Design of planar inverted-F antennas (PIFA) for multiband wireless applications

A small three bands printed inverted-F antenna with independently controlling the resonant frequency is presented. The proposed antenna consists of two arms supported by shorting walls fed by 50 Ω microstrip transmission line and a ground plane. The antenna occupied a compact size of 26 x 25 x 3.75 mm. The main radiated patch injected with slot and another arm to generate and control the three resonant frequencies to cover 2.4, 3.7 and 5.2GHz Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX). The simulated and measured results show that the antenna achieves a gain of 2, 3 and 5 dBi respectively and radiation efficiency of 50%, 60% and 85% for the three bands respectively. The simulated and measured result for the return loss is in good agreements

Circularly Polarized Solar Antenna for Airborne Communication Nodes

A circularly polarized solar cell antenna consisting of four sequentially rotated printed inverted-F antennas is proposed. Four multicrystalline silicon solar cells act as the ground plane and the antenna is suitable for low power airborne communication nodes and wireless sensor networks. The antenna design was developed to allow 100% insolation of the cells when directly facing a light source. The low-profile antenna minimises shadowing of the solar cell for oblique angle insolation

Study of multiple antennas with defected ground slot for low-band LTE application

This study is focused on highly coupled multiple antennas with defected ground slot techniques. Two Printed Inverted-F Antenna (PIFA) are positioned at the top edge of chassis symmetrically. Both antennas are operating at low-band Long-Term Evolution (LTE) with center frequency, 829MHz. Rectangular defected ground slot is implemented to reduce the coupling effect between the antennas on the ground plane of the small chassis. Parameter study of the rectangular defected ground slot is studied with different width, W and length, L. Furthermore, the optimized dimensions of rectangular defected ground slot, W and L are simulated and presented. The optimized defected ground slot reduced the mutual coupling up to -4.5 dB. The envelope correlation coefficient (ECC) achieved less than 0.5. The ground plane of the multiple antenna structure has been further investigated by introducing another slot with a gap of 1mm between them. The achieved result is not significant in term of S-parameter and ECC compared to single defected ground slot

ANTENA PARA COSECHA DE ENERGÍA DENTRO Y FUERA DE BANDA EN RADIOFRECUENCIA DE 2.4 GHZ (ANTENNA FOR ENERGY HARVESTING WITHIN AND OUT OF BAND IN RADIOFREQUENCY OF 2.4 GHZ)

ResumenLa cosecha de energía en las bandas de radiofrecuencia (RF) es una solución prometedora para lograr sistemas de comunicación inalámbricos energéticamente auto-sustentables. La cosecha de energía busca captar energía del entorno que pueda ser recolectada y utilizada para alimentar dispositivos electrónicos. En este trabajo se analizan las oportunidades de cosecha de energía en RF dentro y fuera de la banda ISM de 2.4 GHz a través del diseño y simulación una de antena F-invertida impresa (PIFA). Se utiliza información de la energía disponible en el espectro en la banda de 1800 a 2600 MHz por medio de una campaña de medición espectral en la ciudad de San Luis Potosí.  Al analizar el ancho de banda de la antena se logra estimar la cantidad de energía de RF que pudiera ser cosechada dentro y fuera de la banda ISM de 2.4 GHz en el rango de 2-3 GHz.Palabras Claves: cosecha de energía, diseño de antena F-invertida impresa, radiofrecuencia. AbstractEnergy harvesting in the radio frequency (RF) bands is a promising solution to achieve self-sustaining energy-efficient wireless communication systems. The energy harvesting seeks to capture energy from the environment that can be collected and used to power electronic devices. This paper analyzes the opportunities for harvesting energy in RF inside and outside the 2.4 GHz ISM band through the design and simulation of a printed inverted F antenna (PIFA). Information on the energy available in the spectrum in the 1800-2600 MHz band is used through a spectral measurement campaign in the city of San Luis Potosí. By analyzing the bandwidth of the antenna, it is possible to estimate the amount of RF energy that could be harvested inside and outside the 2.4 GHz ISM band in the 2-3 GHz range.Keywords: energy harvesting, printed inverted F antenna design, radiofrequency

