The bore-sight direction of an antenna corresponds to an axis of maximum gain (maximum radiated power). In many cases there is a requirement for thin, directional, wideband or even Ultra-Wideband antennas to have suitable bore-sight performance. One such example is used in medical devices, where the bore-sight direction can be configured for use in/on human tissue, either attached against skin for a non-invasive application, or against muscle or any internal tissue/organ for invasive applications.
In prior art directional antennas, the antenna is designed so that a substantial percentage of the antenna's power is typically radiated in the bore-sight direction. However, in such prior art antennas, some residual power (in some cases, up to about 20%) typically radiates in an opposite direction, which is known as “back-lobe” radiation. These prior art antennas typically include a reflector at a distance of λ/4 that allow the energy radiated backwards to be properly reflected towards the main lobe. However, in some instances, upon antenna dimensions or the radiated bandwidth do not allow for such structure, other alternatives must be sought to avoid, for example, out-of-phase interference with the main lobe direction propagating waves, and/or avoid back lobe radiation.
Embodiments of the present disclosure provide methods, apparatuses, devices and systems related to a broadband transceiver slot antenna configured to radiate and receive in the UHF frequency band. Such antenna embodiments may include several slot-shapes configured to optimize one and/or other antenna parameters, such as, for example, bandwidth, gain, beam width. Such embodiments may also be implemented using, for example, a number of different, printed radiating elements such, for example, a spiral and/or dipole.
In some embodiments, antenna systems and devices are provided to achieve reasonable performance with thin directional RF antennas, and in particular, those used in medical devices (for example).
In some embodiments, a system, method and/or device are presented which implements back-lobe, dissipation and/or reflection functionality. Accordingly, in the case of back reflection, some embodiments of the disclosure present a PCB based antenna which includes an absorbing material which helps to eliminate non-in phase reflection. In some embodiments, this may be accomplished by minimizing the thickness dimension of the antenna, typically parallel to the bore-sight. In some embodiments, the noted functionality may be incorporated in internal printed-circuit-board (PCB) layers of an antenna. In some embodiments, the thickness of the antenna is less than λ/4, and in some embodiments, much less (e.g., is <<λ/4). To that end, absorbing material included in some embodiments includes a thickness less than λ/4 (and in some embodiments is <<λ/4).
In some embodiments, a printed circuit board (PCB) is configured with radio-frequency functionality. The PCB board may comprise a plurality of layers (the PCB structure may also be a separate component in addition to the plurality of layers). In some embodiments, at least one layer (which may be an internal and/or centralized layer) may comprise one or more printed radio-frequency (RF) components and at least one embedded element comprising at least one of a magnetic material and an absorbing material.
In some embodiments, the PCB further comprises an antenna, which may comprise a wideband bi-directional antenna. The PCB may additionally or alternatively include a delay line.
In some embodiments, the PCB can further include a temperature resistant absorbing material, e.g., which may be resistant to temperatures fluctuations between 150° C. and 300° C., for example.
In some embodiments, the absorbing material may be covered with a conductive material comprising, for example, at least one of a row of conductive vias, a coated PCB layer(s), and other structure(s). Additionally, the absorbing material may be placed above the radiator layer of at least one antenna, embedded (for example) in the plurality of layers comprised by the PCB. In some further embodiments, the absorbing material can be surrounded by a conductive hedge structure.
In some embodiments, the PCB (e.g., one or more, or all of the layers thereof) may be made of at least one of a ceramic, silicon based polymer (i.e., a high temp polymer), and ferrite material.
In some embodiments, the PCB structure includes a plurality of electronic components. Such components may comprise radio-frequency generating components, data storage components (for storing data corresponding to reflected radio waves), and processing components (for analyzing collected data and/or other data).
In some embodiments, the PCB can include a directional antenna with a radiating element backed by a metallic reflector. The distance between the radiating element and the metallic reflector can configured, for example, to be less than about a quarter of the wavelength of a received or transmitted RF signal, and in some embodiments, substantially less (e.g., in some embodiments between greater than 0 and about 15% the wavelength, and in some embodiments, between greater than 0 and about 10% the wavelength).
In some embodiments, the PCB may further comprise a cavity resonator, a radiating element, and a plurality of rows of conducting vias. The resonator may be arranged behind the radiating element—being separated by at least one of the plurality of rows of conducting vias. The radiating element may include internal edges having a coating of conductive material.
