Method and system for controlling modal antennas with acknowledgement

Abstract

An antenna system is provided. In one example embodiment, the antenna system may include a modal antenna that is operable in a plurality of different modes, and each mode may be associated with a different radiation pattern. The antenna system may include a tuning circuit configured to operate a modal antenna in a plurality of different modes. The transmission line may be coupled to the tuning circuit. The antenna system may also include one or more control devices. The control device may be configured to modulate a control signal onto a radio frequency (RF) signal to generate a modulated signal for transmission through a transmission line to a tuning circuit. The control device may also be configured to generate an acknowledgement (ACK) signal based at least in part on the control signal.

Description

[0001] Priority Claim

[0002] This application claims priority to U.S. Provisional Application No. 63 / 423,241, filed on Nov. 7, 2022, entitled “Method and System for Controlling a Modal Antenna with Acknowledgement”, which is incorporated herein by reference in its entirety and for all purposes. Field of the Disclosure

[0003] Example aspects of the present disclosure relate to antennas. Background Art

[0004] Modal antennas are increasingly being used in wireless communication, such as in smartphones. Compared to traditional passive antennas, such antennas generally provide improved signal quality and a more compact form factor. One modal antenna configuration involves a parasitic element that is configured to alter the radiation pattern associated with a driving element. In this way, the modal antenna can be configured to be in multiple different modes. Additionally, each of the multiple modes can have a different radiation pattern and / or polarization. Summary of the Invention

[0005] Aspects and advantages of embodiments of the present disclosure will be set forth in part in the following description, or may be learned from the description, or may be learned by practice of the embodiments.

[0006] An example aspect of the present disclosure relates to an antenna system that includes a modal antenna that is capable of operating in a plurality of different modes, and each of the plurality of modes can be associated with a different radiation pattern. The antenna system can include a tuning circuit that is configured to control the modal antenna to operate in each of the plurality of modes. The antenna system can include a transmission line that is coupled to the tuning circuit. The antenna system can include one or more control devices that are configured to modulate a control signal onto a radio frequency (RF) signal to generate a modulated signal for transmission to the tuning circuit via the transmission line. The one or more control devices can also be configured to generate an acknowledgement (ACK) signal at least partially based on the control signal.

[0007] These and other features, aspects, and advantages of the various embodiments will be better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with the description, serve to explain the relevant principles. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] A detailed discussion of embodiments is set forth in this specification with reference to the drawings, in which:

[0009] Figure 1A An embodiment of an antenna according to an exemplary embodiment of the present disclosure is shown;

[0010] Figure 1B is shown in connection with Figure 1A the two-dimensional antenna radiation pattern associated with the antenna in;

[0011] Figure 1C An example frequency chart of the antenna in Figure 1A is shown according to an exemplary embodiment of the present disclosure;

[0012] Figure 2 A schematic diagram of an example antenna system according to an exemplary embodiment of the present disclosure is shown;

[0013] Figure 3 A schematic diagram of an example control circuit of an antenna system according to an exemplary embodiment of the present disclosure is shown;

[0014] Figure 4A A series of time-aligned charts representing a simplified example of binary amplitude shift keying modulation is shown;

[0015] Figure 4B A series of time-aligned charts representing a simplified example of multi-level amplitude shift keying modulation is shown;

[0016] Figure 5 A schematic diagram of an example tuning circuit of an antenna system according to an exemplary embodiment of the present disclosure is shown;

[0017] Figure 6 A schematic diagram of an example reverse channel modulator of an antenna system according to an exemplary embodiment of the present disclosure is shown;

[0018] Figure 7 A schematic diagram of an example reverse channel receiver of an antenna system according to an exemplary embodiment of the present disclosure is shown;

[0019] Figure 8 A flowchart depicting an example method according to an exemplary embodiment of the present disclosure is shown;

[0020] Figure 9 An example coding scheme of an antenna system according to an exemplary embodiment of the present disclosure is shown;

[0021] Figure 10 Illustrates an example error detection in accordance with example embodiments of the present disclosure;

[0022] Figure 11 Illustrates an example control of a modal antenna in accordance with example embodiments of the present disclosure;

[0023] Figure 12 Illustrates an example general confirmation of a modal antenna in accordance with example embodiments of the present disclosure;

[0024] Figure 13 Illustrates an example specific confirmation of a modal antenna in accordance with example embodiments of the present disclosure;

[0025] Figure 14 Illustrates an example specific confirmation of a modal antenna in accordance with example embodiments of the present disclosure; and

[0026] Figure 15 Depicts a flowchart of an example method in accordance with example embodiments of the present disclosure. Detailed Description

[0027] Reference will now be made in detail to embodiments, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of these embodiments and not limitation of the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments without departing from the scope or spirit of the present disclosure. For example, features shown or described as part of one embodiment can be used with another embodiment to yield yet another embodiment. Accordingly, aspects of the present disclosure are intended to cover these modifications and variations.

[0028] Example aspects of the present disclosure generally relate to the field of antenna control. For example, example aspects of the present disclosure relate to the control of a modal antenna configured to operate in multiple different modes.

[0029] Modal antennas are increasingly being used in wireless communication. Compared to traditional passive antennas, such antennas generally provide improved signal quality and a more compact form factor. A modal antenna can be configured in multiple different modes, each different mode having a different radiation pattern and / or polarization state.

[0030] An antenna system can include a modal antenna that includes a drive element and a parasitic element positioned close to the drive element. The antenna system can include a tuning circuit configured to control the electrical characteristics associated with the parasitic element to cause the modal antenna to operate in multiple different modes.

[0031] An antenna system may include radio frequency (RF) circuitry and a transmission line (e.g., a single coaxial cable) that couples the RF circuitry to a modal antenna. The RF circuitry may be configured to modulate a control signal onto an RF signal, e.g., using amplitude shift keying modulation or other suitable modulation, to generate a transmission signal for transmission via the transmission line to a tuning circuit. The tuning circuit may be configured to demodulate the control signal such that the tuning circuit can adjust the mode of the modal antenna at least in part based on the control signal. For example, the tuning circuit may control the modal antenna to operate in a selected one of multiple modes at least in part based on the control signal.

[0032] In some instances, the control signal transmitted by the RF circuitry to the tuning circuit is unidirectional. More specifically, when the RF circuitry modulates the control signal onto the RF signal for transmission via the transmission line to the tuning circuit, the tuning circuit does not send an acknowledgement (ACK) signal or a negative acknowledgement (NAK) signal back to the RF circuitry to confirm receipt of the control signal. Accordingly, the RF circuitry does not know whether the control signal has been successfully received by the tuning circuit. The RF circuitry also does not know the real-time configuration of the modal antenna. More specifically, the RF circuitry does not know which one of the multiple modes the modal antenna is operating in at any given moment.

[0033] According to an example aspect of the present disclosure, the antenna system may include a current-mode reverse channel that includes modulation and demodulation circuitry. More specifically, the antenna system may include one or more control devices configured to generate a modulated signal for transmission via the transmission line to the tuning circuit by modulating a control signal onto the RF signal. The one or more control devices may also be configured to generate an acknowledgement (ACK) signal at least in part based on the control signal received by the tuning circuit. Aspects of the present disclosure are discussed with reference to the ACK signal. As used herein, the ACK signal may include a negative acknowledgement (NAK) signal without departing from the scope of the present disclosure.

