CN101958698A - The television broadcasting signal receiver turning - Google Patents
The television broadcasting signal receiver turning Download PDFInfo
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- CN101958698A CN101958698A CN2010102163611A CN201010216361A CN101958698A CN 101958698 A CN101958698 A CN 101958698A CN 2010102163611 A CN2010102163611 A CN 2010102163611A CN 201010216361 A CN201010216361 A CN 201010216361A CN 101958698 A CN101958698 A CN 101958698A
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Abstract
The invention provides a kind of PAL mode and SECAM-L mode and do not reduce the television broadcasting signal receiver turning of key property on can corresponding VHF low-frequency band.A kind of television broadcasting signal receiver turning (1) that receives the television broadcasting signal of PAL mode and SECAM-L mode, possesses a tuning circuit (11), secondary tuning circuit (12) and RF tuning circuit (4), this RF tuning circuit (4) has the coupling inductance (L5) of the degree of coupling of adjusting a tuning circuit (11) and secondary tuning circuit (12), and during the television broadcasting signal of the SECAM-L mode on receiving the VHF low-frequency band, when RF tuning circuit (4) makes based on coupling with the degree of coupling of inductance less than the television broadcasting signal that receives the PAL mode based on the degree of coupling of coupling with inductance.
Description
Technical field
The present invention relates to the television broadcasting signal receiver turning of the television broadcasting signal of a kind of PAL of reception mode and SECAM mode.
Background technology
In Europe, adopt PAL mode and SECAM-L mode as the television broadcasting mode, and exploitation can receive the tuner of the television broadcasting signal of PAL mode and SECAM (L) mode.In the past, as the television broadcasting signal receiver turning of corresponding PAL mode and SECAM (L) mode, known tuner (for example, with reference to patent documentation 1) with VHF high frequency band and VHF low-frequency band commutation circuit structure.
Represent as Fig. 6, this television broadcasting signal receiver turning 21 possesses antenna tuning circuit 22, RF amplifying circuit 23, RF tuning circuit 24, VHF mixting circuit 25, VHF local oscillation circuit 26 and IF tuning circuit 27, by switching the circuit structure of RF tuning circuit 24, can receive the television broadcasting signal of VHF high frequency band and VHF low-frequency band.
Secondary tuning circuit 32 is connected an end of the inductance L 32 of a tuning circuit 31.One end of the inductance L 32 of a tuning circuit 31 is connected on the series circuit that is made of inductance L 33, capacitor C32, inductance L 34 and variable capacitance diode VD32.The negative electrode of variable capacitance diode VD32 is connected the power supply B31 that exports tuning voltage by resistance R 32, and anode is connected the input of VHF mixting circuit 25.Contact between the negative electrode of inductance L 34 and variable capacitance diode VD32 is by variable capacitance diode VD33 and ground ground connection.The negative electrode of variable capacitance diode VD33 is connected the power supply B31 that exports tuning voltage, anode and ground ground connection by resistance R 32.
And the inductance L 31 of a tuning circuit 31, the contact of L32 are connected on the contact of the inductance L 33 of secondary tuning circuit 32 and capacitor C32 by the round about circuit 33 that is provided with switching diode SD31, SD32.The anode of switching diode SD31 is connected the contact of inductance L 31, L32, and negative electrode is connected the negative electrode of switching diode SD32.And the anode of switching diode SD32 is connected on the contact of inductance L 33 and capacitor C32.The contact of the negative electrode of switching diode SD31, SD32 is connected switching type power supply 34 by resistance R 33 simultaneously by capacitor C33 and ground ground connection.
Contact between tuning circuit 31 and the secondary tuning circuit 32 by coupling with inductance L35 and capacitor C34 and ground ground connection.Coupling is connected power supply B32 with the contact between inductance L35 and the capacitor C34.Power supply B32 is connected on the collector electrode of switching transistor T31 by resistance R 34.The collector electrode of switching transistor T31 is connected with power supply B32 by resistance R 34, and there are conducting resistance in emitter and ground ground connection between the collector and emitter.
In having the RF tuning circuit 24 of this structure, when receiving the television broadcasting of VHF high frequency band, switching type power supply 34 and switching transistor T31 are cut off.So the output voltage of power supply B32 output is applied to the anode of switching diode SD31, SD32 by inductance L 35, L32, L33, tuning circuit 31 and secondary tuning circuit 32 are switched on by round about circuit 33.At this moment, on a tuning circuit 31, constitute antiresonant circuit, on secondary tuning circuit 32, constitute antiresonant circuit by inductance L 34 and variable capacitance diode VD32, VD33 by variable capacitance diode VD31 and inductance L 31.
