Patent Application
20250105909
The present invention relates to a multi-function antenna system for wireless microphones and in-ear monitors, and more particularly, the present invention relates to an antenna system using printed log periodic dipole array (PLPDA) antennas.
The problems to be solved involve convenience, cost, and size of antenna deployment for wireless systems in the live entertainment and broadcast fields. This includes wireless microphones, wireless instrument systems, in-ear monitor systems, cue control systems, full-duplex communications systems, etc. In the live entertainment and broadcast fields, it is common to have at least two antenna inputs for every receiver so that the diversity reception scheme can be realized to help reduce dropouts due to fading. This requires two separate antennas separated by some distance known as spatial diversity. In the past decade having a single antenna deployment that includes two antenna elements oriented orthogonally in a polarization diversity configuration has become very popular. This is because it has become desirable to take up less space, not having to deploy two separate antennas to achieve spatial diversity. This is also popular as it reduces the time of setup having one antenna system do the work of two. This method of polarization diversity puts an antenna in two different planes, usually horizontal and vertical, rather than in two physically different locations separated by some space, like with spatial diversity. However, such specialized antenna systems have limited utility and are expensive.
On the other hand, in transmitters, circular polarization to transmit wireless signals for the live entertainment and broadcast fields has become quite popular. This is because many wireless systems in these fields, such as wireless microphones or in-ear monitor systems, change orientation often during use. Circular polarization helps reduce fading due to polarization mismatch of devices with signals of an unknown polarization. Even in situations where these devices are not changing orientation, circular polarization can help mitigate multipath interference, where a direct signal and a reflected signal arrive at the same time and can cause fading. This circular polarization has almost exclusively been achieved using axial mode helical antennas. The problem with axial mode helical antennas is the large size and high cost. To help with size, a collapsing axial mode helical antenna has been developed. In a typical collapsing axial mode helical antenna, the depth of the antenna is reduced by collapsing along the z-axis, however, the length and width of this antenna remain large. Moreover, the high cost limits the use of such antennas for small companies and technicians.
In the end, multiple specialized antennas need to be purchased to cover the needs of the different transmit and receive systems used in the live entertainment and broadcast fields today. A need is therefore appreciated for an antenna system that can overcome the aforementioned drawbacks and limitations with antennas.
A U.S. patent application No. 20190107617, assigned to Rf Venue Inc., discloses an antenna that solves the issue of quick deployment. The antenna takes up less space by utilizing polarization diversity with two orthogonally positioned antenna elements. However, one element is an LPDA, and the other is a dipole, which makes the system complex. Moreover, the dipole has efficiency issues as it is not a wideband antenna and can only be used for diversity reception. The reference discloses a wing-type structure that folds out to make the horizontal LPDA.
Another, U.S. Pat. No. 9,142,882, assigned to Rf Venue Inc., discloses a folding axial mode helical antenna. It solves the issue of condensing the size of a circularly polarized antenna with forward passive gain. However, the Z axis of this antenna can be reduced, the X and Y axis are still quite large. The high cost is a major limitation and is of limited use.
The following presents a simplified summary of one or more embodiments of the present invention in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments and is intended to neither identify key or critical elements of all embodiments nor delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later.
The principal object of the present invention is directed to an antenna system that is compact and has wide-spread use avoiding the need for multiple antennas.
Another object of the present invention is that the antenna system can work with different devices used in entertainment and wireless broadcasting.
Yet another object of the present invention is that the antenna system is cost-effective.
Still, another object of the present invention is that the antenna system is simple to use.
A further object of the present invention is that the antenna system is for multi-purpose use, including circular polarization.
Still, a further object of the present invention is that the antenna system has a more consistent axial ratio.
An additional object of the present invention is that the antenna system can be assembled and disassembled into a smaller space.
In one aspect, the disclosed antenna system uses two printed log periodic dipole array (PLPDA) antennas that are inherently wide bandwidth in nature. When used in polarization diversity mode, the inputs of the disclosed antenna system are easily recognizable, preventing any margin of error.
In one aspect, horizontal and vertical antennas of the antenna system can be used independently.
In one aspect, the antenna system can be used for circular-polarized transmit/reception, spatial diversity, or polarization diversity reception.
The accompanying figures, which are incorporated herein, form part of the specification and illustrate embodiments of the present invention. Together with the description, the figures further explain the principles of the present invention and to enable a person skilled in the relevant arts to make and use the invention.
Subject matter will now be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific exemplary embodiments. Subject matter may, however, be embodied in a variety of different forms and, therefore, covered or claimed subject matter is intended to be construed as not being limited to any exemplary embodiments set forth herein; exemplary embodiments are provided merely to be illustrative. Likewise, a reasonably broad scope for claimed or covered subject matter is intended. Among other things, for example, the subject matter may be embodied as methods, devices, components, or systems. The following detailed description is, therefore, not intended to be taken in a limiting sense.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. Likewise, the term “embodiments of the present invention” does not require that all embodiments of the invention include the discussed feature, advantage or mode of operation.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising,”, “includes” and/or “including”, when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The following detailed description includes the best currently contemplated mode or modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense but is made merely to illustrate the general principles of the invention since the scope of the invention will be best defined by the allowed claims of any resulting patent.