[0034] According to an example aspect of the present disclosure, the one or more control devices may be configured to generate an ACK signal at least in part based on the control signal received by the tuning circuit. More specifically, the one or more control devices may be configured to encode a plurality of bits according to an encoding scheme. For example, the encoding scheme may assign a unique code to each antenna mode of the multiple modes. In some instances, the encoding scheme may assign unique codes to a general acknowledgement (general ACK) request and a plurality of specific acknowledgement (specific ACK) requests.

[0035] In some instances, the one or more control devices may include a current source circuit and a current sensing circuit. More specifically, the one or more control devices may include: a switchable current source configured to operate as a reverse channel modulator; and a current sensor configured to operate as a reverse channel receiver. The reverse channel modulator may be coupled to a tuning circuit and configured to generate an ACK signal, such as a pulsed direct current (DC) current signal, at least in part based on a control signal received by the tuning circuit. The reverse channel receiver may be coupled to the RF circuit and configured to monitor and / or sense the ACK signal generated by the reverse channel modulator.

[0036] The systems and methods according to example embodiments of the present disclosure provide several technical effects and benefits. For example, example aspects of the present disclosure provide a read-back mechanism for an antenna system. More specifically, the present disclosure provides an ACK signal mechanism and / or a real-time indicator indicating configuration metrics of the antenna system by providing a current-mode reverse channel. In this way, the present disclosure may provide a read-back mechanism for the antenna system configuration running through a transmission line in some instances. The resulting current-mode reverse channel may provide accurate and efficient control over the operation of the modal antenna and the antenna system.

[0037] Figure 1A An embodiment of a modal antenna 10 according to aspects of the present disclosure is shown. The modal antenna 10 may include a circuit board 12 (e.g., including a ground plane) and a driven antenna element 14 disposed on the circuit board 12. A first parasitic element 15 may be positioned adjacent to the driven antenna element 14. For example, the first parasitic element 15 may be positioned such that the current in the first parasitic element 15 affects the radiation pattern of the driven element. For example, an antenna volume may be defined between the circuit board (e.g., and the ground plane) and the driven antenna element 14. The first parasitic element 15 may be at least partially positioned within the antenna volume.

[0038] A first active tuning element 16 may be coupled to the first parasitic element 15. The first active tuning element 16 may be a passive component or an active component or a series component, and may be configured to change the reactance on the first parasitic element 15 by a variable reactance or shorting to ground, thereby causing a frequency shift of the antenna.

[0039] In some embodiments, the second parasitic element 18 may be arranged adjacent to the circuit board 12 and close to the drive antenna element 14 such that the current in the second parasitic element 18 affects the radiation pattern of the drive element. The second parasitic element 18 may be positioned outside the antenna volume. The drive antenna element 14 may have a width 19. The second parasitic element 18 may be spaced apart from the drive antenna element 14 by a spacing distance 21. The ratio of the width 19 of the drive antenna element 14 to the spacing distance 21 may be in the range of from about 0.2 to about 10, in some embodiments from about 0.5 to about 8, and in some embodiments from about 1 to about 5.

[0040] The second parasitic element 18 may further include a second active tuning element 20, which may individually include one or more active components and / or passive elements. The second parasitic element 18 may be positioned adjacent to the drive antenna element 14 and may also be positioned outside the antenna volume.

[0041] The described configuration may provide the ability to shift the radiation pattern characteristics of the drive antenna element by changing the reactance on the drive antenna element. Shifting the antenna radiation pattern may be referred to as "beam steering". In instances where the antenna radiation pattern includes nulls, a similar operation may be referred to as "null steering" because the nulls may be shifted to alternative positions around the antenna (e.g., to reduce interference). In some embodiments, the second active tuning element 20 may include a switch that is used to connect the second parasite to ground when "On" and to terminate the short circuit when "Off". However, it should be noted that variable reactance on the first parasitic element or the second parasitic element (e.g., by using variable capacitors or other tunable components) may further provide a variable shift in the antenna pattern or frequency response. For example, the first active tuning element 16 and / or the second active tuning element 18 may include at least one of the following: a tunable capacitor, a microelectromechanical systems (MEMS) device, a tunable inductor, a switch, a tunable phase shifter, a field effect transistor, or a diode.

[0042] Figure 1B Shown is associated with Figure 1A a two-dimensional antenna radiation pattern of a modal antenna. The radiation pattern may be shifted by controlling the electrical characteristics associated with at least one of the first parasitic element 15 and the second parasitic element 18 of the modal antenna 10. For example, in some embodiments, the radiation pattern may be shifted from a first mode 22 to a second mode 24 or a third mode 26.

[0043] Figure 1C Shown in accordance with some aspects of the present disclosure Figure 1AExample frequency charts of the modal antenna in []. The frequency of the antenna can be shifted by controlling the electrical characteristics associated with at least one of the first parasitic element 15 or the second parasitic element 18 of the modal antenna 10. For example, when the first parasitic element and the second parasitic element are switched to "off", the first frequency (f0) of the antenna can be achieved; when the second parasitic element is shorted to ground, the frequencies (f L ) and (f H ) can be generated; and when both the first parasitic element and the second parasitic element are shorted to ground, the frequencies (f4; f0) can be generated. It should be understood that within the scope of the present disclosure, other configurations are possible. For example, more parasitic elements or fewer parasitic elements can be employed. The positioning of the parasitic elements can be changed to achieve additional modes, which can exhibit different frequencies and / or combinations of frequencies.

[0044] Figures 1A to 1C An example modal antenna with multiple modes is depicted for purposes of illustration and discussion. Those of ordinary skill in the art will understand, using the disclosure provided herein, that other modal antennas and / or antenna configurations can be used without departing from the scope of the present disclosure. As used herein, a "modal antenna" refers to an antenna capable of operating in multiple modes, where each mode is associated with a different radiation pattern.

[0045] Figure 2 A schematic diagram of an embodiment of an antenna system 100 according to an example aspect of the present disclosure is shown. The antenna system 100 can include a modal antenna 102. The modal antenna 102 can include a drive element 104 and a parasitic element 106, which is positioned close to the drive element 104. The modal antenna 102 can be capable of operating in multiple different modes. Each mode can be associated with a different radiation pattern, for example as described above with reference to Figures 1A to 1C .

[0046] A tuning circuit 108 (e.g., a receiver) can be configured to control the electrical characteristics associated with the parasitic element 106 to cause the modal antenna 102 to operate in multiple different modes. For example, as more detailedly explained with reference to FIGS. 4 and Figure 5 , the tuning circuit 108 can be configured to demodulate a control signal from a transmitted signal and control the electrical characteristics of the parasitic element 106 based on control instructions associated with the control signal.

[0047] A tunable component 110 can be coupled to the parasitic element 106. The tuning circuit 108 can be configured to control the tunable component 110 to change the electrical connection of the parasitic element 106 to a voltage or current source or a voltage or current sink, e.g., connect the parasitic element 106 to ground.

[0048] The radio frequency (RF) circuit 112 (e.g., a transmitter) can be configured to transmit an RF signal to the drive element 104 of the modal antenna 102. For example, the transmission line 114 can couple the RF circuit 112 to the modal antenna 102. In some embodiments, the transmission line 114 can be a single coaxial cable. The RF circuit 112 can be configured to amplify the RF signal or otherwise generate an RF signal that is transmitted via the transmission line 114 (as a component of the transmission signal) to the drive element 104 of the modal antenna 102.

