Patent Description:
In general, a vehicle refers to a moving device or a transport device which travels on a road or a track by using fossil fuel, electricity, or the like as a power source.

The vehicle serves as a living space to provide relaxation to a driver beyond merely being the moving device or the transport device. In addition, various electronic devices for vehicles are installed in the vehicle to provide comfort and relaxation to the driver.

Further, the vehicle is provided with an antenna configured to receive radio waves to receive radio broadcasts or the like. The antenna for the vehicle has a high resonance frequency gain, but a gain of the antenna decreases as a frequency deviates from the resonance frequency. Conventionally, in order to compensate for such performance problems, the antenna is provided with an amplifier configured to amplify strengths of signals in both side frequency bands with respect to the resonance frequency.

However, when the amplifier is provided, a strength of noise as well as the strengths of signals in both side frequency bands is amplified, so that a signal-to-noise ratio has difficulty in improvement.

In addition, in order to optimize power efficiency, impedance matching for the antenna has been considered. However, since it is difficult for a conventional amplifier to implement the impedance matching for a high impedance of the antenna, a power is wasted in general.

<CIT> discloses an antenna module including a plurality of monopole antenna elements (e.g., <NUM> to <NUM> antenna elements) that can be coupled together by one or more Switches to provide for a tunable, wideband antenna module. For example, the Switches may change the overall length of the antenna Such that the frequency range of the antenna is changed. The frequency response may also be controlled by a low voltage micro sized varicap, or a varactor diode, and instantiated as a tuned, resonant matching filter network residing with the antenna module. Additionally, Switches may be used to "switch in and "switch out capacitive elements to adjust the bandwidth of the antenna. The resonant matching filter network may then be used for fine tuning the frequency of that bandwidth.

Therefore, it is an aspect of the present disclosure to provide a vehicle, a control method thereof, and an antenna apparatus for a vehicle, which have high signal-to-noise ratio characteristics regardless of a frequency band.

It is another aspect of the present disclosure to provide a vehicle, a control method thereof, and an antenna apparatus for a vehicle, which are capable of implementing optimum impedance matching for an antenna according to a frequency.

It is still another aspect of the present disclosure to provide a vehicle, a control method thereof, and an antenna apparatus for a vehicle, which are capable of automatically changing a frequency according to an area.

In accordance with the present invention a vehicle is provided, as defined by independent claim <NUM>. The a vehicle includes: an antenna having different gain characteristics in different operating frequency bands; and a controller configured to use a mathematical expression that reflects the gain characteristics of the antenna (<NUM>) and carrying identical content; change the operating frequency band of the antenna (<NUM>) by adjusting length of a coil (<NUM>) included in the antenna (<NUM>) based on the reception strengths of the plurality of signals by a switching unit (<NUM>) of the antenna (<NUM>); and correct the reception strength of the plurality of signals based on at least one of a first characteristic function, a second characteristic function of the mathematical expression, that indicate the different gain characteristics of the antenna, wherein the controller (<NUM>) comprises: the first characteristic function of a gain curve of the antenna when the switch is a first position corresponding to a first operating frequency band; and the second characteristic function of a gain curve of the antenna when the switch is a second position corresponding to a second operating frequency band, wherein the controller (<NUM>) is further configured to: obtain the content from the signal having a first frequency among the plurality of signal received by the antenna and carrying identical content, based on whether an output value of the first characteristic function for the received signal having the first frequency is greater than an output value of the second characteristic function for a received signal having a second frequency.

The antenna may include a coil configured to receive a wireless signal and a switch configured to adjust an operating frequency band of the coil, and the controller may change the operating frequency band of the coil by controlling the switch based on the corrected reception strengths of the signals.

The switch may be connectable to the coil at a plurality of connection points, and the operating frequency band of the coil may be adjusted as the connection point of the switch is changed based on the corrected reception strengths of the signals.

The controller may determine the operating frequency band of the coil based on a frequency selected by a user.

The vehicle may further include an amplifying unit configured to amplify a wireless signal received from the antenna, and the controller may control an impedance fluctuation range of the amplifying unit based on the corrected reception strengths of the signals.

The amplifying unit may include a switch, a plurality of inductors, and an amplifying circuit, and the controller may connect the switch to one of the inductors based on the corrected reception strengths of the signals.

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application or uses.

<FIG> is a view illustrating a vehicle in one form of the present disclosure. <FIG> is a view illustrating a structure of an antenna apparatus in one form of the present disclosure.

