Low-Profile Frequency-Reconfigurable LTE-CRLH Antenna for Smartphones

A Shahgholi,G Moradi,A Abdipour

doi:10.1109/access.2020.2971518

Abstract

This paper presents a monopole antenna loaded with one frequency-reconfigurable composite right/left-handed (CRLH) unit cell. This antenna is designed by means of two varactor diodes and with changing capacitance operating at LTE700 (698-798 MHz), LTE850 (824-894 MHz), LTE900 (880-960 MHz), LTE1700 (1710-2155 MHz), LTE1800 (1710-1880 MHz), LTE1900 (1850-1990 MHz), LTE2100 (1920-2170 MHz), LTE2300 (2305-2360 MHz), LTE2500 (2496-2690 MHz), LTE2600 (2500-2690 MHz), and GPS (1176 MHz, 1227 MHz) frequencies that cover most of the LTE bands for smartphone handsets, which is a combination of two distributed and compact modes, in which the varactor diodes, as compact elements, play a significant role in reducing the antenna dimensions. By changing the capacitance, the entire frequency band of 700 MHz and 900 MHz was achieved. The CRLH structure, in turn, reduces the dimensions of the antenna and generates resonant frequencies less than the resonance frequency of the monopole. At these frequencies, the radiation patterns are quasi-omnidirectional.

Highlights

In recent years, the development of smart handsets as an indispensable part of modern life has rapidly grown
The present article discusses the improvement of the composite right/left-handed (CRLH) multiband monopole antenna from reference [21] for full coverage of the LTE700 and LTE900 frequency bands that consists of two parts: optimization of the antenna unit cell size, which includes a distributed segment, and the addition of varactor diodes to enable antenna frequency reconfigurability to select and access the frequencies that provide the antenna’s compression portion
This study focuses on CRLH propagation as one of the many variations of MTMs, which represents the most general MTM structure possible

Summary

INTRODUCTION

The development of smart handsets as an indispensable part of modern life has rapidly grown. The increment of the electrical length of the based antennas is achieved by hybrid termination as well as by adding the possible frequency bands at a low profile size [19] In another case, the dipole antenna is loaded with two new and different CRLH unit cells that cause smaller sized dipole antennas with three bands [20]. The present article discusses the improvement of the CRLH multiband monopole antenna from reference [21] for full coverage of the LTE700 and LTE900 frequency bands that consists of two parts: optimization of the antenna unit cell size, which includes a distributed segment, and the addition of varactor diodes to enable antenna frequency reconfigurability to select and access the frequencies that provide the antenna’s compression portion. For every capacitance that the varactor diodes create for each applied voltage, the proposed antenna produces two additional frequencies below the monopole resonance

MONOPOLE ANTENNA LOADED WITH RECONFIGURABLE CRLH UNIT CELL MT

CONCLUSION