[0049] In some embodiments, the RF circuit 112 can include a front-end module 116 and / or a control circuit 118. The front-end module 116 can be configured to generate and / or amplify the RF signal transmitted to the drive element 104. For example, as explained in more detail with reference to Figure 4A and Figure 4B the control circuit 118 can be configured to modulate a control signal onto the RF signal using amplitude shift keying modulation to generate a transmission signal.

[0050] The transmission line 114 can be coupled to various components (e.g., using a Bias Tee circuit) configured to assist in the combination and / or separation of signals occupying various frequency bands. For example, a first Bias Tee circuit 120 can couple the front-end module 116 and the control circuit 118 to the transmission line 114. The first Bias Tee circuit 120 can include a capacitor 122 that couples the transmission line 114 to the front-end module 116, and an inductor 124 that couples the control circuit 118 to the transmission line 114. A second Bias Tee circuit 126 can couple the drive element 104 and the tuning circuit 108 to the transmission line 114. The second Bias Tee circuit 126 can include a capacitor 128 that couples the transmission line 114 to the drive element 104, and an inductor 130 that couples the transmission line 114 to the tuning circuit 108.

[0051] The front-end module 116 can transmit the RF signal through the capacitor 122 of the first Bias Tee circuit 120. The control circuit 118 can modulate the control signal onto the RF signal through the inductor 124 of the first Bias Tee circuit 120 to generate a control signal in the transmission line 114.

[0052] The tuning circuit 108 (e.g., a receiver) can be configured to demodulate the control signal and extract clock information associated with the transmitter. For example, the tuning circuit 108 can demodulate the control signal from the transmission signal via the inductor 130 of the second Bias Tee circuit 126. The RF signal component of the transmission signal can be transmitted to the drive element 104 of the modal antenna 102 via the capacitor 128 of the second Bias Tee circuit 126.

[0053] In some embodiments, the antenna system 100 may further include a control device 133 (e.g., a reverse channel modulator). As will be discussed in more detail below with reference to Figure 6 The control device 133 may be any suitable current source, such as a switchable current source. In some embodiments, the control device 133 may be positioned between the second biasing tee circuit 126 and the tuning circuit 108. For example, the control device 133 may be positioned between the inductor 130 and the tuning circuit 108 and coupled to the inductor and the tuning circuit. As will be discussed in more detail below with reference to Figures 8 to 14 The control device 133 may be configured to generate an acknowledgment (ACK) signal and transmit the ACK signal to the radio frequency circuit 112 via the transmission line 114.

[0054] In some embodiments, the antenna system 100 may further include a control device 135 (e.g., a reverse channel receiver). As will be discussed in more detail below with reference to Figure 7 The control device 135 may be any suitable current sensing device, such as a high-side current sensing circuit. In some embodiments, the control device 135 may be positioned between the first biasing tee circuit 120 and the control circuit 118. For example, the control device 135 may be positioned between the inductor 124 and the control circuit 118 and coupled to the inductor and the control circuit. As will be discussed in more detail below with reference to Figure 15 The control device 135 may be configured to sense and decode the acknowledgment (ACK) signal generated by the control device 133.

[0055] In some embodiments, the antenna system 100 may include a first circuit board 129 and a second circuit board 131, which are physically separated from the first circuit board 129. The radio frequency circuit 112 and the control device 135 may be disposed on the first circuit board 129. The antenna circuit including at least one of the tuning circuit 108 or the mode antenna 102 may be disposed on the second circuit board 131. In some embodiments, the control device 133 may also be disposed on the second circuit board 131. This may allow the radio frequency circuit 112 to be physically separated from the tuning circuit 108 and / or the mode antenna 102 without using multiple transmission lines or adversely affecting the operation of the antenna system 100.

[0056] In some embodiments, the RF signal may be limited to a first frequency band. The control signal may be limited to a second frequency band different from the first frequency band. For example, the first frequency band may be in the range of from about 500 megahertz (MHz) to about 50 gigahertz (GHz), in some embodiments from about 1 GHz to about 25 GHz, in some embodiments from about 2 GHz to about 7 GHz (e.g., about 5 GHz). The second frequency band may be in the range of from about 10 MHz to about 1 GHz, in some embodiments from about 20 MHz to about 800 MHz, in some embodiments from about 30 MHz to about 500 MHz, in some embodiments from about 50 MHz to about 250 MHz (e.g., about 100 MHz).

[0057] Figure 3 Shows Figure 2 1 is a schematic diagram of an embodiment of a control circuit 118 of the antenna system 100 shown in FIG. The control circuit 118 may include a processor 132. The processor 132 may be configured to generate or receive control instructions for changing the modal antenna 102 (in Figure 2 ) or otherwise adjust the azimuth or frequency of the radiation pattern of modal antenna 102. For example, processor 132 may receive a signal from another processor (in Figure 3 control instructions (represented by the host (HOST) in the ) and can generate outputs (represented by the host (HOST) in the Figure 3 DATA N denoted). The data may have any suitable bit depth. For example, in some embodiments, the data may be in binary format. In other embodiments, the data may be in hexadecimal format, decimal format, etc. As will be discussed in detail below, according to example embodiments of the present disclosure, the data may be encoded using a coding scheme that enhances error detection.

[0058] The control circuit 118 may also include a carrier signal source 134. In some embodiments, the carrier signal source 134 may be configured to generate a carrier signal including a sine wave, which may have a substantially constant frequency. In other embodiments, the carrier signal may be or include any suitable signal. For example, in some embodiments, the carrier signal may be or include any suitable repeating pattern and is not limited to being sinusoidal or having a substantially constant frequency.

[0059] The control circuit 118 may also include a modulator 136 configured to modulate the output of the processor onto a carrier signal to generate a control signal (in Figure 3 TX CH NThe modulator 136 may include a multiplexer 138 configured to output (in Figure 3 DATA N 4 ) is combined with a carrier signal from a carrier signal source 134. For example, the modulator 136 can be configured to scale the amplitude of the carrier signal from the carrier signal source 134 to generate the control signal, for example, by performing amplitude shift keying modulation (e.g., on-off keying modulation), such as described in more detail below with reference to FIG. 4 . The modulator 136 can also include an amplifier 140 and a bias tee circuit 142.

[0060] Figure 4A A series of time-aligned graphs 400 representing a simplified example of binary amplitude shift keying modulation are shown. A binary signal 401 may alternate between a first voltage level 402 and a second voltage level 404 in a manner that describes a binary data set. The binary signal 401 may correspond to a simplified example of an output of the processor 132, such as described above with reference to FIG. Figure 3 As described, the output may include data describing the control instruction. Amplitude shift keying modulation may include representing a binary signal 401 by representing a first voltage level 402 as a sinusoidal signal 406 having a varying amplitude. For example, the sinusoidal signal 406 may have a first amplitude 408 representing the first voltage level 402 of the binary signal 401. The sinusoidal signal 406 may have a second amplitude 410 representing the second voltage level 404 of the binary signal 401.

