Planar inverted-L Research Articles

Related Reviews: Multiband Planar Inverted Antenna for Mobile Communication

Research in the field of planar inverted antennas with multiband frequencies is currently being developed. Due to the hugely increased number of mobile users, at least every time a new generation is released, a mobile communication system is released with additional features. All additional features of a mobile communication system require an antenna that resonates over a specific frequency spectrum range, meaning multiple antennas are required in a single mobile device to function across all generations for all frequency spectrums. To reduce the number of antennas on a mobile communication system device, it is necessary to design a new type of antenna that operates in a different frequency range. The inverted planar multiband antenna is designed to have changing sizes, shapes, and material properties. Types of inverted planar antennas include planar inverted-L antennas (PILA) and planar inverted-F antennas (PIFA). After analysis, the antenna designed by Juan Zhang et al. is the best solution for mobile communication systems. The designed antenna has compact antenna dimensions and four frequency bands that can be applied to N1/N78/N79 5G and 5.8 GHz WLAN. The antenna has a high gain of almost 5dB in the 5.60–7.00 GHz frequency range. They also claim that the antenna has a beam efficiency of four very high-frequency antenna points and a small side lobe that appears only at the top at the highest frequency point. But unfortunately, the antenna cannot cover the entire frequency range that must exist in a mobile communication system

Stacked Planar Inverted-L Antenna With Enhanced Capacitance for Compact Tag Design

A compact tag antenna, which has a geometrical dimension of 31.5 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times31.5$ </tex-math></inline-formula> mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times3.2$ </tex-math></inline-formula> mm, is constructed using a stacked planar inverted-L antenna (PILA) for metal-mountable applications in the UHF radio frequency identification (RFID) passband. The new antenna is formed by inserting a shorted patch into a PILA structure to create a double-layered inverted antenna, which can be viewed as a cascade of two parallel resonant tanks. An increase in electric field intensity in the antenna structure has brought in sufficient capacitance for reducing the tag resonant frequency effectively to the useful UHF RFID passband. Due to the increase in the antenna reactance, conjugate impedance matching can be easily achieved between the antenna and the microchip. Fine-tuning schemes such as stubs and slits are also incorporated with the proposed tag antenna for adjusting the operating frequency to an exact precision. Measurements show that the proposed tag antenna can achieve a read distance of 7.25 m at an EIRP power of 4 W. The resonance of the proposed tag antenna is found to be very stable and it is insensitive to changes in the backing metal platform.

A Novel 3D PILA-Type UHF RFID Tag Antenna Mountable on Metallic Objects for IoT Indoor Localization

In this paper, a novel 3D planar inverted-L antenna (PILA) Ultrahigh Frequency (UHF) Radio Frequency Identification (RFID) tag mountable on metallic surfaces is proposed for the Internet of Things (IoT) indoor localization applications. The proposed tag antenna (45 mm × 82 mm × 4 mm or 0.137λ × 0.25λ × 0.012λ) is designed for mounting on metallic objects. The 3D PILA antenna is fabricated using a copper sheet of thickness 1 mm and air as the dielectric substrate in order to minimize costs for materials and realization. In the design, T-slot has been inserted in the radiating element for tuning of the tag’s resonance for achieving good matching with the chip. Also, a simple equivalent circuit model has been obtained to analyze the impedance of the 3D PILA. Based on the optimized design, the fabricated prototype has been measured in the anechoic chamber. The resonant frequency of the proposed tag is stable, and it is not affected much by the metallic object. The measurement results of the antenna prototype demonstrated a reasonable agreement with the simulation results, and a read range of 3.6 m was measured inside an anechoic chamber. Most importantly, in the building hallway, the proposed tag is able to achieve a maximum read distance of 18 m with a transmitted power of 31.5 dBm at 867 MHz when placed on metal. With the 3D PILA antenna structure, the proposed antimetal tag is a suitable solution that can be integrated into an indoor localization scenario.

