded dipole and the microstrip feedline, a 10-dB return-loss operating bandwidth of 107% (1.23 ~ 4.07 GHz) is achieved. By adding a metal plate, a wideband unidirectional antenna can be obtained with a measured impedance bandwidth of 113% (1.15 ~ 4.07 GHz) with better than 10 dB return loss. Its fabricated prototype is also measured with stable unidirectional radiation patterns in working band 1.13 ~ 3.3 GHz with a gain in + z-direction higher than 8.2 dBi and a front-to-back ratio better than 11.5 dB.

A Broadband Dual-Element Folded Dipole Antenna With a Reflector

Design and fabrication of triple‐band folded dipole antenna for GPS/DCS/WLAN/WiMAX applications

A compact wideband planar microstrip-fed quasi-Yagi antenna is presented. In order to achieve a high gain, the traditional rectangular director in one row is replaced by two rows of directors with an angle, and the overall size of the antenna is unchanged. By adjusting the angle between the two rows of directors, a better performance is achieved. The measurement results show that a broadband impedance about 85.5% (1.84{4.59GHz) for S11 less than i10dB and a gain about 4.5{9.3dBi are obtained. Simulation and measurement results are provided and discussed. The agreements between the simulation and measurement results indicate that the antenna is suitable for wireless communication applications and phased arrays.

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Design of a Wideband Planar Microstrip-Fed Quasi-Yagi Antenna

The problem of electromagnetic waves radiation by a vibrators system with variable distributed surface impedance along their axes located in free space is solved by the generalized method of induced electromotive forces (EMF). The distinctive peculiarity of this method is the use of the functional distributions, obtained as a result of the analytical solution of the integral equation for the current by the asymptotic averaging method before, as the basic approximations for the currents along the impedance vibrators. The multi-parameter characteristics of three-element and multi-element antennas with variable impedance vibrators are calculated.

Electromagnetic Waves Radiation by a Vibrators System with Variable Surface Impedance

Compact broadband printed quasi‐Yagi antenna with series‐fed double monopole

In this paper, a printed wideband Yagi-Uda antenna with a novel folded dipole driver is proposed. The folded dipole driver is comprised of a folded dipole and a microstrip feedline which functions as an internal balun to mainly determine its wide impedance bandwidth. With the optimized parameters, an operating band of 1:69GHz » 2:72GHz can be obtained. Besides the folded dipole driver, the broadband printed Yagi-Uda antenna also consists of three directors and a re∞ector. Its wideband performance is mainly determined by the folded dipole driver, while the re∞ector and directors improve its performance slightly. By optimizing the geometrical parameters of the folded dipole driver, a bandwidth of 61.8% (1:53GHz » 2:93GHz) for return loss being higher than 10dB is achieved. The proposed printed Yagi-Uda antenna is realized on FR4 substrate with a measured operating bandwidth of 62% (1:51GHz » 2:94GHz), a ∞at gain (5:6dB » 7:3dB), more than 10dB front-to-back ratio and lower than i15dB cross-polarization level.

https://www.jpier.org/pierc/pierc46/03.13111803.pdf

Zhaoxing Li

Papers

A Novel Design of Folded Dipole for Broadband Printed Yagi-Uda Antenna