Patent Application
20150311591
The present invention relates to printed antennas for radiating and receiving electromagnetic waves and, more particularly to a low profile, printed circuit board (PCB) antenna.
Printed antennas such as PCB based antennas as known in the art may include a plurality of layers having various shapes, size and thickness, where each layer is interconnected with conductive vias, to further provide electrical connections for complex electronic circuitry. Conventional PCBs include a rigid substrate to provide support for mounting electronic components in communications and sensing devices. In addition, conductive materials are plated over such substrates and etched to provide electrically conductive traces for interconnecting these components.
For many devices, antennas are typically formed on the same PCBs, which also carry transmitting and receiving radio frequency (RF) circuitry. A common technique employed to form antennas on PCBs is to simply etch conducting surfaces composing the antenna, having an antenna feeder trace coupled to desired components on the PCB. Since space is limited in the ever-decreasing size of today's devices, such antenna traces are typically formed near one or more ground planes formed on the same PCB. In such arrangements, a portion of the PCB substrate, typically the area of a PCB having the highest density of electromagnetic energy, remains in between the antenna and the ground plane, impacting antenna efficiency and bandwidth.
More specifically, as radio signals travel along an antenna trace, a portion of the signals are typically “lost” through energy loss or dissipation in the medium around the antenna trace, especially the medium between the antenna trace and the ground plane. The portion of total initial RF signals radiated into the surrounding space determines the antenna transmission efficiency (measured in dB) of the antenna. The same principle applies for antenna reception. Ideally, a 100% efficiency (0 dB loss) would be achieved if all of the RF signals traveling through the antenna were radiated into the surrounding space. However, as may be expected, the material from which a PCB is constructed has a large impact on the percentage of RF signals that are dissipated into PCB material surrounding the antenna structure.
According to one embodiment of the prior art, a printed antenna may include a single conducting layer and a single dielectric layer while a more complicated printed antenna design may include a multi-layer configuration, including a plurality of conducting interconnections (e.g. via holes) between the conducting layers.
A multi-layer printed antenna may be formed on a dielectric substrate (non-conducting) and conducting substrate, where each adjacent pair of conducting layers are separated by at least one dielectric layer. Commonly used materials used for a multi-layer PCB antenna include for example glass-epoxy or Teflon (PTFE) (i.e. the dielectric materials) and copper (i.e. the conducting material).
Printed circuit antennas are often used in antenna arrays, when the printed circuit board technology is used to produce a group of antennas using a common substrate.
There are multiple performance criteria applicable to antennas: gain, bandwidth, matching, impulse response duration are an example of some. In antenna arrays, coupling between antennas in an array is an important factor.
It is an objective of the present invention to provide printed circuit antennas with low ringing time and reduced mutual coupling between the antennas, for example in an antenna array.
It is an object of the present invention to provide an antenna or an antenna array system with an improved input impedance and port matching.
It is another object of the present invention to provide an antenna array with an optimal isolation between the antenna elements in an array.
It is further another object of the present invention to provide an antenna array with an increased antenna bandwidth.
According to a first aspect of some embodiments of the present invention, there is provided an antenna comprising: a plurality of dielectric layers, and a plurality of conducting layers, wherein at least one of said dielectric layers comprises one or more regions with differing dielectric properties.
In an embodiment the regions differ in the dielectric constant of a material embedded in said regions.
In an embodiment the antenna the regions are lateral regions in said dielectric layers.
In an embodiment the regions differ in the absorption coefficient of the material.
In an embodiment the antenna is produced using printed circuit board manufacturing techniques.
In an embodiment said material is embedded within said plurality of layers.
According to a second aspect of some embodiments of the present invention, there is provided an antenna array having a plurality of dielectric and conducting layers, said antenna comprising: a radiating component etched in said array top first layer; a reflector embedded in a second layer below said top layer; a feeding network located in a third layer below said reflector; a ground plane bottom layer configured to shield said feeding network in said bottom layer, wherein one of said layers is a non-uniform dielectric layer, said non-uniform dielectric layer comprises a material having a substantially different electrical properties compared to said array dielectric and conducting layers.
Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.
Implementation of the method and/or system of embodiments of the invention can involve performing or completing selected tasks manually, automatically, or a combination thereof. Moreover, according to actual instrumentation and equipment of embodiments of the method and/or system of the invention, several selected tasks could be implemented by hardware, by software or by firmware or by a combination thereof using an operating system.
For example, hardware for performing selected tasks, according to embodiments of the invention, could be implemented as a chip or a circuit.
The subject matter disclosed may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
The present invention relates to printed antennas for radiating and receiving electromagnetic waves and, more particularly to a low profile, printed antenna comprising non-uniform dielectric layers.
As illustrated in
The present invention provides a printed antenna, such as a multi-layer antenna comprising one or more non-uniform dielectric layers. More specifically the present invention provides a printed antenna comprising a plurality of dielectric layers, and a plurality of conducting layers, wherein at least one of the antenna's dielectric layer contains regions, such as lateral regions or sections with differing dielectric properties. According to one embodiment of the invention an absorbing material, such as an ECCOSORB® by Emerson & Cuming, is embedded within the dielectric layers, resulting in a non-uniform dielectric layer.
Typically, a power reflection coefficient of −10 db or lower is considered to be adequate in many applications having antennas or antenna arrays. The present invention provides an easy and simple mechanism to allow a broadband input matching, which according to prior art solutions is difficult and cumbersome to implement.
Reference is now made to
According to one embodiment of the invention at least one of the layers such as the dielectric layer 215 may be a non-uniform dielectric layer including an element 219 comprising a material having a substantially different electrical properties compared to the layers (i.e. 215) hosting original material (i.e. FR4 Fiberglass as shown in
According to another embodiment of the invention there is provided a low profile antenna array embedded in a substrate such as a multi-layer PCB including one or more non-uniform layers such as a non-uniform dielectric layer surrounding the antenna array.
The introduction of an absorbing material as part of a standard laminate as illustrated in
These advantages are further illustrated in
The terms “comprises”, “comprising”, “includes”, “including”, “having” and their conjugates mean “including but not limited to”. This term encompasses the terms “consisting of” and “consisting essentially of”.
As used herein, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise.
It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.
Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.
| Number | Date | Country | |
|---|---|---|---|
| 61984820 | Apr 2014 | US |
