Active UHF/VHF antenna

Abstract

An active antenna for UHF/VHF signal receiving is described, the active antenna being capable of configuration in one of a plurality of possible modes. The active antenna includes an antenna element configured for multiple resonances in the UHF/VHF bands, and capable of generating multiple radiation modes as well as active impedance matching using a microprocessor and multi-port switch having variable or multiple selectable modes. The active antenna may include a second antenna element arranged in a right-angle orientation with respect to the first antenna element. The first antenna element, second antenna element, or a combination may be selected for receiving signals in at a desired frequency. A three-dimensional antenna assembly is also described. Each of the examples illustrate an active beam steering antenna capable of UHF/VHF signal receiving.

Claims

1. An active antenna comprising: an antenna element disposed on a surface of a substrate, the antenna element extending between a first end and a second end, the antenna element including a serpentine portion positioned between the first end and the second end, the serpentine portion including a plurality of passes, the antenna element configured for multiple resonances in an ultra-high frequency (UHF) band or a very-high frequency (VHF) band; a parasitic element disposed on the surface of the substrate; a plurality of conductor elements disposed on the surface of the substrate, the plurality of conductor elements coupled between the antenna element and a ground plane, the plurality of conductor elements comprising a first conductor element coupled to the antenna element via a first filter and a second conductor element coupled to the first conductor element via a second filter; a first multi-port switch coupled between the ground plane and the plurality of conductor elements, the first multi-port switch configured to adjust a reactance of the antenna element; and a second multi-port switch coupled between the parasitic element and the ground plane, the second multi-port switch configured to adjust a reactance of the parasitic element.

2. The active antenna of claim 1, wherein the first filter comprises a second-order filter.

3. The active antenna of claim 2, wherein the second-order filter comprises an inductor and a capacitor.

4. The active antenna of claim 2, wherein the second filter comprises a low-pass filter.

5. The active antenna of claim 1, further comprising: a third conductor element formed on the surface of the substrate, the third conductor element coupled to the ground plane via the first multi-port switch, the third conductor element coupled to the second conductor element via a third filter.

6. The active antenna of claim 1, wherein a processor coupled to the first multi-port switch and the second multi-port switch, the processor configured to: control operation of the first multi-port switch and the second multi-port switch to configure the active antenna in each of a plurality of modes having a distinct radiation pattern; obtain data indicative of performance of the active antenna when the active antenna is configured in each of the plurality of modes; select one of the plurality of modes as a selected mode for the active antenna based, at least in part, on the data; and control operation of at least one of the first multi-port switch and the second multi-port switch to configure the active antenna in the selected mode.

7. The active antenna of claim 5, wherein the antenna element comprises: a bypass junction coupled across a first pass of the plurality of passes.

8. The active antenna of claim 7, further comprising: a fourth filter element coupled between the bypass junction and a portion of the first pass of the plurality of passes of the antenna element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows an active UHF/VHF antenna in accordance with a first illustrated embodiment.

(2) FIG. 2 shows an active UHF/VHF antenna in accordance with a second illustrated embodiment.

(3) FIG. 3A shows a plan view of an active UHF/VHF antenna in accordance with a third illustrated embodiment.

(4) FIG. 3B shows a perspective view of the active UHF/VHF antenna in accordance with the third illustrated embodiment.

(5) FIG. 4 shows a perspective view of the active UHF/VHF antenna in accordance with another embodiment.

(6) 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

(7) 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

(8) 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 102a positioned adjacent to a ground plane 101, the antenna element is coupled to one or more conductor elements 102b; 102c; 102d in a series extension; wherein between the antenna element 102a and a first conductor 102b of the one or more conductor elements is disposed a first component, first plurality of components, or first filter 103a configured to pass VHF1 and VHF2 signals to the first conductor 102b; and wherein between the first conductor 102b and a second conductor 102c is disposed a second component, second plurality of components, or second filter 103b configured to pass VHF1 signals. In this regard, the antenna element 102a, first conductor 102b, second and subsequent conductors 102c; 102d, 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.sup.th conductor and (n−1).sup.th conductor. The n.sup.th component(s) or filter being configured to pass one or more desired signals and block unwanted signals.

(9) Here, the antenna element 102a is coupled to a first conductor 102b at a first filter 103a; a second conductor 102c is coupled to the first conductor 102b at a second filter 103b; and a third conductor 102d is coupled to the second conductor 102c at a third filter 103c. 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.

(10) In the illustrated embodiment, the third conductor 102d is further coupled to the ground plane at a first multi-port switch 107a. 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 107a 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.

(11) Each of the first through third filters 103a; 103b; and 103c, 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” 103a thru 103c.

(12) In the instant example, the first filter 103a may comprise an LC circuit; the second filter 103b may comprise a low pass filter; and third filter 103c 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.

(13) Now, the antenna is further characterized by a parasitic element 105 positioned adjacent to the antenna element 102a, the parasitic element 105 being coupled to the ground plane 101 via a second multi-port switch 107b. The second multi-port switch 107b 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.

(14) The antenna element 102a is further shown with a bypass junction 106 for providing a path for high frequency signals. A fourth filter 103d 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.

(15) Each of the first multi-port switch 107a; second multi-port switch 107b, 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.

(16) 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.

(17) 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

(18) Now turning to a second illustrated embodiment as shown in FIG. 2, an active UHF/VHF antenna includes a first antenna element 202a, a second antenna element 202b, a ground plane 201, and first and second parasitic elements 205a; 205b, 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 202a 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 202b is oriented perpendicular to the first antenna element 202a. 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 202a further comprises a first bypass junction 206a extending between two points along a first bent portion of the first antenna element. Similarly, the second antenna element 202b further comprises a second bypass junction 206b 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 206a; 206b. The ground plane includes a first ground plane extension 204a positioned adjacent to the first antenna element 202a; and further includes a second ground plane extension 204b positioned adjacent to the second antenna element 202b. 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 202a; 202b, respectively, thereby providing a first mode utilizing the first antenna element 202a, a second mode utilizing the second antenna element 202b, and a third mode utilizing a combined signal of both the first and second antenna elements 202a and 202b.

(19) A first parasitic element 205a is formed by a first portion 205a-1 and a second portion 205a-2, wherein a first filter 203a 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 202a. A first multi-port switch 207a 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.

(20) A second parasitic element 205b is formed by a first portion 205b-1 and a second portion 205b-2, wherein a second filter 203b 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 202b. A second multi-port switch 207b 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.

(21) 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.

(22) Each of the first and second multi-port switches 207a; 207b, 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

(23) 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 300a having a first active UHF/VHF antenna 301a thereon, and a second planar substrate portion 300b having a second active UHF/VHF antenna 301b 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 301a 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 305a and a second section 305b 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.

(24) The second planar substrate 300b is shown extending out of the page in FIG. 3A, and is configured orthogonal with respect to the first planar substrate 300a. 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 301b is positioned on the second planar substrate 300b. The first microprocessor may be used to control both the first and second active antennas; or multiple microprocessors may be implemented.

(25) The second antenna 301b may be oriented perpendicular with regard to the first antenna 301a; or at any angle as desired. Additionally, the second antenna 301b may be a mirror image of the first antenna, or the first and second antennas may be of the same orientation.

(26) Any change in orientation of the second antenna with respect to the first may be similarly implemented as is illustrated in FIG. 4.

(27) 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.

(28) 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.

(29) Other embodiments or variations will be recognized by those having skill in the art.