[0061] Figure 4B Another series of time-aligned graphs 420 representing a simplified example of a multi-level amplitude shift keying modulation is shown. The multi-level amplitude shift keying modulation can include a data signal representing a bit depth greater than two. In other words, the data signal can be "m-ary", where m represents an integer greater than two. The multi-level signal 440 can switch between multiple voltage levels 452, 454, 456, 458 in a manner that describes a data set with a bit depth greater than two. The voltage levels 452, 454, 456, 458 of the multi-level signal 440 can be represented as a sinusoidal signal 430 with varying amplitudes. For example, each of the voltage levels 452, 454, 456, 458 of the multi-level signal 440 can be associated with a corresponding amplitude 462, 464, 466, 468 of the sinusoidal signal 430. The multi-level signal 440 can correspond to a simplified example of an output of the processor 132, such as described above with reference to FIG. Figure 3 As described, the output may include data describing the control instructions.

[0062] As described above, in some embodiments, a receiver (e.g., tuning circuit 108) may be configured to extract clock information from a transmitted signal. The receiver may be configured to synchronize the operation of the receiver (e.g., control electrical characteristics associated with parasitic element 106 to cause modal antenna 102 to operate in a plurality of different modes) with the operation of a transmitter (e.g., radio frequency circuit 112) based on the extracted clock information. For example, in some embodiments, the receiver may not have a clock source separate from the clock source of the transmitter (e.g., carrier signal source 134 associated with control circuit 118). In other embodiments, the receiver may include an unused clock source. Alternatively, the receiver may rely on the extracted clock information associated with the clock source of the transmitted signal.

[0063] In some embodiments, the control signal may include a data frame that includes a training portion 470. A tuning circuit (e.g., a receiver) may be configured to identify the training portion 470 within the data frame to identify at least one of a start or an end of the data frame. For example, referring Figure 4B , the vertical dashed lines in the diagram of the multi-level signal 440 may represent divisions between multiple bits. For example, as Figure 4B shown, one byte may include 8 bits.

[0064] The data frame may further include a data portion 472 that contains or describes data (e.g., control instructions for adjusting the mode of the modal antenna as discussed above with reference to Figures 1A to 1C ). The receiver may also be configured to locate the data portion 472 within the data frame based on the position of the identified training portion 470 within the data frame. The training portion 470 may include a predetermined sequence of bits and / or have a predetermined position within the data frame. For example, as Figure 4A and Figure 4B shown, the training portion 470 may include a set of consecutive bits at the start of the data (e.g., the first three bits). The data portion 472 may include another set of consecutive bits (e.g., the next five bits after the training portion 470). The training portion 470 may have any suitable bit depth, length, and position within the data frame. Similarly, the data portion 472 may have any suitable bit depth, length, and position within the data frame. The data frame may have any suitable bit depth and length. As an example, in some embodiments, the data frame may include multiple bytes. A single training portion 470 may be included in the data frame, or multiple training portions 470 may be located within the data frame. Thus, one or more training portions 470 may be configured to provide a reference point to the receiver such that the receiver can locate the start of the data frame, the end of the data frame, or the data portion 472 within the data frame.

[0065] In some embodiments, the transmitter may be configured to modulate a clock signal onto an RF signal using multi-level amplitude shift keying. The receiver may be configured to demodulate a control signal and extract a clock signal from the RF signal, the clock signal including clock information associated with the transmitter. For example, referring to Figure 4B , the clock signal may be or include at least a portion of the training portion 470. The receiver may be configured to identify the position of the data portion 472 within the data frame based on the clock information associated with the transmitter.

[0066] In some embodiments, the transmitter may be configured to modulate a clock signal onto an RF signal using a first set of amplitude levels and modulate a control signal onto the RF signal using a second set of amplitude levels, the second set of amplitude levels including at least one amplitude level different from the first set of amplitude levels. As an example, in one embodiment, the clock signal may be at least partially represented or described within the training portion 470. Referring to Figure 4B , in a simplified example, the first set of amplitude levels may correspond to the amplitudes 462, 464 of the sine signal 430 and the voltage levels 452, 454 of the multi-level signal 440. The second set of amplitude levels may correspond to the amplitudes 466, 468 of the sine signal 430 and the voltage levels 456, 458 of the multi-level signal 440. In this example, the first set of amplitude levels (associated with the control signal) is completely separate from the second set of amplitude levels (associated with the clock signal). However, in other embodiments, the first set of amplitude levels and the second set of amplitude levels may partially overlap (e.g., may include one or more identical amplitude levels). Such a configuration may allow the receiver to more accurately and reliably locate the clock signal and information and extract the clock signal and information from the RF signal.

[0067] Figure 5 FIG. shows a schematic diagram of an embodiment of a tuning circuit 500 (e.g., a receiver) according to aspects of the present disclosure, the tuning circuit corresponding, for example, to the tuning circuit 108 discussed above with reference to Figure 2 . The tuning circuit 500 may include a demodulator 502 and a biaser 504. The demodulator 502 may include a bias tee circuit 506 coupled to the biaser 504 and a multiplexer 507 coupled to a transmission line 114 (as Figure 2 shown).

[0068] The tuning circuit 500 may further include a low-pass filter 508 configured to filter at least one frequency band. For example, the low-pass filter 508 may be configured to filter at least one frequency band having a frequency higher than the carrier signal frequency. In this way, the low-pass filter 508 may isolate or relatively increase the intensity of the carrier signal frequency. The demodulator 502 may further include a diode 510, such as a Zener diode. The diode 510 may be coupled to a logic circuit 512 configured to interpret control instructions associated with (e.g., included in) the control signal.

[0069] The logic circuit 512 (e.g., a processor configured to execute computer-readable instructions to implement logical operations, application-specific integrated circuits (ASICs), etc.) may also be configured to control the operation of the switch 514 based on control instructions associated with (e.g., included in) the control signal. The switch 514 may be connected to ground and configured to switch between one or more of a plurality of states. For example, the switch 514 may be configured to selectively connect the output 516 of the switch 514 to ground or otherwise change the electrical connection of the output 516 to control the electrical characteristics associated with the parasitic element 106 (shown in Figure 2 and cause the modal antenna to operate in a plurality of different modes. For example, the switch 514 may be configured to adjust the operation of the tunable component 110 (shown in Figure 2 to change the electrical connection of the parasitic element 106 to a source or sink (e.g., a voltage source / sink or a current source / sink). For example, the switch 514 may be configured to selectively connect the parasitic element 106 to ground.

[0070] In some embodiments, the tuning circuit 500 (e.g., a receiver) may not have a clock source. For example, the receiver may be configured to demodulate a control signal and extract clock information associated with the transmitter. The receiver may synchronize the operation of the receiver with the transmitter based on the extracted clock information, rather than using a clock source separate from the clock source of the receiver. For example, the logic circuit 512 of the tuning circuit 500 (e.g., a receiver) may not use a clock source separate from the clock source of the transmitter (e.g., the carrier signal source 134 associated with the control circuit 118). Instead, the tuning circuit 500 (e.g., a receiver) may synchronize the operation of the tuning circuit with the control circuit 118 (e.g., a transmitter) based on the extracted clock information. For example, the tuning circuit 500 may be configured to demodulate a control signal. For example, the logic circuit 512 may be configured to sample the received signal (e.g., from the diode 510), extract clock information from the received signal, and then use the clock information to locate the data portion within the received signal (e.g., as described above with reference to Figure 4A and Figure 4B ).

[0071] In some embodiments, the receiver may be configured to sample the transmitted signal at a frequency significantly greater than the signal frequency associated with the transmit frequency. For example, the signal frequency associated with the transmit frequency may correspond to the frequency of a carrier signal (e.g., the sine signal 430 described above with reference to Figure 4A ). As another example, the signal frequency associated with the transmit frequency may correspond to the frequency at which the amplitude of the carrier signal (e.g., sine signal 430) changes or switches between amplitude levels.