Loop-Fed Planar Inverted-L Antennas (PILAs) for Omnidirectional UHF on-Metal Tag Design

A new type of tag antenna, which is made by placing four identical planar inverted-L antennas (PILAs) in rotational symmetry constellation, is proposed for designing a miniature on-metal tag antenna. It shows good omnidirectional characteristics in the azimuth plane. In the design, the directive radiation beams of the respective PILAs are tactfully combined to form a stable omnidirectional pattern. The proposed tag is compact with a small size of 40 mm × 40 mm × 1.6 mm (0.122 λ × 0.122 λ × 0.005 λ). Here, all the PILAs are inductively excited by a circular loop, which also introduces additional reactance for improving the impedance matching. The proposed tag antenna is able to achieve a stable read distance of 5.9 m on metal in the azimuth plane when it is tested using equivalent isotropic radiated power of 4 W. The operating frequency of the tag is stable and it is not affected much by changes in the backing metal.

Compact Folded C-Shaped Antenna for Metal-Mountable UHF RFID Applications

A new type of C-shaped antenna, which is designed by combining a loop antenna and a planar inverted-L antenna, is proposed for designing a miniature tag antenna for on-metal applications. The proposed tag antenna can be easily made by folding a piece of flexible substrate. It is electrically small and low in profile, with a circuit size of 40 mm $\times40$ mm $\times1.6$ mm ( $0.122\lambda \times 0.122\lambda \times 0.005\lambda$ ). The antenna consists of five patch segments, which can be adjusted for achieving multiple degrees of tuning freedom. By tuning the antenna impedance, a conjugate match can be easily obtained. When mounted on a $20 \times 20$ cm2 metal plate, the proposed tag antenna is able to achieve a maximum read distance of 9.2 m with equivalent isotropic radiated power of 4 W, which is much better than the conventional loop antenna. The operating frequency of the proposed tag antenna is found to be very stable and it is not affected much when the dimensions of the backing metal object are varied.

Low-Profile EndFire Leaky-Wave Antenna With Air Media

A low-profile endfire leaky-wave antenna is proposed in this paper. The proposed low profile antenna utilizes microstrip line to excite planar inverted-L antenna (PILA) elements. Air media is utilized in the proposed array to realize the endfire property. By using air media, the proposed leaky-wave array maintains phase constant slightly larger than the wavenumber in free space and achieves endfire radiation. PILA elements are periodically spaced to radiate and the spacing period is designed as $\lambda _{0}$ /4 ( $\lambda _{0}$ is the wavelength in free space) to achieve a relatively wide impedance bandwidth. A prototype of the proposed endfire antenna is fabricated and tested. The measured results are consistent with full-wave simulation results. The length of the whole leaky-wave array is about $6\lambda _{0}$ , and the measured gain in the endfire direction is 11.5 dBi at 5.1 GHz.

A Compact Dual-Band MIMO Antenna for WLAN Applications

This paper presents a compact dual-band MIMO antenna that is compatible to the IEEE 802.11n wireless LAN standards. The MIMO antenna contains two tree-type elements placed back to back with distance of one-sixth wavelength of 2.4GHz; the element in the MIMO antenna is structured with a two-branch tree-type planar inverted-L monopoles, the lengths in both branches are set to the electrical quarter-wavelength of the frequency bands of 5.2GHz and 2.4GHz respectively. The MIMO antenna characterized by small size, low mutual coupling effect and nearly omni-directional coverage in radiation pattern make it entirely applicable to the mobile wireless network applications. The measurement results of the fabricated MIMO antenna demonstrate the success of the suggested design topologies.