In addition, when receiving the television broadcasting of VHF low-frequency band, switching type power supply 34 and switching transistor T31 are switched on.Because of switching type power supply 34 is switched on, revers voltage is applied on the negative electrode of switching diode SD31, SD32 by resistance R 33 from switching type power supply 34.At this moment, forward voltage is applied to by inductance L 35, L32, L33 on the anode of switching diode SD31, SD32 from power supply B32, but the revers voltage that is applied to switching diode SD31, SD32 is bigger than forward voltage, so round about circuit 33 is cut off.
At this moment, on a tuning circuit 31, constitute antiresonant circuit, on secondary tuning circuit 32, constitute antiresonant circuit by inductance L 33, L34 and variable capacitance diode VD32, VD33 by variable capacitance diode VD31 and inductance L 31, L32.At this moment, tuning circuit 31 and secondary tuning circuit 32 by inductance L 35 by high-frequency coupling.Switch the circuit structure of the RF tuning circuit 24 of television broadcasting signal receiver turning 21 by the way, thereby formed the structure that can receive VHF high frequency band and VHF low-frequency band television broadcasting signal.
Patent documentation 1:(Japan) spy opens flat 11-341391 communique
But the television broadcasting signal of the SECAM-L mode on the VHF low-frequency band is compared with the television broadcasting signal of PAL mode, and the frequency height of vision signal P and voice signal S is opposite.At this moment, shown in Fig. 7 (a) and (b), when the television broadcasting signal of the PAL mode that receives the VHF low-frequency band, voice signal S is existed the interference signal UD that is equivalent to adjacent frequency interference, when receiving the television broadcasting signal of SECAM-L mode, existence is equivalent to the adjacent down interference signal UD that disturbs frequently to voice signal S.
Above-mentioned television broadcasting signal receiver turning 21, shown in Fig. 7 (a), be designed to the key property of preferential PAL mode and the upward adjacent frequency interference signal UD that decays, therefore shown in Fig. 7 (b), when receiving the television broadcasting signal of SECAM-L mode, adjacent frequency interference signal UD down just can not fully decay.Therefore, the key property of 21 pairs of defineds such as EMC patience of above-mentioned television broadcasting signal receiver turning does not have leeway, and the key property when be difficult to absorbing volume production is uneven.
Summary of the invention
The present invention proposes in view of above-mentioned problem in the past, and its purpose is, a kind of PAL mode and SECAM-L mode and do not reduce the television broadcasting signal receiver turning of key property on can corresponding VHF low-frequency band is provided.
Television broadcasting signal receiver turning of the present invention is the television broadcasting signal receiver turning that can receive the television broadcasting signal of PAL mode and SECAM-L mode, it is characterized in that, possesses tuning circuit one time, secondary tuning circuit and double-tuned circuit, this double-tuned circuit has the coupling inductance of the degree of coupling that is used to adjust an above-mentioned tuning circuit and above-mentioned secondary tuning circuit, and during the television broadcasting signal of the above-mentioned SECAM-L mode on receiving the VHF low-frequency band, above-mentioned double-tuned circuit make based on above-mentioned coupling with the degree of coupling of inductance when receiving the television broadcasting signal of above-mentioned PAL mode.
According to said structure, during the TV signal of the PAL mode on receiving the VHF low-frequency band, be adjusted greatlyyer based on the degree of coupling that is coupled with inductance, go up adjacent frequency interference signal so can fully decay.On the other hand, during the television broadcasting signal of the SECAM-L mode on receiving the VHF low-frequency band, with receive the VHF low-frequency band on the television broadcasting signal of PAL mode the time compare, be adjusted lessly based on the degree of coupling that is coupled with inductance, the bandwidth of receive frequency is dwindled, thereby can decay adjacent frequency interference signal down fully.Therefore, in the television broadcasting signal receiver turning of corresponding PAL mode and SECAM-L mode, guaranteed the key property of defineds such as EMC patience, thereby the key property can absorb volume production the time is uneven.
Feature of the present invention also is, above-mentioned television broadcasting signal receiver turning possesses switch portion, the changeable resistance of this switch portion is connected in above-mentioned coupling in parallel with the connection status of inductance with make the unconnected notconnect state of above-mentioned resistance, and above-mentioned coupling is connected between the contact and ground between an above-mentioned tuning circuit and the above-mentioned secondary tuning circuit with inductance, during the television broadcasting signal of the SECAM-L mode of above-mentioned switch portion on receiving above-mentioned VHF low-frequency band, connect above-mentioned resistance on inductance in above-mentioned coupling.