Referring to <FIG> and <FIG>, a vehicle <NUM> includes a body configured to form an exterior of the vehicle <NUM> and accommodate a driver and/or a luggage, a chassis including components of the vehicle <NUM> other than the body, and electrical components configured to protect the driver or provide convenience to the driver. The body may form an interior space accommodated for the driver, an engine room configured to accommodate an engine, and a trunk room configured to accommodate a cargo. The chassis may include devices configured to generate a power to allow the vehicle <NUM> to travel according to control of the driver, and drive/brake/steer the vehicle <NUM> by using the power. The electrical components may control the vehicle <NUM>, and provide safety and convenience for the driver and a passenger.

A roof panel of the vehicle <NUM> is provided with an antenna apparatus <NUM> configured to receive wireless signals such as a radio signal, a broadcast signal, and a satellite signal, and transmit and receive signals to and from other vehicles, servers, and base stations.

The antenna apparatus <NUM> includes a housing <NUM> including a bottom member 101a mounted on the roof panel of the vehicle <NUM> and a cover member 101b coupled to the bottom member 101a to cover internal components.

The bottom member 101a is formed of a material including a synthetic resin, and attached to the body to prevent foreign substances from entering between the body and the cover member 101b and mitigate an impact transmitted from the body.

The bottom member 101a is provided at an upper rear portion of the vehicle to obtain less apprehension about interference with peripheral components and achieve a high reception rate of the wireless signal.

In addition, the bottom member 101a has a sectional shape gradually widened toward a rear to reduce wind resistance and noise generated when the body moves.

The housing <NUM> may be provided in a shark fin type.

The antenna apparatus <NUM> includes a base member <NUM> disposed on the bottom member 101a, and a reception module <NUM> disposed on the base member <NUM>.

The base member <NUM> may be coupled to the bottom member 101a in a bonding or bolting scheme, and may be coupled to the reception module <NUM> in a bolting scheme.

The base member <NUM> provides a space for mounting the reception module <NUM> and antennas <NUM>.

The reception module <NUM> may be provided as a printed circuit board (PCB) having wiring formed by etching copper or the like on a substrate.

The reception module <NUM> may include a hole through which a wire passes.

The reception module <NUM> may include a signal processing circuit configured to perform signal processing by amplifying or filtering a signal received by the antenna <NUM>.

The reception module <NUM> transmits a signal to an electronic control unit (ECU) or a terminal mounted inside the body.

The reception module <NUM> extracts and optimizes a signal of a predetermined frequency band, for example, a broadcast signal such as a frequency modulation (FM) signal, a amplitude modulation (AM) signal, a digital audio broadcasting (DAB) signal, or a digital multimedia broadcasting signal.

The reception module <NUM> may be implemented as a single integrated reception module by mounting components, such as a band pass filter (BPF), a switch, a tuner, a buffer, and a digital signal processor (DSP), on a circuit board.

One or more antennas <NUM> may be provided and may be seated in the reception module <NUM>.

The antenna <NUM> refers to an antenna configured to receive a signal in one frequency band as a signal in a fundamental frequency band. The one frequency band may be, for example, a frequency band of various broadcast signals, such as an FM band, an AM band, a DAB band, or a DMB band.

The antenna <NUM> is mounted on the reception module <NUM> to transmit the received signal to the reception module <NUM>.

A coil antenna may be used as the antenna <NUM>, and various other antennas such as a chip antenna and a microstrip patch antenna may be used as the antenna <NUM>.

<FIG> is a view illustrating a configuration of the antenna apparatus in one form of the present disclosure.

The antenna apparatus <NUM> includes a reception module <NUM> and an antenna <NUM>.

The reception module <NUM> may include an amplifying unit <NUM>, a tuner <NUM>, and a controller <NUM>. Although not shown, the reception module <NUM> may further include a filter configured to extract only a signal of a predetermined frequency band among signals received from the antenna <NUM>.

The amplifying unit <NUM> is a component for amplifying the signal received from the antenna <NUM>, and may include an amplifier configured to amplify the signal of the predetermined frequency band.

The tuner <NUM> tunes to a frequency selected by a user to extract a signal of the selected frequency.

The tuner <NUM> may provide the signal of the frequency selected by the user to an audio system of the vehicle <NUM> as an acoustic signal. The tuner <NUM> may tune to the selected frequency through the audio system of the vehicle <NUM>.

The signal extracted from the tuner <NUM> may be transmitted to the audio system of the vehicle <NUM>, and the audio system may transmit the transmitted signal as a sound.

The controller <NUM> controls a frequency band that is receivable by the antenna <NUM> or controls an impedance fluctuation range of the amplifying unit <NUM>.

