The present disclosure relates generally to communication devices. More particularly, the present disclosure relates to multi-band strip antennas with dynamic bandwidth selection.
Arial vehicles (e.g., airplanes and satellites) need numerous antennas for various purposes (e.g., radio communication, radar, Electronic Warfare (EW), location tracking, navigation, etc.). These antennas must fit into a constrained volume of the vehicle, and take valuable real estate from payloads (e.g., weapons) that are essential for efficient and effective mission performance.
Some conventional platforms use an antenna for each band. In order to mitigate real estate issues, these antennas are stacked on top of each other and separated from each other by a lossy substrate. The lossy substrate reduces the efficiency of the antennas, adds weight to the aperture assembly, and adds manufacturing complexity to the aperture assembly due to isolation of via and feed through.
The present disclosure concerns implementing systems and methods for operating an antenna assembly. The methods comprise receiving a command for tuning the antenna assembly to a first frequency selected from a plurality of different frequencies to which a strip antenna structure of the antenna assembly is tunable. The strip antenna structure comprises a trace formed on a substrate. In response to the command, ground is selectively connected to the strip antenna structure at a first location along an elongated length of the trace. A transceiver is connected to the strip antenna structure at a second location along the elongated length of the trace using a first tank circuit of a plurality of tank circuits provided with the antenna assembly. The tank circuits are respectively associated with the plurality of different frequencies to which the strip antenna structure is tunable. The first tank circuit is associated with the first frequency to which the strip antenna structure is to be tuned.
In some scenarios, the methods also comprise connecting ground to the strip antenna structure at a third location along the elongated length of the strip antenna structure by using a second tank circuit of the plurality of tank circuits provided with the antenna assembly. The ground connections can be made when the trace extends away from the third location in two opposing directions. The strip antenna structure may be tuned to a frequency lower than the first frequency by disconnecting ground from the third location along the elongated length of the trace. Alternatively, the transceiver is connected to the strip antenna structure at a fourth location along an elongated length of the trace so as to simultaneously provide two dipole antennas using a single trace formed on the substrate.
In those or other scenarios, the methods comprise tuning the strip antenna structure to a second frequency selected from the plurality of different frequencies to which the strip antenna structure is tunable. This frequency tuning is achieved by: disconnecting ground from the strip antenna structure at the first location along the elongated length of the trace; disconnecting the transceiver from the strip antenna structure at the second location along the elongated length of the trace; connecting ground to the strip antenna structure at the second location along the elongated length of the trace; and connecting the transceiver to the strip antenna structure at a third location along the elongated length of the trace using a second tank circuit of the plurality of tank circuits. The strip antenna structure may be tuned to a frequency lower than the second frequency by disconnecting ground from the strip antenna structure at the second location along the elongated length of the trace.
In those or other scenarios, the tank circuits may comprise a plurality of selectable sub-circuits respectively associated with different bandwidths to which the strip antenna structure is tunable. Accordingly, the methods may comprise: receiving a command for tuning the antenna assembly to a first bandwidth selected from a plurality of different bandwidths to which the strip antenna structure is tunable; and selecting a first LC circuit from a plurality of LC circuits of the first tank circuit based on the command for bandwidth tuning, the plurality of LC circuits of the first tank circuit being associated with the plurality of different bandwidths to which the strip antenna structure is tunable. Notably, the command for frequency tuning and the command for bandwidth tuning may be separate commands or comprises a single command. The transceiver is connected to the strip antenna structure at the second location along the elongated length of the trace through the at least one first LC circuit of the first tank circuit.
The methods may also comprise: receiving an additional command for tuning the antenna assembly to a second bandwidth selected from the plurality of bandwidths to which the strip antenna structure is tunable; selecting a second LC circuit from the plurality of LC circuits of the first tank circuit based on the this command; disconnecting the transceiver from the first LC circuit of the first tank circuit; and connecting the transceiver to the second LC circuit of the first tank circuit.
The present document also concerns system with an antenna assembly. The system comprises: a substrate with a plurality of vias formed therein; a strip antenna structure comprising a trace disposed on a first surface of the substrate; a ground layer disposed on a second opposing surface of the substrate; a plurality of conductive elements extending through the vias of the substrate so as to be respectively coupled between the trace and a plurality of tank circuits; and a control circuit. The controller is configured to: receive a command for tuning the antenna assembly to a first frequency selected from a plurality of different frequencies to which a strip antenna structure is tunable; cause ground to be connected to the strip antenna structure at a first location along an elongated length of the trace, responsive to the command; and cause a transceiver to be connected to the strip antenna structure at a second location along the elongated length of the trace via a first tank circuit of the plurality of tank circuits. The tank circuits are respectively associated with the plurality of different frequencies to which the strip antenna structure is tunable. The first tank circuit is associated with the first frequency to which the strip antenna structure is to be tuned.
