CN101170656A - Television tuner - Google Patents
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- CN101170656A CN101170656A CNA2007101671696A CN200710167169A CN101170656A CN 101170656 A CN101170656 A CN 101170656A CN A2007101671696 A CNA2007101671696 A CN A2007101671696A CN 200710167169 A CN200710167169 A CN 200710167169A CN 101170656 A CN101170656 A CN 101170656A
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Abstract
A television tuner employs a triple-conversion architecture to translate VHF/UHF TV signals to various standard IF frequencies. The television tuner includes a harmonic rejection mixer, a first image rejection mixer and a second image rejection mixer. The television tuner receives a television signal. The harmonic rejection mixer up-converts the television signal into a first IF signal according to a first reference signal with a fixed frequency. The first image rejection mixer further up-converts the first IF signal into a second IF signal according to a second reference signal with a tunable frequency. The second image rejection mixer down-converts the second IF signal into a third IF signal according to a third reference signal with a tunable frequency.
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, very high frequency(VHF) (Very High Frequency, be called for short VHF) with the frequency spectrum (Spectrum) of the hyperfrequency radio frequency of (Ultra highFrequency is called for short UHF) (Radio Frequency is called for short RF) TV signal 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 CarrierFrequency), frequency apart from the high 3.58MHz of video carrier frequency is color carrier frequency (ColorCarrier 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 by 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 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 refer to Fig. 1, it is the single frequency inverted schematic diagram of commentaries on classics tuner down.Comprise a plurality of channels in the radio television signal (I), be multiplied by a reference frequency (f by 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 (HarmonicFrequency) in the reference signal, for example 3f
LO, 5f
LO, 7f
LOOr the like resonance frequency.Therefore, as shown in the figure in the radio television signal carrier wave be 3 times of reference frequency (3f
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 (SNRdegradation) 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 (RFtracking filter) before radio television signal enters 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 tuner of changeing (Up-Down DualConversion) that are integrated in single substrate.
Please refer to Fig. 2, it is known two up and down commentaries on classics tuner schematic diagram.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 (CutoffFrequency) 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 the output signal of low noise trsanscondutance amplifier (LNTA) 406 and this first reference signal and export first intermediate-freuqncy signal, and making the carrier frequency of specific channel in the intermediate-freuqncy signal of winning (Desired Channel) is 1200MHz.That is to say, utilize the frequency of adjusting first reference signal, the carrier wave of specific channel can be converted to 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 specific channel of 20MHz.That is to say that the carrier wave of this specific channel is converted to 20MHz by second frequency mixer (MIX2) 410.First frequency mixer (MIX1) 408 of known two up and down commentaries on classics tuners will go to 1200MHz on the carrier frequency of this specific channel, and second frequency mixer (MIX2) 410 will go to 20MHz under the carrier frequency of this specific channel.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 ControlledOscillator VCO) just can realize.
Please refer to Fig. 3, it is known another two up and down commentaries on classics tuner schematic diagrames.For the mirror image (Image) that prevents the 1160MHz frequency, first intermediate-frequency filter (First IF Filter) 409 is connected between first frequency mixer (MIX1) 408 and second frequency mixer (MIX2) 410, removes in order to the frequency content with the 1160MHz in first intermediate-freuqncy signal.
As shown in the above, 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, comprising: a radio frequency selects band filter, produces filtered radiofrequency signal in order to received RF signal to filter; First local oscillator can produce first group of reference signal of a fixed frequency; One resonance frequency suppresses frequency mixer, can filtered radiofrequency signal be converted to first intermediate-freuqncy signal according to this first group of reference signal; Second local oscillator can produce second group of reference signal of frequency adjustable; First image-reject mixer can be according to this this first intermediate-freuqncy signal of second group of reference signal mixing, and produces second intermediate-freuqncy signal, makes the carrier wave of a specific channel be converted to first frequency; The 3rd local oscillator can produce the 3rd group of reference signal of frequency adjustable; And second image-reject mixer can be according to the 3rd group of this second intermediate-freuqncy signal of reference signal mixing, and produce a Low Medium Frequency signal, makes the carrier wave of this specific channel be converted to second frequency; Wherein, this first frequency is greater than this second frequency.
