CN102610931A - Frequency range adjustable antenna and frequency range adjustable antenna system and mobile terminal - Google Patents

Abstract

The invention discloses a frequency range adjustable antenna which comprises an antenna element and a resonant circuit, wherein the antenna element is electrically connected with the resonant circuit, the resonant circuit comprises a first inductor and a first capacity-variable element with variable capacitance capacity, and the first inductor is serially connected with the first capacity-variable element. The invention also discloses a frequency range adjustable antenna system comprising the frequency range adjustable antenna, a frequency detection unit and a processor, wherein the frequency detection unit is used for detecting a communication frequency of a communication channel, and the processor is used for changing the capacitance capacity of the first capacity-variable element on the basis of the communication frequency detected by the frequency detection unit. The invention also discloses a mobile terminal using the frequency range adjustable antenna system. According to the frequency band adjustable antenna, the resonant frequency in the matched resonant circuit is changed through a capacitive element capable of changing the capacitance, thus bandwidth movement is realized. The frequency range adjustable antenna system adapts to the communication frequency of the communication channel through changing the resonant frequency.

Description

Frequency range adjustable antenna and frequency range adjustable antenna system and portable terminal

Technical field

The present invention relates to a kind of antenna, antenna system and portable terminal; Particularly relate to a kind of as adjustable antenna of the frequency range of CMMB (China Mobile multimedia broadcasting) antenna and the frequency range adjustable antenna system that comprises said antenna, and the portable terminal that comprises said antenna system.

Background technology

Antenna in the portable terminal generally adopts external antenna or these two kinds of forms of built-in aerial at present, and wherein said external antenna is generally telescopic antenna, but telescopic antenna has greatly limited the mode of appearance of portable terminal.If adopt the form of built-in aerial, then need to have bigger headroom area in the portable terminal again in addition, portable terminal is piled up space requirement than higher.

When especially in portable terminal, adopting the CMMB antenna; Because the bandwidth of the working frequency range of CMMB antenna is very wide, promptly said CMMB antenna belongs to ultra-wideband antenna, so in the capacitor and inductor match circuit that adopts fixing appearance sense value; The bandwidth range that resonance covered of the fixed frequency that produces is not enough; Therefore can't change antenna resonance along with the variation of the working channel of portable terminal, so the bandwidth length of the resonance of antenna can't cover whole frequency, thereby antenna performance often is difficult to up to standard.

Summary of the invention

The technical problem that the present invention will solve is in order to lack the defective of the CMMB antenna of effective bandwidth in the portable terminal that overcomes prior art; A kind of frequency range adjustable antenna is provided; Change the resonance frequency in the coupling resonant circuit through the capacitive element that can change the appearance value, thereby realize moving of bandwidth.

The present invention also provides a kind of frequency range adjustable antenna system, and through adopting above-mentioned frequency range adjustable antenna, and the communication channel that detects in using confirms the bandwidth that CMMB works at this moment, thereby adapts to the communication frequency of communication channel through the change resonance frequency.

And its present invention provides a kind of portable terminal that uses above-mentioned frequency range adjustable antenna system, thereby makes and no matter use external or built-in aerial in the portable terminal, all can reduce the requirement of bandwidth to antenna pattern, size and headroom etc. effectively.

The present invention solves above-mentioned technical problem through following technical proposals:

The invention provides a kind of frequency range adjustable antenna, be characterized in that said frequency range adjustable antenna comprises:

One antenna element and a resonant circuit, said antenna element and said resonant circuit are electrically connected, and comprise one first varactor element that one first inductance and capacitance are variable in the wherein said resonant circuit, said first inductance and the series connection of first varactor element.

Preferably, also comprise one second inductance in the said resonant circuit, said second inductance is parallelly connected with said first varactor element.

Preferably, also comprise one first capacitive element in the said resonant circuit, said first capacitive element is parallelly connected with said first inductance.

Preferably, said first capacitive element is electric capacity or variable capacitance diode.

