Abstract:
A multi-band VOC includes a plurality of oscillators, each oscillators having an oscillatory range respectively; a plurality of capacitor tanks is provided in each oscillators, and each capacitors is composed of a plurality of capacitors in series connection; a voltage detecting device is provided to detect a voltage signal, and to select an oscillator; one end of a logic controller is provided to electrically connect to the voltage detecting device, and another end is provided to electrically connect to the capacitor tank, which is provided a control signal to drive capacitance of the capacitor tank; and a multiple device is provided to output an oscillation frequency.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is related to a tuner, and more particularly, is a tunable multi-bands voltage-controlled oscillator (VCO) and a tuner formed thereof. 
         [0003]    2. Description of the Prior Art 
         [0004]    Because the improvement of the communicative and the depressive technique, the global television broadcast system is switched from analog to digital. The change of the digital TV broadcast will trigger the high development of the relative industry, such as Set-Top-Box (STB) or high definition television (HDTV). In future, the digital TV broadcast will go mobile and the TV shows will be available at anytime and anywhere. Therefore, the tuner circuit in the STB and HDTV is a key issue in the industry. 
         [0005]      FIG. 1A  is a view of a conventional tuner included single conversion with intermediate frequency (IF). As shown in  FIG. 1A , the tuner  100  includes a filter  101 , a low noise amplifier  102  (LNA), a mixer  106 , a local oscillator  110  and a filter  112 . The filter  101  and the filter  112  are SAW filter. The radio frequency (RF) (such as frequency within 50˜860 MHz) received by the antenna (not shown) of the tuner  100  is transmitted from the filter  101  to the LNA  102  to be amplified. Then, the mixer  106  and the local oscillator  110  are used to decrease the amplified radio frequency to be the frequency within the intermediate frequency range, such as 36 MHz. The filter  112  is used to select the suitable channel. 
         [0006]      FIG. 1B  is a view of a conventional tuner included dual conversion with IF. As shown in  FIG. 1B , the tuner  100  includes a low noise amplifier  102  (LNA), an IF/RF mixer  106   a,  a band-pass filter  104 , an IF/IF mixer  106   b,  and a filter  112 . One end of the low noise amplifier  102  is connected the antenna and the low noise amplifier  102  amplifiers the radio frequency. Then, the mixer  106   a  and the local oscillator  110 A are used to increase the amplified radio frequency to be the frequency within the intermediate frequency range, such as 1 GHz. One end of the mixer  106   a  is connected to the output end of the low noise amplifier. The local oscillator  110 A is connected to another end of the mixer  106   a  and used to provide a frequency of the local oscillator, such as 1 GHz˜2 GHz. Then, the input end of the band-pass filer  104  is connected to the output end of the mixer  106   a  and used to filer the noise and output the intermediate frequency from another end. The mixer  106   b  and the local oscillator  110 B are used to decrease the first intermediate frequency to be the second intermediate frequency. The filter  112  is used to select the suitable channel. Moreover, the filter  112  can be a channel select filter used to select a desired channel and filter other unwanted channels. Obviously, the tuner with the dual conversion with IF is able to filter the mirror signals without using a lot of filters. 
         [0007]      FIG. 1C  is a view of a conventional tuner including dual conversion with low IF. As shown in  FIG. 1C , the radio frequency is transmitted into the low noise amplifier  102  to be amplified and divided into I Path and Q Path by a RF poly-phase filter. Then the frequency is transmitted into the complex mixer (also called dual quadrature mixer). The complex mixer  114  is made by a plurality of mixers  106 . The quadrature local oscillator  111  will transmit the oscillated frequency to the complex mixer  114  to be mixed into I Path and Q Path quadrature low IF. The quadrature local oscillator  111  is generated by the local oscillator  111  and a divider  110  (such as divided by 2). Another IF poly-phase filter  113  will transform the I Path and Q Path low IF quadrature signal to be the I Path and Q Path low IF signal to decrease the frequency and filter the mirror frequency. At final, the channel select filter is used to select the desired channel and filter other unwanted channels. Therefore, the function of the tuner is completed. 