Aforesaid TV tuner, wherein this first local oscillator comprises:
First voltage controlled oscillator can produce the oscillator signal of first frequency; And
First treatment circuit can carry out the frequency elimination action of first integer so that produce this first group of reference signal to this oscillator signal.
Aforesaid TV tuner, 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 can produce the oscillator signal of a frequency adjustable; And
Second treatment circuit, the frequency elimination action that can carry out second integer to the oscillator signal of this frequency adjustable is so that produce this second group of reference signal.
Aforesaid TV tuner, 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 can produce the oscillator signal of a frequency adjustable; And
The 3rd treatment circuit, the frequency elimination action that can carry out the 3rd integer to the oscillator signal of this frequency adjustable is so that produce the 3rd group of reference signal.
Aforesaid TV tuner, 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, comprising: a radio frequency selects band filter, in order to received RF signal filter to produce after filtration a radiofrequency signal; First local oscillator can produce first group of reference signal of a fixed frequency; One resonance frequency suppresses frequency mixer, can filtered radiofrequency signal be converted to first intermediate-freuqncy signal according to this first group of reference signal; One inductor-capacitor-tank is in order to the target signal filter outside first frequency band in this first intermediate-freuqncy signal; Second local oscillator can produce second group of reference signal of frequency adjustable; First image-reject mixer can be according to this first intermediate-freuqncy signal behind this second group of reference signal mixing and filtering, and produces second intermediate-freuqncy signal, makes the carrier wave of a specific channel be converted to first frequency; The 3rd local oscillator can produce the 3rd group of reference signal of frequency adjustable; And second image-reject mixer can be according to the 3rd group of this second intermediate-freuqncy signal of reference signal mixing, and produce a Low Medium Frequency signal, makes the carrier wave of this specific channel be converted to second frequency; Wherein, this first frequency is greater than this second frequency.
Aforesaid TV tuner, wherein this first local oscillator comprises:
First voltage controlled oscillator can produce the oscillator signal of first frequency; And
First treatment circuit can carry out the frequency elimination action of first integer so that produce this first group of reference signal to this oscillator signal.
Aforesaid TV tuner, 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 can produce the oscillator signal of a frequency adjustable; And
Second treatment circuit, the frequency elimination action that can carry out second integer to the oscillator signal of this frequency adjustable is so that produce this second group of reference signal.
Aforesaid TV tuner, 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 can produce the oscillator signal of a frequency adjustable; And
The 3rd treatment circuit, the frequency elimination action that can carry out the 3rd integer to the oscillator signal of this frequency adjustable is so that produce the 3rd group of reference signal.
Aforesaid TV tuner, 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, comprising: a radio frequency selects band filter, in order to received RF signal filter to produce after filtration a radiofrequency signal; First local oscillator can produce first group of reference signal of a fixed frequency; One resonance frequency suppresses frequency mixer, can filtered radiofrequency signal be converted to first intermediate-freuqncy signal according to this first group of reference signal; Second local oscillator can produce second group of reference signal of frequency adjustable; First image-reject mixer can be according to this this first intermediate-freuqncy signal of second group of reference signal mixing, and produces second intermediate-freuqncy signal, makes the carrier wave of a specific channel be converted to first frequency; One surface acoustic wave filter becomes the 3rd intermediate-freuqncy signal in order to this second intermediate-freuqncy signal of filtering, makes that this specific channel is present in the 3rd intermediate-freuqncy signal at least; The 3rd local oscillator can produce the 3rd group of reference signal of frequency adjustable; And second image-reject mixer can be according to the 3rd group of reference signal mixing the 3rd intermediate-freuqncy signal, and produce a Low Medium Frequency signal, makes the carrier wave of this specific channel be converted to second frequency; Wherein, this first frequency is greater than this second frequency.