Preferably, also comprise one the 3rd inductance and one second varactor element in the said resonant circuit, said the 3rd inductance and the parallel connection of second varactor element, and said antenna element is through said the 3rd inductance and the second varactor element ground connection of parallel connection.

Preferably, said frequency range adjustable antenna also comprises one first electric capacity, and said first electric capacity is connected with said second varactor element and is parallelly connected with said second inductance.

Preferably, said second varactor element is a variable capacitance diode.

Preferably, said first varactor element is a variable capacitance diode.

Preferably, said frequency range adjustable antenna also comprises one second electric capacity, and said second capacitance series is between said antenna element resonant circuit.

Preferably, also comprise one the 3rd electric capacity in the said resonant circuit, said the 3rd electric capacity is electrically connected with said resonant circuit.

The present invention also provides a kind of frequency range adjustable antenna, is characterized in that said frequency range adjustable antenna comprises:

One antenna element and a resonant circuit, said antenna element and said resonant circuit are electrically connected, and comprise one first varactor element that one first inductance and capacitance are variable in the wherein said resonant circuit, said first inductance and the parallel connection of first varactor element.

Preferably, also comprise one first capacitive element in the said resonant circuit, said first inductance and first varactor element of parallel connection are connected with said first capacitive element.

Preferably, said first capacitive element is an electric capacity.

Preferably, said first varactor element is a variable capacitance diode.

Preferably, said frequency range adjustable antenna also comprises one first electric capacity, and said first capacitance series is between said antenna element resonant circuit.

Preferably, also comprise one second electric capacity in the said resonant circuit, said second electric capacity is electrically connected with said resonant circuit.

The present invention provides a kind of frequency range adjustable antenna system again; Be characterized in comprising aforesaid frequency range adjustable antenna; Said frequency range adjustable antenna system also comprises a frequency detecting unit and a processor of the communication frequency that is used to detect communication channel, and the communication frequency that wherein said processor detects based on said frequency detecting unit changes the capacitance of first varactor element described in the said frequency range adjustable antenna.

Another frequency range adjustable antenna system of the present invention; Be characterized in comprising aforesaid frequency range adjustable antenna; Said frequency range adjustable antenna system also comprises a frequency detecting unit and a processor of the communication frequency that is used to detect communication channel, and the communication frequency that wherein said processor detects based on said frequency detecting unit changes the capacitance of first varactor element described in the said frequency range adjustable antenna and second varactor element.

The present invention provides a kind of portable terminal again, is characterized in that said portable terminal comprises aforesaid frequency range adjustable antenna system.

Positive progressive effect of the present invention is:

Frequency range adjustable antenna of the present invention changes the resonance frequency in the coupling resonant circuit through the capacitive element that can change the appearance value, thereby realizes moving of bandwidth.

Frequency range adjustable antenna of the present invention system is through adopting above-mentioned frequency range adjustable antenna, and the communication channel that detects in using confirms the bandwidth that CMMB works at this moment, thereby adapts to the communication frequency of communication channel through the change resonance frequency.

And its portable terminal of the present invention also uses above-mentioned frequency range adjustable antenna system; Thereby make and no matter to use external or built-in aerial in the portable terminal; All can reduce the requirement of bandwidth effectively, so lowered the designing requirement of portable terminal to antenna pattern, size and headroom etc.

Description of drawings

Fig. 1 is the structural representation of first embodiment of frequency range adjustable antenna of the present invention.

Fig. 2 is the structural representation of the system of the frequency range adjustable antenna that comprises said first embodiment of the present invention.

Fig. 3 is the structural representation of second embodiment of frequency range adjustable antenna of the present invention.

Fig. 4 is the structural representation of the 3rd embodiment of frequency range adjustable antenna of the present invention.

Fig. 5 is the structural representation of the system of the frequency range adjustable antenna that comprises said the 3rd embodiment of the present invention.

Fig. 6 is the structural representation of the 4th embodiment of frequency range adjustable antenna of the present invention.