According to said structure, during the TV signal of the SECAM-L mode on receiving the VHF low-frequency band, the resistance that is connected in parallel on being coupled with inductance makes based on the degree of coupling of coupling with inductance to diminish.
The invention is characterized in, in above-mentioned television broadcasting signal receiver turning, above-mentioned switch portion has transistor, this transistorized collector electrode is connected the end of above-mentioned coupling with inductance, emitter is connected the other end of above-mentioned coupling with inductance, between collector electrode and emitter, be provided with conducting resistance, and during the television broadcasting signal of the SECAM-L mode on receiving above-mentioned VHF low-frequency band, above-mentioned transistor is switched on.
According to said structure, during the TV signal of the SECAM-L mode on receiving the VHF low-frequency band, transistor is switched on, thereby can make conducting resistance be connected in coupling in parallel with on the inductance, and makes based on the degree of coupling of coupling with inductance and diminish.
The invention is characterized in, in above-mentioned television broadcasting signal receiver turning, above-mentioned switch portion has switching diode and resistance, the anode of this switching diode is connected the end of above-mentioned coupling with inductance, this resistance is arranged on the negative electrode and the above-mentioned coupling of above-mentioned switching diode and uses between the other end of inductance, and during the television broadcasting signal of the SECAM-L mode on receiving above-mentioned VHF low-frequency band, above-mentioned switching diode is in conducting state.
According to said structure, during the TV signal of the SECAM-L mode on receiving the VHF low-frequency band, switching diode is switched on, thereby makes resistance be connected in coupling in parallel with on the inductance, and makes based on the degree of coupling of coupling with inductance and diminish.
According to the present invention, PAL mode and SECAM-L mode on can corresponding VHF low-frequency band under the situation that does not reduce key property.
Description of drawings
Fig. 1 is, represents the figure of the television broadcasting signal receiver turning execution mode that arrives involved in the present invention, is the circuit structure diagram of television broadcasting signal receiver turning.
Fig. 2 is, represents the figure of the television broadcasting signal receiver turning execution mode that arrives involved in the present invention, the figure of a response characteristic example when being illustrated in the television broadcasting signal that receives on the VHF low-frequency band.
Fig. 3 is, represents the figure of the television broadcasting signal receiver turning execution mode that arrives involved in the present invention, not have the figure of the characteristic example of videoing of the demodulator circuit of expression from the television broadcasting signal receiver turning to figure for expression.
Fig. 4 is, represents the figure of the television broadcasting signal receiver turning variation that arrives involved in the present invention, is the part-structure figure of television broadcasting signal receiver turning.
Fig. 5 is, represents the figure of other variation of television broadcasting signal receiver turning that arrives involved in the present invention, is the part-structure figure of television broadcasting signal receiver turning.
Fig. 6 is, represents the television broadcasting signal receiver turning that the arrives involved in the present invention figure of example in the past, is the circuit structure diagram of television broadcasting signal receiver turning.
Fig. 7 is, represents the television broadcasting signal receiver turning that the arrives involved in the present invention figure of example in the past, the figure of a response characteristic example when being illustrated in the television broadcasting signal that receives on the VHF low-frequency band.
Symbol description:
1 television broadcasting signal receiver turning, 2 antenna tuning circuits, 3RF amplifying circuit, 4RF tuning circuit (double-tuned circuit), 5VHF mixting circuit, 6VHF local oscillation circuit, the 7IF tuning circuit, 11 tuning circuits, 12 secondary tuning circuits, 13 round about circuits, 14 switching type power supplies, L5, L11, L21 inductance (coupling inductance), T11, T21 switching transistor (switch portion), SD11 switching diode (switch portion), R11 resistance (switch portion).
Embodiment
Describe embodiments of the present invention below with reference to accompanying drawings in detail.In addition; the television broadcasting signal receiver turning that embodiment of the present invention is involved; during the television broadcasting signal of the SECAM-L mode on receiving the VHF low-frequency band; by reducing the degree of coupling between tuning circuit and the secondary tuning circuit, in corresponding PAL mode of state and the SECAM-L mode of guaranteeing key property.Fig. 1 is the circuit structure diagram of the television broadcasting signal receiver turning that embodiment of the present invention is involved.
As shown in Figure 1, television broadcasting signal receiver turning 1 corresponding PAL mode and SECAM (L) mode possess antenna tuning circuit 2, RF amplifying circuit 3, RF tuning circuit 4, VHF mixting circuit 5, VHF local oscillation circuit 6 and IF tuning circuit 7.Separate the tuned frequency composition in the high-frequency signal that antenna element received that antenna tuning circuit 2 will not have to represent from figure.
