Recently, a 16 slot electrically small te10mode antenna yielding the quality factor q 3. While the performance characteristics of all these antennas are admirable, their structured ground planes are nontrivial and not electrically small. Electrically small folded slot antenna utilizing capacitive loaded slot lines maximilian c. Braaten department of electrical and computer engineering. Although the theory requires an infinite spread conductive surface, the deviation from the theoretical value is small when the surface is greater than the square of the wavelength. Electrically small acsfed antenna consists of an fshaped monopole radiator with a ushaped slot inserted into it. Enhancement of electrically small antennas prop erties with.
Electrically small acsfed flipped mimo antenna for usb. The sshaped metamaterial has been transform and adapted to the mobile phone requirements to obtain a small z antenna. Electrically small folded slot antenna utilizing capacitive loaded slot. Efficient radiation by electrically small antennas made of. An electrically small or electrically short antenna is an antenna much shorter than the wavelength of the signal it is intended to transmit or receive. Tsutsumi et al electrically small slot loop antenna with miniaturized matching circuit 1023 fig.
Principles and methods of creating small antenna sa. Pdf electrically small folded slot antenna utilizing capacitive. In one example, the dualband antenna includes a combination of a semispiral antenna for the uhf frequencies and a microstrip patch antenna for the lband frequencies. These slot antennas can be formed by simply making a cut on the surface, where they are mounted on. It is fabricated on a lowloss fused silica wafer through a backetch of a 5000aring golden metal film, which is 31. Skrivervik, lema, june 2008 1 electrically small antenna design anja k. An electrically small cpw fed frequency recongurable antenna muhammad saeed khan and antoniodcapobianco department of information engineering university of padova via gradenigo 6b, 351 padova, italy email. Long slot antennas andrew alford consulting engineer abstract. Mimo antenna consists of two electrically small antennas inserted inside a 3dprinted usb prototype. A study of the performance properties of small antennas. In one embodiment, the antenna is formed as an l shaped slot along two edges of the circuit board of a miniature radio transceiver.
Electrically small antenna esa the conventional slot antenna is a onewavelength center feed slot antenna as shown in fig. The following image shows the model of a slot antenna. Electrically short antennas are generally less efficient and more challenging to design than longer antennas such as quarterand halfwave antennas, but are nonetheless common due to their compact size and low cost. Pdf design and performance of an electrically small slot. Miniaturization is achieved through symmetric inductive loading of an electrically small slot section. Obtained frequency characteristic of the return loss and the calculations taking account of a kinetic inductance, and b permittivity variation. Electrically small antenna performance enhancement for nearfield detuning environments christian w. Electrically small antenna esa an esa is an antenna that satisfies the condition ka electrically small antenna degenerate band edgebased ground plane, 6. Us8629811b2 dual band electrically small tunable antenna. This can be understood by observing the image of a slot antenna. Adams, flush mounted rectangular cavity slot antennas theory. This invention discloses a small slot antenna incorporated within a flat circuit board and having a three dimension omnidirectional radiation pattern. Size reduction of cavitybacked slot antennas electrical.
Small antenna validation university of california, san diego. The highest gain for small antennas operating at 2. This paper presents an electrically small, coplanar waveguide fed, folded slot antenna that uses capacitive loading. An electrically small dualband planar tunable uhflband antenna. Efficient design of electrically small antenna using. In fact, the latter result was also predicted by wheeler in 1958 10. Pdf slot loaded electrically small rectangular patch. In the late 1930s, slot antennas and ferrite antennas were put.
Theproposed mimo antenna has dual bands which caters to wimax. In general, the slot antenna is not free to radiate on both sides of the surface on which it is cut because one side is either completely enclosed, e. Slot loaded electrically small rectangular patch antenna for. For example, placing such a slot antenna in close proximity of a large metallic object, such as a vehicle, can signi. Contrary to convention, the cava is an electrically small antenna, with an antenna width and length on the order of a quarter freespace wavelength at the lowest frequency of operation. Design and performance of an electrically small slot loop antenna with a miniaturized superconducting matching circuit. Development of an electrically small onesided directional. Let us have a look at the structure of a slot antenna. Nasa glenn research center, 2 brookpark road, cleveland, ohio, 445 usa. This paper presents three novel electrically small antenna.
An electrically small cpw fed frequency reconfigurable antenna. In this paper, we present an electrically small, lowpro. Skrivervik, lema, june 2008 17 maximum gain of an antenna the fields are expressed in spherical waves outside the sphere enclosing the antenna the poynting vector is computed in the far field the gain expressed in speherical modes is obtained from the poynting vector the gain is maximized with respec to the size of the sphere enclosing the antenna. Also included is the use of such slot antennas in arrays to obtain. Bandwidth enhancement of lowprofile omnidirectional, electrically small antennas has evolved from the design and construction of am transmitter towers eighty years ago to current market demand for battery.
The antenna includes two twinspiral type slot line short stubs and three opencircuited seriesstubs with slot line loaded at the central feed line of the cpw as impedance matching network. Nasa glenn research center, 2 brookpark road, cleveland, ohio, 445 usa 2. Dec 15, 2017 efficient design of electrically small antenna using metamaterials for wireless applications. For a practical design, however, the ground plane may be finite but large in size. Pdf this paper presents an electrically small, coplanar waveguide fed, folded slot antenna that uses capacitive loading. Electrically small, complementary electricfieldcoupled resonator antennas h. The most common definition is that the largest dimension of the antenna is no more than onetenth of a wavelength. The frequency range used for the application of slot antenna is 300 mhz to 30 ghz. When an infinite conducting sheet is made a rectangular cut and the fields are excited in the aperture which is called as a slot, it is termed as slot antenna. Guney2 1electroscience laboratory and department of electrical and computer engineering, the ohio state university, columbus, ohio, 43235, usa 2department of electrical and computer engineering, michigan technological university. Development of an electrically small onesided directional antenna with matching circuit haruichi kanaya1, ryusuke nabeshima1, ramesh pokharel1, keiji yoshida1, masato tsujii2, and ryoichi iino2 1graduate school of information science and electrical engineering, kyushu university. The thickness of the substrate and copper top metal is 0.
A dualband electrically small antenna based on impedance matching circuit is proposed. Electrically small, complementary electricfieldcoupled. Lowq electrically small spherical magnetic dipole antennas. Since antenna integration and miniaturization are two major challenges in mimo systems, we propose a slot loaded electrically small rectangular patch antenna that operates in the 0. An antenna is considered to be electrically small as a function of its overall size or occupied volume relative to the wavelength. The slot antenna was designed from the intuition of babinets principle, that a horizontal electric dipole in free space is the dual of a vertical slot and will have the same radiation pattern as. It is realized by removing a small area of metal from an infinite ground plane. Design of an efficient miniaturized uhf planar antenna electrical. The proposed antenna is compact with dimensions 11.1541 516 140 557 1393 1155 949 1241 543 1009 1154 157 1100 56 1019 934 955 184 1071 443 1054 1361 1579 273 1332 1377 1191 285 114 1374 1009 190 877 313 840