The controller <NUM> may control the frequency band that is receivable by the antenna <NUM> (hereinafter referred to as "operating frequency band") by adjusting an operation range of a coil included in the antenna <NUM>. When the coil becomes longer, the operating frequency band of the antenna <NUM> becomes lower.

The controller <NUM> may change the impedance fluctuation range of the amplifying unit <NUM> by changing an element value of the amplifying unit <NUM>. In this case, the controller <NUM> may select the element value of the amplifying unit <NUM> such that impedance matching can be performed with respect to the antenna <NUM>.

The controller <NUM> may adjust the operation range of the coil included in the antenna <NUM>, and change the element value of the amplifying unit <NUM> as described above.

A control process of the controller <NUM> of the antenna apparatus <NUM> will be described in detail below.

The controller <NUM> may generate various control signals for controlling components in the antenna apparatus <NUM>.

The controller <NUM> may be implemented as a module separate from the reception module <NUM>, or as a module integrated with the electronic control unit (ECU) of the vehicle <NUM>.

The controller <NUM> may be implemented as a memory (not shown) configured to store an algorithm for controlling operations of the components in the antenna apparatus <NUM>, or data of a program for reproducing the algorithm, and a processor (not shown) configured to perform operations described above by using the data stored in the memory. In this case, the memory and the processor may be implemented as separate chips. Alternatively, the memory and the processor may be implemented as a single chip.

The controller <NUM> may transmit a signal to an electronic control unit (ECU), a terminal, or the like. In this case, a controller area network (CAN) communication scheme may be used to transmit the signal.

<FIG> is a view illustrating a detailed configuration of the antenna apparatus and an operating frequency according to an available range of a coil in one form of the present disclosure. <FIG> and <FIG> are views illustrating a frequency to a signal strength when using the antenna apparatus in one form of the present disclosure. <FIG> is a view illustrating an effect obtained in a strong electric field when using the antenna apparatus in one form of the present disclosure.

Referring to <FIG>, the antenna <NUM> in one form of the present disclosure may include a coil <NUM> and a switching unit <NUM>.

The coil <NUM> is operated by a current received through the switching unit <NUM>. When a length of the coil <NUM> to be operated becomes longer, that is, the length of the coil <NUM> through which the current flows becomes longer, the frequency band that is receivable by the antenna <NUM> becomes lower.

The switching unit <NUM> may include a switch, and adjust the length of the coil <NUM> to be operated (that is, the operating range of the coil <NUM>) by changing a connection point between the switching unit <NUM> and the coil <NUM> according to the control signal of the controller <NUM>. In addition, as the operating range of the coil <NUM> is changed, the operating frequency band may be changed.

For example, as shown in <FIG>, the operating frequency band may be in the range of <NUM> or higher and lower than <NUM> when the controller <NUM> places the switch of the switching unit <NUM> at a point SW1, the operating frequency band may be in the range of <NUM> or higher and lower than <NUM> as the operating range of the coil <NUM> is reduced when the controller <NUM> places the switch at a point SW2, the operating frequency band may be in the range of <NUM> or higher and lower than <NUM> as the operating range of the coil <NUM> is further reduced when the controller <NUM> places the switch at a point SW3, and the operating frequency band may be in the range of <NUM> or higher and lower than <NUM> as the operating range of the coil <NUM> is reduced even further when the controller <NUM> places the switch at a point SW4.

Referring to <FIG>, the controller <NUM> may improve a ratio of a signal S to noise N ratio in comparison with a conventional antenna apparatus (upper graphs) by flexibly adjusting the operating frequency of the antenna <NUM> as described above.

In detail, when the switch is located at the point SW1 as shown in <FIG>, the operating frequency band may be a certain frequency band of <NUM> or higher and lower than <NUM> as shown in <FIG>, and a higher ratio of the signal S to the noise N than a ratio of a signal S to noise N of the conventional antenna apparatus <NUM> can be obtained at the frequency of <NUM> selected by the user.

In addition, when the switch is located at the point SW2, the operating frequency band may be a certain frequency band of <NUM> or higher and lower than <NUM> as shown in <FIG>, and a higher ratio of the signal S to the noise N than a ratio of the signal S to the noise N of the conventional antenna apparatus <NUM> can be obtained at the frequency of <NUM> selected by the user.

In addition, when the switch is located at the point SW3, the operating frequency band may be a certain frequency band of <NUM> or higher and lower than <NUM> as shown in <FIG>, and a higher ratio of the signal S to the noise N than a ratio of the signal S to the noise N of the conventional antenna apparatus <NUM> can be obtained at the frequency of <NUM> selected by the user.