The high-frequency signal that has passed through antenna tuning circuit 2 amplifies at RF amplifying circuit 3, and separates the tuned frequency composition in RF tuning circuit 4.The high-frequency signal that has passed through RF tuning circuit 4 is imported in the VHF mixting circuit 5 with the local oscillation signal of VHF local oscillation circuit 6 outputs.The high-frequency signal that is imported into VHF mixting circuit 5 mixes with local oscillation signal, and its frequency inverted becomes intermediate-freuqncy signal.Be converted the intermediate-freuqncy signal of frequency at VHF mixting circuit 5, separate the tuned frequency compositions at IF tuning circuit 7, and be output to late-class circuit.
At this television broadcasting signal receiver turning 1, when receiving the television broadcasting signal of VHF high frequency band and VHF low-frequency band, the circuit structure of changeable RF tuning circuit 4.RF tuning circuit 4 is a double-tuned circuit, has the secondary tuning circuit 12 that tuning circuit 11 being connected with the output of RF amplifying circuit 3 is connected with input with VHF mixting circuit 5.
In tuning circuit 11, the output of RF amplifying circuit 3 is by capacitor C1 and variable capacitance diode VD1 and ground ground connection.The negative electrode of variable capacitance diode VD1 is connected anode and ground ground connection by resistance R 1 with the power supply B1 of output tuning voltage.And the negative electrode of variable capacitance diode VD1 is connected on the series circuit that is made of inductance L 1, L2 by capacitor C1.
Secondary tuning circuit 12 is connected an end of inductance L 2 ground side of a tuning circuit 11.One end of the inductance L 2 of a tuning circuit 11 is connected on the series circuit of being made up of inductance L 3, capacitor C2, inductance 4 and variable capacitance diode VD2.The negative electrode of variable capacitance diode VD2 is connected on the power supply B1 of output tuning voltage by resistance R 2, and anode is connected the input of VHF mixting circuit 5.Contact between the negative electrode of inductance L 4 and variable capacitance diode VD2 is by variable capacitance diode VD3 and ground ground connection.The negative electrode of variable capacitance diode VD3 is connected by resistance R 2 on the power supply B1 of output tuning voltage, anode and ground ground connection.
In addition, the contact of the inductance L 1 of a tuning circuit 11, L2 is connected with the inductance L 3 of secondary tuning circuit 12 and the contact of capacitor C2 by the round about circuit 13 that is provided with switching diode SD1, SD2.The anode of switching diode SD1 is connected with the contact of inductance L 1, L2, and negative electrode is connected with the negative electrode of switching diode SD2.And the anode of switching diode SD2 is connected with the contact of inductance L 3 with capacitor C2.When the contact of the negative electrode of switching diode SD1, SD2 passes through capacitor C3 and ground ground connection, be connected with switching type power supply 14 by resistance R 3.
Contact between tuning circuit 11 and the secondary tuning circuit 12 by coupling with inductance L5 and capacitor C4 and ground ground connection.This coupling is the coupling coil of tuning circuit 11 of high-frequency coupling and secondary tuning circuit 12 with inductance L5, adjusts receive frequency bandwidth on the RF tuning circuit 4 by the degree of coupling of this coupling coil.In addition, about the adjustment action of coupling, will do narration in the back with the degree of coupling of inductance L5.
With the end of coupling, be connected with the collector electrode of switching transistor T1 by capacitor C5 with the opposite side of the ground side of inductance L5.The collector electrode of switching transistor T1 is connected with power supply B2 by resistance R 4, and emitter and ground ground connection are provided with conducting resistance between collector electrode and the emitter.And coupling is connected with power supply B2 with the contact between inductance L5 and the capacitor C4.
And in the present embodiment, VHF mixting circuit 5, VHF local oscillation circuit 6, IF tuning circuit 7, switching type power supply 14 and switching transistor T1 are set in the IC of television broadcasting signal receiver turning 1.But, being not limited to this structure, it is also passable outward that it is arranged on IC.
In having the television broadcasting signal receiver turning 1 of said structure,, can receive the television broadcasting signal of VHF high frequency band and VHF low-frequency band by the enablement and disablement state of switching type power supply 14 and switching transistor T1.Also have,, enlarge the bandwidth of receive frequency during the television broadcasting signal of the PAL mode on receiving the VHF low-frequency band, and when receiving the television broadcasting signal of SECAM-L mode, the bandwidth of receive frequency is narrowed down by adjusting based on the degree of coupling of coupling with inductance L5.
