CN102761719A - Triple-conversion television tuner - Google Patents
Triple-conversion television tuner Download PDFInfo
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- CN102761719A CN102761719A CN2012101323449A CN201210132344A CN102761719A CN 102761719 A CN102761719 A CN 102761719A CN 2012101323449 A CN2012101323449 A CN 2012101323449A CN 201210132344 A CN201210132344 A CN 201210132344A CN 102761719 A CN102761719 A CN 102761719A
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Abstract
A television tuner includes a receiving terminal for receiving an RF TV signal,a low pass filter for distinguishing a first band signal from the RF TV signal,a high pass filter for distinguishing a second band signal from the RF TV signal,a local oscillator for generating a reference signal set with a tunable frequency,a harmonic rejection quadrature mixer for mixing the first band signal in response to the reference signal set to generate a first in-phase signal and a first quadrature-phase signal, wherein harmonic frequencies of the first in-phase signal and the first quadrature-phase signal are cancelled,a quadrature mixer for mixing the second band signal in response to the reference signal set to generate a second in-phase signal and a second quadrature-phase signal,a first digital circuit for receiving the first in-phase signal and the first quadrature-phase signal or receiving the second in-phase signal and the second quadrature-phase signal to cancel image signals therefore,and, a second digital circuit for receiving the image-cancelled signals to generate an analog composite video broadcast signal and an analog sound intermediate frequency signal.
Description
Technical field
The present invention relates to a kind of TV tuner (Television Tuner), particularly a kind of high integrated TV tuner that is made on single substrate (single substrate).
Background technology
In general, the frequency spectrum (Spectrum) of radio frequency (Radio Frequency the is called for short RF) TV signal of very high frequency(VHF) (Very High Frequency is called for short VHF) and hyperfrequency (Ultra high Frequency is called for short UHF) is between 48MHz to 860MHz.And the frequency spectrum between 48MHz to 860MHz includes a plurality of channels (Channel); The bandwidth of each channel (Bandwidth) is 6MHz (or 8MHz); The frequency of the high 1.25MHz in distance low-frequency edge is video carrier frequency (Video Carrier Frequency); Frequency apart from the high 3.58MHz of video carrier frequency is color carrier frequency (Color Carrier Frequency), is sound carrier frequency (Audio Carrier Frequency) apart from the frequency of the high 4.5MHz of video carrier frequency.For instance, the 6MHz bandwidth of second channel (Channel 2) is by 54Mhz to 60MHz, and video carrier frequency is 55.25MHz, and color carrier frequency is 58.83MHz, and the sound carrier frequency is 59.75MHz.
Above-mentioned radio television signal can be sent to TV tuner through antenna (Antenna) and cable (Cable); And TV tuner can be selected one or more specific channel and be converted into an intermediate frequency (Intermediate Frequency; Abbreviation IF) behind signal or fundamental frequency (Base-band Frequency) signal, is sent to processor (Processor) and carries out the processing of follow-up intermediate-freuqncy signal or fundamental frequency signal.
Early stage TV tuner is single (Single Down-Conversion) tuner that changes down, and this tuner is to be combined by a plurality of independently electronic building bricks, thus bulky, can be referred to as metal-back tuner (CAN Tuner) again.Comprise a frequency mixer (Mixer) in the single down commentaries on classics tuner, the major function of this frequency mixer changes into radio television signal under directly exactly and is intermediate-freuqncy signal or fundamental frequency signal.Please with reference to Fig. 1, it is the single frequency inverted sketch map of commentaries on classics tuner down.Comprise a plurality of channels in the radio television signal (I), be multiplied by a reference frequency (f through frequency mixer
LO) reference signal (II) after, be positioned at reference frequency (f in the radio television signal
LO) channel A can by under go to fundamental frequency.
(Switching Mixer) is example with the switching mode frequency mixer, and it is 50% square wave (Square Wave) that reference signal is actually duty ratio, that is to say, can comprise many resonance frequencys (Harmonic Frequency) in the reference signal, for example 3f
LO, 5f
LO, 7f
LOOr the like resonance frequency.Therefore, carrier wave is 3 times of reference frequency (3f in the radio television signal as shown in the figure
LO) channel B, carrier wave be 5 times of reference frequency (5f
LO) channel C, carrier wave be 7 times of reference frequency (7f
LO) channel D, all can by under go to fundamental frequency.Therefore, there is the signal of channel A, B, C, D can come across fundamental frequency at least simultaneously, shown in signal (III).
The energy intensity (Power) of supposing radio television signal mid band B, C, D exceeds 30dB than the intensity of channel A; In order to reduce the Signal-to-Noise deterioration (SNR degradation) that causes by resonance frequency; And make the intensity of fundamental frequency among channel B, C, the D than the little 30dB of intensity of channel A; Therefore, must provide a resonance rejection ratio (Harmonic Rejection Ratio) to be higher than the assembly of 60dB.
Therefore; Can utilize a plurality of Radio Frequency Tracking filters (RF tracking filter) before radio television signal gets into frequency mixer, to reduce the intensity of resonance channel in the radio television signal earlier in advance in the known single commentaries on classics tuner down, and solve the resonance problems that frequency mixer produces in fundamental frequency.Yet, Radio Frequency Tracking filter bulky and need carry out the adjustment of frequency band, so the relative raising of cost by high voltage, and be unfavorable for being integrated among the integrated circuit of single substrate.
