Patent Publication Number: US-11380992-B2

Title: Active UHF/VHF antenna

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is a continuation of U.S. patent application Ser. No. 15/824,956, filed on Nov. 28, 2017, titled “Active UHF/VHF Antenna,” which claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Scr. No. 62/427,071, filed Nov. 28, 2016, titled “Active UHF/VHF Antenna,” disclosure of which is hereby expressly incorporated by reference as part of the present application as if fully set forth herein. 
    
    
     BACKGROUND 
     Field of the Invention 
     This invention relates to antennas for signal reception in UHF and VHF bands; and more particularly, to active antennas capable of dynamic tuning to achieve improved signal performance in the UHF and VHF bands. 
     Description of the Related Art 
     Ultra-high frequency (UHF) bands span the range between 470 MHz and 698 MHz. Very high frequency (VHF) bands span the range between 30 MHz to 300 MHz. In North America, VHF Band 1 (“VHF1”) includes channels 2 thru 6 and spans range of 54 MHz to 88 MHz. Also in North America, VHF Band 2 (“VHF2”) includes channels 7-13 and spans the range of 174 MHz thru 216 MHz. Each of these bands is utilized for over-the-air (“OTA”) television signaling, also known as “broadcast television” or “terrestrial television”. 
     While antennas exist for use with television sets to receive OTA signals, these conventional antennas are saturated with performance limitations and other problems which impede commercial success and end user experiences. High definition services offered by cable television and satellite service providers caused many to leave OTA television for the much improved HD television access. 
     Satellite television, while available for many years, emerged onto the market as a solution to access premium content channels with high quality for supporting high definition transmissions. 
     However, with the advent of the internet, and as internet speeds continue to improve with advances in communication technologies, it has become a standard practice for individual consumers to increasingly access streaming media through the internet. As a result, there has been a significant decline in subscription sales to satellite and cable television services. 
     Today, many consumers prefer to access content through online streaming services, such as HULU® or NETFLIX®, and the like. However, these online streaming services, at least for now, do not offer local television programming such as local news, weather, etc. As such, these customers who prefer internet-streamed media are often without access to local content. In order to fill this void, many of these “cord-cutters” are once again looking to OTA antennas in order to access broadcast television for accessing local television content. 
     Now that OTA television is becoming relevant again, there is a need for improved antennas which are capable of accessing OTA transmissions, and with improved signaling sufficient to support high definition televisions. 
     The same limitations of OTA antennas exist today that existed many years ago; i.e., the requirement for strategic placement and elevation for receiving signals, matching requirements and signal conditioning, antenna size, aesthetics, among others. 
     SUMMARY 
     Active UHF/VHF antennas are configured to provide the ability to (i) access broadcast television signals, (ii) receive and deliver optimal signaling and quality to the television display, and (iii) integrate with the TV receiver to optimize a mode of the antenna for accessing the desired channel. 
     Three embodiments are illustrated, wherein in each of the embodiments an active UHF/VHF antenna is provided having an antenna element positioned adjacent to a ground plane, and a parasitic element positioned adjacent to each of the antenna element and the ground plane, wherein the parasitic element is coupled to the ground plane at a multi-port switch configured to open, short, or reactively load the parasitic element. The multi-port switch is further coupled to a microprocessor, which, in turn, is further coupled to a television receiver. As a user selects a television channel for viewing, the receiver chipset is configured to communicate one or more control signals to the microprocessor, and the microprocessor samples data from memory to determine an optimal mode for reconfiguring the active UHF/VHF antenna. For example, receive signal strength indicator (RSSI) can be sampled from each mode of the antenna, and an optimal mode of each of the modes is selected, wherein the multi-port switch is configured by the microprocessor communicating a signal to the multi-port switch for activating the corresponding switch port(s) and inducing the desired antenna mode. 
     Various configurations of antenna element and parasitic element structures are contemplated and disclosed. 
     Additionally, various configurations of passive components, active components, and filters are contemplated and disclosed. 
     The result of these embodiments is provided an active UHF/VHF antenna capable of significantly improved signal reception in the UHF and VHF bands. 
     Other features and advantages will be recognized by those with skill in the art upon a thorough review of the following descriptive examples and detailed embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an active UHF/VHF antenna in accordance with a first illustrated embodiment. 
         FIG. 2  shows an active UHF/VHF antenna in accordance with a second illustrated embodiment. 
         FIG. 3A  shows a plan view of an active UHF/VHF antenna in accordance with a third illustrated embodiment. 
