Patent Description:
As mobile telecommunications standards evolve, time is required to adapt existing infrastructure in multiple areas to accommodate new standards. Rollout rates are therefore non-homogeneous. It would therefore be desirable to provide an antenna system that is compatible with new and existing standards.

<CIT>) describes a radio frequency identification (RFID) label and an RFID label antenna. <CIT> (A1) describes a loaded antenna. <NPL>, describes a uniplanar triple-band dipole antenna.

Accordingly, in a first aspect, the present invention provides a printed dipole antenna as defined by claim <NUM>. Further embodiments are provided as defined by the dependent claims.

Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

The detailed description set forth below in connection with the appended drawings is intended as a description of presently preferred embodiments of the invention, and is not intended to represent the only forms in which the present invention may be practiced. It is to be understood that the same functions may be accomplished by different embodiments that are intended to be encompassed within the scope of the invention.

The term "about" as used herein refers to both numbers in a range of numerals and is also used to indicate that a value includes the standard deviation of error for the device or method being employed to determine the value. The term "about" as used herein can allow for a degree of variability in a value or range, for example, within <NUM>%, within <NUM>%, or within <NUM> % of a stated value or of a stated limit of a range.

Referring now to <FIG>, a printed dipole antenna <NUM> is shown. The printed dipole antenna <NUM> includes a dielectric substrate <NUM>. A plurality of antenna elements <NUM> and a reference ground <NUM> are provided on the dielectric substrate <NUM>. Each of the antenna elements <NUM> is configured to generate resonant modes for a frequency band in a radio-frequency spectrum.

The frequency band in the radio-frequency spectrum may be a first frequency spectrum of between about <NUM> megahertz (MHz) and about <NUM>, a second frequency spectrum of between about <NUM>,<NUM> and about <NUM>,<NUM>, more particularly, between about <NUM> gigahertz (GHz) and about <NUM>, and a third frequency spectrum of between about <NUM>,<NUM> and about <NUM>,<NUM>.

In the embodiment shown, the printed dipole antenna <NUM> includes a signal excitation port <NUM> coupled to the antenna elements <NUM>, the signal excitation port <NUM> being arranged to receive a first feed cable <NUM>. The signal excitation port <NUM> attached to the antenna elements <NUM> provides a signalling conductive pathway to the the printed dipole antenna <NUM>. The printed dipole antenna <NUM> may further include a first ground port <NUM> coupled to the reference ground <NUM>, the first ground port being arranged to also receive the first feed cable <NUM>. A second ground port <NUM> coupled to the reference ground <NUM> may further be provided, the second ground port <NUM> being arranged to receive a second feed cable <NUM>.

The printed dipole antenna <NUM> may have a length L of about <NUM> millimetres (mm), a width W of about <NUM> and a thickness T of about <NUM>. In the present embodiment, the printed dipole antenna <NUM> comprises two stacks or layers: a first stack or layer being the dielectric substrate <NUM> for the printed dipole antenna <NUM> and a second stack or layer being a thin copper layer printing of the antenna elements <NUM> and the reference ground <NUM>.

The dielectric substrate <NUM> may be made of a polymer film such as, for example, a polyimide film or a pyromellitic dianhydride-oxydianiline (PMDA-ODA) film. In one or more embodiments, the dielectric substrate <NUM> may be a commercially available polyimide laminate film like DuPont Pyralux® with a thickness of about <NUM> and a dielectric constant of about <NUM>. Advantageously, the polyimide film is flexible and therefore bendable. This facilitates placement of the printed dipole antenna <NUM> on various objects due to flexibility of the dielectric substrate <NUM>. An example of this is shown in <FIG> with the printed dipole antenna <NUM> being attached to a cylindrical body <NUM>.