In addition, when the switch is located at the point SW4, the operating frequency band may be a certain frequency band of <NUM> or higher and lower than <NUM> as shown in <FIG>, and a higher ratio of the signal S to the noise N than a ratio of the signal S to the noise N of the conventional antenna apparatus <NUM> can be obtained at the frequency of <NUM> selected by the user.

When the antenna <NUM> is operated by dividing the operating frequency band as described above, as shown in <FIG>, a higher ratio of the signal S to the noise N than a ratio of a signal S to noise N of a conventional configuration can be obtained at the frequency of <NUM>, <NUM>, <NUM>, or <NUM> selected by the user.

In some forms of the present disclosure, the frequency band is described as being divided into four operating frequency bands by the controller <NUM> and the switching unit <NUM>, but a number of operating frequency bands is not limited thereto.

In addition, referring to <FIG>, under a strong electric field condition, an intermodulation signal Eb due to strong electric field signals E1a and E2a may be generated, and signal interference may be increased by the intermodulation signal Eb. However, since the antenna <NUM> is operated only in some frequency bands, the intermodulation signal Eb can be reduced, so that reception performance can be improved.

<FIG> is a view illustrating a configuration of an antenna apparatus in another form of the present disclosure. <FIG> is a view illustrating a detailed circuit of an amplifying unit of the antenna apparatus in another form of the present disclosure. <FIG>, <FIG>, <FIG>, <FIG>, and <FIG> are views illustrating a complex plane Smith chart for an impedance of the antenna apparatus in another form of the present disclosure.

The antenna apparatus <NUM> may perform impedance matching with respect to the antenna <NUM> by adjusting the impedance fluctuation range of the amplifying unit <NUM>.

The amplifying unit <NUM> of the antenna apparatus <NUM> includes a selector 111a and a matcher 111b to adjust the impedance fluctuation range of an internal amplifying circuit 111c.

The selector 111a may include a switch, and may control the impedance fluctuation range of the amplifying circuit 111c by selecting a connection point between the selector 111a and the matcher 111b according to the control signal of the controller <NUM>.

The matcher 111b may include a plurality of inductors having different capacitances and connected in parallel with the amplifying circuit 111c, and adjust the impedance fluctuation range of the amplifying circuit 111c by selecting one of the inductors by the selector 111a.

The amplifying circuit 111c may be a typical circuit configured to amplify a signal strength, which is a well-known technique, so the detailed description thereof will be omitted.

Referring to <FIG>, the controller <NUM> may control the selector 111a such that the amplifying circuit 111c is connected to one of the inductors of the matcher 111b, so that one inductor can be selected to control the impedance fluctuation range of the amplifying circuit 111c.

In this case, the controller <NUM> may change the impedance fluctuation range of the amplifying circuit 111c based on the frequency selected by the user.

In detail, referring to <FIG>, when an impedance AI of the antenna <NUM> is R+jX at a frequency of <NUM> or higher and lower than <NUM>, which is an entire frequency band in which the antenna <NUM> is operable, an ideal impedance of the amplifying unit <NUM> for performing the impedance matching (hereinafter referred to as "impedance matching area OP") is a conjugate complex value R-jX.

When a capacitance of the selected inductor (i.e., inductance) becomes smaller, the impedance fluctuation range of the amplifying unit <NUM> at the frequency of <NUM> or higher and lower than <NUM> is shifted away from the impedance AI of the antenna <NUM> on an upper trace of <FIG>. In addition, the frequency band corresponding to the impedance matching area OP is increased (in <FIG>, the frequency band corresponding to the impedance matching area OP is increased to <NUM> to <NUM> when selecting an inductor of <NUM> mH, <NUM> to <NUM> when selecting an inductor of <NUM> mH, and <NUM> to <NUM> when selecting an inductor of <NUM> mH).

Therefore, the controller <NUM> of the antenna apparatus <NUM> may adjust the impedance fluctuation range of the amplifying unit <NUM> such that the frequency selected by the user is present in the impedance matching area OP. In other words, the controller <NUM> may adjust the impedance fluctuation range of the amplifying unit <NUM> such that a region corresponding to the frequency selected by the user within the impedance fluctuation range of the amplifying unit <NUM> becomes the impedance matching area OP.

For example, when the frequency selected by the user is determined to be in the range of <NUM> or higher and lower than <NUM>, the controller <NUM> may change the impedance fluctuation range of the amplifying unit <NUM> at the frequency of <NUM> or higher and lower than <NUM> (i.e., the entire frequency band that is receivable by the antenna <NUM>) as shown in an upper portion of <FIG>, so that an impedance of the amplifying unit <NUM> can be present in the impedance matching area OP at a frequency of <NUM> or higher and lower than <NUM>.