         FIG. 3B  shows a perspective view of the active UHF/VHF antenna in accordance with the third illustrated embodiment. 
         FIG. 4  shows a perspective view of the active UHF/VHF antenna in accordance with another embodiment. 
         FIG. 5  shows an example of a multi-port switch with capacitive and inductive loadings for use with any of the embodiments herein. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following description, for purposes of explanation and not limitation, details and descriptions are set forth in order to provide a thorough understanding of the present invention in accordance with an illustrated embodiment. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments that depart from these details and descriptions without departing from the spirit and scope of the invention. An illustrated embodiment will be described below with reference to the drawings wherein illustrative features are denoted by reference numerals. 
     Example 1 
     In a first illustrated embodiment, as illustrated in  FIG. 1 , an active UHF/VHF antenna is formed on a substrate  100  and includes: an antenna element  102   a  positioned adjacent to a ground plane  101 , the antenna element is coupled to one or more conductor elements  102   b ;  102   c ;  102   d  in a series extension; wherein between the antenna element  102   a  and a first conductor  102   b  of the one or more conductor elements is disposed a first component, first plurality of components, or first filter  103   a  configured to pass VHF1 and VHF2 signals to the first conductor  102   b ; and wherein between the first conductor  102   b  and a second conductor  102   c  is disposed a second component, second plurality of components, or second filter  103   b  configured to pass VHF1 signals. In this regard, the antenna element  102   a , first conductor  102   b , second and subsequent conductors  102   c ;  102   d , etc. form an antenna with multiple resonances. Up to “n” conductors can be linked each with a component, plurality of components, or filter disposed between the n th  conductor and (n−1) th  conductor. The n th  component(s) or filter being configured to pass one or more desired signals and block unwanted signals. 
     Here, the antenna element  102   a  is coupled to a first conductor  102   b  at a first filter  103   a ; a second conductor  102   c  is coupled to the first conductor  102   b  at a second filter  103   b ; and a third conductor  102   d  is coupled to the second conductor  102   c  at a third filter  103   c . While this example illustrates a first preferred embodiment, it should be understood that any number of conductors and filters may be similarly implemented to achieve the same result. Moreover, the length, position, orientation and relation of these features can be varied to achieve desired antenna performance as would be understood by those having skill in the art. 
     In the illustrated embodiment, the third conductor  102   d  is further coupled to the ground plane at a first multi-port switch  107   a . The first multi-port switch can be configured with multiple ports, wherein each of the ports is capable of open-circuiting, short-circuiting, or coupling a reactive loading to the third conductor. As a result, the first multi-port switch  107   a  is capable of adjusting a reactance associated with the antenna with multiple resonances, and/or can be used to open/short the third conductor to ground. This first multi-port switch provides a first means for actively controlling the antenna function. 
     Each of the first through third filters  103   a ;  103   b ; and  103   c , respectively, can be configured as: (i) a passive reactance component or “passive component”, such as a capacitor or inductor; (ii) a circuit comprising two or more passive components, such as an LC circuit (inductor and capacitor); or (iii) a filter, such as a low pass filter. Those with skill in the art will be able to appreciate the various components and arrangements of components which will filter out signals at each of the “filters”  103   a  thru  103   c.    
     In the instant example, the first filter  103   a  may comprise an LC circuit; the second filter  103   b  may comprise a low pass filter; and third filter  103   c  may comprise a passive inductor. In yet another example, one or more of the first through third filters may comprise a tunable component, such as a tunable capacitor, tunable inductor, or other tunable component known by those having skill in the art. 
     Now, the antenna is further characterized by a parasitic element  105  positioned adjacent to the antenna element  102   a , the parasitic element  105  being coupled to the ground plane  101  via a second multi-port switch  107   b . The second multi-port switch  107   b  may be configured to open-circuit, short-circuit, or reactively load the parasitic element. These changes to the reactive loading of the parasitic element tend to induce a radiation pattern change about the antenna element and conductors extending therefrom. In this regard, the antenna assembly as a whole (antenna element, conductors, parasitic element, ground plane, etc.) is configured for active beam steering for changing a radiation pattern mode of the antenna. 
     The antenna element  102   a  is further shown with a bypass junction  106  for providing a path for high frequency signals. A fourth filter  103   d  is provided to block low frequency signals; the fourth filter is shown with a passive capacitor, however, a tunable capacitor can be similarly implemented between the feed  104  and the bypass junction  106 . 