In some embodiments, the PCB may include one or more openings configured to release gas pressure during a lamination process to produce the PCB. The one or more openings may comprise vias, channels and/or slots. The vias may be configured as through-hole vias, blind vias and/or buried vias, for example. The one or more openings may be filled with a conducting or a non-conductive material.
In some embodiments, the RF structures may comprise delay lines, circulators, filters and the like.
In some embodiments, the antenna may comprise an antenna array 100 which includes a plurality of antennas 102 (e.g., two or more antennas), and one or more of antennas 102 may comprise at least one of a wideband directional antenna(s) and an omnidirectional antenna(s). In the embodiments illustrated in
Accordingly, by implementing the antenna and electronics on a single printed circuit board (PCB) structure, a reduction in cost and size can be realized, as well as an elimination of the need for RF connectors.
In some embodiments, arranging radiating element 212 at a distance λ/4 from the reflector 214, the in-phase reflected waves 210 are coherently summed to signals/waves 208 transmitted from the radiating element 212 and propagated in the opposite direction to that of the reflector 214 direction. In such cases, a maximum efficiency may be achieved by configuring the distance 202 between the radiating element 212 and the reflector 214.
Accordingly, when the reflector 214 is arranged at a distance equivalent to d<<λ/4 (i.e., a distance that is much less than the transmitted RF wavelength's divided by four) such that, the reflected waves 210 are summed out-of-phase with the signals 208 propagated from the radiating element 212, which can substantially degrade the antenna's performance, up to, for example, a full main lobe cancelation.
In some embodiments, where the distance d is <<λ/4, an absorptive material may be arranged between the radiating element 212 and the reflector 214, enabling proper gain performance at the main lobe direction of some embodiments in the ultra-wide band bandwidth, and moreover, may substantially reduce the antenna's thickness. In some embodiments, depending on the required performance, the thickness of an antenna may be reduced up to a factor of ten or more.
The absorbing material 302 can be used to dissipate back-lobe radiation, can be placed above the antenna radiator layer embedded in the internal layers of the PCB structure. In some embodiments, the shape and thickness of this absorbing material is optimized for example larger dimensions may improve performance for lower frequencies. For example a thicker absorbing material improves performance but increases the antenna's dimensions. The absorbing material may comprise and/or be based on a dissipater made of a ferrite material and/or flexible, magnetically loaded silicone rubber non-conductive materials material such as Eccosorb, MCS, and/or absorbent materials, and/or electrodeposited thin films for planar resistive materials such as Ohmega resistive sheets.
Example embodiments of the devices, systems and methods have been described herein. As may be noted elsewhere, these embodiments have been described for illustrative purposes only and are not limiting. Other embodiments are possible and are covered by the disclosure, which will be apparent from the teachings contained herein. Thus, the breadth and scope of the disclosure should not be limited by any of the above-described embodiments but should be defined only in accordance with features and claims supported by the present disclosure and their equivalents. Moreover, embodiments of the subject disclosure may include methods, systems and devices which may further include any and all elements/features from any other disclosed methods, systems, and devices, including any and all features corresponding to antennas, including the manufacture and use thereof. In other words, features from one and/or another disclosed embodiment may be interchangeable with features from other disclosed embodiments, which, in turn, correspond to yet other embodiments. One or more features/elements of disclosed embodiments may be removed and still result in patentable subject matter (and thus, resulting in yet more embodiments of the subject disclosure). Furthermore, some embodiments of the present disclosure may be distinguishable from the prior art by specifically lacking one and/or another feature, functionality or structure which is included in the prior art (i.e., claims directed to such embodiments may include “negative limitations”).
Any and all references to publications or other documents, including but not limited to, patents, patent applications, articles, webpages, books, etc., presented anywhere in the present application, are herein incorporated by reference in their entirety.
This application claims priority under 35 USC § 119 to U.S. provisional patent application No. 61/897,036 filed Oct. 29, 2013, entitled “ANTENNA SYSTEMS FOR USE IN MEDICAL DEVICES AND METHODS OF MANUFACTURE THEREOF,” the entire contents of which are herein incorporated by reference. This application may contain material that is subject to copyright, mask work, and/or other intellectual property protection. The respective owners of such intellectual property have no objection to the facsimile reproduction of the disclosure by anyone as it appears in published Patent Office file/records, but otherwise reserve all rights.
Number | Date | Country | |
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61897036 | Oct 2013 | US |
Number | Date | Country | |
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Parent | 16852252 | Apr 2020 | US |
Child | 17384302 | US | |
Parent | 15033576 | Apr 2016 | US |
Child | 16852252 | US |