Fig. 7 is the structural representation of the system of the frequency range adjustable antenna that comprises said the 4th embodiment of the present invention.

Embodiment

Provide preferred embodiment of the present invention below in conjunction with accompanying drawing, to specify technical scheme of the present invention.

First embodiment:

As shown in Figure 1, comprise an antenna element 1 and a resonant circuit 2, one second electric capacity 3 and one the 3rd electric capacity 4 in the frequency range adjustable antenna of present embodiment.

Comprise one first inductance 21, one first transfiguration device 22 and one first capacitive element 23 in the wherein said resonant circuit 2.And it is as shown in Figure 1; Said first inductance 21 of present embodiment is that an inductance, the said first transfiguration device 22 are a variable capacitance diode; Said first capacitive element 23 is an electric capacity, and said in addition first capacitive element 23 can also adopt the capacitive variable elements, for example variable capacitance diode etc.Said second electric capacity 3 and the 3rd electric capacity 4 are an electric capacity.

Wherein said first inductance 21 and 22 series connection of first varactor element, said first capacitive element 23 is parallelly connected with said first inductance 21.The said first transfiguration device 22 is connected with said antenna element 1 through said second electric capacity 3, and said first inductance 21 is electrically connected with said the 3rd electric capacity 4.Said the 3rd electric capacity 4 can be electrically connected with the equipment such as signal processing apparatus of outside.

Said second electric capacity 3 of present embodiment is used for the flip-flop of the signal of said antenna element 1 reception of filtering; Said the 3rd electric capacity 4 is used for said resonant circuit 2 output signals are carried out filtering, and also is used for the DC component that the said resonant circuit 2 output signals of filtering possibly exist.

The sense value of first inductance 21 is L described in the present embodiment ₁, the appearance value of the said first transfiguration device 22 is C ₂, the appearance value of said first capacitive element 23 is C ₁So, can get following resonance formula 1:

$Z\left(\mathrm{\&omega;}\right)=\frac{1}{\mathrm{J\&omega;}{C}_1}+\frac{\mathrm{J\&omega;}{L}_1\&CenterDot;\frac{1}{\mathrm{J\&omega;}{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}}{\mathrm{J\&omega;}{L}_1+\frac{1}{\mathrm{J\&omega;}{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}}=\frac{1}{\mathrm{J\&omega;}{C}_1}+\frac{\mathrm{J\&omega;}{L}_1}{1-{\mathrm{\&omega;}}^2{L}_1{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}=-j\frac{1-{\mathrm{\&omega;}}^2{L}_1({\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_2+C_1)}{\mathrm{\&omega;}{C}_1(1-{\mathrm{\&omega;}}^2{L}_1{C}_2)}$ Formula 1

Can get so find the solution $\mathrm{\&omega;}=\frac{1}{\sqrt{L_1({\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_2+C_1)}}.$

So pass through to change the appearance value C of the first transfiguration device 22 in the present embodiment ₂Size, just can change the size of ω, thereby change the resonance frequency of resonant circuit described in the present embodiment, thereby change the scope of the bandwidth of frequency band further.

As shown in Figure 2; In the frequency range adjustable antenna system of the frequency range adjustable antenna that comprises present embodiment, also comprise a frequency detecting unit 5 and a processor 6; Wherein said frequency detecting unit 5 is used to detect external equipment; Equipment such as signal processing apparatus for example; The communication frequency of communication channel, promptly detect the communications band in the work at present, the communication frequency that said processor 6 detects based on said frequency detecting unit 5 correspondingly changes the capacitance of first varactor element 22 described in the said frequency range adjustable antenna.Thereby make that the corresponding band limits of the resonance frequency of said frequency range adjustable antenna is identical with the communications band of the communication port in the said work.

So when using said frequency range adjustable antenna system, when especially being applied to use the portable terminal of CMMB antenna, can effectively reduce the complexity of Antenna Design in a portable terminal.