A Low-Profile and Wideband PILA-Based Antenna for Handset Diversity Applications

A low-profile (5 mm) and wideband planar inverted-L antenna (PILA) is proposed for handset diversity and MIMO applications. It occupies a footprint area of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$702 (= 351 \times 2) ~\hbox{mm}^2$</tex></formula> over the ground plane and consists of two elements arranged utilizing both pattern and spatial diversities to provide a reasonable isolation level. The radiators consist of modified PILAs coupled with a ground plane notch that works as a parasitic radiator; a small ground plane strip is added to shift the lower edge frequency down to 1700 MHz. The single-element and dual-element antennas are analyzed in terms of the reflection coefficient and antenna impedance. Prototypes are made and the measurement results show that this design is good for mobile applications over the frequency range 1700–2850 MHz with a fractional bandwidth of 51%; it covers applications such as DCS 1800, PCS 1900, UMTS, LTE 2300 and LTE 2500, Wi-Fi, and Bluetooth (2400-2448 MHz). Finally, the diversity performance parameters are obtained and evaluated based on both simulation and measurement results. It is demonstrated that the proposed antenna design is a promising candidate for wireless hand-portable applications.

Coplanar Waveguide Fed Compact Wide Circular-Slotted Antenna for Wi-Fi/WiMAX Applications

A coplanar waveguide (CPW) fed printing and wide circular slotted, dual band antenna for Wi-Fi/WiMAX applications are presented. The antenna mainly encompasses a ground with a wide circular slot in the centre, a rectangular feeding strip, and two pairs of symmetric planar invertedL(SPIL) strips connecting with the slotted ground. The tuning effects of the rectangular patch, ground size, and SPIL strips to the resonance and matching condition are examined by HFSS and the prototype is fabricated and measured. The simulation and experimental results show that the antenna has an impedance bandwidth with −10 dB reflection coefficients 600 MHz (3.26–3.86 GHz, lower band) and 1040 MHz (5.02–6.26 GHz, upper band), which can cover both the Wi-Fi 5.2/5.5/5.8 GHz and WiMAX 3.3/3.5/3.7/5.8 GHz bands. Moreover, a stable omnidirectional radiation pattern and average peak gain for lower band 3.23 dB and upper band 5.93 dB have been achieved, respectively.

A band-suppression UWB suspended planar antenna incorporating a slotted spiral resonator

A novel miniaturized planar inverted F-L antenna assembly is considered for UWB radio operations. The antenna design utilizes the electromagnetic coupling between an air dielectric planar inverted-F antenna (PIFA) and a parasitic planar inverted-L (PIL) element, with broadband feeding from a rectangular plate. To improve the functionality of the channel, a simple notch filter has been introduced through a local modification to the broadband feed plate, this takes the form of a simple slotted rectangular spiral resonator which is etched directly onto the plate. This allows the proposed antenna to maintain its full band UWB coverage, with the HYPERLAN/2 band centered at 5.35 GHz to be effectively rejected over the sub-band 5.15–5.725 GHz, without the need for substantial re-optimization of its principal structure parameters. The impedance bandwidth operates over the full UWB band, with VSWR better than 2, this performance is not degraded by the presence of the band rejection. The observed gains, radiation patterns, and group delay confirm that the antenna has appropriate characteristics for short range wireless applications. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.

Planar Inverted-L Antenna With a Dielectric Resonator Feed in a Mobile Device

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A compact multiband planar inverted-L antenna (PILA) using a ceramic dielectric disk fed by a microstrip line in the mobile phone for GSM/DCS/PCS/UMTS operation is proposed. In this configuration, the PILA performs the functions of an effective radiator and the coupling feed structure of the ceramic dielectric disk is proposed to excite the PILA. By optimizing the proposed structure parameters, the structure resonates at two different bands to cover the desired multiband operation. In order to determine the performance of varying design parameters on bandwidth and resonance frequency, parametric study is carried out using simulation software HFSS and experimental results. The measured and simulated results show excellent agreement. </para>

Design and Performance Analysis of Compact Planar Inverted-L Diversity Antenna for Handheld Terminals

A compact planar inverted-L diversity antenna for handheld terminals is presented. Three diversity antennas operating at 2.15GHz are designed. The isolation is found to be higher than 13 dB and the usable bandwidth is about 13% in measurement. The measured radiation patterns of the proposed diversity antenna attain 2 dBi gain. Furthermore, the diversity performance with mean effective gain (MEG) is evaluated by taking both azimuth and elevation spectrum into account. A closed-form expression for MEG is presented. The effect of some parameters on MEG is analyzed numerically in indoor propagation environments.