Ground independent planar inverted-F antenna (PIFA) for very small mobile phone

Copyright @ 2010 LAPCA small ultr-thin tri-band Planar Inverted-F Antenna (PIFA) is presented. The proposed antenna consists of slotted radiated parts supported by shorting walls and a ground plane. Intensive investigations are carried out in this paper to show that the ground plane and the antenna locations have insignificant effect on the performance of the antenna while the physical height of the radiated parts can be more significant. The radiated parts occupied a total size of 26 x 25.6 x 3.57 mm3. It designed to operate at UMTS, m-WiMAX and 5 GHz WLAN bands. Simulated and measured results are in good agreements

The Study of Reconfigurable Antennas and Associated Circuitry

This research focuses on the design of pattern reconfigurable antennas and the associated circuitry. The proposed pattern reconfigurable antenna designs benefit from advantages such as maximum pattern diversity and optimum switching circuits to realise 5G reconfigurable antennas. Whereas MIMO based solutions can provide increased channel capacity, they demand high computational capability and power consumption due to multiple channel processing. This prevents their use in many applications most notably in the Internet of Things where power consumption is of key importance. A switched-beam diversity allows an energy-efficient solution improving the link budget even for small low-cost battery operated IoT/sensor network applications. The main focus of the antenna reconfiguration in this work is for switched-beam diversity. The fundamental switching elements are discussed including basic PIN diode circuits. Techniques to switch the antenna element in the feed or shorting the antenna element to the ground plane are presented. A back-to-back microstrip patch antenna with two hemispherical switchable patterns is proposed. The patch elements on a common ground plane, are switched with a single-pole double-throw PIN diode circuit. Switching the feed selects either of two identical oppositely oriented radiation patterns for maximum diversity in one plane. The identical design of the antenna elements provides similar performance control of frequency and radiation pattern in different states. This antenna provides a simple solution to cross-layer PIN diode circuit designs. A mirrored structure study provides an understanding of performance control for different switching states. A printed inverted-F antenna is presented for monopole reconfigurable antenna design. The proposed low-profile antenna consists of one main radiator and one parasitic element. By shorting the parasitic element to the ground plane using only one PIN diode, the antenna is capable of switching both the pattern and polarisation across the full bandwidth. The switched orthogonal pattern provides the maximum spatial pattern diversity and is realised using a simple structure. Then, a dual-stub coplanar Vivaldi antenna with a parasitic element is presented for the 5G mm-Wave band. The use of a dual-stub coupled between the parasitic element and two tapered slots is researched. The parasitic element shape and size is optimised to increase the realised gain. A bandpass coupled line filter is used for frequency selective features. The use of slits on the outer edge of the ground plane provides a greater maximum gain. This integrated filtenna offers lower insertion loss than the commercial DC blocks. The UWB antenna with an integrated filter can be used for harmonic suppression. The influence of the integrated filter circuit close to the antenna geometry informs the design of PIN diode circuit switching and power supply in the 5G band. Based on the filter design in the mm-Wave band, a method of designing a feasible DC power supply for the PIN diode in the mm-Wave band is studied. A printed Yagi-Uda antenna array is integrated with switching circuitry to realise a switched 180° hemispheres radiation pattern. The antenna realises a maximum diversity in one plane. The study offers the possibility to use PIN diodes in the mm-Wave band for reconfigurable antenna designs. For the presented antennas, key geometric parameters are discussed for improved understanding of the trade-offs in radiation pattern/beamwidth and gain control for reconfigurable antenna applications

A 2.45/5.8 GHz Folded Monopole Antenna for WLAN Applications

A probe-fed printed folded monopole antenna for WLAN applications is presented. The antenna operates at 2.45 GHz and 5.8 GHz, is compact and has omni-directional characteristics in both bands. A parametric study of key geometrical parameters is reported