Because the manufacturing process technology of semiconductor silicon chips is showing improvement or progress day by day; In order to reduce the cost of TV tuner effectively; The TV tuner that is integrated in single silicon substrate is developed; For example U.S. Pat 5,737, the 035 disclosed two up and down TV tuners that change (Up-Down Dual Conversion) that are integrated in single substrate.
Please with reference to Fig. 2, it is known two up and down commentaries on classics tuner sketch map.The radio television signal that is received by antenna 402 (perhaps cable) is the radio frequency low pass filter of 900MHz (RF Low Pass Filter) 404 through cut-off frequency (Cutoff Frequency) earlier, makes the frequency band of filtered radio television signal be limited in below the 900MHz.Then, filtered radio television signal is amplified 20dB by a low noise trsanscondutance amplifier (Low-Noise Transconductance Amplifier is called for short LNTA) 406.Moreover, first local oscillator (Local Oscillator), 411 outputs, first reference signal, its adjustable frequency scope is between 1200MHz and 2100MHz.And first frequency mixer (MIX1) 408; It is the frequency mixer (Subtractive Mixer) of a subtraction; It can mix output signal and this first reference signal of low noise trsanscondutance amplifier (LNTA) 406 and export first intermediate-freuqncy signal, and making the carrier frequency of special channels in the intermediate-freuqncy signal of winning (Desired Channel) is 1200MHz.That is to say, utilize the frequency of adjustment first reference signal, can convert the carrier wave of special channels into 1200MHz.
Because second local oscillator, 412 exportable second reference signals, its frequency is 1180MHz.And second frequency mixer (MIX2) 410; It is the frequency mixer (Image-Rejection Mixer) that a mirror image suppresses; It can mix second reference signal and first intermediate-freuqncy signal and export second intermediate-freuqncy signal, makes second intermediate-freuqncy signal comprise that carrier frequency is the special channels of 20MHz.That is to say that the carrier wave of this special channels converts 20MHz into through second frequency mixer (MIX2) 410.Go to 1200MHz on the carrier frequency of first frequency mixer (MIX1) 408 with this special channels of known two up and down commentaries on classics tuners, and go to 20MHz under the carrier frequency of second frequency mixer (MIX2) 410 with this special channels.Moreover; Because the frequency adjustment range of first reference signal of first local oscillator, 411 outputs is between 1200MHz and 2100MHz; So first local oscillator 411 must utilize a plurality of voltage controlled oscillators, and (Voltage Controlled Oscillator VCO) just can realize.
Please with reference to Fig. 3, it is known another two up and down commentaries on classics tuner sketch mapes.For the mirror image (Image) that prevents the 1160MHz frequency; First intermediate-frequency filter (First IF Filter) 409 is connected in first frequency mixer (MIX1) 408 and second frequency mixer (MIX2) between 410, removes in order to the frequency content with the 1160MHz in first intermediate-freuqncy signal.
Can know that by foregoing known two up and down commentaries on classics tuners all are to utilize second local oscillator 412 that can adjust first local oscillator 411 of first reference signal frequency and have second a fixing reference signal frequency to realize.
Summary of the invention
The tuner that proposes another kind of different structure then is the topmost purpose of the present invention.The objective of the invention is to propose a kind of tuner that is easy to be integrated into single semiconductor substrate.
Therefore; The present invention proposes a kind of TV tuner; Comprise: a radio frequency selects band filter; In order to receive a radiofrequency signal and this radiofrequency signal is divided into first frequency band signals and second frequency band signals, wherein this radiofrequency signal medium frequency less than 450MHz partly be first frequency band signals, this radiofrequency signal medium frequency partly is second frequency band signals greater than 450MHz's; One first local oscillator produces one first group of reference signal of a fixed frequency; One resonance frequency suppresses frequency mixer, perhaps converts this first frequency band signals into one first intermediate-freuqncy signal on this second frequency band signals according to this first group of reference signal; One second local oscillator, one second group of reference signal of generation frequency adjustable; One first image-reject mixer makes the carrier wave of a special channels be converted to a first frequency according to this second group of reference signal with converting one second intermediate-freuqncy signal on this first intermediate-freuqncy signal into; One the 3rd local oscillator, one the 3rd group of reference signal of generation frequency adjustable; And one second image-reject mixer, make and be converted to a second frequency under the carrier wave of this special channels converting a Low Medium Frequency signal under this second intermediate-freuqncy signal into according to the 3rd group of reference signal; Wherein, this first frequency is greater than this second frequency.