         [0008]      FIG. 1D  is a view of a conventional tuner including dual conversion with low IF. As shown in  FIG. 1D , the radio frequency is transmitted into the low noise amplifier  102  to be amplified, and increased the frequency to be IF and mixed into in-phase frequency  1  (IIF 1 ) and quadrature phase by a first quadrature mixer  120  and a first quadrature LO  117 . Then the frequency is mixed into quadrature low IF of the IIF 1  and the QIF 1  by the complex mixer  122  and the second quadrature LO  119 . The IF poly-phase filter  118  is used to transform the quadrature low IF signals of the IIF 1  and the QIF 1  into low IF signals to decrease the frequency and filter the mirror frequency. The channel select filter  116  is used to select the desired channel and filter other unwanted channels. Therefore, the function of the tuner is completed. 
         [0009]    Besides, in a tuner, the voltage-controlled oscillator is an important device, because it is a local oscillator used to form the up conversion or down conversion device. Because the basic oscillated theory of the oscillator is using inductance and capacitance to form an oscillated frequency, the basic formula is f=½π(LC)½. 
         [0010]    In addition, in order to integrate the tuner, the regular voltage-controlled oscillator (VCO) uses a constant inductance and the adjustable capacitance is used to adjust the oscillated frequency. In prior art, the phase lock loop is used to phase symphonize the input signal and the oscillated frequency, as shown in  FIG. 2A . 
         [0011]    However, in a VCO, in order to generate a desired oscillated frequency, the capacitor tank is used. In U.S. Pat. No. 6,803,830, it is a device can automatically adjust the output signal of the VCO, as shown in  FIG. 2B . The output signal of the VCO is used to be the feedback signal to adjust the signal in the desired frequency range. In addition, in U.S. Pat. No. 6,836,193, it is a method using a similar capacitor tank to adjust the oscillated frequency of the VCO, as shown in  FIG. 2C . However, the capacitor tank includes a complex structure, the semiconductor manufacture complication is increased and those complicated capacitor occupy too many area of the integrated circuit. 
         [0012]    Obviously, only a short band is able to be adjusted in prior art. But the multi-bands adjustable function can not be achieved. 
       SUMMARY OF THE INVENTION 
       [0013]    According to the problems described above, a multi-band VCO is disclosed in the present invention. 
         [0014]    The main object of the present invention is to provide a function with multi-band tuning. 
         [0015]    Another object of the present invention is to provide a multi-band VCO and the multi-band VCO can choose one of the multi-bands to let the oscillator can adjust in the best setting. 
         [0016]    Besides, one object of the present invention is to provide a tuner structure with multi-bands VCO. The tuner can have a better phase noise. 
         [0017]    Another object of the present invention is to provide a low noise amplifier structure to broadband noise optimum to enhance gain and the gain flatness. 
         [0018]    One object of the present invention is to provide a tuner structure and the tuner can be operated at optimum power consumption to decrease the power lost in the tuner. 
         [0019]    Other object of the present invention is to provide a tuner structure to be operated at optimum power consumption and optimum performance condition. 
         [0020]    According to the objects described above, a tunable multi-bands voltage-controlled oscillator (VCO) is disclosed herein and comprises a plurality of oscillators, a plurality of capacitor tanks, a voltage detector, a logic controller and a multiplexer. Each of the oscillators includes different oscillated range. The capacitor tanks are respectively disposed in each one of the oscillators and each one of the capacitors includes a plurality of parallel connective capacitors. The voltage detector is used to detect a voltage signal and choose one of the oscillators in accordance with the voltage signal. One end of the logic controller is connected to the voltage detector and the other end of the logic controller is connected to the capacitor tanks and provides a controlled signal to drive the capacitors of the capacitor tanks. One end of the multiplexer is connected to the logic controller and the oscillators to output an oscillated frequency. 