Below, with the reception action of explanation television broadcasting signal receiver turning.When receiving the television broadcasting signal of VHF high frequency band, switching type power supply 14 is cut off, and switching transistor T1 is cut off.According to this structure, forward voltage is applied to the anode of switching diode SD1, SD2 from power supply B2 by inductance L 5, L2, L3, makes tuning circuit 11 and secondary tuning circuit 12 by round about circuit 13 conductings.
And, on a tuning circuit 11, constitute antiresonant circuit by variable capacitance diode VD1 and inductance L 1, on secondary tuning circuit 12, constitute antiresonant circuit by inductance L 4 and variable capacitance diode VD2, VD3.By on the negative electrode of variable capacitance diode VD1, the VD2 of two resonant circuits, VD3, applying tuning voltage, can be adjusted at the tuned frequency of the RF tuning circuit 4 when receiving VHF high frequency band television broadcasting signal with said structure.
During the television broadcasting signal of the PAL mode on receiving the VHF low-frequency band, switching type power supply 14 is switched on, and switching transistor T1 is cut off.Because the conducting of switching type power supply 14, revers voltage is applied to the negative electrode of switching diode SD1, SD2 by resistance R 3 from switching type power supply 14.At this moment, though forward voltage is applied to the anode of switching diode SD1, SD2 from power supply B2 by inductance L 5, L2, L3, because the revers voltage that is applied to switching diode SD1, SD2 is greater than forward voltage, so round about circuit 13 is cut off.
According to this structure, tuning circuit 11 and secondary tuning circuit 12 by coupling with inductance L5 high-frequency coupling.And owing to ending of switching transistor T1, the conducting resistance of switching transistor T1 is separated with inductance L5 from coupling.Therefore, adjusted significantly with the degree of coupling of inductance L5 based on coupling.In addition, the bandwidth of Ci Shi receive frequency is set to that the PAL mode that can receive low-frequency band is expected the ripple signal and the bandwidth of the interference signal that can fully decay.
And, on a tuning circuit 11, constitute antiresonant circuit by variable capacitance diode VD1 and inductance L 1, L2, on secondary tuning circuit 12, constitute antiresonant circuit by inductance L 3, L4 and variable capacitance diode VD2, VD3.By applying tuning voltage at variable capacitance diode VD1, the VD2 of resonant circuit, the negative electrode of VD3 with said structure, the tuned frequency of the RF tuning circuit 4 in the time of can being adjusted at the television broadcasting signal that receives the PAL mode on the VHF low-frequency band.
During the television broadcasting signal of the SECAM-L mode on receiving the VHF low-frequency band, switching type power supply 14 is switched on, and switching transistor T1 also is switched on.Because the conducting of switching type power supply 14, revers voltage is applied to the negative electrode of switching diode SD1, SD2 by resistance R 3 from switching type power supply 14.At this moment, though forward voltage is applied to the anode of switching diode SD1, SD2 from power supply B1 by inductance L 5, L2, L3, owing to be applied to revers voltage on switching diode SD1, the SD2 greater than forward voltage, round about circuit 13 is cut off.
According to said structure, tuning circuit 11 and secondary tuning circuit 12 are coupled the high-frequency coupling with inductance L5.And, because the conducting of switching transistor T1, with an end of the ground side opposition side of inductance L 5, between the collector and emitter by capacitor C5 and switching transistor T1, with ground ground connection.So the conducting resistance of switching transistor T1 is connected in coupling in parallel with on the inductance L5.
By the way, with receive the VHF low-frequency band on the television broadcasting signal of PAL mode the time compare, adjusted with the degree of coupling of inductance L5 based on coupling lessly.In addition, the bandwidth of receive frequency of this moment is set to, and can receive the expectation ripple signal of the SECAM mode on the low-frequency band and the reverse bandwidth of the interference signal that shows of can fully decay height and PAL mode.
And, on a tuning circuit 11, constitute antiresonant circuit by variable capacitance diode VD1 and inductance L 1, L2, on secondary tuning circuit 12, constitute antiresonant circuit by inductance L 3, L4 and variable capacitance diode VD2, VD3.Apply tuning voltage by variable capacitance diode VD1, the VD2 that gives resonant circuit, the negative electrode of VD3, the tuned frequency of the RF tuning circuit 4 in the time of can adjusting the television broadcasting signal that receives the PAL mode on the VHF low-frequency band with said structure.
Below, the response characteristic when the television broadcasting signal that receives on the VHF low-frequency band being described between antenna-VHF mixting circuit with reference to Fig. 2.The figure of response characteristic one example of Fig. 2 during for the television broadcasting signal of the involved television broadcasting signal receiver turning of expression embodiment of the present invention on receiving the VHF low-frequency band.In addition, in Fig. 2, response characteristic when (a) being illustrated in the television broadcasting signal that receives the PAL mode in the present embodiment, response characteristic when (b) being illustrated in the television broadcasting signal that receives the SECAM-L mode in the comparative example, the response characteristic when (c) being illustrated in the television broadcasting signal that receives the SCAM-L mode in the present embodiment.