Aforesaid TV tuner, wherein this first local oscillator comprises:
One first voltage controlled oscillator produces the oscillator signal of a first frequency; And
One first treatment circuit, the frequency elimination that this oscillator signal is carried out one first integer moves so that produce this first group of reference signal, and wherein this first group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Aforesaid TV tuner, wherein this second local oscillator comprises:
One second voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One second treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one second integer is so that produce this second group of reference signal, and wherein this second group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Aforesaid TV tuner, wherein the 3rd local oscillator comprises:
One the 3rd voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One the 3rd treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one the 3rd integer is so that produce the 3rd group of reference signal, and wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
The present invention also proposes a kind of TV tuner; Comprise: a radio frequency selects band filter; In order to receive a radiofrequency signal and this radiofrequency signal divided into first frequency band signals and second frequency band signals; Wherein this radiofrequency signal medium frequency less than 450MHz partly be first frequency band signals, this radiofrequency signal medium frequency partly is second frequency band signals greater than 450MHz's; One first local oscillator produces one first group of reference signal of a fixed frequency; One resonance frequency suppresses frequency mixer, perhaps converts this first frequency band signals into one first intermediate-freuqncy signal on this second frequency band signals according to this first group of reference signal; One lc-tank is in order to the target signal filter outside first frequency band in this first intermediate-freuqncy signal; One second local oscillator, one second group of reference signal of generation frequency adjustable; One first image-reject mixer makes the carrier wave of a special channels be converted to a first frequency according to this second group of reference signal with converting one second intermediate-freuqncy signal on filtered this first intermediate-freuqncy signal; One the 3rd local oscillator, one the 3rd group of reference signal of generation frequency adjustable; And one second image-reject mixer, make the carrier wave of this special channels be converted to a second frequency according to the 3rd group of reference signal with converting a Low Medium Frequency signal under this second intermediate-freuqncy signal into; Wherein, this first frequency is greater than this second frequency.
Aforesaid TV tuner, wherein this first local oscillator comprises:
One first voltage controlled oscillator produces the oscillator signal of a first frequency; And
One first treatment circuit, the frequency elimination that this oscillator signal is carried out one first integer moves so that produce this first group of reference signal, and wherein this first group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Aforesaid TV tuner, wherein this second local oscillator comprises:
One second voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One second treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one second integer is so that produce this second group of reference signal, and wherein this second group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Aforesaid TV tuner, wherein the 3rd local oscillator comprises:
One the 3rd voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One the 3rd treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one the 3rd integer is so that produce the 3rd group of reference signal, and wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Wherein this lc-tank is the target signal filter outside first frequency band in this first intermediate-freuqncy signal, and this first frequency band is between 956MHz to 1362MHz.
The present invention also proposes a kind of TV tuner; Comprise: a radio frequency selects band filter; In order to receive a radiofrequency signal and this radiofrequency signal divided into first frequency band signals and second frequency band signals; Wherein this radiofrequency signal medium frequency less than 450MHz partly be first frequency band signals, this radiofrequency signal medium frequency partly is second frequency band signals greater than 450MHz's; One first local oscillator produces one first group of reference signal of a fixed frequency; One resonance frequency suppresses frequency mixer, perhaps converts this first frequency band signals into one first intermediate-freuqncy signal on this second frequency band signals according to this first group of reference signal; One second local oscillator, one second group of reference signal of generation frequency adjustable; One first image-reject mixer makes the carrier wave of a special channels be converted to a first frequency according to this second group of reference signal with converting one second intermediate-freuqncy signal on this first intermediate-freuqncy signal into; One surface acoustic wave filter is in order to this second intermediate-freuqncy signal of filtering, thereby becomes the 3rd intermediate-freuqncy signal, makes that this special channels is present in the 3rd intermediate-freuqncy signal at least; One the 3rd local oscillator, one the 3rd group of reference signal of generation frequency adjustable; And one second image-reject mixer, make the carrier wave of this special channels be converted to a second frequency according to the 3rd group of reference signal with converting a Low Medium Frequency signal under the 3rd intermediate-freuqncy signal into; Wherein, this first frequency is greater than this second frequency.
Aforesaid TV tuner, wherein this first local oscillator comprises:
One first voltage controlled oscillator produces the oscillator signal of a first frequency; And
One first treatment circuit, the frequency elimination that this oscillator signal is carried out one first integer moves so that produce this first group of reference signal, and wherein this first group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Aforesaid TV tuner, wherein this second local oscillator comprises:
One second voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One second treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one second integer is so that produce this second group of reference signal, and wherein this second group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Aforesaid TV tuner, wherein the 3rd local oscillator comprises:
One the 3rd voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One the 3rd treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one the 3rd integer is so that produce the 3rd group of reference signal, and wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Aforesaid TV tuner, wherein, this first image-reject mixer makes the carrier wave of a special channels be converted to 1575MHz according to this second group of reference signal with converting one second intermediate-freuqncy signal on this first intermediate-freuqncy signal into.
The present invention also proposes a kind of TV tuner; Comprise: a radio frequency selects band filter; In order to receive a radiofrequency signal and this radiofrequency signal divided into first frequency band signals and second frequency band signals; Wherein this radiofrequency signal medium frequency less than 450MHz partly be first frequency band signals, this radiofrequency signal medium frequency partly is second frequency band signals greater than 450MHz's; One first local oscillator produces one first group of reference signal of a fixed frequency; One resonance frequency suppresses frequency mixer, perhaps converts this first frequency band signals into one first intermediate-freuqncy signal on this second frequency band signals according to this first group of reference signal; One lc-tank is in order to the target signal filter outside first frequency band in this first intermediate-freuqncy signal; One second local oscillator, one second group of reference signal of generation frequency adjustable; One first image-reject mixer makes the carrier wave of a special channels be converted to a first frequency according to converting one second intermediate-freuqncy signal on this second group of reference signal this first intermediate-freuqncy signal after with the rate ripple; One surface acoustic wave filter is in order to the signal beyond this special channels in this one second intermediate-freuqncy signal of filtering and become one the 3rd intermediate-freuqncy signal, makes this special channels be present in the 3rd intermediate-freuqncy signal; One the 3rd local oscillator, one the 3rd group of reference signal of generation frequency adjustable; And one second image-reject mixer, make the carrier wave of this special channels be converted to a CF according to the 3rd group of reference signal with converting a Low Medium Frequency signal under the 3rd intermediate-freuqncy signal into; Wherein, this first frequency is greater than this second frequency.