In some scenarios, the controller is also configured to cause ground to be connected to the strip antenna structure at a third location along the elongated length of the trace via a second tank circuit of the plurality of tank circuits. This ground connection can be made when the trace extends away from the third location in two opposing directions. The controller may further be configured to: tune the strip antenna structure to a frequency lower than the first frequency by causing ground to be disconnected from the third location along the elongated length of the trace; and/or cause the transceiver to be connected to the strip antenna structure at a fourth location along an elongated length of the trace so as to simultaneously provide two dipole antennas using a single trace formed on the substrate.
In those or other scenarios, the controller is configured to tune the strip antenna structure to a second frequency selected from the plurality of different frequencies to which the strip antenna structure is tunable. This frequency tuning is caused by: disconnecting ground from the strip antenna structure at the first location along the elongated length of the trace; disconnecting the transceiver from the strip antenna structure at the second location along the elongated length of the trace; connecting ground to the strip antenna structure at the second location along the elongated length of the trace; and connecting the transceiver to the strip antenna structure at a third location along the elongated length of the trace using a second tank circuit of the plurality of tank circuits.
In those or other scenarios, the controller is configured to tune the strip antenna structure to a frequency lower than the second frequency by causing ground to be disconnected from the strip antenna structure at the second location along the elongated length of the trace. The controller may also be configured to: receive a command for tuning the antenna assembly to a first bandwidth selected from a plurality of different bandwidths to which the strip antenna structure is tunable; and select a first LC circuit from a plurality of LC circuits of the first tank circuit based on the command for bandwidth tuning, the plurality of LC circuits of the first tank circuit being associated with the plurality of different bandwidths to which the strip antenna structure is tunable. The transceiver is connected to the strip antenna structure at the second location along the elongated length of the trace through the at least one first LC circuit of the first tank circuit.
In those or other scenarios, the controller is further configured to: receive a command for tuning the antenna assembly to a second bandwidth selected from the plurality of bandwidths to which the strip antenna structure is tunable; select a second LC circuit from the plurality of LC circuits of the first tank circuit based on the this command; cause the transceiver to be disconnected from the first LC circuit of the first tank circuit; and cause the transceiver to be connected to the second LC circuit of the first tank circuit.
The present solution will be described with reference to the following drawing figures, in which like numerals represent like items throughout the figures.
It will be readily understood that the components of the embodiments as generally described herein and illustrated in the appended figures could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the figures, is not intended to limit the scope of the present disclosure, but is merely representative of various embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
The present solution may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the present solution is, therefore, indicated by the appended claims rather than by this detailed description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present solution should be or are in any single embodiment of the present solution. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present solution. Thus, discussions of the features and advantages, and similar language, throughout the specification may, but do not necessarily, refer to the same embodiment.
Furthermore, the described features, advantages and characteristics of the present solution may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, in light of the description herein, that the present solution can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the present solution.
Reference throughout this specification to “one embodiment”, “an embodiment”, or similar language means that a particular feature, structure, or characteristic described in connection with the indicated embodiment is included in at least one embodiment of the present solution. Thus, the phrases “in one embodiment”, “in an embodiment”, and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
As used in this document, the singular form “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. As used in this document, the term “comprising” means “including, but not limited to”.
The present solution uses a programmable strip antenna for multi-band application, which is realized through carefully designing of the stacked antenna assembly. The radiating length of the antenna is controlled by the user to achieve a resonant frequency as well as bandwidth allocation and impedance matching. The resonant frequency of the antenna can be altered by changing the length (dipole or monopole) of the antenna element utilizing the following mathematical equation (1).
where L represents a resonant length of a dipole antenna, A represents a wave length in free space, and εr represents a dielectric constant of a substrate material. The resonant frequency is also influenced with the ground plane dimension, substrate thickness and strip width (impedance matching).