[0072] The receiver may be configured to sample the transmitted signal at a sampling frequency significantly greater than the signal frequency associated with the transmit frequency such that changes in the amplitude of the carrier signal can be detected with sufficient accuracy to demodulate the control signal and / or clock signal from the transmitted signal and decrypt the data (e.g., instructions) contained in the control signal and / or clock signal. For example, the receiver may be configured to sample the transmitted signal at a sampling frequency that is at least the Nyquist rate or Nyquist frequency of the signal frequency. In some embodiments, the receiver may be configured to sample the transmit frequency at a sampling frequency that is a predetermined multiple of the signal frequency associated with the transmit frequency. For example, in some embodiments, the frequency may be from 2 to 1000 times the signal frequency, in some embodiments from 5 to 500 times, and in some embodiments from 10 to 100 times.

[0073] Figure 6 FIG. shows a schematic diagram of an example embodiment of a reverse channel modulator 600 (e.g., a switchable current source) according to an example aspect of the present disclosure, the reverse channel modulator corresponding, for example, to the control device 133 discussed above with reference to Figure 2 . The reverse channel modulator 600 may include a switching device 602 and a current source 604.

[0074] The switching device 602 may be used to control the operation of the reverse channel modulator 600. More specifically, the switching device 602 may be used to selectively couple the current source 604 to the tuning circuit 108 (as Figure 2 shown) and the second bias tee circuit 126 (as Figure 2 shown). For example, the switching device 602 may be a single-pole-single-throw (SPST) switch that can move between a first position 606 and a second position 608. When the switching device 602 is in the first position 606, the current source 604 is not coupled to the tuning circuit 108 and the second bias tee circuit 126. However, when the switching device 602 is in the second position 608, the current source 604 may be triggered to supply power to the control device 135 (asFigure 2 Send a current pulse as shown.

[0075] The switching device 602 may also include, for example, a transistor, an integrated circuit, an on / off circuit interrupter (such as a toggle switch, a relay (mechanical relay, electrical relay, or digital relay), a double-pole-single-throw (DPST) switch), or other switching devices. For purposes of illustration and discussion, aspects of the present disclosure are described with reference to an SPST switch. Those of ordinary skill in the art will understand, using the disclosure provided herein, that aspects of the present disclosure may be implemented using any suitable switching device without departing from the scope of the present disclosure.

[0076] Figure 7 A schematic diagram of an example embodiment of a reverse channel receiver 700 (e.g., a current sensor) according to an example aspect of the present disclosure is shown, which is, for example, corresponding to the control device 135 discussed above with reference to Figure 2 as discussed.

[0077] The reverse channel receiver 700 may include an operational amplifier 702 having a non-inverting input 704, an inverting input 706, and an output 708. The reverse channel receiver 700 may also include a current sensing device, such as a current sensing resistor 710 positioned between the non-inverting input 704 and the inverting input 706 and coupling the non-inverting input and the inverting input. The reverse channel receiver 700 may also include a load 712 positioned between the current sensing resistor 710 and ground.

[0078] In an example embodiment, the reverse channel receiver 700 may operate as a current sensor. For example, the reverse channel receiver 700 may be configured to sense current pulses generated by the reverse channel modulator 600 as Figure 6 shown and provide a signal indicative of the current to the control circuit 118 as Figure 2 shown. More specifically, the operational amplifier 702 may be configured to monitor and / or sense the current flowing into the inductor 124 and provide a signal indicative of the received current pulse to the control circuit 118 via the output 708.

[0079] The reverse channel receiver 700 may also be any device suitable for sensing current pulses generated by the reverse channel modulator 600. For purposes of illustration and discussion, aspects of the present disclosure are described with reference to Figure 7 the high-side current sensing circuit in. Those of ordinary skill in the art will understand, using the disclosure provided herein, that aspects of the present disclosure may be implemented using any suitable current sensing device without departing from the scope of the present disclosure.

[0080] Now refer to Figure 6 and Figure 7 which, as will be discussed in more detail with reference to method 800 below, in some embodiments, the tuning circuit 108 (as shown in Figure 8 ) can respond to a received acknowledgement (ACK) request from the radio frequency circuit 112 (as shown in Figure 2 ) and trigger the reverse channel modulator 600 to send a pulsed DC current signal. The antenna system 100 can be configured to facilitate transmission of the pulsed DC current signal to the reverse channel receiver 700 via the transmission line 114 (as shown in Figure 2 ). The reverse channel receiver 700 can be configured to sense the pulsed DC current signal generated by the reverse channel modulator 600. In some embodiments, the reverse channel receiver 700 can be configured to decode the received pulsed DC current signal from the reverse channel modulator 600 into an acknowledgement (ACK) signal. Figure 2 ).

[0081] Figure 8 FIG. depicts a flowchart of an example method 800 in accordance with an example embodiment of the present disclosure. For purposes of illustration and discussion, Figure 8 FIG. depicts a plurality of steps performed in a particular order. Those of ordinary skill in the art using the disclosure provided herein will understand that the various steps of any of the methods described herein can be omitted, extended, performed simultaneously, rearranged, and / or modified in various ways without departing from the scope of the present disclosure. Additionally, various steps (not shown) can be performed without departing from the scope of the present disclosure. Additionally, method 800 is discussed generally with reference to the antenna system 100 described above with reference to Figure 2 . However, it should be understood that aspects of the present method 800 can be applied to any suitable antenna system including a modal antenna.

[0082] At (802), method 800 can include: modulating a control signal onto an RF signal to generate a transmission signal. For example, the control signal can include control instructions for changing the mode of the modal antenna or otherwise adjusting the azimuth or frequency of the radiation pattern of the modal antenna. For example, as described above with reference to Figure 3 , Figure 4A and Figure 4B , the radio frequency circuit 112 can include a control circuit 118 configured to modulate a control signal onto an RF signal to generate a transmission signal.

[0083] The control signal can be implemented in one or more frames. Each frame can include multiple bits. The one or more frames can specify a selected mode among multiple modes for operating the mode antenna. The control signal (e.g., instruction) can be encoded by a tuning circuit using an encoding scheme that enhances error detection. For example, the encoding scheme can assign a unique code to each of the multiple modes.

[0084] In some embodiments, an 11-bit or more bit (e.g., 11 bits, 21 bits) can be used to encode the unique code. The unique code for each mode can differ from the unique code for each of the other modes among the multiple modes by at least two bits, such as at least three bits, such as at least four bits, such as at least five bits, such as at least six bits, such as at least seven bits, such as at least eight bits, etc. Thus, the unique code for each mode among the multiple modes is separated by a relatively large distance (e.g., represented in binary code) from the unique code for each of the other antenna modes.

[0085] For example, Figure 9 An example encoding scheme 900 in accordance with an example embodiment of the present disclosure is depicted. Encoding scheme 900 assigns a unique 11-bit code to each of four different antenna modes (mode 0, mode 1, mode 2, and mode 3). More specifically, code 902 is assigned to mode 0. Code 904 is assigned to mode 1. Code 906 is assigned to mode 2. Code 908 is assigned to mode 3. Encoding scheme 900 similarly assigns a unique 11-bit code to each of a general acknowledgment request and four different mode-specific acknowledgment requests (general ACK, mode 0 ACK, mode 1 ACK, mode 2 ACK, and mode 3 ACK). More specifically, code 910 is assigned to the general ACK. Code 912 is assigned to mode 0 ACK. Code 914 is assigned to mode 1 ACK. Code 916 is assigned to mode 2 ACK. Code 918 is assigned to mode 3 ACK.