     Each of the first multi-port switch  107   a ; second multi-port switch  107   b , and the feed  104  may be coupled to a microprocessor  110  via transmission lines  108  extending therebetween as shown. Here, the microprocessor is configured to communicate one or more signals to each of the first and second multi-port switches for controlling a switch state or activating switch ports. Additionally, the microprocessor can be configured to control a matching circuit associated with the antenna feed. The matching circuit may be incorporated into the microprocessor, or positioned outside the processor, and generally comprises one or a plurality of passive and/or active reactance components, such as capacitors, inductors, and tunable variants thereof as known by those with skill in the art. A function of the microprocessor  110  is to determine a mode for configuring the active UHF/VHF antenna, and sending control signals to configure the antenna in the desired mode. The processor may further comprise a memory module and an algorithm resident in the memory module, the algorithm configured to determine the optimal antenna mode, and through the processor, communicate the proper settings for configuring the antenna in the desired mode. 
     The microprocessor  110  is generally coupled to a television receiver/baseband  111 . As a user selects a channel, the receiver communicates the desired channel information to the processor, which in turn executes the algorithm to determine an optimal antenna mode, and the processor then configures the antenna in the optimal mode. For example, the algorithm can sample a metric such as receive signal strength indicator (RSSI) at each mode of the antenna, and select the optimal mode based on that metric. 
     While  FIG. 1  shows an exemplary embodiment, the illustrated arrangement is not intended to be limiting. In fact, many variations can be implemented in a similar fashion which provides substantially the same results. As such, we follow with additional embodiments for providing a similar active UHF/VHF antenna. Any combination or rearrangement of these features may be implemented to produce a non-illustrated embodiment which is intended to be within the invention as-claimed. 
     Example 2 
     Now turning to a second illustrated embodiment as shown in  FIG. 2 , an active UHF/VHF antenna includes a first antenna element  202   a , a second antenna element  202   b , a ground plane  201 , and first and second parasitic elements  205   a ;  205   b , respectively, each formed on a substrate  200 . The substrate may comprise a rigid FR4 substrate, a flexible polyimide substrate, or other substrate available to those with skill in the art. The ground plane  201  is formed at a corner of the rectangular substrate. The first antenna element  202   a  extends in a first direction, vertically from the ground plane in orientation with respect to the drawing as shown. The second antenna element extends in a second direction, horizontally from the ground plane in orientation with respect to the drawing as shown. Accordingly, the second antenna element  202   b  is oriented perpendicular to the first antenna element  202   a . The first and second antenna elements can be configured as one being horizontally polarized, and the other being vertically polarized. The first and second antenna elements are further configured as mirror opposites, or configured to oppose one another. The first antenna element  202   a  further comprises a first bypass junction  206   a  extending between two points along a first bent portion of the first antenna element. Similarly, the second antenna element  202   b  further comprises a second bypass junction  206   b  extending between two points along a first bent portion of the second antenna element. A passive or tunable reactive component may be implemented at the either or both of the first and second bypass junctions  206   a ;  206   b . The ground plane includes a first ground plane extension  204   a  positioned adjacent to the first antenna element  202   a ; and further includes a second ground plane extension  204   b  positioned adjacent to the second antenna element  202   b . Each of the first and second ground plane extensions are configured to impedance match the adjacent antenna structures. A two-port switch  212  is implemented with connection to each of the first and second antenna elements  202   a ;  202   b , respectively, thereby providing a first mode utilizing the first antenna element  202   a , a second mode utilizing the second antenna element  202   b , and a third mode utilizing a combined signal of both the first and second antenna elements  202   a  and  202   b.    
     A first parasitic element  205   a  is formed by a first portion  205   a - 1  and a second portion  205   a - 2 , wherein a first filter  203   a  is disposed between the first and second portions of the first parasitic element. The first parasitic element is positioned adjacent to the first antenna element  202   a . A first multi-port switch  207   a  is coupled between the first parasitic element and the ground plane. The first multi-port switch is configured to open-circuit, short-circuit, and/or reactively load the first parasitic element. 
     A second parasitic element  205   b  is formed by a first portion  205   b - 1  and a second portion  205   b - 2 , wherein a second filter  203   b  is disposed between the first and second portions of the second parasitic element. The second parasitic element is positioned adjacent to the second antenna element  202   b . A second multi-port switch  207   b  is coupled between the second parasitic element and the ground plane. The second multi-port switch is configured to open-circuit, short-circuit, and/or reactively load the second parasitic element. 
     Here, the first and second parasitic elements are arranged to oppose one another; however, any orientation or rearrangement of these features can be similarly implemented by those with skill in the art. 