Aforesaid TV tuner, wherein this first local oscillator comprises:
First voltage controlled oscillator, the oscillator signal of generation first frequency; And
First treatment circuit carries out the frequency elimination action of first integer to this oscillator signal, so that produce this first group of reference signal, wherein this first group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Aforesaid TV tuner, wherein this second local oscillator comprises:
Second voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
Second treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out second integer is so that produce this second group of reference signal, and wherein this second group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Aforesaid TV tuner, wherein the 3rd local oscillator comprises:
The 3rd voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
The 3rd treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out the 3rd integer is so that produce the 3rd group of reference signal, and wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Aforesaid TV tuner, wherein this lc-tank is the target signal filter outside first frequency band in this first intermediate-freuqncy signal, and this first frequency band is between 956MHz to 1362MHz.
Aforesaid TV tuner, wherein, this first image-reject mixer makes the carrier wave of a special channels be converted to 1575MHz according to this second group of reference signal with converting one second intermediate-freuqncy signal on this first intermediate-freuqncy signal into.
Therefore; The invention has the advantages that utilizing on one up and down three TV tuners that change to make only needs the very little voltage controlled oscillator of frequency adjustment range to accomplish in all local oscillators of the present invention; Therefore, can significantly simplify the design of TV tuner and being integrated in the one chip easily.Simultaneously, the frequency planning of the embodiment of the invention can be realized general (universal) TV tuner of full range band.
In order further to understand characteristic of the present invention and technology contents, see also followingly about detailed description of the present invention and accompanying drawing, but accompanying drawing only provides reference and explanation, can not be used for the present invention is limited.
Description of drawings
Fig. 1 is the single frequency inverted sketch map of commentaries on classics tuner down.
Fig. 2 is known two up and down commentaries on classics tuner sketch map.
Fig. 3 is known another two up and down commentaries on classics tuner sketch mapes.
Fig. 4 is the sketch map of first embodiment of three TV tuners that change up and down in the present invention.
Fig. 5 is the sketch map of second embodiment of three TV tuners that change up and down in the present invention.
And each description of reference numerals in the above-mentioned accompanying drawing is following:
402 antennas, 404 radio frequency low pass filters
406 low noise trsanscondutance amplifiers, 408 first frequency mixers
409 first intermediate-frequency filters, 410 second frequency mixers
411 first local oscillators, 412 second local oscillators
602 antennas, 604 radio frequencies select band filter
605 first variable gain amplifiers, 606 low pass filters
607 second variable gain amplifiers, 608 high pass filters
610 resonance frequencys suppress frequency mixer 611 first local oscillators
612 first voltage controlled oscillators, 614 first treatment circuits
616 lc-tank, 618 first image-reject mixers
622 second voltage controlled oscillators, 624 second treatment circuits
625 second local oscillators, 630 surface acoustic wave filters
642 the 3rd voltage controlled oscillators 644 the 3rd treatment circuit
645 the 3rd local oscillators, 646 second image-reject mixers
702 antennas
703 is single-ended to differential converter
704 radio frequencies select band filter 705 first variable gain amplifiers
706 low pass filters, 707 second variable gain amplifiers
708 high pass filters, 710 resonance frequencys suppress frequency mixer
711 first local oscillators, 712 first voltage controlled oscillators
714 first treatment circuits, 716 lc-tank
718 first image-reject mixers, 722 second voltage controlled oscillators
724 second treatment circuits, 725 second local oscillators
730 surface acoustic wave filters 742 the 3rd voltage controlled oscillator
744 the 3rd treatment circuits 745 the 3rd local oscillator
746 second image-reject mixers
Embodiment
Please with reference to Fig. 4, its in the present invention up and down three change the TV tuner of (Up-Up-Down Triple Conversion) the sketch map of first embodiment, carefully study following explanation carefully after, can recognize that the hardware that this novel structure brings implements advantage.By antenna 602 through radio television signal that cable received through one can adjust the filtering frequency range radio frequency select band filter (RF band selection filter) 604; Make first frequency band signals or second frequency band signals of radio television signal in can the initial option radio television signal, just radiofrequency signal through filtering.In this embodiment; Selecting band filter 604 to select this first frequency band signals with radio frequency is example; This first frequency band signals then can be imported a resonance frequency and suppress frequency mixer (Harmonic Rejection Mixer) 610, so that eliminate first group of higher order resonances frequency that reference signal caused.Resonance frequency inhibition frequency mixer changes into this first frequency band signals according to first group of reference signal for the first time be first intermediate-freuqncy signal, and this first intermediate-freuqncy signal is broadband intermediate-freuqncy signal (Broad Band IF).