BNC Connector: It is a quick connect/disconnect coaxial connector, its structure and functioning of it is well known in the art.
MCX (Micro Coaxial connector): It is a coaxial connector with a snap-on interface, the structure and functioning of which is well known in the art.
Disclosed is a multifunctional antenna system that can achieve spatial diversity for receiver systems, polarization diversity for receiver systems, and circular polarization for transmit and receive systems. The disclosed system can work in three modes as per the requirement i.e., the spatial diversity mode, the polarization diversity mode, and the circular polarized in/out mode. This makes the invention versatile and cost-effective. Also, the installation of the system is easy and quick, depending on the intended use. Moreover, the disclosed system is compact for stowing in a very compact space.
Disclosed antenna system 10 includes two Printed Log Periodic Dipole Array (PLPDA) antennas i.e., a vertical antenna as shown in
In addition to the BNC connectors on each antenna, each of the two antennas also has an MCX Input Connector. One of the two antennas can include a circular polarization adapter (CP adapter) that consists of a 90-degree hybrid coupler with a single BNC input and two MCX outputs. When the horizontal and vertical antennas are interlocked, a transmitter such as an in-ear monitor transmitter can be plugged into the BNC connector of the CP adapter. Thereafter, two MCX cables, from the two MCX output connectors of the CP adapter, are plugged into the MCX Input Connectors of the horizontal and vertical antennas, resulting in a circular-polarized antenna that has a more consistent axial ratio than most axial mode helical antennas with forward passive gain known commercially designed for wireless systems in the live entertainment and broadcast fields.
The result is an antenna system consisting of two specialized PLPDA-type antennas that can satisfy the needs of all the previously specialized antenna systems needed for the receive and transmit systems in live entertainment and broadcast fields. This reduces the need to have multiple specialized antenna systems by a company or technicians. The disclosed system being compact also reduces the transport cost and requires less storage space. Also, the system, when used in circular-polarized mode, is smaller than any known circular-polarized antenna system with forward passive gain. Moreover, the better axial ratio makes it more circular.
The system may also provide for the storage of two MCX cables on the respective antenna itself with the CP adapter. This prevents losing the small and thin MCX cables. The drawing shows the vertical antenna having two MCX connectors for storing the MCX cables. The terms “MCX cable” and “MCX jumper” are interchangeably used herein. Also, the disclosure describes the system as having specific connectors, such as the BNC connector and MCX connectors, however, it should be obvious to those reading this disclosure that different connectors can be used, if so desired, and any suitable connector is within the scope of the present invention.
The disclosed antenna system is versatile in that having the functionality of three different antenna types. The system provides cross cross-polarized PCB antenna with forward gain without heavy modification to the feed system, detriment to radiation pattern, or impedance match. The two antennas can operate on their own or as part of the system in one of the three modes of operation. Most elements to make the antenna operate in CP mode can be attached to the antenna to prevent any pieces from getting lost in the field. The system provides a circular-polarized antenna with forward passive gain that can be folded into a form smaller than anything available for wireless microphone-type systems used in the live entertainment/broadcast fields.
In certain implementations, the impedance match can be controlled easily by controlling the length of the RG405 coaxial feed line that connects to the back of the antenna at the BNC connector and then feeds the antenna at the front at the feed point. LPDAs have to be fed at the front. Increasing the length of the RG405 feedline changes the phase at the antenna's feed point. This changes the reactance portion of the complex impedance seen at the antenna's feed point and can be carefully tuned by changing the length to create a 50-ohm match across the antenna's tuning bandwidth. Or at least a match reasonably close to 50 ohms across the antenna's tuning bandwidth.
However, these lengths also have to consider the phase relationship between the two antennas. The way to make Circular polarization from two cross-polarized antennas such as in this case is to have a 90-degree phase shift to one of the antennas. However, if both antennas have different lengths of RG405 feeding the feed point of the LPDA. The 90-degree phase shift can be offset by a delay in the arrival time caused by the different lengths of the RG405 feedline. For instance, one antenna may see 10 degrees of phase shift and the antenna with the 90-degree phase shift may actually see 110 degrees of phase shift. This can be corrected by adding more RG405 as the phasing line to make sure the antennas see a phase relationship of 90 degrees.
Referring to
While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above-described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention as claimed.
This application claims priority from a U.S. Provisional Patent Appl. No. 63/585,067, filed on Sep. 25, 2023, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63585067 | Sep 2023 | US |
