Tunable Magneto-Dielectric Material for Electrically Small and Reconfigurable Antenna Systems at Vhf Band (original) (raw)

Magnetodielectric Material for VHF Antenna Devices Tunable by a Low DC Magnetic Field

IEEE Transactions on Magnetics

This study presents the performance of a magneto-dielectric material (MDM) specially developed to enable the tunability of antenna devices operating in the VHF band. A current flowing through the sample, which creates a DC magnetic field inside the sample with the same symmetry as the magnetic domains, controls the magnetic susceptibility variation of the MDM. By changing the magnetization state of the MDM with a low DC magnetic field of 740 A.m-1 , a tunability of 40% can be observed. The MDM tunability at VHF frequencies is also highlighted by microwave measurements for different magnetization states.

Overview of reconfigurable and compact antennas using a magneto-dielectric material

2011

This paper presents two novel designs based on the design of a 3D compact inverted F antenna which is dedicated to low frequencies handheld applications. Good performances, compactness and low frequencies are obtained thanks to a magneto-dielectric material. Indeed, using a magneto-dielectric material in comparison to use a pure dielectric material allows obtaining a wideband compact antenna. A complete study will show the advantage of using a magneto-dielectric material. Since reconfigurable radiation patterns allow improving the quality and reliability of wireless links, for both designs, two antennas are used to release this feature over its matched band.

Experimental studies on antenna miniaturisation using magneto-dielectric and dielectric materials

IET Microwaves, Antennas & Propagation, 2011

Measurement results for a meandered planar inverted-F antenna (PIFA) loaded with magnetodielectric and dielectric materials are presented. Figures of merit and ways to compare antennas with different fillings materials are discussed. The used magneto-dielectric material is described, the radiation mechanism of the meandered PIFA is studied, and the proper position for dielectric and magneto-dielectric filling is discussed and identified. Identical-size antennas with dielectric and magneto-dielectric fillings are compared at the same resonance frequency using the radiation quality factor as the figure of merit. It is seen, that the benefit from the magneto-dielectric filling material is moderate and strongly dependent on the positioning of the filling.

Experimental Studies of Antenna Miniaturization Using Magneto-Dielectric and Dielectric Materials

2009

Measurement results for a meandered planar inverted-F antenna (PIFA) loaded with magneto-dielectric and dielectric materials are presented. Figures of merit and ways to compare antennas with different fillings materials are discussed. The used magneto-dielectric material is described, the radiation mechanism of the meandered PIFA is studied, and the proper position for dielectric and magneto-dielectric filling is discussed and identified. Identical-size

A New Magneto-Dielectric Material Loaded, Tunable UHF Antenna for Handheld Devices

IEEE Antennas and Wireless Propagation Letters, 2000

In this letter, the impact of a magneto-dielectric resonator on a DVB-H antenna is investigated. A frequency reconfigurable antenna using a folded monopole antenna structure and varactor diodes is proposed. Two different designs are realized with and without the resonator. A measured instantaneous 6-dB bandwidth wider than 8 MHz is obtained continuously between 470 and 862 MHz for both prototypes. Design methodology is described. Measured return loss, gain, directivity, and radiation pattern are presented for different frequencies.

Ultra-miniature UHF antenna using magneto-dielectric material

Electronics Letters, 2011

This paper introduces an ultra-miniature UHF antenna. The design combines different technologies to reduce the size:(meta-material inspired shape, use of a magnetodielectric material as antenna support, use of an active component and a passive matching network for frequency tuning and impedance matching over the whole UHF band.) This antenna has been simulated and measured on nomad type terminal well suited for video applications.

Electronically Tunable Miniaturized Antennas on Magnetoelectric Substrates With Enhanced Performance

IEEE Transactions on Magnetics, 2008

Achieving relative permeability larger than 1 in antenna substrates can lead to antenna miniaturization, enhanced bandwidth, and tunable resonant frequency. Metallic magnetic films and self-biased ferrite films were introduced as a practical means to tune a patch antenna by loading a commercially available substrate in this paper. Novel antenna designs with metallic magnetic films and self-biased NiCo-ferrite films were investigated. Magnetic patch antennas were demonstrated at 2.1 GHz with a tuning resonant frequency range of 5-10 MHz (with the metallic magnetic films) and 7-23 MHz (with self-biased ferrite films). Three different cases of annular ring antennas with NiCo-ferrite films loading were also designed and analyzed. Antennas with self-biased magnetic films loading working at 1.7 GHz with a tuning range of 3-20 MHz were achieved.

MAGNETO-DIELECTRIC LOADED PATCH ANTENNAS

In this section we study application of nanotechnology to passive electronic communication RF device microstrip patch antennas for miniaturization (size reduction) and bandwidth enhancement by engineering the antenna substrate part without altering the radiating part. Present day communication systems demand highly miniaturized and higher data rate bandwidth antennas. However, at present conventional patch antennas suffer from narrow bandwidth and lower gain performance if we try to miniaturize using high permittivity dielectric substrates, slots in the patch, meandering the radiating patch, highly sophisticated algorithms design and fracturing the conductive parts of the antenna etc. Rapid advances in nanotechnology have made it possible to develop a new substrate called magneto-dielectric material. These materials contain both electric permittivity (ɛ r) and magnetic permeability (µ r) properties greater than one. (ɛ r, µ r > 1). Using nanotechnology the above properties can be tailored. The magneto-dielectrics find applications in miniaturizing of RF devices like microstrip patch antennas and two dimensional high frequency planar capacitors and inductors. However, magneto-dielectrics are not available in nature. They have to be synthesized and fabricated using nanotechnology tools and techniques. To fabricate magneto-dielectrics, nano magnetic particles are added into dielectric material. The effect of adding nano magnetic particles in to dielectric material reduces strong field boundaries and the medium is far less capacitive when compared to high permittivity material only. So, with magneto-dielectric material, in addition to RF component miniaturization, improvement in bandwidth and near impedance match between material (Z m) and free air (Z free space) can be achieved.

Frequency Tunable Antenna Using a Magneto-Dielectric Material for DVB-H Application

IEEE Transactions on Antennas and Propagation, 2000

This paper presents an ultracompact antenna design suited for digital video broadcasting-handheld (DVB-H) reception devices. The DVB-H frequency band is ranging from 470 to 862 MHz and divided in 49 channels of 8 MHz. Designed to be integrated in a tablet, it is not only heavily miniaturized ( at 470 MHz), but also able to cover each channel thanks to the use of a magneto-dielectric material. The advantage of using such a material is studied and described in this paper. Moreover, the operating frequency is continuously tuned over the whole DVB-H band by the integration of a varactor diode. This varactor diode has been characterized and modeled to properly cosimulate its behavior within the antenna. Limitations in terms of accepted power by the diode are emphasizing. Finally, the antenna design, including both magneto-dielectric material and varactor diode is integrated in the DVB-H receiver device. Measurement performances are presented and discussed.

Miniature reconfigurable antenna with magneto dielectric substrate for DVB-H band

2013

In this article, we present a frequency reconfigurable antenna for digital video broadcasting on handheld devices standard. By loading a printed inverted F antennas with a varactor diode, the resonance frequency can be tuned from 470 to 862 MHz. Furthermore, a magneto dielectric superstrate is used to reduce the dimension of the antenna while keeping a large bandwidth. To study the performance improvement due to the magneto-dielectric resonator,a comparison is performed with a reference antenna without magneto-dielectric superstrate.