     Each of the first and second multi-port switches  207   a ;  207   b , respectively, are further coupled to a microprocessor  210  via control lines  208  extending therebetween. The microprocessor is configured to couple with a television receiver. In a similar manner, a user can select a channel from the television control, the television receiver or related chipset then sends a request to the microprocessor of the antenna, which in turn determines the optimal mode of the antenna and configures each of the multi-port switches and other tunable components (if any) to configure the antenna in the desired mode for providing optimized signal reception. 
     Example 3 
     Now turning to a third illustrated embodiment as shown in  FIGS. 3 (A-B), a three-dimensional antenna assembly includes a first planar substrate portion  300   a  having a first active UHF/VHF antenna  301   a  thereon, and a second planar substrate portion  300   b  having a second active UHF/VHF antenna  301   b  thereon. The first active UHF/VHF antenna may comprise any structure as described herein, or a modification thereof, however, for illustrative purposes is shown a first active UHF/VHF antenna having a first antenna element  301   a  disposed adjacent to a first ground plane  302 . The first ground plane  302  is shown with an optional first ground plane extension  304  for impedance matching the first active antenna. A first feed  303  is used to communicate signals between the first antenna element and the receiver. A first bypass junction  306  is shown for providing a distinct path for high-frequency signals. A first parasitic element  305  with a first section  305   a  and a second section  305   b  is shown. The first section may optionally be separated from the second section by one or more first passive and/or active components, or first filters; though none is shown in this illustrated embodiment. The first parasitic element  305  is however coupled to the first ground plane at a first multi-port switch. The first multi-port switch  307  may comprise any number of ports, or “n”-ports, wherein each port is individually selected to open-circuit, short circuit, or reactively load the first parasitic element. A first microprocessor  310  is shown coupled to the first multi-port switch, the first microprocessor receives signals from baseband, or a receiver circuit, in a television unit; the signals include information related to the user-selected channel, wherein the first microprocessor is configured to determine an optimal mode of the first UHF/VHF antenna for receiving the desired channel. The first microprocessor may sample up to all possible modes of the first active antenna, and select the mode exhibiting the optimal metric, such as RSSI, etc. Once a mode is selected, control signals are communicated to the first multi-port switch for configuring the first active antenna in the desired mode. 
     The second planar substrate  300   b  is shown extending out of the page in  FIG. 3A , and is configured orthogonal with respect to the first planar substrate  300   a .  FIG. 3B  further shows the antenna of  FIG. 3A  from a perspective view, wherein it can be recognized that a second active UHF/VHF antenna  301   b  is positioned on the second planar substrate  300   b . The first microprocessor may be used to control both the first and second active antennas; or multiple microprocessors may be implemented. 
     The second antenna  301   b  may be oriented perpendicular with regard to the first antenna  301   a ; or at any angle as desired. Additionally, the second antenna  301   b  may be a mirror image of the first antenna, or the first and second antennas may be of the same orientation. 
     Any change in orientation of the second antenna with respect to the first may be similarly implemented as is illustrated in  FIG. 4 . 
     The radiation pattern of the first antenna, second antenna, or a combination of the first and second antennas may be used for reception of signals. 
       FIG. 5  shows one example of a multi-port switch that can be implemented in any of the above embodiments. While the switch is being illustrated in  FIG. 5 , it should be understood by those with skill in the art that a switch with any number of ports, and any configuration, may be alternatively implemented, such that the result is the ability to open-circuit, short-circuit, or reactively load an antenna feature such as a parasitic element. The illustrated multi-port switch includes switch  107  coupled to ground  501 , and configured to short circuit via output port  502 , reactively load via output ports  503 ;  504 ;  505 ; and  506 , or open circuit at port  507 . Port  503  shows a passive capacitor for reactively loading the antenna feature coupled to the multi-port switch  107 . Port  504  shows a passive inductor for reactively loading the antenna feature coupled to the multi-port switch  107 . Port  505  shows a tunable capacitor for reactively loading the antenna feature coupled to the multi-port switch  107 . Port  506  shows a plurality of passive components for reactively loading the antenna feature coupled to the multi-port switch  107 . Control input signals from the microprocessor are provided to the multi-port switch for configuring the switch with the selected port or path for placing the antenna in a desired mode. The switch and reactive component(s) may be configured as a circuit on the antenna substrate, or may be implemented in a unitary module, as shown. 
     Other embodiments or variations will be recognized by those having skill in the art.