Aforesaid TV tuner, wherein this first local oscillator comprises:
First voltage controlled oscillator can produce the oscillator signal of first frequency; And
First treatment circuit can carry out the frequency elimination action of first integer so that produce this first group of reference signal to this oscillator signal.
Aforesaid TV tuner, 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 can produce the oscillator signal of a frequency adjustable; And
Second treatment circuit, the frequency elimination action that can carry out second integer to the oscillator signal of this frequency adjustable is so that produce this second group of reference signal.
Aforesaid TV tuner, 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 can produce the oscillator signal of a frequency adjustable; And
The 3rd treatment circuit, the frequency elimination action that can carry out the 3rd integer to the oscillator signal of this frequency adjustable is so that produce the 3rd group of reference signal.
Aforesaid TV tuner, 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, comprising: a radio frequency selects band filter, in order to received RF signal filter to produce after filtration a radiofrequency signal; First local oscillator can produce first group of reference signal of a fixed frequency; One resonance frequency suppresses frequency mixer, can filtered radiofrequency signal be converted to first intermediate-freuqncy signal according to this first group of reference signal; One inductor-capacitor-tank is in order to the target signal filter outside first frequency band in this first intermediate-freuqncy signal; Second local oscillator can produce second group of reference signal of frequency adjustable; First image-reject mixer can be according to this first intermediate-freuqncy signal behind this second group of reference signal mixing and filtering, and produces second intermediate-freuqncy signal, makes the carrier wave of a specific channel be converted to first frequency; One surface acoustic wave filter becomes the 3rd intermediate-freuqncy signal in order to this second intermediate-freuqncy signal of filtering, makes that this specific channel is present in the 3rd intermediate-freuqncy signal at least; The 3rd local oscillator can produce the 3rd group of reference signal of frequency adjustable; And second image-reject mixer can be according to the 3rd group of reference signal mixing the 3rd intermediate-freuqncy signal, and produce a Low Medium Frequency signal, makes the carrier wave of this specific channel be converted to second frequency; Wherein, this first frequency is greater than this second frequency.
Aforesaid TV tuner, wherein this first local oscillator comprises:
First voltage controlled oscillator can produce the oscillator signal of first frequency; And
First treatment circuit can carry out the frequency elimination action of first integer so that produce this first group of reference signal to this oscillator signal.
Aforesaid TV tuner, 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 can produce the oscillator signal of a frequency adjustable; And
Second treatment circuit, the frequency elimination action that can carry out second integer to the oscillator signal of this frequency adjustable is so that produce this second group of reference signal.
Aforesaid TV tuner, 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 can produce the oscillator signal of a frequency adjustable; And
The 3rd treatment circuit, the frequency elimination action that can carry out the 3rd integer to the oscillator signal of this frequency adjustable is so that produce the 3rd group of reference signal.
Aforesaid TV tuner, wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Therefore, the invention has the advantages that utilizing on one up and down three TV tuner of changeing to make only needs the very little voltage controlled oscillator of frequency adjustment range to finish 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 feature of the present invention and technology contents, see also following about detailed description of the present invention and accompanying drawing, but accompanying drawing only provide with reference to and explanation, can not be used for the present invention is limited.
Description of drawings
Fig. 1 is the single frequency inverted schematic diagram of commentaries on classics tuner down.
Fig. 2 is known two up and down commentaries on classics tuner schematic diagram.
Fig. 3 is known another two up and down commentaries on classics tuner schematic diagrames.
Fig. 4 is the schematic diagram of first embodiment of three TV tuner of changeing up and down in the present invention.