The present solution is discussed herein in relation to communication systems for transmitting and receiving communication signals. The present solution is not limited in this regard. The present solution can be used in other applications such as Global Position System (GPS) applications, radio controlled clock applications, broadcast reception applications, satellite communication applications, telemetry applications, wireless transmission of RF power applications, radar application, electronic warfare application (e.g., sign jamming, electronic attack, electronic surveillance), and/or aviation communications.
Referring now to
Referring now to
Communication device 200 may include more or less components than those shown in
Communication device 200 comprises an multi-band tunable strip antenna assembly 202 for receiving and transmitting signals. In some scenarios, the multi-band tunable strip antenna assembly 202 operates between 700 MHz and 200 GHz. The present solution is not limited to this operational frequency range. The operational bandwidth of the antenna 202 is adjustable through the user control of a tank circuit. The tank circuit will be discussed in detail below.
A receive/transmit (“Rx/Tx”) switch 204 selectively couples the antenna assembly 202 to the transmitter circuitry 206 and the receiver circuitry 208 in a manner familiar to those skilled in the art. The receiver circuitry 208 demodulates and decodes the signals received from an external device. The receiver circuitry 208 is coupled to a controller (or microprocessor) 210 via an electrical connection 234. The receiver circuitry 208 provides the decoded signal information to the controller 210. The controller 210 uses the decoded signal information in accordance with the function(s) of the communication device 200. The controller 210 also provides information to the transmitter circuitry 206 for encoding and modulating information into signals. Accordingly, the controller 210 is coupled to the transmitter circuitry 206 via an electrical connection 238. The transmitter circuitry 206 communicates the signals to the antenna 202 for transmission to an external device via the Rx/Tx switch 204.
The controller 210 may store received and extracted information in memory 212 of the communication device 200. Accordingly, the memory 212 is connected to and accessible by the controller 210 through electrical connection 232. The memory 212 may be a volatile memory and/or a non-volatile memory. For example, memory 212 can include, but is not limited to, a Random Access Memory (“RAM”), a Dynamic Random Access Memory (“DRAM”), a Read Only Memory (“ROM”) and a flash memory. The memory 212 may also comprise unsecure memory and/or secure memory. The memory 212 can be used to store various other types of data 260 therein, such as authentication information, cryptographic information, location information, and various object-related information (e.g., object identifier, operational states, etc.).
As shown in
The controller 210 is also connected to a user interface 230. The user interface 230 comprises input devices 216, output devices 224 and software routines (not shown in
The input and output devices may include, but are not limited to, a display 228, a speaker 226, a keypad 220, a directional pad (not shown in
Notably, the multi-band tunable strip antenna assembly 202 comprises a novel multi-band tunable strip antenna architecture. Various multi-band tunable strip antenna assembly architecture will now be described in relation to
Referring now to
A plurality of vias 314, 316, 318 are formed through the substrate 302. The vias can be equally spaced apart as shown in
As shown in
The tank circuits 310, 312 are configured to facilitate user controlled selection/setting/tuning of a frequency for the strip antenna structure 306 at any given time. In this regard, each tank circuit is configured to cause operation of the strip antenna structure 306 at a given frequency. For example, as shown in the graph of
The tank circuits 310, 312 are also configured to facilitate user controlled selection/setting/tuning of a bandwidth for the strip antenna structure 306 at any given frequency. In this regard, each tank circuit comprises a plurality of circuits 330, 350, . . . , 352 respectively associated with different bandwidths to which the strip antenna 306 can be tuned. The circuits 330, 350, . . . , 352 can include, but are not limited to, LC circuits. Each LC circuit is configured to cause the strip antenna structure 306 to function at a respective bandwidth of a plurality of bandwidths. For example, as shown by line 600 in the graph of
Although three LC circuit/switch elements are shown in
The LC circuits 330, 350, . . . , 352 are respectively connected to switches 332, 334, . . . , 340. Each of the switches is in a normally open position as shown in
In the closed position, switch 332 of tank circuit 310 electrically connects a transceiver (e.g., transceiver 204-208 of
The transceiver can be connected directly to the strip antenna structure 306 via closure of switches 336, 338 of a given tank circuit (while switches 332, 334, 340 remain open). The strip antenna structure 306 can be coupled to ground via closure of switch 340 of each tank circuit (while switches 332-338 remain open).
