• Kavitha, K.

Abstract

<jats:p>Modern communication demands a low-profile, versatile antenna. In this paper, a low-profile antenna of size <jats:inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1"><mn>38</mn><mo>×</mo><mn>40</mn><mo>×</mo><mn>0.787</mn><mtext> </mtext><mtext>m</mtext><msup><mrow><mtext>m</mtext></mrow><mrow><mn>3</mn></mrow></msup></math></jats:inline-formula> is proposed to reconfigure frequency and radiation pattern. The Rogers RT Duroid 5870 of dielectric constant 2.33 is used as a substrate. Frequency reconfiguration is achieved by connecting patches of different lengths corresponding to the resonant frequencies through three PIN diode switches. Switching on/off these three diodes results in frequency switching between four distinct frequency bands. The Yagi-Uda principle is utilized to alter the radiation pattern. Simple parasitic elements are loaded on either side of the radiating structure. Changing the electrical lengths of the parasitic elements using PIN diode switches facilitates pattern reconfiguration by making them behave as a reflector/director. The presented structure resonates at four distinct frequencies (5.3 GHz/3.82 GHz/2.77 GHz/2.2 GHz) with a maximum of three beam tilt angles for each resonating frequency. SMP1345-079LF PIN diode is used for switching operation. Biasing circuit has been designed to ensure RF and DC isolation. The proposed antenna offers acceptable radiation performance in all the switching states. The average measured gains are 2.43 dBi, 2.42 dBi, 3.5 dBi, and 3.29 dBi at 5.3 GHz, 3.82 GHz, 2.77 GHz, and 2.2 GHz, respectively. On an average, the proposed antenna exhibits the simulated efficiency of 81%. The proposed antenna is suitable for 5G communication as its bandwidth covers band 1, band 7, band 46, and band 77 of the 5G new radio (NR) standard. Fabrication and testing are done to validate the results.</jats:p>

Topics

• impedance spectroscopy
• dielectric constant