Fig. 5 is the schematic diagram of second embodiment of three TV tuner of changeing up and down in the present invention.And each description of reference numerals in the above-mentioned accompanying drawing is as follows:
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 inductor-capacitor-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 all vibration frequency suppress frequency mixer
711 first local oscillators, 712 first voltage controlled oscillators
714 first treatment circuits, 716 inductor-capacitor-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 refer to Fig. 4, it is for three changeing the schematic diagram of first embodiment of the TV tuner of (Up-Up-Down Triple Conversion) up and down in the present invention, carefully study following explanation carefully after, can recognize that the hardware that this novel structure brings implements advantage.Select band filter (RF band selection filter) 604 by the radio television signal that cable received through the radio frequency that can adjust the filtering frequency range by antenna 602, make first frequency band signals or second frequency band signals of radio television signal in can the initial option radio television signal, just filtered radiofrequency signal.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 BandIF).
In this embodiment, resonance frequency suppresses frequency mixer 610 and carries out a wide band conversion (BroadBand Conversion), so that will transfer 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 produced by first local oscillator 611, this first local oscillator 611 comprises first voltage controlled oscillator 612 and first treatment circuit 614, wherein, after first voltage controlled oscillator 612 produces 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 is 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 the first above-mentioned local oscillator 611 to produce, 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 by 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 first frequency band signals is converted to first intermediate-freuqncy signal of frequency range between 956MHz～1362MHz according to first group of reference signal, at this moment, the carrier wave of specific channel 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 second frequency band signals is converted to first intermediate-freuqncy signal of frequency range between 956MHz～1362MHz according to first group of reference signal, therefore, resonance frequency inhibition frequency mixer 610 all is converted to first intermediate-freuqncy signal of frequency range between 956MHz～1362MHz with the radio television signal of different frequency range signal.
Then, first intermediate-freuqncy signal is passed through an inductor-capacitor-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 for the second time with first intermediate-freuqncy signal after can receiving second group of reference signal, and produces second intermediate-freuqncy signal, makes the carrier wave of specific channel be converted to 1575MHz.
In this embodiment, second local oscillator 625 comprises second voltage controlled oscillator 622 and second treatment circuit 624.For the carrier wave of specific channel being converted to 1575MHz, utilize second voltage controlled oscillator 622 of adjustable frequency ranges between 5040MHz to 5880MHz, undertaken by 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 specific channel in the intermediate-freuqncy signal of winning be converted to second intermediate-freuqncy signal of 1575MHz, and eliminate image frequency therefore by suitable selection.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 by 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, it can comprise one or more channel signals, for example includes 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.For the carrier wave of specific channel being converted to Low Medium Frequency, utilize three voltage controlled oscillator 642 of adjustable frequency ranges, and undertaken by 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, therefore by suitable selection, can make that the carrier wave of specific channel is converted to this Low Medium Frequency in the 3rd intermediate-freuqncy signal, and the elimination image frequency.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 will go to fundamental frequency under the 3rd intermediate-freuqncy signal, and provides it to late-class circuit and handle.
Single-ended (Single Ended) Signal Processing can't be eliminated the common-mode noise (CommonMode Noise) in the circuit.Second embodiment of three TV tuner of changeing about Fig. 5 shows in the present invention.First through a single-ended radio television signal that radio television signal is converted to difference to differential converter (Singleto Differential Converter) 703 by antenna 702 by the radio television signal that cable received.Afterwards, as mentioned above, select band filter 704, resonance frequency to suppress frequency mixer 710, inductor-capacitor-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 signal.
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 Singleto 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 inductor-capacitor-tank 716 outputs, first image-reject mixer 718 can produce the second single-ended intermediate-freuqncy signal, and be 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 tuner of changeing to make only needs the very little voltage controlled oscillator of frequency adjustment range to finish 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 be not be used for limiting of the present invention, any those skilled in the art, without departing 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 (28)
1. TV tuner comprises:
One radio frequency selects band filter, in order to receive a radiofrequency signal to filter generation one radiofrequency signal after filtration;
First local oscillator can produce first group of reference signal of a fixed frequency;
One resonance frequency suppresses frequency mixer, can should filtered radiofrequency signal be converted to first intermediate-freuqncy signal according to this first group of reference signal;
Second local oscillator can produce second group of reference signal of a frequency adjustable;
First image-reject mixer can be according to this this first intermediate-freuqncy signal of second group of reference signal mixing, and produces second intermediate-freuqncy signal, makes the carrier wave of a specific channel be converted to first frequency;
The 3rd local oscillator can produce the 3rd group of reference signal of a frequency adjustable; And
Second image-reject mixer can be according to the 3rd group of this second intermediate-freuqncy signal of reference signal mixing, and produce a Low Medium Frequency signal, makes the carrier wave of this specific channel be converted to second frequency;
Wherein, this first frequency is greater than this second frequency.