         [0021]    The present invention also discloses a frequency synthesizer including a phase/frequency detector, a power pump, a loop filter and a multi-bands VCO, and the multi-bands VCO is characterized in that comprising a plurality of oscillators, a plurality of capacitor tanks, a voltage detector, a logic controller and a multiplexer. Each of the oscillators includes different oscillated range. The capacitor tanks are respectively disposed in each one of the oscillators and each one of the capacitors includes a plurality of parallel connective capacitors. The voltage detector is used to detect a voltage signal and choose one of the oscillators in accordance with the voltage signal. One end of the logic controller is connected to the voltage detector and the other end of the logic controller is connected to the capacitor tanks and provides a controlled signal to drive the capacitors of the capacitor tanks. One end of the multiplexer is connected to the logic controller and the oscillators to output an oscillated frequency. 
         [0022]    The present invention also discloses a frequency synthesizer including a multi-bands VCO and a mixer, and the multi-bands VCO is characterized in that comprises a plurality of oscillators, a plurality of capacitor tanks, a voltage detector, a logic controller and a multiplexer. Each of the oscillators includes different oscillated range. The capacitor tanks are respectively disposed in each one of the oscillators and each one of the capacitors includes a plurality of parallel connective capacitors. The voltage detector is used to detect a voltage signal and choose one of the oscillators in accordance with the voltage signal. One end of the logic controller is connected to the voltage detector and the other end of the logic controller is connected to the capacitor tanks and provides a controlled signal to drive the capacitors of the capacitor tanks. One end of the multiplexer is connected to the logic controller and the oscillators to output an oscillated frequency. 
         [0023]    The present invention also discloses a broadband tuner including a filter, a low noise amplifier, a mixer and a multi-bands VCO, and the multi-bands VCO is characterized in that comprises a plurality of oscillators, a plurality of capacitor tanks, a voltage detector, a logic controller and a multiplexer. Each of the oscillators includes different oscillated range. The capacitor tanks are respectively disposed in each one of the oscillators and each one of the capacitors includes a plurality of parallel connective capacitors. The voltage detector is used to detect a voltage signal and choose one of the oscillators in accordance with the voltage signal. One end of the logic controller is connected to the voltage detector and the other end of the logic controller is connected to the capacitor tanks and provides a controlled signal to drive the capacitors of the capacitor tanks. One end of the multiplexer is connected to the logic controller and the oscillators to output an oscillated frequency. 
         [0024]    The present invention also discloses a broadband tuner made by serial connective of a first single frequency conversion device and a second single frequency conversion device, wherein the first single frequency conversion device includes a filter, a low noise amplifier, a mixer and a multi-bands VCO, and the second single frequency conversion device includes a filter, a low noise amplifier, a mixer and a multi-bands VCO, are characterized in that and comprise a plurality of oscillators, a plurality of capacitor tanks, a voltage detector, a logic controller and a multiplexer. Each of the oscillators includes different oscillated range. The capacitor tanks are respectively disposed in each one of the oscillators and each one of the capacitors includes a plurality of parallel connective capacitors. The voltage detector is used to detect a voltage signal and choose one of the oscillators in accordance with the voltage signal. One end of the logic controller is connected to the voltage detector and the other end of the logic controller is connected to the capacitor tanks and provides a controlled signal to drive the capacitors of the capacitor tanks. One end of the multiplexer is connected to the logic controller and the oscillators to output an oscillated frequency. 