In addition, when the frequency selected by the user is determined to be in the range of <NUM> or higher and lower than <NUM>, the controller <NUM> may change the impedance fluctuation range of the amplifying unit <NUM> at the frequency of <NUM> or higher and lower than <NUM> as shown in an upper portion of <FIG>, so that the impedance of the amplifying unit <NUM> can be present in the impedance matching area OP at a frequency of <NUM> or higher and lower than <NUM>.

In some forms of the present disclosure, a case where the entire frequency band that is receivable by the antenna <NUM> is in the range of <NUM> or higher and lower than <NUM> is described for illustrative purposes, but the entire frequency band that is receivable by the antenna <NUM> is not limited thereto.

In addition, in some forms of the present disclosure, a case where the frequency selected by the user is divided into the frequency band of <NUM> or higher and lower than <NUM>, the the frequency band of <NUM> or higher and lower than <NUM>, the frequency band of and <NUM> or higher and lower than <NUM> by the controller <NUM> is described for illustrative purposes, but the controller <NUM> may divide the frequency selected by the user into various sections other than the above sections.

The antenna apparatus <NUM> includes the antenna <NUM> including the coil <NUM> and the switching unit <NUM> of the antenna apparatus <NUM> in one form of the present disclosure, and may include the amplifying unit <NUM> including the selector 111a, the matcher 111b, and the amplifying circuit 111c. The amplifying unit <NUM>, the tuner <NUM>, the controller <NUM>, and the antenna <NUM> are described above, so the detailed description thereof will be omitted.

<FIG> is a view illustrating a configuration of an antenna apparatus in another form of the present disclosure. <FIG> is a view illustrating a frequency gain to explain an operation of the antenna apparatus in another form of the present disclosure. <FIG> and <FIG> are views illustrating gain correction values of the antenna apparatus in another form of the present disclosure.

Referring to <FIG>, an antenna apparatus <NUM> includes a reception module <NUM> and an antenna <NUM>.

The antenna <NUM> may include a coil <NUM> and a switching unit <NUM>, and the reception module <NUM> may include an amplifying unit <NUM>, a tuner <NUM>, and a controller <NUM>.

Operations of the coil <NUM>, the switching unit <NUM>, the amplifying unit <NUM>, and the tuner <NUM> may be identical to the operations of the coil, the switching unit, the amplifying unit, and the tuner shown in <FIG> and <FIG>.

The controller <NUM> controls the frequency band that is receivable by the antenna <NUM>, or controls the impedance fluctuation range of the amplifying unit <NUM>.

The controller <NUM> may control the frequency band that is receivable by the antenna <NUM> (hereinafter referred to as "operating frequency band") by adjusting an operation range of a coil included in the antenna <NUM>, and change the impedance fluctuation range of the amplifying unit <NUM> by changing an element value of the amplifying unit <NUM>.

The controller <NUM> may detect a change in an area (or the administrative area) where the vehicle <NUM> is located, or detect a change in a frequency of a broadcast signal currently being listened to.

The controller <NUM> may adjust the operation range of the coil in response to the change of the area (or the administrative area) or the frequency change of the broadcast signal. Accordingly, the controller <NUM> may control the frequency band that is receivable by the antenna <NUM> (hereinafter referred to as "operating frequency band").

In addition, the controller <NUM> may change the element value of the amplifying unit <NUM> in response to the change of the area (or the administrative area) or the frequency change of the broadcast signal. Accordingly, the controller <NUM> may change the impedance fluctuation range of the amplifying unit <NUM>.

For example, content of a radio broadcast or digital media may be carried by a signal having a first frequency f<NUM> in an area A, and the content of the radio broadcast or the digital media may be carried by a signal having a second frequency f<NUM> in an area B.

The antenna apparatus <NUM> may receive the signal having the first frequency f<NUM> while the vehicle <NUM> is traveling in the area A. In this case, the signal may be a radio broadcast signal, a digital media signal, or the like, and the first frequency f<NUM> may indicate a frequency at which the content of the radio broadcast or the digital media is carried in the area A.

As shown in <FIG>, the first frequency f<NUM> may be in an operating frequency band of <NUM> or higher and lower than <NUM>, and may be included in an operating range of the antenna apparatus <NUM> when the switch is located at the point SW2. The second frequency f<NUM> may be in an operating frequency band of <NUM> or higher and lower than <NUM>, and may be included in the operating range of the antenna apparatus <NUM> when the switch is located at the point SW3. The signal having the first frequency f<NUM> and the signal having the second frequency f<NUM> may transmit identical broadcast content.