Response characteristic during at first, with the television broadcasting signal of the PAL mode of explanation on receiving the VHF low-frequency band.During the television broadcasting signal of the PAL mode on receiving the VHF low-frequency band, switching type power supply 14 is switched on, and switching transistor T1 is cut off, and tuning circuit 11 and secondary tuning circuit 12 are coupled the high-frequency coupling with inductance L5.At this moment, coupling is set significantly with the degree of coupling of inductance L5, can obtain the response characteristic shown in Fig. 2 (a).
In this response characteristic, frequency acceptance band is display video signal P, color signal C, voice signal S successively from the low-frequency range side to the high band side, shows the interference signal UD of adjacent channel in the high band side of voice signal S.At this moment, the bandwidth of receive frequency is set to, but the bandwidth of receiving video signals P, color signal C, voice signal S and the interference signal UD that can fully decay.
Response characteristic during secondly, with the television broadcasting signal of the SECAM-L mode of explanation on receiving the VHF low-frequency band.Here as a comparative example, the situation when receiving the television broadcasting signal of SECAM-L mode with circuit structure identical with the television broadcasting signal that receives the PAL mode on the VHF low-frequency band time is done explanation while comparing.When the television broadcasting signal of the SECAM-L mode that receives comparative example, will obtain the response characteristic shown in Fig. 2 (b).
In this response characteristic, compare the counter-rotating of expectation ripple signal and interference signal with the television broadcasting signal of PAL mode, display word tone signal S, color signal C, vision signal P be (for example successively from the low-frequency range side to the high band side, 63.75MHz), the interference signal UD of adjacent channel (for example, 55.75MHz) under the low-frequency range side of voice signal S shows.At this moment, in comparative example, because the bandwidth of receive frequency is corresponding to the PAL mode, so interference signal UD becomes big to the influence of voice signal S.
Then, when giving 55.75MHz (interference signal UD) input 68dB μ V when giving 63.75MHz (vision signal P) input 70dB μ V, shown in Fig. 3 (a), the video properties that does not have the demodulator circuit of expression from the television broadcasting signal receiver turning to figure forms the shape of heaving from vision signal P to the mid portion the color signal C.Under this condition,, the key property by regulations such as EMC patience there is not leeway though do not detect beat.Therefore, the television broadcasting signal receiver turning that comparative example is involved can not absorb the uneven of key property that volume production etc. brings.
In addition, at the involved television broadcasting signal receiver turning 1 of present embodiment, during the television broadcasting signal of the SECAM-L mode on receiving the VHF low-frequency band, switching type power supply 14 is switched on, and tuning circuit 11 and secondary tuning circuit 12 are coupled the high-frequency coupling with inductance L5.And switching transistor T1 is switched on, and the conducting resistance of switching transistor T1 is connected in coupling in parallel with on the inductance L5.By the way, compare during with the television broadcasting signal that receives the PAL mode, coupling is set with the degree of coupling of inductance L5 lessly, thereby obtains the response characteristic shown in Fig. 2 (c).
This response characteristic is compared with comparative example, and the bandwidth of receive frequency narrows down, and forms precipitous waveform.Also have, from the low-frequency range side to the high band side successively display word tone signal S, color signal C, vision signal P (for example, 63.75MHz), the interference signal UD of adjacent channel (for example, 55.75MHz) under the low-frequency range side of voice signal S shows.At this moment, because signal level is attenuated in the low-frequency range side of receive frequency, therefore the signal level of the interference signal UD of adjacent channel is decayed significantly down.
And, when giving 55.75MHz (interference signal UD) input 68dB μ V when giving 63.75MHz (vision signal P) input 70dB μ V, shown in Fig. 3 (b), there is not from the television broadcasting signal receiver turning to figure the video properties the demodulator circuit of expression to form the shape that narrows down towards color signal C from vision signal P.At this moment, to the key property by regulations such as EMC patience, the detection limit of beat is improved to+6dB μ V.Thus, the involved television broadcasting signal receiver turning of present embodiment can absorb the uneven of key property that volume production etc. brings.