         [0025]    The present invention also discloses an adjusting output frequency of a multi-bands VCO a plurality of oscillators, a plurality of capacitor tanks, a voltage detector, a logic controller and a multiplexer. Each of the oscillators includes different oscillated range. The capacitor tanks are respectively disposed in each one of the oscillators and each one of the capacitors includes a plurality of parallel connective capacitors. The voltage detector is used to detect a voltage signal and choose one of the oscillators in accordance with the voltage signal. One end of the logic controller is connected to the voltage detector and the other end of the logic controller is connected to the capacitor tanks and provides a controlled signal to drive the capacitors of the capacitor tanks. One end of the multiplexer is connected to the logic controller and the oscillators to output an oscillated frequency. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
           [0027]      FIG. 1A  is a view of a conventional tuner included single conversion with IF; 
           [0028]      FIG. 1B  is a view of a conventional tuner included dual conversion with IF; 
           [0029]      FIG. 1C  is a view of a conventional tuner included dual conversion with low IF; 
           [0030]      FIG. 1D  is a view of a conventional tuner including dual conversion with low IF; 
           [0031]      FIGS. 2A-2C  are views showing a conventional voltage-controlled oscillator (VCO) in prior art; 
           [0032]      FIG. 3  is a view showing that a main structure of a multi-bands VCO in the present invention; 
           [0033]      FIG. 4  is a view showing the multi-bands VCO of the present invention including phase lock loop circuit; 
           [0034]      FIG. 5  is a view showing the multi-bands VCO of the present invention; 
           [0035]      FIG. 6  is view showing another embodiment of the multi-bands VCO in the present invention; 
           [0036]      FIG. 7  is a view showing the dual conversion tuner of the present invention including the multi-bands VCO; 
           [0037]      FIGS. 8A-8B  are views showing the low noise amplifier of the present invention; 
           [0038]      FIGS. 9A-9B  are views showing another embodiment of the low noise amplifier of the present invention; and 
           [0039]      FIG. 10  is one another embodiment of the low noise amplifier of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0040]      FIG. 3  is view showing that a main structure of a multi-bands voltage-controlled oscillator (VCO) in the present invention. As shown in  FIG. 3 , the multi-bands VCO  1100  includes a voltage detector  1110 , a logic controller  1120 , a multiplexer  1160 , a plurality of oscillator  115   n  (n =1, 2, 3 . . . ) with different oscillated ranges, and a plurality of capacitor tanks  1130 . Each one of the capacitor tanks is connected to a oscillator  115   n  (n=1, 2, 3 . . . ). Each one of the capacitor tanks includes a plurality of capacitors C N  (N=1, 2, 3 . . . ). Each one of the capacitors in the capacitor tank includes a switch SN (N=1, 2, 3 . . . ) used to control the capacitor value of the capacitor tank in accordance with the digital signals provided by the logic controller  1120 . 
         [0041]    Besides, because the oscillator  115   n  (n=1, 2, 3 . . . ) includes at least one active component, an inductance and a capacitor. The inductance and the capacitor are parallel to form the oscillated source of the oscillator  115   n  (n=1, 2, 3 . . . ). Therefore, when the capacitors C N  (n=1, 2, 3 . . . ) of the capacitor tank  1130  is parallel and connected to the capacitor of the oscillators  115   n  (n=1, 2, 3 . . . ), the capacitor value of the oscillators  115   n  (n=1, 2, 3 . . . ) can be changed by controlling the switch SN (N=1, 2, 3 . . . ) of the capacitor tanks  1130 . The oscillator  115   n  is adjusted in optimum condition and the output is transmitted by the multiplexer  1160 . 
         [0042]    Still referring to  FIG. 3 , when the multi-bands VCO  1100  is driven by a tuning voltage (V t ) input, one of the oscillator  115   n  (n=1, 2, 3 . . . ) will be chosen in accordance with the voltage (V t ) detected by the voltage detector  1110  and the logic controller  1120  and the multiplexer  1160 . For example, multi-bands VCO  1100  includes the oscillator  115   n  (n=1, 2, 3 . . . ) with four different ranges. When the voltage (V t ) detected by the voltage detector  1110  is within the oscillated range of the multi-bands VCO  1100 , such as V t =1V, the voltage detector  1110  will transmit the voltage V t  to the logic controller  1120  and the logic controller  1120  can output control signals to the multiplexer  1160  and the multiplexer can choose the oscillator  1151 . 
         [0043]    If the voltage V t  detected by the voltage detector  1110  is not within the oscillated range, such as V t =5V, the voltage detector  1110  will transmit the voltage V t  to the logic controller  1120 . And the logic controller  1120  will control the number of the capacitors in the capacitor tanks  1130  of the oscillators  115   n  (n=1, 2, 3 . . . ). For example, during the period of the adjusting of the number of the capacitors, the logic controller  1120  will output a digital control signal with ramp up or ramp down to the counter (not shown) of the logic controller  1120  by increasing or decreasing the capacitor value to adjust the oscillated range of the oscillator  1151 . Therefore, the oscillator  1151  will be adjusted in the optimum condition. 