Referring again to <FIG>, the antenna elements <NUM> may include a plurality of first decoupling loops <NUM>, <NUM> and <NUM>, the first decoupling loops <NUM>, <NUM> and <NUM> being decoupled from one another in a signal conduction path. The first decoupling loops <NUM>, <NUM> and <NUM> form mutual electromagnetic fields coupling to one another to generate multiple resonant modes in a plurality of different frequency spectrums. In the embodiment shown, the first decoupling loops <NUM>, <NUM> and <NUM> are combined to define a first antenna pattern on the dielectric substrate <NUM>. Each of the first decoupling loops <NUM>, <NUM> and <NUM> may represent or cover a different section of the radio-frequency spectrum. For example, a first of the first decoupling loops <NUM> may be designed or configured to generate or simulate antenna resonant modes for a low frequency spectrum, namely frequency bands of from about <NUM> to about <NUM>, a second of the first decoupling loops <NUM> may be designed or configured to generate or simulate antenna resonant modes for a middle frequency spectrum, namely frequency bands of from about <NUM> to about <NUM> or more particularly from about <NUM> to about <NUM>, and a third of the first decoupling loops <NUM> may be designed or configured to generate or simulate antenna resonant modes for a high frequency spectrum, namely frequency bands of from about <NUM> (<NUM>) to about <NUM> (<NUM>). In this manner, the three (<NUM>) internal or first decoupling loops <NUM>, <NUM> and <NUM>, decoupled from each other in the signalling conductive pathway starting from the excitation port <NUM>, may form comprehensive sets of resonant modes covering the entire frequency spectrum from <NUM> to <NUM> bands, thereby providing wideband antenna capabilities. Although three (<NUM>) internal decoupling loops are shown in the present embodiment, it will be appreciated by those of ordinary skill in the art that the present invention is not limited by the number of such decoupling loops. In alternative embodiments, fewer or greater numbers of such decoupling loops may be provided depending on system requirements. The antenna elements <NUM> act as a source of excitation for the printed dipole antenna <NUM> and mutually decouple the electromagnetic fields generated by antenna elements <NUM> to the reference ground <NUM>.

In the present embodiment, the reference ground <NUM> includes a reference ground plane defining a second antenna pattern on the dielectric substrate <NUM>. In the embodiment, the reference ground plane <NUM> includes a second decoupling loop <NUM>. The second decoupling loop <NUM> acts as a reference ground plane for the antenna elements <NUM> in the first antenna pattern.

In the embodiment shown, the reference ground plane <NUM> further includes a square-wave-shaped edge <NUM> adjacent the antenna elements <NUM>. The square-wave-shaped edge or teeth-shaped pattern <NUM> forms a defective ground pattern which simulates a slow-wave surface current to produce strong magnetic fields coupling to the antenna elements <NUM>. The square-wave-shaped edge <NUM> also distorts a return path of surface currents to the second decoupling loop <NUM> in the reference ground plane <NUM>. Advantageously, this increases antenna impedance bandwidth. Although illustrated as being of square-wave-shape in the embodiment shown, the edge <NUM> adjacent the antenna elements <NUM> may be a rectangular-wave-shaped edge, a triangular-wave-shaped edge or a combination of the described shapes in alternative embodiments.

Although the first decoupling loops <NUM>, <NUM> and <NUM> and the second decoupling loop <NUM> in the embodiment shown are of rectangular form, it will be appreciated by those of ordinary skill in the art that the present invention is not limited by shape or arrangement of the decoupling loops. In alternative embodiments, the decoupling loops may be of different shapes and may be differently positioned.

The first and second feed cables <NUM> and <NUM> feeding the printed dipole antenna <NUM> may be flexible cables. The first and second ground ports <NUM> and <NUM> may be soldered to the reference ground plane <NUM> with standard soldering joints to mechanically secure and electrically connect the first and second feed cables <NUM> and <NUM> to the printed dipole antenna <NUM>.

The first feed cable <NUM> may be a commonly available coaxial cable having a diameter of either <NUM> or <NUM>. The coaxial cable <NUM> may have a length of from about <NUM> to about <NUM>. The length of the coaxial cable <NUM> may be determined by performing antenna impedance matching when the printed dipole antenna <NUM> and the coaxial cable <NUM> are electrically connected to a circuit board, such as a printed circuit board (PCB), during a final product assembly stage at system level.

The second feed cable <NUM> may be utilized as a current return path or for grounding. The ground cable <NUM> may be a single core wire connecting to a ground port of either a PCB or system. As an example, the single core wire may be a <NUM>-gauge wire having a core diameter of <NUM> according to the American Wire Gauge (AWG) system.