A strength of the signal having the first frequency f<NUM> is greater than a strength of the signal having the second frequency f<NUM> while the vehicle <NUM> is traveling in the area A. Therefore, the controller <NUM> may place the switch at the point SW2 so that the antenna apparatus <NUM> can have a maximum gain for the signal having the first frequency f<NUM>.

As a result, a reception strength of the signal having the first frequency f<NUM> is significantly greater than a reception strength of the signal having the second frequency f<NUM> while the vehicle <NUM> is traveling in the area A.

While the vehicle <NUM> is traveling on a boundary between the area A and the area B, the strength of the signal having the first frequency f<NUM> is decreased, whereas the strength of the signal having the second frequency f<NUM> increased. Accordingly, as shown in <FIG>, the reception strength of the signal which has the first frequency f<NUM> and is received by the antenna apparatus <NUM> may be decreased, and the reception strength of the signal having the second frequency f<NUM> may be increased.

The strength of the signal having the first frequency f<NUM> may become smaller than the strength of the signal having the second frequency f<NUM> while the vehicle <NUM> is traveling in the area B. However, since the switch is located at the point SW2, that is, the antenna apparatus <NUM> is optimized to receive signals at <NUM> or higher and lower than <NUM>, as shown in <FIG>, the reception strength of the signal which has the first frequency f<NUM> and is received by the antenna apparatus <NUM> may be similar to or greater than the reception strength of the signal having the second frequency f<NUM>.

The controller <NUM> may simply compare the reception strength of the signal having the first frequency f<NUM> with the reception strength of the signal having the second frequency f<NUM>, and the controller <NUM> may place the switch at the point SW2 according to a comparison result. As a result, a reception rate of the signal in the area B may be reduced in comparison with a reception rate of the signal in the area A.

In order to prevent the above case, the controller <NUM> may estimate the reception strength of the signal having the second frequency f<NUM>, and change a frequency at which the broadcast signal is received based on the estimated reception strength of the signal.

As shown in <FIG>, the reception strength of the signal having the first frequency f<NUM> is significantly greater than the reception strength of the signal having the second frequency f<NUM> while the vehicle <NUM> is traveling in the area A.

While the vehicle <NUM> is traveling on the boundary between the area A and the area B, the reception strength of the signal which has the first frequency f<NUM> and is received by the antenna apparatus <NUM> may be decreased, whereas the reception strength of the signal having the second frequency f<NUM> may be increased.

The controller <NUM> may determine a frequency change with regard to a maximum gain of signals having respective frequencies. For example, the controller <NUM> may correct the reception strength of the signal having the first frequency f<NUM> of <NUM> or higher and lower than <NUM> into a reception strength when the switch is located at the point SW2, and correct the.

The controller <NUM> may determine a frequency change with regard to a maximum gain of signals having respective frequencies. For example, the controller <NUM> may correct the reception strength of the signal having the first frequency f<NUM> of <NUM> or higher and lower than <NUM> into a reception strength when the switch is located at the point SW2, and correct the reception strength of the signal having the second frequency f<NUM> of <NUM> or higher and lower than <NUM> into a reception strength when the switch is located at the point SW3. The controller <NUM> may compare the corrected reception strength of the signal having the first frequency f<NUM> with the corrected reception strength of the signal having the second frequency f<NUM>, and determine a frequency change according to a comparison result. As shown in <FIG>, the corrected reception strength of the signal having the first frequency f<NUM> may still be greater than the corrected reception strength of the signal having the second frequency f<NUM>, and the controller <NUM> may not change a reception frequency.

The strength of the signal having the first frequency f<NUM> may become smaller than the strength of the signal having the second frequency f<NUM> while the vehicle <NUM> is traveling in the area B, and the controller <NUM> may determine the frequency change with regard to the maximum gain of the signals having the respective frequencies. For example, as shown in <FIG>, the corrected reception strength of the signal having the first frequency f<NUM> may be smaller than the corrected reception strength of the signal having the second frequency f<NUM>, and the controller <NUM> may change the reception frequency from the first frequency f<NUM> to the second frequency f<NUM>.

As a result, the vehicle <NUM> may receive the signal having the first frequency f<NUM>, which is strong in the strength of the signal in the area A, and receive the signal having the second frequency f<NUM>, which is strong in the strength of the signal in the area B.

The controller <NUM> may use a mathematical expression that reflects antenna characteristics or a lookup table that reflects the antenna characteristics in order to correct the strengths of the signals having the respective frequencies into a strength of the maximum gain.

For example, the controller <NUM> may correct the strengths of the signals having the respective frequencies to the strength of the maximum gain by using a function similar to a gain curve of an antenna according to a position of the switch.