DESIGN OF COMPACT PLANAR INVERTED-L DIVERSITY ANTENNA FOR HANDHELD TERMINALS

Antenna diversity is a well-known technique to enhance the performance of wireless communication systems. In order to create an antenna diversity system on a wireless device, two or more antenna elements could be placed in positions. However, it is difficult to implement multiple antennas on handheld terminal. A compact planar inverted-L diversity antenna for handheld terminals is provided. Three diversity antennas operating at 2.15 GHz are designed. The isolation is found to be better than 13 dB and the usable bandwidth is about 13% in measurement. The measured radiation patterns are obtained that the proposed diversity antenna attains 2 dBi gain.

A PIFA-Type Varactor-Tunable Slim Antenna With a PIL Patch Feed for Multiband Applications

A novel varactor-tuned compact multiband slim antenna for covering the digital cellular system (DCS; 1710-1880 MHz), personal communication service (PCS; 1850-1990 MHz), Universal Mobile Telecommunications System (UMTS; 1900-2200 MHz), WiBro (2300-2390 MHz), and wireless LAN (WLAN; 5150-5350 and 5725-5850 MHz) bands is presented. The proposed antenna consists of a main patch and a planar inverted-L (PIL) patch with a feed line for the broadband characteristic. A varactor diode is attached to the radiating element for frequency shift. This antenna occupied in a total volume of 27 mm times 11 mm times 5 mm can be easily placed in commercial mobile handsets. The computer simulation technology (CST) microwave studio is used to design and optimize the antenna. We found good agreement between the simulated and measured results

Dual frequency planar inverted-L bow-tie patch antenna

The characteristics of a planar inverted-L (PIL) bow-tie patch antenna in the 1–3.5-GHz band are investigated. The proposed design is based on a modified PIL patch antenna in a finite-sized ground with 50Ω microstrip feed line. The patch antenna can achieve a more flexible frequency ratio and has the advantage of easy fabrication. The experimental results are presented and discussed. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 367–369, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20988

Dual‐frequency planar inverted‐L antenna with circular‐sided patch

AbstractThe design of a dual‐frequency planar inverted‐L antenna with a circular‐sided patch is described. The proposed antenna exhibits good dual‐frequency characteristics with the frequency ratio ranging from 1.70 to 1.98. Measured results of the performance of the antenna are presented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 40–41, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20200

Dual‐frequency operation of a planar inverted‐L antenna with tapered patch width

A planar inverted-L antenna with a linearly tapered patch width for dual-frequency operation is proposed. The proposed antenna is directly fed by a 50 Ω microstrip line, and by varying the tapering angle of the radiating patch, dual-frequency operation with a frequency ratio of about 1.67–2.29 can be obtained. The two operating frequencies have the same polarization planes, and have good broadside radiation characteristics. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 28: 126–127, 2001.

Broadband planar inverted-L antennas

A new feeding arrangement applied to a broadband planar inverted-L antenna (PILA) is experimentally presented. The proposed feeding structure comprises a narrow strip excited by a coaxial probe and a grounded wall, which are etched onto a vertical finite-size dielectric slab. The measurements on the proposed square PILAs with the new feeding structures are executed. 50% impedance bandwidths for VSWR = 2:1 have been obtained and the radiation patterns similar to those of conventional planar inverted-L or -F antennas are suitable for land mobile communication systems.

Dual-frequency operation of a planar inverted-L antenna with tapered patch width

Dual-frequency operation of a planar inverted-L antenna with tapered patch width