[0086] For purposes of illustration and discussion, aspects of the present disclosure have been discussed with reference to four modes. Those of ordinary skill in the art will understand, using the disclosure provided herein, that any number of modes can be used without departing from the scope of the present disclosure, such as 8 modes, 16 modes, 32 modes, etc. Additionally, aspects of the present disclosure have been discussed with reference to unique codes implemented in binary format. Those of ordinary skill in the art will understand, using the disclosure provided herein, that other numerical schemes (e.g., decimal, hexadecimal) can be used without departing from the scope of the present disclosure.

[0087] Referring to Figure 9, the codes 902, 904, 906, 908, 910, 912, 914, 916, and 918 in the coding scheme 900 differ from each other by at least two bits, for example, at least five bits. Thus, the codes 902, 904, 906, 908, 910, 912, 914, 916, and 918 are spaced relatively far apart from each other. As described below, this helps with error detection.

[0088] Reference Figure 8 , at (804), the method 800 may include: transmitting a transmission signal to a tuning circuit via a single coaxial transmission line. For example, as referenced above Figure 2 described, the radio frequency circuit 112 may include a front-end module 116 that may transmit an RF signal to a drive element 104 of the modal antenna 102 through a capacitor 122 of a first bias tee circuit 120, through a transmission line 114, and through a capacitor 128 of a second bias tee circuit 126. The control circuit 118 may modulate a control signal onto the RF signal, and the RF signal reaches the tuning circuit 108 through an inductor 124 of the first bias tee circuit 120, through the transmission line 114, and through an inductor 130 of the second bias tee circuit 126.

[0089] At (806), the method 800 may include: demodulating the control signal at the tuning circuit. For example, as referenced above Figure 2 and Figure 5 described, the tuning circuits 108, 500 may be configured to demodulate the control signal from the transmission signal via the inductor 130 of the second bias tee circuit 126. The tuning circuits 108, 500 may also be configured to filter and / or amplify the control signal to isolate or relatively increase the intensity of a carrier signal frequency associated with the carrier signal. The logic circuit 512 may be configured to obtain and / or interpret control instructions associated with (e.g., contained in) the control signal.

[0090] For example, at (808), the method 800 may include: processing one or more frames (e.g., bits in the control signal) of the control signal for error detection. For example, at (810), the logic circuit 512 may process multiple bits in the one or more frames to determine whether a unique code matches a unique code in the coding scheme 900.

[0091] As an illustrative example, Figure 10The logic circuit 512 depicts an example tuning circuit that processes multiple bits 920. The multiple bits 920 are different from each of the multiple bits associated with the unique codes 902, 904, 906, 908, 910, 912, 914, 916, and 918. However, since the multiple bits 920 do not match the unique codes in the coding scheme 900, the logic circuit 512 can easily detect an error. Reducing the incorrect matching with other unique codes by separating each unique code in the coding scheme by a relatively large distance can facilitate such error detection.

[0092] Reference Figure 8 , at (810), if an error is detected (e.g., the unique code does not match any of the unique codes in the coding scheme 900), the method 800 can proceed to (812), where the tuning circuit maintains the current mode of the antenna. In other words, the tuning circuit does not respond to the control signal containing the error and maintains the modal antenna in its current mode.

[0093] Reference Figure 8 , at (810), if no error exists, the method 800 can proceed to (814) to determine whether the unique code matches the unique code assigned to the mode in the coding scheme 900. For example, the tuning circuit can determine whether the unique code matches any of the unique codes 902, 904, 906, and 908.

[0094] Reference Figure 8 , at (814), if the unique code matches the unique code assigned to the mode in the coding scheme 900, the method 800 can proceed to (816) to control the modal antenna according to the selected mode specified by the unique code. For example, the method 800 can include controlling the electrical characteristics associated with the parasitic elements of the modal antenna at least partially based on the control signal to control the modal antenna in the selected mode.

[0095] As an illustrative example, Figure 11 The logic circuit 512 depicts an example tuning circuit that processes multiple bits in one or more frames received via a transmission line. The logic circuit 512 can process these bits and determine that these bits match the unique code 904. As discussed above regarding the coding scheme 900 in Figure 9 , the unique code 904 is associated with mode 1. Therefore, the logic circuit 512 can determine that the control signal has a control instruction to operate the modal antenna in mode 1. For example, as described above with reference to Figure 5 , the logic circuit 512 can control the switch 514 to change the electrical characteristics associated with the parasitic element 106 (shown in Figure 2 ) in such a way that the modal antenna will operate in mode 1.

[0096] Reference Figure 8 , in (814), if the unique code does not match the unique code assigned to the pattern in coding scheme 900, method 800 can proceed to (818) to determine whether the unique code matches the unique code assigned to the general acknowledgment request in coding scheme 900. For example, the tuning circuit can determine whether the unique code matches unique code 910.

[0097] Reference Figure 8 , in (818), if the unique code matches the unique code 910 assigned to the general acknowledgment request, method 800 can proceed to (820) to send an acknowledgment (ACK) signal via the reverse channel modulator. For example, method 800 can include: controlling device 133 (e.g., reverse channel modulator 600) to send an ACK signal to radio frequency circuit 112 through transmission line 114.

[0098] As an illustrative example, Figure 12 logic circuit 512 of an example tuning circuit that processes multiple bits in one or more frames received through a transmission line is depicted. Logic circuit 512 can process these bits and determine that these bits match unique code 910. As discussed above with respect to Figure 9 coding scheme 900 in, unique code 910 is associated with the general ACK request. Thus, logic circuit 512 can determine that the control signal includes a control instruction containing the general acknowledgment request. In response to determining that the control signal includes an instruction containing the general acknowledgment request, controlling device 133 (e.g., reverse channel modulator 600) can send an ACK signal to radio frequency circuit 112 through transmission line 114. For example, as referenced above Figure 6 described, when logic circuit 512 determines that the control signal includes an instruction containing the general ACK request, switching device 602 can be triggered to move from the first position 606 to the second position 608 such that current source 604 is coupled to tuning circuit 108 and the second bias tee circuit 126. Additionally, then, current source 604 can be triggered to send an ACK signal (e.g., a current pulse) to radio frequency circuit 112 through transmission line 114.

[0099] Reference Figure 8, if there is no error at (810), the unique code does not match the unique code assigned to the pattern at (814), and the unique code does not match the unique code assigned to the general confirmation request at (818), then the unique code is associated with the pattern-specific confirmation request, and method 800 can proceed to (822). At (822), method 800 may include: comparing the pattern associated with the unique code (e.g., the pattern associated with the pattern-specific confirmation request) with the current pattern of the configuration of the modal antenna. For example, at (824), logic circuit 512 may determine whether the current operating mode of the modal antenna matches the pattern specified by the unique code associated with the pattern-specific confirmation request.

