Designing a Compact Filtering Quasi-Yagi Antenna with Multiple Radiation Nulls Using Embedded Resistor-Loaded Arms

Abstract

In this paper, a compact quasi-Yagi antenna with embedded resistor-loaded arms is proposed to obtain a filtering response with four radiation nulls. The embedded resistor-loaded arms achieve two additional radiation nulls caused by reverse currents and absorb the unwanted out-of-band resonant points brought by themselves. The director close to the driver provides a resonant point and a radiation null caused by opposite currents between the driver and the director. Compared with other filtering quasi-Yagi antennas, the proposed one can achieve a filtering response with a compact size along the endfire direction. For demonstration, a balun-integrated prototype covering the 5G band N78 (3.3–3.8 GHz) is designed with the size along the endfire direction (without ground) of 0.13 λ0 (λ0 is the wavelength in the free space at center frequency), and the measured results show a 10 dB impedance-matching bandwidth of 22.9% (3.21–4.04 GHz), four radiation nulls, and a peak gain of 4.73 dBi.

A Compact Filtering Antenna With Step and Continuous Tuning Modes for WiMAX Cognitive Radio Communication

“…The authors in [11] also proposed a combination of sensing and communication antennas but with step tuning communication mode switching between the WiMAX and the WLAN frequency bands. A quasi-Yagi filtering antenna was proposed in [12] to cover the 5G mid-band applications. Some non-planar structures were also used for the communication mode of the CR systems.…”

Passive Electrical Components Based on Cotton Fabric Decorated with Iron Oxides Microfibers: The Influence of Static and Pulsed Magnetic Fields on the Equivalent Electrical Properties

“…Passive electrical components (PECs) are elements of electrical circuits consisting of laminated solid alloy materials, often drawn in the form of semiconducting wires, that function without a power source but that can dissipate or store electrical power [1,2]. The most common elements are resistors [3][4][5], with the role of delimiting the intensity of the electric current through the electric circuits; capacitors [6], with the role of storing electrical energy in direct current circuits and with the functions of storing electrical and reactive energy in alternating current circuits; and inductors [7], with the role of storing energy in a magnetic field when an electric current flows through it. Other important categories are coils, with resistive functions in direct current circuits, and resistive and reactive functions in alternating current circuits; ferrites, which can be represented as a combination of a coil, a capacitor, and an electrical resistance; potentiometers, defined as variable resistors [8]; varistors [9]; photoresistors [10]; and thermistors [11].…”