During operation, the switches can be controlled to provide dipole antennas with given frequencies and/or bandwidths. For example, a first dipole antenna with a total length 320-322 can be provided between conductive elements 320, 324 when (i) a first end of the strip antenna structure 306 is connected to ground via switch 308, (ii) switch(es) of tank circuit 310 is(are) in its(their) closed position(s) so that the transceiver is connected to the strip antenna structure 306 via conductive element 322, and (iii) the conductive element 324 is connected to ground via switch 340 of tank circuit 312. An illustrative beam pattern for the dipole antenna element is shown by line 400 of
A second dipole antenna with a total length of 320, 322, 350 can be provided when (i) a first end of the strip antenna structure 306 is connected to ground via switch 308, (ii) switch(es) of tank circuit 312 is(are) in its(their) closed position(s) so that the transceiver is connected to the strip antenna structure 306 via conductive element 322, and (iii) the conductive element 324 is not connected to the transceiver or ground via tank circuit 310. An illustrative beam pattern for the dipole antenna element is shown by line 402 of
A third dipole antenna with a frequency of f3=2f1 can also be provided via the circuit 300 of
A fourth dipole antenna with a frequency of f1=1.5f3 can also be provided via the circuit 300 of
Referring now to
A plurality of vias 814, 816, 818, 862, 872 are formed through the substrate 802. The vias can be equally spaced apart as shown in
The tank circuits 810, 812, 866, 876 are configured to facilitate user controlled selection/setting/tuning of a frequency for the strip antenna structure 806 at any given time. In this regard, each tank circuit is configured to cause operation of the strip antenna structure 806 at a given frequency. For example, selection of tank circuit 810 causes the strip antenna structure 806 to operate at a first frequency f1 (e.g., 700 MHz). Selection of tank circuit 812 causes the strip antenna structure 806 to operate at a second frequency f2 (e.g., 900 MHz). Selection of tank circuit 866 causes the strip antenna structure 806 to operate a third frequency f3 (e.g., 2 GHz). Selection of tank circuit 876 causes the strip antenna structure 806 to operate a fourth frequency f4 (e.g., 4 GHz). The present solution is not limited to the particulars of this example.
The tank circuits 810, 812, 866, 876 are also configured to facilitate user controlled selection/setting/tuning of a bandwidth for the strip antenna structure 806 at any given frequency. In this regard, each tank circuit comprises a plurality of LC circuits 830, 850, . . . , 852. Each LC circuit is configured to cause the strip antenna structure 806 to function at a respective bandwidth of a plurality of bandwidths. For example, LC circuit 830 is configured to cause the strip antenna structure 806 to function at a first bandwidth (e.g., 35 MHz). LC circuit 850 is configured to cause the strip antenna structure 806 to function at a second different bandwidth (40 MHz). LC circuit 852 is configured to cause the strip antenna structure 806 to function at a third different bandwidth (e.g., 60 MHz). The present solution is not limited to the particulars of this example. The inductor and capacitor values of each LC circuit can be selected to provide any bandwidth selected in accordance with a given application.
The LC circuits 830, 850, . . . , 852 are respectively connected to switches 832, 834, . . . , 840. Each of the switches is in a normally open position as shown in
In the closed position, switch 832 of tank circuit 810 electrically connects a transceiver (e.g., transceiver 204-208 of
The transceiver can be connected directly to the strip antenna structure 806 via closure of switches 836, 838 of each tank circuit (while switches 832, 834, 840 remain open). The strip antenna structure 806 can be coupled to ground via closure of switch 840 of each tank circuit (while switches 832-838 remain open).
During operation, the switches of each tank circuit 810, 812, 866, 876 can be controlled to provide dipole antennas with given frequencies and/or bandwidths. The antenna(s) can have the same or different frequencies and/or bandwidths. For example, a dipole antenna with a total length of 880-882 can be provided between conductive elements 820, 824 when (i) a first end of the strip antenna structure 806 is connected to ground via switch 808, (ii) switch(es) of tank circuit 810 is(are) in its(their) closed position(s) so that the transceiver is connected to the strip antenna structure 806 via conductive element 822, and (iii) the conductive elements 824 is connected to ground. The bandwidth of the dipole antenna can be changed via the selective connection/disconnection of the LC circuits 830, 850, . . . , 852 of the tank circuit 810 to/from the strip antenna structure 806. The dipole antenna has a frequency of f1.