In this embodiment, resonance frequency suppresses frequency mixer 610 and carries out a wide band conversion (Broad Band Conversion), so that with transferring first intermediate-freuqncy signal on this first frequency band signals or this second frequency band signals.As shown in Figure 4; Resonance frequency suppresses frequency mixer 610 and can receive three frequency is identical but first group of reference signal that phase place is different; And carry out mixing; Make this first frequency band signals or this second frequency band signals by on transfer this first intermediate-freuqncy signal to, its frequency range is between 956MHz～1362MHz.Moreover; First group of reference signal is by 611 generations of first local oscillator; This first local oscillator 611 comprises first voltage controlled oscillator 612 and first treatment circuit 614; Wherein, after first voltage controlled oscillator 612 produced the oscillator signal of frequency 3632MHz, oscillator signal being carried out the frequency elimination action of integer 4 and produced three frequencies by first treatment circuit 614 was 908MHz and phase place is respectively first group of reference signal of 0,45,90; In general, first treatment circuit 614 can be polyphase signa generator (multi-phase signal generator).Certainly, first group of reference signal is not limited to utilize above-mentioned 611 generations of first local oscillator, and those skilled in the art also can utilize different reference signal generation circuits to produce first group of reference signal of identical result.
In this embodiment, it is two frequency band signals that radio television signal selects band filter 604 to be formulated for through radio frequency, and for example first frequency band signals is that 48MHz～450MHz, second frequency band signals are 450MHz～860MHz.When the channel of want demodulation is positioned at first frequency band signals; Radio frequency select band filter 604 with radio television signal through first variable gain amplifier (Variable Gain Amplifier), 605 and one low pass filter 606 after, with the target signal filter more than first frequency band signals.At this moment; Resonance frequency suppresses the frequency mixer that frequency mixer 610 can be considered an addition; And convert first frequency band signals first intermediate-freuqncy signal of frequency range between 956MHz～1362MHz into according to first group of reference signal, at this moment, the carrier wave of special channels can be between 956MHz～1362MHz.Moreover, when the channel of want demodulation is positioned at second frequency band signals, radio frequency select band filter 604 with radio television signal through second variable gain amplifier 607 and a high pass filter 608 after with the target signal filter below second frequency band signals.At this moment; Resonance frequency suppresses the frequency mixer that frequency mixer 610 can be considered a subtraction; And convert second frequency band signals first intermediate-freuqncy signal of frequency range between 956MHz～1362MHz into according to first group of reference signal; Therefore, resonance frequency inhibition frequency mixer 610 all converts the radio television signal of different frequency range signal first intermediate-freuqncy signal of frequency range between 956MHz～1362MHz into.
Then, first intermediate-freuqncy signal is passed through a lc-tank (LC Tank) 616 once more with the target signal filter of frequency range outside 956MHz～1362MHz.Afterwards; Filtered first intermediate-freuqncy signal is input in first image-reject mixer 618; This first image-reject mixer 618 is gone up commentaries on classics with first intermediate-freuqncy signal after can receiving second group of reference signal for the second time, and produces second intermediate-freuqncy signal, makes the carrier wave of special channels convert 1575MHz into.
In this embodiment, second local oscillator 625 comprises second voltage controlled oscillator 622 and second treatment circuit 624.In order the carrier wave of special channels to be converted to 1575MHz; Utilize second voltage controlled oscillator 622 of adjustable frequency ranges between 5040MHz to 5880MHz; Carry out through second treatment circuit 624 can producing the second group reference signal of frequency range between 2520MHz to 2940MHz behind the frequency elimination of integer 2, preferably including two phase phasic differences is the orthogonal signalling of 90 degree.Because second local oscillator 625 can be adjusted the frequency of second group of reference signal of output,, can make the carrier wave of special channels in the intermediate-freuqncy signal of winning be converted to second intermediate-freuqncy signal of 1575MHz, and eliminate image frequency therefore through suitable choice.In general, second treatment circuit 624 can be orthogonal signalling generator (quadrature phase signal generator).Second intermediate-freuqncy signal is a surface acoustic wave filter (the Surface Acoustic Wave Filter of 1575MHz again through centre frequency; SAW Filter) 630 with the target signal filter outside the want frequency band; Therefore; Surface acoustic wave filter 630 outgoing carriers are the 3rd intermediate-freuqncy signal of 1575MHz, and it can comprise one or more channel signals, for example include the signal of three channels.Then, the 3rd intermediate-freuqncy signal is input in second image-reject mixer 646, and this second image-reject mixer 646 is converted into Low Medium Frequency signal, for example a 40MHz with the 3rd intermediate-freuqncy signal after can receiving the 3rd group of reference signal.
In this embodiment, the 3rd local oscillator 645 comprises the 3rd voltage controlled oscillator 642 and the 3rd treatment circuit 644.In order the carrier wave of special channels to be converted to Low Medium Frequency; Utilize three voltage controlled oscillator 642 of adjustable frequency ranges, and carry out through the 3rd treatment circuit 644 can producing the three group reference signal of two frequency ranges behind the frequency elimination of integer 2 between 1513MHz to 1637MHz and phase phasic difference 90 degree between 3026MHz to 3274MHz.In general, the 3rd treatment circuit 644 can be orthogonal signalling generator (quadrature phase signal generator).Because the 3rd local oscillator 645 can be adjusted the frequency of the 3rd group of reference signal of output,, can make that the carrier wave of special channels is converted to this Low Medium Frequency in the 3rd intermediate-freuqncy signal, and eliminate image frequency therefore through suitable choice.Therefore, Low Medium Frequency signal clean and high s/n ratio is exportable and offers late-class circuit and handle.Perhaps, the 3rd local oscillator 645 also can change the frequency of the 3rd group of reference signal, makes this second image-reject mixer 646 directly with going to fundamental frequency under the 3rd intermediate-freuqncy signal, and it is offered late-class circuit handles.