As previously discussed, according to the involved television broadcasting signal receiver turning 1 of present embodiment, when receiving the TV signal of PAL mode,, go up adjacent frequency interference signal so can fully decay owing to adjusted significantly with the degree of coupling of inductance L5 based on coupling.On the other hand, during the television broadcasting signal of the SECAM-L mode on receiving the VHF low-frequency band, with receive the VHF low-frequency band on the television broadcasting signal of PAL mode the time compare, adjusted with the degree of coupling of inductance L5 based on coupling lessly, therefore frequency acceptance band narrows down, thereby can fully decay adjacent frequency interference signal down.So the television broadcasting signal receiver turning of corresponding PAL mode and SECAM-L mode can be guaranteed the key property by regulation such as EMC patience, the key property in the time of can absorbing volume production uneven.
In addition, in the present embodiment, adopted by switching transistor and adjusted, but be not limited to this structure based on the structure of coupling with the degree of coupling of inductance with conducting resistance.Get final product with the structure on the inductance so long as be connected in resistance in parallel coupling, for example also can adopt replacement circuit shown in Figure 4.
Replacement circuit shown in Figure 4 is, and the end and ground of coupling with the ground side opposition side of inductance L11 between, be provided with the series circuit that constitutes by switching diode SD11, resistance R 11, capacitor C11.At this moment, the contact between resistance R 11 and the capacitor C11 is connected by the power supply that does not have among resistance R 12 and the figure to represent.Be applied to the negative electrode of switching diode SD11 by the output voltage that makes this power supply, resistance R 11 is separated with inductance L11 from coupling.And by stopping to apply of output voltage, resistance R 11 is connected in coupling in parallel with on the inductance L11.
As mentioned above,, compare, can suppress based on coupling uneven with the degree of coupling of inductance L11 with the structure of conducting resistance in being connected switching transistor by the series circuit of switching diode SD11 and resistance R 11.
In addition, in the present embodiment, adopted by being located at IC switch inside transistor and adjusted, still, be not limited to this structure based on the structure of coupling with the degree of coupling of inductance.As shown in Figure 5, adopt by the switching transistor T21 that is provided with in the IC outside and adjust the structure of coupling, also can with the degree of coupling of inductance L21.At this moment, between the end and ground of coupling, capacitor C21 and switching transistor T21 are set with inductance L21.The collector electrode of switching transistor T21 is connected its emitter and ground ground connection by resistance R 21 with power supply B21.
And when switching transistor T21 was cut off, coupling separated from the conducting resistance of switching transistor T21 with inductance L21.On the other hand, when switching transistor T21 is switched on, coupling with the end of inductance L21 by capacitor C21 and switching transistor T21 collector electrode and emitter between with ground ground connection, coupling is connected in parallel in the conducting resistance of switching transistor T21 with inductance L21.
By the way, even adopt structure at IC outer setting switching transistor, at the television broadcasting signal receiver turning of corresponding PAL mode and SECAM-L mode, the key property in the time of also can guaranteeing the key property of regulation such as EMC patience and absorb volume production uneven.
In addition, adopted in the present embodiment by switching transistor etc. and be connected in resistance in parallel coupling with on the inductance, when making the television broadcasting signal that receives the SECAM-L mode on the VHF low-frequency band based on coupling with the degree of coupling of the inductance structure when receiving the PAL mode, but be not limited to this structure.So long as when receiving the television broadcasting signal of the SECAM-L mode on the VHF low-frequency band based on coupling with the degree of coupling of inductance the structure during less than the PAL mode, no matter which type of structure can.
And, constitute the coupling inductance with coupling with coil in the present embodiment, but be not limited to this structure.As long as can tuning circuit of high-frequency coupling and secondary tuning circuit, for example adopt the cascade type inductance that stacked tabular conductor plate constitutes, the film-type inductance that printing swirl shape conductive pattern constitutes, can.
And, for example understand the television broadcasting signal receiver turning of corresponding PAL mode and SECAM-L mode broadcast singal in the present embodiment, but be not limited to this structure.The present invention for example is applicable to that applicable to the corresponding television broadcasting signal receiver turning of television broadcasting mode that just reverses with the frequency of expectation ripple signal the television broadcasting signal receiver turning of corresponding SECAM-L mode and other broadcast mode is also passable.
In addition, current disclosed execution mode is example on all parts, and is not limited to this execution mode.Scope of the present invention is not the explanation that only comprises above-mentioned execution mode, but represents with the scope of patent request, plans to comprise the meaning identical with the scope of patent request and all the change contents in the scope.
As described above, the present invention has when not reducing key property the PAL mode on can corresponding VHF low-frequency band and the effect of SECAM-L mode, and is especially useful to the television broadcasting signal receiver turning of the television broadcasting signal that can receive PAL mode and SECAM mode.