The printed dipole antenna <NUM> was simulated and performance was verified using full-wave electromagnetics Computer Aided Design (CAD) simulation tools, specifically, CST Microwave Studio. The simulation results are shown in <FIG> described below.

Referring now to <FIG>, reflection coefficient or return loss in decibels (dB) of the printed dipole antenna <NUM> was simulated across a frequency spectrum of from <NUM> to <NUM> to cover both Long-Term Evolution (LTE) and fifth-generation-New Radio (<NUM>-NR) bands. The simulation results show that typical reflection coefficient ranges of from <NUM> dB to <NUM> dB over frequency was achieved, meeting the minimum requirement of <NUM> dB in an industrial standard.

Referring now to <FIG>, peak gain of the printed dipole antenna <NUM> against frequency is shown. As can be seen from <FIG>, a gain of <NUM> to <NUM> decibels-isotropic (dBi) was observed across the LTE bands and a gain of <NUM> dBi was observed across the <NUM>-NR bands.

Referring now to <FIG>, a two-dimensional radiation pattern plot in the YZ plane of realized gain against angular theta angles with phi angle fixed at <NUM> degrees (°) and frequency targeted at <NUM> overlapping with the printed dipole antenna <NUM> is shown.

Referring now to <FIG>, a three-dimensional radiation pattern plot of realized gain targeted at <NUM> overlapping with the printed dipole antenna <NUM> is shown. The donut structure of the radiation pattern shown in <FIG> demonstrates that the printed dipole antenna <NUM> contains the characteristics of a dipole antenna.

Referring now to <FIG>, a three-dimensional radiation pattern plot of realized gain targeted at <NUM> overlapping with the printed dipole antenna <NUM> is shown.

The simulation results show that the wideband printed dipole antenna <NUM> is able to achieve good performance over wideband across the frequency spectrum of from <NUM> to <NUM> bands and also yield high peak gain ranges from <NUM> to <NUM> dBi.

As is evident from the foregoing discussion, the present invention provides a wideband printed dipole antenna with multiband capability and high gain. Advantageously, the wideband antenna of the present invention may serve as a bridging channel between existing and new wireless telecommunications standards. For example, the wideband antenna of the present invention may be compatible with evolving fifth-generation-New Radio (<NUM>-NR) technology and at the same time, serve as a bridging channel for existing Long-Term Evolution (LTE) technology in Artificial Intelligence (AI), machine learning, Internet-of-Things (IoT), Machine-to-Machine (M2M) in wireless communications, medical and real-time transportation monitoring.

While preferred embodiments of the invention have been illustrated and described, it will be clear that the invention is not limited to the described embodiments only. Numerous modifications, changes and variations will be apparent to those skilled in the art without departing from the scope of the invention as described in the claims.

Claim 1:
A printed dipole antenna (<NUM>), comprising:
a dielectric substrate (<NUM>);
a plurality of antenna elements (<NUM>) on the dielectric substrate (<NUM>), wherein each of the antenna elements (<NUM>) is configured to generate resonant modes in a different section of a radio-frequency spectrum to provide wideband antenna capabilities, and wherein the different sections of the radio-frequency spectrum comprise a first frequency spectrum of between about <NUM> megahertz, MHz, and about <NUM>, a second frequency spectrum of between about <NUM>,<NUM> and about <NUM>,<NUM>, and a third frequency spectrum of between about <NUM>,<NUM> and about <NUM>,<NUM>;
a reference ground (<NUM>) on the dielectric substrate (<NUM>);
a signal excitation port (<NUM>) coupled to the antenna elements (<NUM>), wherein the signal excitation port (<NUM>) is arranged to receive a first feed cable (<NUM>);
a first ground port (<NUM>) coupled to the reference ground (<NUM>), wherein the first ground port (<NUM>) is arranged to receive the first feed cable (<NUM>); and
a second ground port (<NUM>) coupled to the reference ground (<NUM>), wherein the second ground port (<NUM>) is arranged to receive a second feed cable (<NUM>) to be utilized as a current return or for grounding.