Planar inverted-L Antenna Research Articles

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.

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 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.

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>

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

A circular planar inverted‐L antenna with a vertical ground plane

AbstractA new broadband planar inverted‐L antenna (PILA) with a vertical ground plane (VGN) is experimentally presented. With the electromagnetic coupling between the radiator and VGN, the 2:1 VSWR impedance bandwidth of &gt; 45% has been attained. The radiation patterns similar to those of conventional planar inverted‐ L or F antennas are applicable for land mobile communication systems. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 315–317, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10594

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