As shown in <FIG>, the controller <NUM> may store a first function F1 indicating a gain curve of the antenna when the switch is located at the point SW1, a second function F2 indicating a gain curve of the antenna when the switch is located at the point SW2, a third function F3 indicating a gain curve of the antenna when the switch is located at the point SW3, and a fourth function F4 indicating a gain curve of the antenna when the switch is located at the point SW4.

The first function F1 may represent a gain of the antenna for a signal having a frequency of <NUM> or higher and lower than <NUM>, the second function F2 may represent a.

For example, when the switch is currently located at the point SW2, and the signal having the first frequency f<NUM> of <NUM> or higher and lower than <NUM> is received, the controller <NUM> may correct the reception strength of the signal having the second frequency f<NUM> of <NUM> or higher and lower than <NUM> by using the second function F2 and the third function F3.

In detail, the controller <NUM> may correct the reception strength of the signal having the second frequency f<NUM> based on a difference between an output of the second function F2 when the second frequency f<NUM> is input and an output of the third function F3 when the second frequency f<NUM> is input. The controller <NUM> may compare the reception strength of the signal having the first frequency f<NUM> with the corrected reception strength of the signal having the second frequency f<NUM>, and determine the frequency change based on the comparison result.

In addition, the controller <NUM> may correct the strength of the signal having the first frequency f<NUM> into the strength of the maximum gain based on an output of the second function F2 when the first frequency f<NUM> is input, and correct the strength of the signal having the second frequency f<NUM> into the strength of the maximum gain based on the output of the third function F3 when the second frequency f<NUM> is input. The controller <NUM> may compare a maximum strength of the signal having the first frequency f<NUM> with a maximum strength of the signal having the second frequency f<NUM>, and determine the frequency change based on a comparison result.

As shown in <FIG>, the controller <NUM> may store a first table including gain curve values of the antenna when the switch is located at the point SW1, a second table including gain curve values of the antenna when the switch is located at the point SW2, a third table including gain curve values of the antenna when the switch is located at the point SW3, and a fourth table including gain curve values of the antenna when the switch is located at the point SW4.

The first table may include gain values of the antenna for signals having a frequency of <NUM> or higher and lower than <NUM>, the second table may include gain values of the antenna for signals having a frequency of <NUM> or higher and lower than <NUM>, the third table may include gain values of the antenna for signals having a frequency of <NUM> or higher and lower than <NUM>, and the fourth table may include gain values of the antenna for signals having a frequency of <NUM> or higher and lower than <NUM>.

For example, when the switch is currently located at the point SW2, and the signal having the first frequency f<NUM> of <NUM> or higher and lower than <NUM> is received, the controller <NUM> may correct the reception strength of the signal having the second frequency f<NUM> of <NUM> or higher and lower than <NUM> by using the second table and the third table.

In detail, the controller <NUM> may correct the strength of the signal having the first frequency f<NUM> into the strength of the maximum gain based on an output of the second table corresponding to the first frequency f<NUM>, and correct the strength of the signal having the second frequency f<NUM> into the strength of the maximum gain based on an output of the third table corresponding to the second frequency f<NUM>. The controller <NUM> may compare the maximum strength of the signal having the first frequency f<NUM> with the maximum strength of the signal having the second frequency f<NUM>, and determine the frequency change based on the comparison result.

In addition, the controller <NUM> may correct the reception strength of the signal having the second frequency f<NUM> based on a difference between an output of the second table corresponding to the second frequency f<NUM> and the output of the third table corresponding to the second frequency f<NUM>. The controller <NUM> may compare the reception strength of the signal having the first frequency f<NUM> with the corrected reception strength of the signal having the second frequency f<NUM>, and determine the frequency change based on the comparison result.

<FIG> is a view illustrating the operation of the antenna apparatus in another form of the present disclosure.

The vehicle <NUM> receives a broadcast signal (<NUM>).

The vehicle <NUM> may receive signals including broadcast content through the antenna apparatus <NUM>.

For example, the vehicle <NUM> may receive the signal having the first frequency f<NUM> and the signal having the second frequency f<NUM>, and output the broadcast content from the signal having the first frequency f<NUM>.

The vehicle <NUM> corrects a reception strength of the broadcast signal having different frequencies (<NUM>).

The vehicle <NUM> may correct the reception strength of the frequencies of the broadcast signal by using the functions F1, F2, F3, and F4 indicating the gain curves of the antenna apparatus <NUM>, or the lookup tables T1, T2, T3, and T4.

For example, the vehicle <NUM> may correct the signal having the first frequency f<NUM> and the signal having the second frequency f<NUM> by using the functions F1, F2, F3, and F4, or the lookup tables T1, T2, T3, and T4.