2. TV tuner as claimed in claim 1, wherein this first local oscillator comprises:
First voltage controlled oscillator can produce the oscillator signal of first frequency; And
First treatment circuit can carry out the frequency elimination action of first integer so that produce this first group of reference signal to this oscillator signal.
3. TV tuner as claimed in claim 1, wherein this first 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 this second local oscillator comprises:
Second voltage controlled oscillator can produce the oscillator signal of a frequency adjustable; And
Second treatment circuit, the frequency elimination action that can carry out second integer to the oscillator signal of this frequency adjustable is so that produce this second group of reference signal.
5. TV tuner as claimed in claim 1, wherein this second group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
6. TV tuner as claimed in claim 1, wherein the 3rd local oscillator comprises:
The 3rd voltage controlled oscillator can produce the oscillator signal of a frequency adjustable; And
The 3rd treatment circuit, the frequency elimination action that can carry out the 3rd integer to the oscillator signal of this frequency adjustable is so that produce the 3rd group of reference signal.
7. TV tuner as claimed in claim 1, wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
8. TV tuner comprises:
Radio frequency selects band filter, in order to receive a radiofrequency signal to filter generation one radiofrequency signal after filtration;
First local oscillator can produce first group of reference signal of a fixed frequency;
Resonance frequency suppresses frequency mixer, can should filtered radiofrequency signal be converted to first intermediate-freuqncy signal according to this first group of reference signal;
Inductor-capacitor-tank is in order to the target signal filter outside first frequency band in this first intermediate-freuqncy signal;
Second local oscillator can produce second group of reference signal of frequency adjustable;
First image-reject mixer can be according to this first intermediate-freuqncy signal behind this second group of reference signal mixing and filtering, and produces second intermediate-freuqncy signal, makes the carrier wave of a specific channel be converted to first frequency;
The 3rd local oscillator can produce the 3rd group of reference signal of frequency adjustable; And
Second image-reject mixer can be according to the 3rd group of this second intermediate-freuqncy signal of reference signal mixing, and produce a Low Medium Frequency signal, makes the carrier wave of this specific channel be converted to second frequency;
Wherein, this first frequency is greater than this second frequency.
9. TV tuner as claimed in claim 8, wherein this first local oscillator comprises:
First voltage controlled oscillator can produce the oscillator signal of first frequency; And
First treatment circuit can carry out the frequency elimination action of first integer to this oscillator signal, so that produce this first group of reference signal.
10. TV tuner as claimed in claim 8, wherein this first group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
11. TV tuner as claimed in claim 8, wherein this second local oscillator comprises:
Second voltage controlled oscillator can produce the oscillator signal of a frequency adjustable; And
Second treatment circuit, the frequency elimination action that can carry out second integer to the oscillator signal of this frequency adjustable is so that produce this second group of reference signal.
12. TV tuner as claimed in claim 8, 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 8, wherein the 3rd local oscillator comprises:
The 3rd voltage controlled oscillator can produce the oscillator signal of a frequency adjustable; And
The 3rd treatment circuit, the frequency elimination action that can carry out the 3rd integer to the oscillator signal of this frequency adjustable is so that produce the 3rd group of reference signal.