Second embodiment:

As shown in Figure 3, the difference of the frequency range adjustable antenna of present embodiment and the first embodiment Mid Frequency adjustable antenna is, resonant circuit described in the present embodiment 2 comprises one first inductance 21, one first transfiguration device 22 and one second inductance 24.Said first inductance 21 and 22 series connection of first varactor element, said first varactor element 22 is parallelly connected with said second inductance 24.

If the sense value of second inductance 24 is L described in the present embodiment ₂The time, can get following resonance formula 2:

$Z\left(\mathrm{\&omega;}\right)=\mathrm{J\&omega;}{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">L</figure-callout>}}_2+\frac{\mathrm{J\&omega;}{L}_1\left(\frac{1}{\mathrm{J\&omega;}{C}_2}\right)}{\mathrm{J\&omega;}{L}_1+\frac{1}{\mathrm{J\&omega;}{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}}=j(\mathrm{\&omega;}{L}_2-\frac{\mathrm{\&omega;}{L}_1}{{\mathrm{\&omega;}}^2{L}_1{C}_2-1})=j\frac{{\mathrm{\&omega;}}^3{L}_1{L}_2{C}_2-\mathrm{\&omega;}(L_1+L_2)}{{\mathrm{\&omega;}}^2{L}_1{C}_2-1}$ Formula 2

Can get so find the solution $\mathrm{\&omega;}=\sqrt{\frac{L_1+L_2}{L_1{L}_2{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}}$

So pass through to change the appearance value C of the first transfiguration device 22 in the present embodiment ₂Size, just can change the size of ω, thereby change the resonance frequency of resonant circuit described in the present embodiment, thereby change the scope of the bandwidth of frequency band further, owing to increased L ₂So, as the appearance value C of the first transfiguration device 22 ₂During variation, can change said ω significantly, so change the resonance frequency of said resonant circuit significantly.

The 3rd embodiment:

As shown in Figure 4, the difference of the frequency range adjustable antenna of present embodiment and the frequency range adjustable antenna of first embodiment is:

Comprise one first inductance 21, one first transfiguration device 22, one the 3rd inductance 25, one second varactor element 26 and one the 3rd electric capacity 27 in the resonant circuit 2 of present embodiment.Said first inductance 21 and the 3rd inductance 25 are an inductance, the said first transfiguration device 22 and second varactor element 26 and are a variable capacitance diode.

Wherein said first inductance 21 and 22 series connection of first varactor element; Said second varactor element 26 is connected with said the 3rd electric capacity 27; And the 3rd electric capacity 27 and second varactor element 26 of series connection are parallelly connected with said the 3rd inductance 25; Said first varactor element 22 is through said the 3rd inductance 25 ground connection, and said antenna element 1 is also through said the 3rd inductance 25 ground connection.

The 3rd electric capacity 27 described in the present embodiment is mainly used in and prevents that the signal that antenna element 1 receives from flowing directly into ground.Said in addition the 3rd electric capacity 27 has contribution to the resonance of circuit equally.And said resonant circuit 2 constituted the series parallel resonance circuit equally, thus based on resonance principle can obtain with first embodiment and second embodiment in similar resonance formula, so the resonance formula of the said resonant circuit 2 that just repeats no more here.

In the present embodiment owing to can regulate, so have the sensitivity of higher adjusting with respect to the frequency range adjustable antenna of first embodiment and second embodiment to the capacitance of said first varactor element 22 and second varactor element 26.

As shown in Figure 5; In the frequency range adjustable antenna system of the frequency range adjustable antenna that comprises present embodiment, yet comprise a frequency detecting unit 5 and a processor 6; Wherein said frequency detecting unit 5 is used to detect external equipment; Equipment such as signal processing apparatus for example; The communication frequency of communication channel, promptly detect the communications band in the work at present, the resonant circuit 2 of present embodiment comprise two can the control capacittance capacity element; I.e. first varactor element 22 and second varactor element 26 are so the communication frequency that detects based on said frequency detecting unit 5 of the said processor 6 of frequency range adjustable antenna system correspondingly changes the capacitance of first varactor element 22 described in the said frequency range adjustable antenna and second varactor element 26 here.Thereby make that the corresponding band limits of the resonance frequency of said frequency range adjustable antenna is identical with the communications band of the communication port in the said work.