The vehicle <NUM> may correct the reception strength of the signal having the second frequency f<NUM> based on the difference between the output of the second function F2 when the second frequency f<NUM> is input and the output of the third function F3 when the second frequency f<NUM> is input. In addition, the vehicle <NUM> may correct the strength of the signal having the first frequency f<NUM> into the strength of the maximum gain based on the output of the second function F2 when the first frequency f<NUM> is input, and correct the strength of the signal having the second frequency f<NUM> into the strength of the maximum gain based on the output of the third function F3 when the second frequency f<NUM> is input.

The vehicle <NUM> may correct the strength of the signal having the first frequency f<NUM> into the strength of the maximum gain based on the output of the second table corresponding to the first frequency f<NUM>, and correct the strength of the signal having the second frequency f<NUM> into the strength of the maximum gain based on the output of the third table corresponding to the second frequency f<NUM>. In addition, the vehicle <NUM> may compare the maximum strength of the signal having the first frequency f<NUM> with the maximum strength of the signal having the second frequency f<NUM>, and determine the frequency change based on the comparison result.

The vehicle <NUM> determines a reception frequency based on a result of comparison performed on corrected reception strengths of the broadcast signal having the different frequencies (<NUM>).

The vehicle <NUM> may compare the corrected reception strengths of the frequencies of the broadcast signal with each other, and determine the reception frequency for receiving the broadcast content based on the comparison result.

For example, the vehicle <NUM> may compare the corrected reception strength of the signal having the first frequency f<NUM> with the corrected reception strength of the signal having the second frequency f<NUM>, and extract the broadcast content from a signal having a stronger corrected strength between the signal having the first frequency f<NUM> and the signal having the second frequency f<NUM> based on the comparison result.

In detail, the broadcast content may be carried in the area A through the first frequency f<NUM>, and identical broadcast content may be carried in the area B through the second frequency f<NUM>. The vehicle <NUM> may place the switch at the point SW2 in the area A to receive the signal having the first frequency f<NUM>, and may place the switch at the point SW3 in the area B to receive the signal having the second frequency f<NUM>.

The vehicle <NUM> may correct reception strengths of a plurality of signals having different frequencies for carrying identical content. In addition, the vehicle <NUM> may obtain the content from a signal having a maximum reception strength based on corrected reception strengths of the signals.

As described above, the vehicle <NUM> may automatically change the reception frequency of the signal and change frequency characteristics of the antenna apparatus <NUM> as an area in which the vehicle <NUM> is traveling is changed.

At least one component may be added or deleted corresponding to performance of the components of the antenna apparatus <NUM>. In addition, it will be readily understood by those skilled in the art that a mutual position of the components can be changed corresponding to performance or a structure of a system.

Meanwhile, some components of the antenna apparatus <NUM> may be software components and/or hardware components such as a field programmable gate array (FPGA) and an application specific integrated circuit (ASIC).

As is apparent from the above description, in accordance with an aspect of the present disclosure, a vehicle, a control method thereof, and an antenna apparatus for a vehicle, which have high signal-to-noise ratio characteristics regardless of a frequency band, can be provided.

In accordance with another aspect of the present disclosure, a vehicle, a control method thereof, and an antenna apparatus for a vehicle, which are capable of implementing optimum impedance matching for an antenna according to a frequency, can be provided.

Claim 1:
A vehicle comprising:
an antenna (<NUM>) having different gain characteristics in different operating frequency bands; and
a controller (<NUM>) configured to:
use a mathematical expression that reflects the gain characteristics of the antenna (<NUM>) in order to correct reception strengths of a plurality of signals having respective frequencies and carrying identical content;
change the operating frequency band of the antenna (<NUM>) by adjusting length of a coil (<NUM>) included in the antenna (<NUM>) based on the reception strengths of the plurality of signals by a switching unit (<NUM>) of the antenna (<NUM>); and
correct the reception strength of the plurality of signals based on at least one of a first characteristic function and a second characteristic function of the mathematical expression, that indicate the different gain characteristics of the antenna (<NUM>),
wherein the controller (<NUM>) comprises:
the first characteristic function of a gain curve of the antenna when the switching unit is a first position corresponding to a first operating frequency band; and
the second characteristic function of a gain curve of the antenna when the switching unit is a second position corresponding to a second operating frequency band,
and wherein the controller (<NUM>) is further configured to:
obtain the content from the signal having a first frequency, among the plurality of signals received by the antenna and carrying identical content, based on whether an output value of the first characteristic function for the received signal having the first frequency is greater than an output value of the second characteristic function for a received signal having a second frequency.