Single-ended (Single Ended) Signal Processing can't be eliminated the common-mode noise (Common Mode Noise) in the circuit.Second embodiment of the TV tuner of three commentaries on classics about Fig. 5 shows in the present invention.First through a single-ended radio television signal that radio television signal is converted into difference to differential converter (Single to Differential Converter) 703 by antenna 702 through the radio television signal that cable received.Afterwards; As stated, select band filter 704, resonance frequency to suppress frequency mixer 710, lc-tank 716, first image-reject mixer 718, surface acoustic wave filter 730 and second image-reject mixer, 746 backs through radio frequency in regular turn and produce Low Medium Frequency signal or fundamental frequency signals.
Single-ended among Fig. 5 can be balun (balun) to differential converter; Those skilled in the art also can be without the external balance imbalance converter directly design on semiconductor substrate to differential converter single-ended, single-ended to differential converter (On Chip Single to Differential Converter) on the just so-called chip.
The transmission of signal also can not be to be to utilize single-ended signal or differential signal all in the TV tuner of the present invention.For instance; After supposing filtered difference first intermediate-freuqncy signal to the first image-reject mixer 718 of lc-tank 716 outputs; First image-reject mixer 718 can produce the second single-ended intermediate-freuqncy signal, and is entered into surface acoustic wave filter 730, and surface acoustic wave filter 730 also can produce the 3rd intermediate-freuqncy signal of difference; And after it is inputed to second image-reject mixer 746, produce the Low Medium Frequency signal of difference or the fundamental frequency signal of difference.
Therefore; The invention has the advantages that utilizing on one up and down three TV tuners that change to make only needs the very little voltage controlled oscillator of frequency adjustment range to accomplish in all local oscillators of the present invention; Therefore, can significantly simplify the design of TV tuner and being integrated in the one chip easily.Simultaneously, the frequency planning of the embodiment of the invention can be realized general (universal) TV tuner of full range band.
In sum, though the present invention with preferred embodiment openly as above, they are not to be used for limiting of the present invention, and any those skilled in the art is not breaking away from the spirit and scope of the present invention, when doing various changes and modification.Therefore, protection scope of the present invention should be as the criterion with appending claims institute restricted portion.
Claims (20)
1. TV tuner comprises:
One radio frequency selects band filter; In order to receive a radiofrequency signal and this radiofrequency signal divided into first frequency band signals and second frequency band signals; Wherein this radiofrequency signal medium frequency less than 450MHz partly be first frequency band signals, this radiofrequency signal medium frequency partly is second frequency band signals greater than 450MHz's;
One first local oscillator produces one first group of reference signal of a fixed frequency;
One resonance frequency suppresses frequency mixer, perhaps converts this first frequency band signals into one first intermediate-freuqncy signal on this second frequency band signals according to this first group of reference signal;
One second local oscillator, one second group of reference signal of generation frequency adjustable;
One first image-reject mixer makes the carrier wave of a special channels be converted to a first frequency according to this second group of reference signal with converting one second intermediate-freuqncy signal on this first intermediate-freuqncy signal into;
One the 3rd local oscillator, one the 3rd group of reference signal of generation frequency adjustable; And
One second image-reject mixer makes and is converted to a second frequency under the carrier wave of this special channels converting a Low Medium Frequency signal under this second intermediate-freuqncy signal into according to the 3rd group of reference signal;
Wherein, this first frequency is greater than this second frequency.
2. TV tuner as claimed in claim 1, wherein this first local oscillator comprises:
One first voltage controlled oscillator produces the oscillator signal of a first frequency; And
One first treatment circuit, the frequency elimination that this oscillator signal is carried out one first integer moves so that produce this first group of reference signal, and wherein this first group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
3. TV tuner as claimed in claim 1, wherein this second local oscillator comprises:
One second voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One second treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one second integer is so that produce this second group of reference signal, and wherein this second group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
4. TV tuner as claimed in claim 1, wherein the 3rd local oscillator comprises:
One the 3rd voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One the 3rd treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one the 3rd integer is so that produce the 3rd group of reference signal, and wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
5. TV tuner comprises:
One radio frequency selects band filter; In order to receive a radiofrequency signal and this radiofrequency signal divided into first frequency band signals and second frequency band signals; Wherein this radiofrequency signal medium frequency less than 450MHz partly be first frequency band signals, this radiofrequency signal medium frequency partly is second frequency band signals greater than 450MHz's;
One first local oscillator produces one first group of reference signal of a fixed frequency;
One resonance frequency suppresses frequency mixer, perhaps converts this first frequency band signals into one first intermediate-freuqncy signal on this second frequency band signals according to this first group of reference signal;
One lc-tank is in order to the target signal filter outside first frequency band in this first intermediate-freuqncy signal;
One second local oscillator, one second group of reference signal of generation frequency adjustable;
One first image-reject mixer makes the carrier wave of a special channels be converted to a first frequency according to this second group of reference signal with converting one second intermediate-freuqncy signal on filtered this first intermediate-freuqncy signal;
One the 3rd local oscillator, one the 3rd group of reference signal of generation frequency adjustable; And
One second image-reject mixer makes the carrier wave of this special channels be converted to a second frequency according to the 3rd group of reference signal with converting a Low Medium Frequency signal under this second intermediate-freuqncy signal into;
Wherein, this first frequency is greater than this second frequency.