Claims (4)
1. television broadcasting signal receiver turning can receive the television broadcasting signal of PAL mode and SECAM-L mode, it is characterized in that,
Possess tuning circuit, secondary tuning circuit and double-tuned circuit one time, this double-tuned circuit has the coupling inductance of the degree of coupling of adjusting an above-mentioned tuning circuit and above-mentioned secondary tuning circuit,
And, during the television broadcasting signal of the above-mentioned SECAM-L mode on receiving the VHF low-frequency band, above-mentioned double-tuned circuit make based on above-mentioned coupling with the degree of coupling of inductance when receiving the television broadcasting signal of above-mentioned PAL mode.
2. television broadcasting signal receiver turning according to claim 1 is characterized in that,
Possess switch portion, this switch portion is switched with respect to above-mentioned coupling to be made the connection status that resistance is connected in parallel and makes the unconnected notconnect state of above-mentioned resistance with inductance,
Above-mentioned coupling is connected between the contact and ground between an above-mentioned tuning circuit and the above-mentioned secondary tuning circuit with inductance,
During the television broadcasting signal of the SECAM-L mode of above-mentioned switch portion on receiving above-mentioned VHF low-frequency band, connect above-mentioned resistance on inductance in above-mentioned coupling.
3. television broadcasting signal receiver turning according to claim 2 is characterized in that,
Above-mentioned switch portion has transistor, and this transistorized collector electrode is connected in the end of above-mentioned coupling with inductance, and emitter is connected in the other end of above-mentioned coupling with inductance, and is provided with conducting resistance between collector and emitter,
And, during the television broadcasting signal of the SECAM-L mode on receiving above-mentioned VHF low-frequency band, make above-mentioned transistor turns.
4. television broadcasting signal receiver turning according to claim 2 is characterized in that,
Above-mentioned switch portion has switching diode and resistance, and the anode of this switching diode is connected in the end of above-mentioned coupling with inductance, and this resistance is arranged on the negative electrode and the above-mentioned coupling of above-mentioned switching diode and uses between the other end of inductance,
During the television broadcasting signal of the SECAM-L mode on receiving above-mentioned VHF low-frequency band, above-mentioned switching diode is switched on.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009165959A JP2011023891A (en) | 2009-07-14 | 2009-07-14 | Tuner for receiving television broadcast signal |
| JP165959/2009 | 2009-07-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101958698A true CN101958698A (en) | 2011-01-26 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010102163611A Pending CN101958698A (en) | 2009-07-14 | 2010-06-23 | The television broadcasting signal receiver turning |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2011023891A (en) |
| CN (1) | CN101958698A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103796059A (en) * | 2012-10-26 | 2014-05-14 | 三星电子株式会社 | Broadcasting signal receiving apparatus and control method thereof |
| CN106788301A (en) * | 2016-12-30 | 2017-05-31 | 陕西烽火电子股份有限公司 | The gain electrically tunable filter and its communicator of VHF/UHF frequency ranges |
| CN106849986A (en) * | 2016-12-15 | 2017-06-13 | 熊猫电子集团有限公司 | A kind of shortwave antenna tuning coupler based on PIN electronic switches |
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| CN85104465A (en) * | 1984-11-13 | 1986-05-10 | 夏普公司 | Multistandard TV receiver |
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| CN1120283A (en) * | 1994-08-08 | 1996-04-10 | 汤姆森消费电子有限公司 | Double tuned RF circuit with balanced secondary |
| JP2000165174A (en) * | 1998-11-26 | 2000-06-16 | Sharp Corp | Tuner circuit |
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| CN101472112A (en) * | 2007-12-28 | 2009-07-01 | 阿尔卑斯电气株式会社 | Double-tuning circuit of television tuner |
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| CN85104465A (en) * | 1984-11-13 | 1986-05-10 | 夏普公司 | Multistandard TV receiver |
| CN1119391A (en) * | 1994-08-08 | 1996-03-27 | 汤姆森消费电子有限公司 | Bandswitchable double tuned RF circuit with balanced secondary |
| CN1120283A (en) * | 1994-08-08 | 1996-04-10 | 汤姆森消费电子有限公司 | Double tuned RF circuit with balanced secondary |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103796059A (en) * | 2012-10-26 | 2014-05-14 | 三星电子株式会社 | Broadcasting signal receiving apparatus and control method thereof |
| CN106849986A (en) * | 2016-12-15 | 2017-06-13 | 熊猫电子集团有限公司 | A kind of shortwave antenna tuning coupler based on PIN electronic switches |
| CN106788301A (en) * | 2016-12-30 | 2017-05-31 | 陕西烽火电子股份有限公司 | The gain electrically tunable filter and its communicator of VHF/UHF frequency ranges |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2011023891A (en) | 2011-02-03 |
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Application publication date: 20110126 |