[0100] Reference Figure 8 , at (824), if the current operating mode of the modal antenna matches the pattern specified by the unique code associated with the pattern-specific confirmation request, then method 800 can proceed to (826) to send an ACK signal via the reverse channel modulator. As discussed above regarding the general confirmation request, method 800 may include: controlling device 133 (e.g., reverse channel modulator 600) to send an ACK signal to radio frequency circuit 112 through transmission line 114.

[0101] As an illustrative example, Figure 13 Logic circuit 512 of an example tuning circuit that processes multiple bits in one or more frames received through transmission line 114 is depicted. Logic circuit 512 may process these bits and determine that these bits match unique code 914. As discussed above regarding Figure 9 coding scheme 900 in, unique code 914 is associated with a mode 1 ACK request. Logic circuit 512 may also determine that the modal antenna is currently operating in mode 1. In response to determining that the modal antenna is operating in the same mode as indicated by the pattern-specific confirmation request, control device 133 (e.g., reverse channel modulator 600) may send an ACK signal to radio frequency circuit 112 through transmission line 114. For example, as referenced above Figure 5 and Figure 6 described, when logic circuit 512 determines that the control signal includes a mode 1 ACK request, logic circuit 512 may control switch 514 in such a way that the modal antenna operates in mode 1. In response to determining that the modal antenna is operating in the same mode as indicated by code 914, control device 133 (e.g., reverse channel modulator 600) may be triggered to send an ACK signal to radio frequency circuit 112 through transmission line 114 in a manner similar to that described above with reference to Figure 12 described.

[0102] Reference Figure 8, at (824), if the current operating mode of the modal antenna does not match the mode specified by the unique code associated with the mode - specific acknowledgment request, method 800 may proceed to (828), where the control device 133 (e.g., the reverse - channel modulator 600) does not respond to the mode - specific acknowledgment request associated with the unique code, and the tuning circuit maintains the current mode of the antenna. In other words, the tuning circuit does not respond to the control signal containing the mode - specific acknowledgment request and maintains the modal antenna in its current operating mode.

[0103] As an illustrative example, Figure 14 depicts a logic circuit 512 of an example tuning circuit that processes multiple bits in one or more frames received via transmission line 114. The logic circuit 512 may process these bits and determine that the bits match the unique code 918. As discussed above with respect to Figure 9 the coding scheme 900 in, the unique code 918 is associated with a mode 3 ACK request. The logic circuit 512 may also determine that the modal antenna is currently operating in mode 1. In response to determining that the modal antenna is not operating in the same mode as indicated by the mode - specific acknowledgment request, the control device 133 (e.g., the reverse - channel modulator 600) does not send an ACK signal to the radio - frequency circuit 112, and the tuning circuit maintains the modal antenna in mode 1. For example, as described above with reference to Figure 6 the switch device 602 may remain in the first position 606 such that the current source 604 is not coupled to the tuning circuit 108 and the second bias tee circuit 126. Thus, the current source 604 will not be triggered to send an ACK signal (e.g., a current pulse) to the radio - frequency circuit 112 via the transmission line 114. Additionally, the logic circuit 512 may control the switch 514 in such a way that the operating mode of the modal antenna remains unchanged.

[0104] Figure 15 depicts a flowchart of an example method 1500 according to an example embodiment of the present disclosure. For purposes of illustration and discussion, Figure 15 depicts multiple steps performed in a particular order. Those of ordinary skill in the art, using the disclosure provided herein, will understand that the various steps of any of the methods described herein may be omitted, extended, performed simultaneously, rearranged, and / or modified in various ways without departing from the scope of the present disclosure. Additionally, various steps (not shown) may be performed without departing from the scope of the present disclosure. Additionally, method 1500 is discussed generally with reference to the antenna system 100 described above with reference to Figure 2 However, it should be understood that aspects of this method 1500 may be applied to any suitable antenna system including a modal antenna.

[0105] At (1502), method 1500 may include: sending a general acknowledgment (general ACK) request frame. For example, the general ACK request frame may include instructions for generating an acknowledgment (ACK) signal in response to receiving the general ACK request frame. More specifically, the general ACK request frame may include a unique code (e.g., code 910) assigned to the general ACK request according to a coding scheme (e.g., the coding scheme 900 described above with reference to Figure 9 ).

[0106] Referring to Figure 15 , method 1500 may proceed to (1504) to determine whether an ACK signal has been successfully received in response to the general ACK request frame sent at (1502). For example, referring to Figure 6 and Figure 7 , in response to sending the general ACK request frame at (1502), if the reverse channel receiver 700 receives a pulsed DC current signal (i.e., the ACK signal) from the reverse channel modulator 600, the general ACK request frame has been successfully received. However, in response to sending the general ACK request frame at (1502), if the reverse channel receiver 700 does not receive a pulsed DC current signal (i.e., the ACK signal) from the reverse channel modulator 600, the general ACK request frame has not been successfully received.

[0107] Referring to Figure 15 , at (1504), if the general ACK request frame sent at (1502) has not been successfully received, method 1500 may proceed to (1506) to determine that there is a mode antenna control channel error. In response to determining that there is a mode antenna control channel error, method 1500 may perform a re-initialization process and return to (1502).

[0108] Referring to Figure 15 , at (1504), if the general ACK request frame sent at (1502) has been successfully received, method 1500 may proceed to (1508). At (1508), method 1500 may include: sending a specific acknowledgment (specific ACK) request frame. For example, the specific ACK request frame may include instructions for generating an acknowledgment (ACK) signal in response to receiving the specific ACK request frame. More specifically, the specific ACK request frame may include unique codes (e.g., codes 912, 914, 916, 918) assigned to the mode-specific ACK request according to a coding scheme (e.g., the coding scheme 900 described above with reference to Figure 9 ).

[0109] Referring to Figure 15, method 1500 can proceed to (1510) to determine whether an ACK signal has been successfully received in response to a specific ACK request frame transmitted at (1508). For example, referring to Figure 13 , if the antenna system 100 is operating in mode 1 and the specific ACK request frame transmitted at (1508) includes code 914 (i.e., the mode-specific ACK request assigned to mode 1 requests by coding scheme 900), then the reverse channel receiver 700 (as Figure 7 shown) receives a pulsed DC current signal (i.e., the ACK signal). On the other hand, referring to Figure 14 , if the antenna system 100 is operating in mode 1 and the specific ACK request frame transmitted at (1508) includes code 918 (i.e., the mode-specific ACK request assigned to mode 3 requests by coding scheme 900), then the reverse channel receiver 700 (as Figure 7 shown) does not receive a pulsed DC current signal (i.e., the ACK signal).

[0110] Referring to Figure 15 , at (1510), if an ACK signal is received in response to the specific ACK request frame transmitted at (1508), method 1500 can proceed to (1512). At (1512), method 1500 can successfully read back the current operating mode of the antenna system 100. For example, as described above, if the specific ACK request frame transmitted at (1508) includes code 914, for example, then successfully receiving the ACK signal at (1510) can provide a real-time indicator at (1512) to confirm that the current operating mode of the antenna system 100 is mode 1.