6. TV tuner as claimed in claim 5, wherein this first local oscillator comprises:
One first voltage controlled oscillator produces the oscillator signal of a first frequency; And
One first treatment circuit, the frequency elimination that this oscillator signal is carried out one first integer moves so that produce this first group of reference signal, and wherein this first group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
7. TV tuner as claimed in claim 5, wherein this second local oscillator comprises:
One second voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One second treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one second integer is so that produce this second group of reference signal, and wherein this second group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
8. TV tuner as claimed in claim 5, wherein the 3rd local oscillator comprises:
One the 3rd voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One the 3rd treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one the 3rd integer is so that produce the 3rd group of reference signal, and wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
9. TV tuner as claimed in claim 5, wherein this lc-tank is the target signal filter outside first frequency band in this first intermediate-freuqncy signal, and this first frequency band is between 956MHz to 1362MHz.
10. TV tuner comprises:
One radio frequency selects band filter; In order to receive a radiofrequency signal and this radiofrequency signal divided into first frequency band signals and second frequency band signals; Wherein this radiofrequency signal medium frequency less than 450MHz partly be first frequency band signals, this radiofrequency signal medium frequency partly is second frequency band signals greater than 450MHz's;
One first local oscillator produces one first group of reference signal of a fixed frequency;
One resonance frequency suppresses frequency mixer, perhaps converts this first frequency band signals into one first intermediate-freuqncy signal on this second frequency band signals according to this first group of reference signal;
One second local oscillator, one second group of reference signal of generation frequency adjustable;
One first image-reject mixer makes the carrier wave of a special channels be converted to a first frequency according to this second group of reference signal with converting one second intermediate-freuqncy signal on this first intermediate-freuqncy signal into;
One surface acoustic wave filter is in order to this second intermediate-freuqncy signal of filtering, thereby becomes the 3rd intermediate-freuqncy signal, makes that this special channels is present in the 3rd intermediate-freuqncy signal at least;
One the 3rd local oscillator, one the 3rd group of reference signal of generation frequency adjustable; And
One second image-reject mixer makes the carrier wave of this special channels be converted to a second frequency according to the 3rd group of reference signal with converting a Low Medium Frequency signal under the 3rd intermediate-freuqncy signal into;
Wherein, this first frequency is greater than this second frequency.
11. TV tuner as claimed in claim 10, wherein this first local oscillator comprises:
One first voltage controlled oscillator produces the oscillator signal of a first frequency; And
One first treatment circuit, the frequency elimination that this oscillator signal is carried out one first integer moves so that produce this first group of reference signal, and wherein this first group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
12. TV tuner as claimed in claim 10, wherein this second local oscillator comprises:
One second voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One second treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one second integer is so that produce this second group of reference signal, and wherein this second group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
13. TV tuner as claimed in claim 10, wherein the 3rd local oscillator comprises:
One the 3rd voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
One the 3rd treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out one the 3rd integer is so that produce the 3rd group of reference signal, and wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
14. TV tuner as claimed in claim 10, wherein, this first image-reject mixer makes the carrier wave of a special channels be converted to 1575MHz according to this second group of reference signal with converting one second intermediate-freuqncy signal on this first intermediate-freuqncy signal into.
15. a TV tuner comprises:
One radio frequency selects band filter; In order to receive a radiofrequency signal and this radiofrequency signal divided into first frequency band signals and second frequency band signals; Wherein this radiofrequency signal medium frequency less than 450MHz partly be first frequency band signals, this radiofrequency signal medium frequency partly is second frequency band signals greater than 450MHz's;
One first local oscillator produces one first group of reference signal of a fixed frequency;
One resonance frequency suppresses frequency mixer, perhaps converts this first frequency band signals into one first intermediate-freuqncy signal on this second frequency band signals according to this first group of reference signal;
One lc-tank is in order to the target signal filter outside first frequency band in this first intermediate-freuqncy signal;
One second local oscillator, one second group of reference signal of generation frequency adjustable;
One first image-reject mixer makes the carrier wave of a special channels be converted to a first frequency according to converting one second intermediate-freuqncy signal on this second group of reference signal this first intermediate-freuqncy signal after with the rate ripple;
One surface acoustic wave filter is in order to the signal beyond this special channels in this one second intermediate-freuqncy signal of filtering and become one the 3rd intermediate-freuqncy signal, makes this special channels be present in the 3rd intermediate-freuqncy signal;
One the 3rd local oscillator, one the 3rd group of reference signal of generation frequency adjustable; And
One second image-reject mixer makes the carrier wave of this special channels be converted to a CF according to the 3rd group of reference signal with converting a Low Medium Frequency signal under the 3rd intermediate-freuqncy signal into;
Wherein, this first frequency is greater than this second frequency.