14. TV tuner as claimed in claim 8, wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
15. a TV tuner comprises:
One radio frequency selects band filter, in order to receive a radiofrequency signal to filter generation one radiofrequency signal after filtration;
First local oscillator can produce first group of reference signal of a fixed frequency;
Resonance frequency suppresses frequency mixer, can should filtered radiofrequency signal be converted to first intermediate-freuqncy signal according to this first group of reference signal;
Second local oscillator can produce second group of reference signal of frequency adjustable;
First image-reject mixer can be according to this this first intermediate-freuqncy signal of second group of reference signal mixing, and produces second intermediate-freuqncy signal, makes the carrier wave of a specific channel be converted to first frequency;
One surface acoustic wave filter in order to this second intermediate-freuqncy signal of filtering, thereby becomes the 3rd intermediate-freuqncy signal, makes that this specific channel is present in the 3rd intermediate-freuqncy signal at least;
The 3rd local oscillator can produce the 3rd group of reference signal of frequency adjustable; And
Second image-reject mixer can be according to the 3rd group of reference signal mixing the 3rd intermediate-freuqncy signal, and produce a Low Medium Frequency signal, makes the carrier wave of this specific channel be converted to second frequency;
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 can produce the oscillator signal of first frequency; And
First treatment circuit can carry out the frequency elimination action of first integer so that produce this first group of reference signal to this oscillator signal.
17. TV tuner as claimed in claim 15, wherein this first 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 this second local oscillator comprises:
Second voltage controlled oscillator can produce the oscillator signal of a frequency adjustable; And
Second treatment circuit, the frequency elimination action that can carry out second integer to the oscillator signal of this frequency adjustable is so that produce this second group of reference signal.
19. TV tuner as claimed in claim 15, wherein this second group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
20. TV tuner as claimed in claim 15, wherein the 3rd local oscillator comprises:
The 3rd voltage controlled oscillator can produce the oscillator signal of a frequency adjustable; And
The 3rd treatment circuit, the frequency elimination action that can carry out the 3rd integer to the oscillator signal of this frequency adjustable is so that produce the 3rd group of reference signal.
21. TV tuner as claimed in claim 15, wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
22. a TV tuner comprises:
One radio frequency selects band filter, in order to receive a radiofrequency signal to filter generation one radiofrequency signal after filtration;
First local oscillator can produce first group of reference signal of a fixed frequency;
One resonance frequency suppresses frequency mixer, can should filtered radiofrequency signal be converted to first intermediate-freuqncy signal according to this first group of reference signal;
One inductor-capacitor-tank is in order to the target signal filter outside first frequency band in this first intermediate-freuqncy signal;
Second local oscillator can produce second group of reference signal of frequency adjustable;
First image-reject mixer can be according to this first intermediate-freuqncy signal behind this second group of reference signal mixing and filtering, and produces second intermediate-freuqncy signal, makes the carrier wave of a specific channel be converted to first frequency;
One surface acoustic wave filter in order to this second intermediate-freuqncy signal of filtering, thereby becomes the 3rd intermediate-freuqncy signal, makes that this specific channel is present in the 3rd intermediate-freuqncy signal at least;
The 3rd local oscillator can produce the 3rd group of reference signal of frequency adjustable; And
Second image-reject mixer can be according to the 3rd group of reference signal mixing the 3rd intermediate-freuqncy signal, and produce a Low Medium Frequency signal, makes the carrier wave of this specific channel be converted to second frequency;
Wherein, this first frequency is greater than this second frequency.
23. TV tuner as claimed in claim 22, wherein this first local oscillator comprises:
First voltage controlled oscillator can produce the oscillator signal of first frequency; And
First treatment circuit can carry out the frequency elimination action of first integer to this oscillator signal, so that produce this first group of reference signal.
24. TV tuner as claimed in claim 22, wherein this first group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
25. TV tuner as claimed in claim 22, wherein this second local oscillator comprises:
Second voltage controlled oscillator can produce the oscillator signal of a frequency adjustable; And
Second treatment circuit, the frequency elimination action that can carry out second integer to the oscillator signal of this frequency adjustable is so that produce this second group of reference signal.