So when using said frequency range adjustable antenna system, when especially being applied to use the portable terminal of CMMB antenna, can reduce the complexity of Antenna Design equally effectively in a portable terminal.

The 4th embodiment:

As shown in Figure 6, the difference of the frequency range adjustable antenna of present embodiment and the frequency range adjustable antenna of first embodiment is:

The resonant circuit 2 of the frequency range adjustable antenna of present embodiment also comprises one first inductance 21, one first transfiguration device 22 and one first capacitive element 23.

And said first inductance 21 and 23 series connection of first capacitive element, the said first transfiguration device 22 is parallelly connected with said first inductance 21.Said first capacitive element 23 is connected with said antenna element 1 through said second electric capacity 3, and said first inductance 21 and first capacitive element 23 of parallel connection are electrically connected with said the 3rd electric capacity 4.

The first transfiguration device 22 is connected with said antenna element 1 through said first electric capacity 3 described in the present embodiment, and said first inductance 21 is electrically connected with said second electric capacity 4.Said second electric capacity 4 can be electrically connected with the equipment such as signal processing apparatus of outside.First electric capacity 3 described in the present embodiment and second electric capacity 4 are an electric capacity and are used for the DC component of filtered signal.

The sense value of said first inductance 21 is L ₁, the appearance value of the said first transfiguration device 22 is C ₂, the appearance value of said first capacitive element 23 is C ₁So, can get following resonance formula 3:

$Z\left(\mathrm{\&omega;}\right)=\frac{1}{\mathrm{J\&omega;}{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}+\frac{\mathrm{J\&omega;}{L}_1\&CenterDot;\frac{1}{\mathrm{J\&omega;}{C}_1}}{\mathrm{J\&omega;}{L}_1+\frac{1}{\mathrm{J\&omega;}{C}_1}}=\frac{1}{\mathrm{J\&omega;}{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}+\frac{\mathrm{J\&omega;}{L}_1}{1-{\mathrm{\&omega;}}^2{L}_1{C}_1}=-j\frac{1-{\mathrm{\&omega;}}^2{L}_1({\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_2+C_1)}{\mathrm{\&omega;}{C}_2(1-{\mathrm{\&omega;}}^2{L}_1{C}_1)}$ Formula 3

Can get so find the solution $\mathrm{\&omega;}=\frac{1}{\sqrt{L_1({\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000151935190000012.png,HDA0000151935190000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_2+C_1)}}.$

So the solving result of present embodiment resonance formula 3 is identical with the solving result of the resonance frequency of the resonant circuit of the frequency range adjustable antenna of first embodiment.So the effect that is realized through the appearance value of regulating the said first transfiguration device 22 in the present embodiment is identical with the effect that the resonant circuit of the frequency range adjustable antenna of first embodiment is realized, just repeats no more here.

As shown in Figure 7; Frequency range adjustable antenna system at the frequency range adjustable antenna that comprises present embodiment; Yet comprise a frequency detecting unit 5 and a processor 6 in the said frequency range adjustable antenna system; And the function of said frequency detecting unit 5 and processor 6 is identical with the frequency range adjustable antenna system of the frequency range adjustable antenna that comprises first embodiment, so repeat no more here.

So equally, when especially being applied to use the portable terminal of CMMB antenna, can effectively reduce the complexity of Antenna Design when the said frequency range adjustable antenna of application system during in a portable terminal.

Though more than described embodiment of the present invention, it will be understood by those of skill in the art that these only illustrate, protection scope of the present invention is limited appended claims.Those skilled in the art can make numerous variations or modification to these execution modes under the prerequisite that does not deviate from principle of the present invention and essence, but these changes and modification all fall into protection scope of the present invention.