[0111] Referring to Figure 15, at (1510), if an ACK signal is not received in response to a specific ACK request frame sent at (1508), method 1500 may proceed to (1514). At (1514), method 1500 may include sending a general ACK request frame in a manner similar to that discussed above with reference to (1502) for error detection. For example, as described above, if the specific ACK request frame sent at (1508) includes, for example, code 918 and the antenna system 100 is operating in mode 1, for example, a pulsed DC current signal (i.e., the ACK signal) will not be received. In this case, an error detection process must be performed to determine whether the failure to successfully receive the pulsed DC current signal (i.e., the ACK signal) at (1510) is due to the antenna system 100 operating in a mode different from the mode associated with the specific ACK request frame sent at (1508), or whether the failure to successfully receive the pulsed DC current signal (i.e., the ACK signal) at (1510) is due to a modal antenna control channel error. More specifically, method 1500 includes performing an error detection process by sending a general ACK request frame at (1514).

[0112] Reference Figure 15 , at (1516), method 1500 may determine whether an ACK signal has been successfully received in response to the general ACK request frame sent at (1514) in a manner similar to that described above with reference to (1504). As described above, method 1500 performs an error detection process to determine whether the antenna system 100 is operating in a mode different from the mode specified in the specific ACK request sent at (1508), or whether there is a modal antenna control channel error.

[0113] Reference Figure 15 , at (1516), if an ACK signal is not received in response to the general ACK request frame sent at (1514), method 1500 may proceed to (1506) to determine that there is a modal antenna control channel error. As discussed above with reference to (1506), method 1500 may perform a re-initialization process in response to determining that there is a modal antenna control channel error. In response to performing the initialization process at (1506), method 1500 may return to (1502).

[0114] Reference Figure 15, at (1516), if an ACK signal is received in response to the general Ack request frame sent at (1514), method 1500 may proceed to (1518) to increment the antenna configuration mode counter. In response to incrementing the antenna configuration mode counter, method 1500 may then return to (1502). For example, if the specific ACK request frame sent at (1508) includes a unique code associated with mode 0, the antenna configuration mode counter will be incremented by 1 and return to (1502). Thus, the next specific ACK request frame will include a unique code associated with mode 1. In this case, if method 1500 returns to (1518), the antenna configuration mode counter will be incremented by 1 again and return to (1502), such that the next specific ACK request frame will include a unique code associated with mode 2. This process may be repeated until the antenna configuration mode counter exhausts each of the plurality of modes of antenna system 100.

[0115] Although the subject matter has been described in detail with respect to specific example embodiments of the subject matter, it will be understood that those skilled in the art, having obtained and understood the foregoing, can readily generate alterations, variations, and equivalents of these embodiments. Accordingly, the scope of the present disclosure is presented by way of example rather than limitation, and the subject matter disclosure does not exclude including such modifications, variations, and / or additions to the subject matter that would be obvious to one of ordinary skill in the art.

Claims

1. An antenna system, comprising: A modal antenna that can operate in multiple modes, with each mode among the multiple modes associated with a different radiation pattern; A tuning circuit configured to control the modal antenna to operate in each of the multiple modes; A transmission line coupled to the tuning circuit; And One or more control devices configured to: Modulate a control signal onto a radio frequency (RF) signal to generate a modulated signal for transmission to the tuning circuit via the transmission line; and Generate an acknowledgment signal at least partially based on the control signal.

2. The antenna system according to claim 1, wherein, The one or more control devices are further configured to transmit the acknowledgment signal via the transmission line.

3. The antenna system according to claim 1, wherein, The transmission line is a single coaxial cable.

4. The antenna system according to claim 1, wherein: The control signal includes a data frame having multiple bits, and The one or more control devices are configured to: encode the multiple bits associated with a selected mode among the multiple modes according to an encoding scheme that assigns a unique code to a general acknowledgment request and multiple specific acknowledgment requests.

5. The antenna system according to claim 4, wherein, The encoding scheme is configured to assign a unique code to each of the multiple modes.

6. The antenna system according to claim 5, wherein, Each of the multiple specific acknowledgment requests is associated with one of the multiple modes.

7. The antenna system according to claim 1, wherein, The one or more control devices further include: A reverse channel modulator configured to: generate the acknowledgment signal at least partially based on the control signal and transmit the acknowledgment signal via the transmission line; and A reverse channel receiver configured to detect the acknowledgment signal, the reverse channel receiver being coupled to the reverse channel modulator via the transmission line.

8. The antenna system according to claim 7, wherein: The reverse channel modulator is a switchable current source, and The reverse channel receiver is a current sensor.

9. The antenna system according to claim 7, further comprising: A first circuit board including the reverse channel modulator; And A second circuit board including the reverse channel receiver, the second circuit board being physically separated from the first circuit board, wherein at least one of the tuning circuit or the modal antenna is disposed on the first circuit board.

10. The antenna system according to claim 1, wherein: The modal antenna includes a drive element and a parasitic element positioned close to the drive element, and The tuning circuit is further configured to: control one or more electrical characteristics associated with the parasitic element at least partially based on the control signal.

11. A method for controlling a modal antenna, comprising: Modulate a control signal onto an RF signal by an RF circuit to generate a modulated signal; Transmit the modulated signal to the tuning circuit via the transmission line; Demodulate the control signal from the modulated signal by the tuning circuit; Process the control signal by the tuning circuit to obtain a code; Determine by the tuning circuit whether the code includes an acknowledgment request; and In response to determining that the code includes an acknowledgment request, transmit an acknowledgment signal to the RF circuit via the transmission line.

12. According to the method of claim 11, wherein, Determining whether the code includes an acknowledgment request further includes: Determining by the tuning circuit whether the code is associated with a selected mode among the multiple modes of the modal antenna; and In response to determining that the code is not associated with a selected mode among the plurality of modes of the modal antenna, the tuning circuit determines whether the code is an acknowledgment code associated with one of the plurality of modes of the modal antenna.

13. According to the method of claim 12, further comprising: In response to determining that the code is an acknowledgment code associated with one of the plurality of modes of the modal antenna, the tuning circuit determines whether the mode associated with the acknowledgment code matches the current mode of the modal antenna.

14. According to the method of claim 13, further comprising: In response to determining that the mode associated with the acknowledgment code matches the current mode of the modal antenna, an acknowledgment signal is transmitted to the RF circuit via the transmission line.

15. According to the method of claim 13, further comprising: When the mode associated with the acknowledgment code does not match the current mode of the modal antenna, the current mode of the modal antenna is maintained.

16. According to the method of claim 12, further comprising: In response to determining that the code is associated with a selected mode among the plurality of modes of the modal antenna, the tuning circuit controls electrical characteristics associated with parasitic elements of the modal antenna at least in part based on the control signal so that the modal antenna operates in the selected mode among the plurality of modes.

17. According to the method of claim 11, wherein, Transmitting the acknowledgment signal to the RF circuit via the transmission line further includes: Transmitting the acknowledgment signal to the RF circuit via the transmission line; and Detecting the acknowledgment signal by the RF circuit.

18. According to the method of claim 11, wherein, The acknowledgment signal is a single-bit DC current increment pulse.

19. An antenna system, comprising: A modal antenna capable of operating in a plurality of modes, each of the plurality of modes being associated with a different radiation pattern; A radio frequency (RF) circuit including a front-end module and a first control device; A transmission line; And An antenna circuit coupled to the RF circuit via the transmission line, the antenna circuit including a tuning circuit and a second control device, the second control device being configured to: generate an acknowledgment signal and transmit the acknowledgment signal through the transmission line, the acknowledgment signal being used to confirm that the modal antenna operates in a selected mode; Wherein the first control device is configured to detect the acknowledgment signal.

20. According to the antenna system of claim 19, wherein: The first control device is a current sensor, and The second control device is a switchable current source.

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