16. TV tuner as claimed in claim 15, wherein this first local oscillator comprises:
First voltage controlled oscillator, the oscillator signal of generation first frequency; And
First treatment circuit carries out the frequency elimination action of first integer to this oscillator signal, so that produce this first group of reference signal, wherein this first group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
17. TV tuner as claimed in claim 15, wherein this second local oscillator comprises:
Second voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
Second treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out second integer is so that produce this second group of reference signal, and wherein this second group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
18. TV tuner as claimed in claim 15, wherein the 3rd local oscillator comprises:
The 3rd voltage controlled oscillator produces the oscillator signal of a frequency adjustable; And
The 3rd treatment circuit, the frequency elimination action that the oscillator signal of this frequency adjustable is carried out the 3rd integer is so that produce the 3rd group of reference signal, and wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
19. TV tuner as claimed in claim 15, wherein this lc-tank is the target signal filter outside first frequency band in this first intermediate-freuqncy signal, and this first frequency band is between 956MHz to 1362MHz.
20. TV tuner as claimed in claim 15, wherein, this first image-reject mixer makes the carrier wave of a special channels be converted to 1575MHz according to this second group of reference signal with converting one second intermediate-freuqncy signal on this first intermediate-freuqncy signal into.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86297806P | 2006-10-25 | 2006-10-25 | |
| US60/862,978 | 2006-10-25 | ||
| CNA2007101671696A CN101170656A (en) | 2006-10-25 | 2007-10-24 | Television tuner |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2007101671696A Division CN101170656A (en) | 2006-10-25 | 2007-10-24 | Television tuner |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102761719A true CN102761719A (en) | 2012-10-31 |
| CN102761719B CN102761719B (en) | 2016-01-20 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2007101671696A Pending CN101170656A (en) | 2006-10-25 | 2007-10-24 | Television tuner |
| CN201210132344.9A Active CN102761719B (en) | 2006-10-25 | 2007-10-24 | TV tuner |
| CNA2007101814242A Pending CN101170658A (en) | 2006-10-25 | 2007-10-25 | Television tuner |
| CN2007101814238A Active CN101170657B (en) | 2006-10-25 | 2007-10-25 | Television tuner |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
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| CNA2007101671696A Pending CN101170656A (en) | 2006-10-25 | 2007-10-24 | Television tuner |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2007101814242A Pending CN101170658A (en) | 2006-10-25 | 2007-10-25 | Television tuner |
| CN2007101814238A Active CN101170657B (en) | 2006-10-25 | 2007-10-25 | Television tuner |
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| Country | Link |
|---|---|
| CN (4) | CN101170656A (en) |
| TW (3) | TWI341688B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102196205A (en) * | 2010-03-15 | 2011-09-21 | 华硕电脑股份有限公司 | Differential antenna and circuit control system of digital television |
| CN102305934A (en) * | 2011-05-13 | 2012-01-04 | 陕西长岭电子科技有限责任公司 | Dual-channel radio-frequency signal processing module for navigation receiver |
| TWI499302B (en) * | 2011-06-27 | 2015-09-01 | Aten Int Co Ltd | Signal transmitting apparatus and transmitter and receiver thereof |
| CN103427866A (en) * | 2012-05-18 | 2013-12-04 | 晨星软件研发(深圳)有限公司 | Oscillation signal provider, in-phase and orthogonal oscillation signal provider and signal processing method |
| TWI610566B (en) | 2016-07-22 | 2018-01-01 | 晨星半導體股份有限公司 | Audio/video signal processing circuit and associated signal processing method |
| CN107770469A (en) * | 2016-08-15 | 2018-03-06 | 晨星半导体股份有限公司 | The TV signal processing method of television video signal processing circuit and correlation |
| WO2019173955A1 (en) * | 2018-03-12 | 2019-09-19 | 华为技术有限公司 | Full-band receiver and television tuner |
| CN115833859B (en) * | 2023-02-20 | 2023-05-02 | 深圳市鼎阳科技股份有限公司 | Differential mixing circuit, spectrum analyzer, differential mixing method and medium |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| DE19805963C2 (en) * | 1998-02-13 | 2001-02-22 | Siemens Ag | Integrated circuit for frequency processing of a radio transceiver working in the UHF range, in particular a cordless telephone |
| JP2006101164A (en) * | 2004-09-29 | 2006-04-13 | Matsushita Electric Ind Co Ltd | Automatic frequency control system |
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2007
- 2007-10-16 TW TW096138692A patent/TWI341688B/en active
- 2007-10-19 TW TW096139257A patent/TWI373970B/en not_active IP Right Cessation
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| TWI341688B (en) | 2011-05-01 |
| CN102761719B (en) | 2016-01-20 |
| TWI373969B (en) | 2012-10-01 |
| TWI373970B (en) | 2012-10-01 |
| TW200820765A (en) | 2008-05-01 |
| CN101170657A (en) | 2008-04-30 |
| CN101170656A (en) | 2008-04-30 |
| CN101170658A (en) | 2008-04-30 |
| TW200820764A (en) | 2008-05-01 |
| CN101170657B (en) | 2013-06-12 |
| TW200820763A (en) | 2008-05-01 |
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Effective date of registration: 20191220 Address after: No.1, Duhang 1st Road, Hsinchu City, Hsinchu Science Park, Taiwan, China Patentee after: MediaTek.Inc Address before: Hsinchu County, Taiwan, China Patentee before: MStar Semiconductor Co., Ltd. |
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