Claims (19)

1. a frequency range adjustable antenna is characterized in that, said frequency range adjustable antenna comprises:

The antenna element and the resonant circuit that are electrically connected comprise one first varactor element that one first inductance and capacitance are variable in the wherein said resonant circuit, said first inductance and the series connection of first varactor element.

2. frequency range adjustable antenna as claimed in claim 1 is characterized in that, also comprises one second inductance in the said resonant circuit, and said second inductance is parallelly connected with said first varactor element.

3. frequency range adjustable antenna as claimed in claim 1 is characterized in that, also comprises one first capacitive element in the said resonant circuit, and said first capacitive element is parallelly connected with said first inductance.

4. frequency range adjustable antenna as claimed in claim 3 is characterized in that, said first capacitive element is electric capacity or variable capacitance diode.

5. frequency range adjustable antenna as claimed in claim 1; It is characterized in that; Also comprise one the 3rd inductance and one second varactor element in the said resonant circuit, said the 3rd inductance and the parallel connection of second varactor element, and said antenna element is through said the 3rd inductance and the second varactor element ground connection of parallel connection.

6. frequency range adjustable antenna as claimed in claim 5 is characterized in that, said frequency range adjustable antenna also comprises one first electric capacity, and said first electric capacity is connected with said second varactor element and is parallelly connected with said second inductance.

7. frequency range adjustable antenna as claimed in claim 5 is characterized in that, said second varactor element is a variable capacitance diode.

8. like each described frequency range adjustable antenna among the claim 1-6, it is characterized in that said first varactor element is a variable capacitance diode.

9. frequency range adjustable antenna as claimed in claim 1 is characterized in that, said frequency range adjustable antenna also comprises one second electric capacity, and said second capacitance series is between said antenna element resonant circuit.

10. frequency range adjustable antenna as claimed in claim 1 is characterized in that, also comprises one the 3rd electric capacity in the said resonant circuit, and said the 3rd electric capacity is electrically connected with said resonant circuit.

11. a frequency range adjustable antenna is characterized in that, said frequency range adjustable antenna comprises:

The antenna element and the resonant circuit that are electrically connected comprise one first varactor element that one first inductance and capacitance are variable in the wherein said resonant circuit, said first inductance and the parallel connection of first varactor element.

12. frequency range adjustable antenna as claimed in claim 11 is characterized in that, also comprises one first capacitive element in the said resonant circuit, said first inductance and first varactor element of parallel connection are connected with said first capacitive element.

13. frequency range adjustable antenna as claimed in claim 12 is characterized in that, said first capacitive element is an electric capacity.

14., it is characterized in that said first varactor element is a variable capacitance diode like each described frequency range adjustable antenna among the claim 11-13.

15. frequency range adjustable antenna as claimed in claim 11 is characterized in that, said frequency range adjustable antenna also comprises one first electric capacity, and said first capacitance series is between said antenna element resonant circuit.

16. frequency range adjustable antenna as claimed in claim 11 is characterized in that, also comprises one second electric capacity in the said resonant circuit, said second electric capacity is electrically connected with said resonant circuit.

17. frequency range adjustable antenna system; It is characterized in that; Comprise like claim 1-10 or like each described frequency range adjustable antenna among the claim 11-16; Said frequency range adjustable antenna system also comprises a frequency detecting unit and a processor of the communication frequency that is used to detect communication channel, and the communication frequency that wherein said processor detects based on said frequency detecting unit changes the capacitance of first varactor element described in the said frequency range adjustable antenna.

18. frequency range adjustable antenna system; It is characterized in that; Comprise like each described frequency range adjustable antenna among the claim 5-7; Said frequency range adjustable antenna system also comprises a frequency detecting unit and a processor of the communication frequency that is used to detect communication channel, and the communication frequency that wherein said processor detects based on said frequency detecting unit changes the capacitance of first varactor element described in the said frequency range adjustable antenna and second varactor element.

19. a portable terminal is characterized in that, said portable terminal comprises the frequency range adjustable antenna system described in claim 17 or claim 18.

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