26. TV tuner as claimed in claim 22, wherein this second group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
27. TV tuner as claimed in claim 22, wherein the 3rd local oscillator comprises:
The 3rd voltage controlled oscillator can produce the oscillator signal of a frequency adjustable; And
The 3rd treatment circuit, the frequency elimination action that can carry out the 3rd integer to the oscillator signal of this frequency adjustable is so that produce the 3rd group of reference signal.
28. TV tuner as claimed in claim 22, wherein the 3rd group of reference signal comprises a plurality of reference signals with same frequency and out of phase.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210132344.9A CN102761719B (en) | 2006-10-25 | 2007-10-24 | TV tuner |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86297806P | 2006-10-25 | 2006-10-25 | |
| US60/862,978 | 2006-10-25 |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210132344.9A Division CN102761719B (en) | 2006-10-25 | 2007-10-24 | TV tuner |
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| Publication Number | Publication Date |
|---|---|
| CN101170656A true CN101170656A (en) | 2008-04-30 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201210132344.9A Active CN102761719B (en) | 2006-10-25 | 2007-10-24 | TV tuner |
| CNA2007101671696A Pending CN101170656A (en) | 2006-10-25 | 2007-10-24 | Television tuner |
| CN2007101814238A Active CN101170657B (en) | 2006-10-25 | 2007-10-25 | Television tuner |
| CNA2007101814242A Pending CN101170658A (en) | 2006-10-25 | 2007-10-25 | Television tuner |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201210132344.9A Active CN102761719B (en) | 2006-10-25 | 2007-10-24 | TV tuner |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2007101814238A Active CN101170657B (en) | 2006-10-25 | 2007-10-25 | Television tuner |
| CNA2007101814242A Pending CN101170658A (en) | 2006-10-25 | 2007-10-25 | Television tuner |
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| Country | Link |
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| CN (4) | CN102761719B (en) |
| TW (3) | TWI341688B (en) |
Cited By (4)
| 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 |
| 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 |
| CN115833859A (en) * | 2023-02-20 | 2023-03-21 | 深圳市鼎阳科技股份有限公司 | Differential mixing circuit, spectrum analyzer, differential mixing method and medium |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
-
2007
- 2007-10-16 TW TW096138692A patent/TWI341688B/en active
- 2007-10-19 TW TW096139257A patent/TWI373970B/en not_active IP Right Cessation
- 2007-10-19 TW TW096139254A patent/TWI373969B/en active
- 2007-10-24 CN CN201210132344.9A patent/CN102761719B/en active Active
- 2007-10-24 CN CNA2007101671696A patent/CN101170656A/en active Pending
- 2007-10-25 CN CN2007101814238A patent/CN101170657B/en active Active
- 2007-10-25 CN CNA2007101814242A patent/CN101170658A/en active Pending
Cited By (6)
| 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 |
| 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 |
| CN111903119A (en) * | 2018-03-12 | 2020-11-06 | 华为技术有限公司 | Full-band receiver and television tuner |
| CN111903119B (en) * | 2018-03-12 | 2022-05-24 | 华为技术有限公司 | Full-band receiver and television tuner |
| CN115833859A (en) * | 2023-02-20 | 2023-03-21 | 深圳市鼎阳科技股份有限公司 | Differential mixing circuit, spectrum analyzer, differential mixing method and medium |
Also Published As
| Publication number | Publication date |
|---|---|
| TWI341688B (en) | 2011-05-01 |
| TW200820764A (en) | 2008-05-01 |
| TWI373969B (en) | 2012-10-01 |
| TW200820763A (en) | 2008-05-01 |
| CN101170658A (en) | 2008-04-30 |
| CN101170657B (en) | 2013-06-12 |
| TWI373970B (en) | 2012-10-01 |
| CN102761719A (en) | 2012-10-31 |
| CN102761719B (en) | 2016-01-20 |
| TW200820765A (en) | 2008-05-01 |
| CN101170657A (en) | 2008-04-30 |
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Application publication date: 20080430 |