Another dipole antenna with a length of 884-9886 can be created at the same time as the above-described dipole antenna with length 880-882 since the two sides of the strip antenna structure 806 are electrically isolated from each other via grounded conductive element 824. This dipole antenna is provided when (i) the conductive elements 824 is connected to ground, (ii) switch(es) of tank circuit 866 is(are) in its(their) closed position(s) so that the transceiver is connected to the strip antenna structure 806 via conductive element 864, and (iii) the conductive element 874 is not connected to ground (e.g., when the strip antenna structure 806 does not extend past the conductive element 874 as shown in
Another dipole antenna can be provided with a length of 880-886 and a frequency f3=2f1. This dipole antenna can be provided when (i) the conductive elements 824 is connected to ground via closure of switch 808, (ii) the conductive element 822 is not connected to the transceiver or ground via tank circuit 810, (iii) the conductive element 824 is connected to the transceiver via tank circuit 812, (iv) the conductive element 864 is not connected to the transceiver or ground via tank circuit 866, and (v) the conductive element 874 is not connected to ground (e.g., when the strip antenna structure 806 does not extend past the conductive element 874 as shown in
Another dipole antenna can be provided with a length of 880-884 and frequency f4=1.5f1. This dipole antenna is provided when (i) the conductive elements 820 is connected to ground via closure of switch 808, (ii) the conductive element 822 is connected to the transceiver via tank circuit 810, (iii) the conductive element 824 is not connected to the transceiver or ground via tank circuit 812, and (iv) the conductive element 864 is connected to ground via tank circuit 866.
Another dipole antenna can be provided with a length of 880-884 and frequency f5=1.5f1. This dipole antenna is provided when (i) the conductive elements 820 is connected to ground via closure of switch 808, (ii) the conductive element 822 is not connected to the transceiver or ground via tank circuit 810, (iii) the conductive element 824 is connected to the transceiver via tank circuit 812, and (iv) the conductive element 864 is connected to ground via tank circuit 866.
Another dipole antenna can be provide with a length of 882-886 and a frequency f6=1.5f1. This dipole antenna is provided when (i) the conductive elements 822 is connected to ground via tank circuit 810, (ii) the conductive element 824 is connected to the transceiver via tank circuit 812, (iii) the conductive element 864 is not connected to the transceiver or ground via tank circuit 866, and (iv) the conductive element 874 is or is not connected to ground via tank circuit 876 (e.g., depending on where the strip antenna structure 806 ends relative to the conductive element 874).
Another dipole antenna can be provided with a length 882-886 and a frequency f7=1.5f2. This dipole antenna is provided when (i) the conductive element 822 is connected to ground via tank circuit 810, (ii) the conductive element 824 is not connected to the transceiver or ground via 812, (iii) the conductive element 864 is connected to the transceiver via tank circuit 866, and (iv) the conductive element 874 is or is not connected to ground via tank circuit 876 (e.g., depending on where the strip antenna structure 806 ends relative to the conductive element 874).
Referring now to
In 910, ground is optionally connected to the strip antenna structure at a third location along the elongated length of the trace (e.g., a location aligned with conductive element 324 of
In 914, the controller receives a second command for tuning the antenna assembly to a second frequency different from the first frequency. In response to the second command, operations of 916-922 are performed. 916-922 involve: disconnecting ground from the strip antenna structure at the first location along the elongated length of the trace; disconnecting the transceiver from the strip antenna structure at the second location along the elongated length of the trace; connecting ground to the strip antenna structure at the second location along the elongated length of the trace; and connecting the transceiver to the strip antenna structure at the third location along the elongated length of the trace using the second tank circuit. The frequency of the strip antenna structure can be optionally lowered as shown by 924. The frequency reduction can be achieved by disconnecting ground from the strip antenna structure at the second location thereof.
In 926, a third command is received by the controller of the antenna assembly. The third command is for tuning the antenna assembly to a first bandwidth. In response to the third command, the controller selects a first LC circuit (e.g., LC circuit 330 of
In 932, the controller receives a fourth command for tuning the antenna assembly to a second bandwidth selected from the plurality of bandwidths to which the strip antenna structure is tunable. The second bandwidth is different than the first bandwidth. Based on the contents of the fourth command, the controller selects a second LC circuit (e.g., LC circuit 350 of
Although the present solution has been illustrated and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In addition, while a particular feature of the present solution may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Thus, the breadth and scope of the present solution should not be limited by any of the above described embodiments. Rather, the scope of the present solution should be defined in accordance with the following claims and their equivalents.