         [0044]    When the multi-bands VCO  1100  is adjusted in the optimum phase noise condition, the logic controller  1120  will transmit a control signal to drive the multiplexer  1160  to choose one of the best oscillator  115   n  (n=1, 2, 3 . . . ). Finally, the output is transmitted by the mixer  106 . It should be noted that the number of the oscillator  115   n  (n=1, 2, 3 . . . ) of the present invention is more than one, the number of the oscillator  115   n  (n=1, 2, 3 . . . ) can be increased or decreased by the requirement. It is not limited herein. 
         [0045]    In other preferred embodiment of the present invention, a frequency synthesizer  1500  formed by a multi-bands VCO  1100  and a phase lock feedback (PLL)  1140 . As shown in  FIG. 4 , the PPL  1140  includes a phase/frequency detector (PFD)  410 , a charge pump  420  (CP) and loop filter  430  (LF). The multi-bands VCO  1100  includes a voltage detector  1110 , a logic controller  1120 , a multiplexer  1160 , a plurality of oscillator  115   n  (n=1, 2, 3 . . . ) with different oscillated ranges and a plurality of capacitor tanks  1130 . 
         [0046]    Each one of the capacitor tanks is connected to an oscillator  115   n  (n=1, 2, 3 . . . ). Each one of the capacitor tanks includes a plurality of capacitors C N  (N=1, 2, 3 . . . ). Each one of the capacitors in the capacitor tank includes a switch S N  (N=1, 2, 3 . . . ) used to control the capacitor value of the capacitor tank in accordance with the digital signals provided by the logic controller  1120 . 
         [0047]    Still referring to  FIG. 4 , the PFD  410  in the phase lock loop  1140  detects the different between the reference frequency input and the inner oscillated signal and converts the compare result into at least one digital signal outputs, such as V UP  and V DN . After the CP  420  received the V UP  and V DN  signals transmitted from the PFD  410 , the V UP  and V DN  signals are transformed to be a controlled voltage V fr  and outputted to the loop filter  430 . The loop filter  430  can filter the high frequency of the controlled voltage. 
         [0048]    Then, the voltage detector  1110  of the multi-bands VCO  1100  will output a voltage signal V t  used to choose a best oscillator in accordance with the loop filter  430 . For example, when the voltage V t  outputted by the loop filter  430  is 1V (near first wave, such as 2˜2.5 GHz), the voltage detector  1110  chooses the oscillator  1151 . The voltage detector  1110  will transmit the voltage V t  to the logic controller  1120 . The logic controller  1120  will output controlled signal to the multiplexer  1160 . The multiplexer  1160  will choose the best oscillator. When the voltage detected by the voltage detector  1110  is not within the oscillated range of the multi-bands VCO  1100 , such as V t =5V, the voltage detector  1110  will output the voltage V t  to the logic controller  1120 . The logic controller  1120  will control the number of the capacitors in the capacitor tanks  1130  connected to the oscillator  115   n  (n=1, 2, 3 . . . ). For example, in the present embodiment, the capacitor tanks can be divided into 16 sub-bands. Each of the capacitor is within 30˜32 MHz frequency range. Besides, the capacitor tanks  1130  can increase or decrease the capacitor value to adjust the oscillated frequency of the oscillator  1151 . The oscillator  1151  can be adjusted in optimum condition. Especially, the frequency device  1150  is adjusted in optimum phase noise, and the output is transmitted from the multiplexer  1160  to the mixer  106 . 
         [0049]    It should be noted that the phase lock loop  1140  is an electronic component well known in the art. Therefore, the detail circuit structure and the operated procedure are not described herein. When the phase lock loop  1140  and the multi-bands VCO  1100  of the present invention are operated together, the stability of the multi-bands VCO  1100  is increased, the bandwidth is increased and the oscillated frequency locked time is decreased. Besides, the phase lock loop  1140  is able to connect a frequency divider  450  and the frequency divider  450  is disposed between the output end of the multi-bands VCO  1100  and the input end of the phase/frequency detector  410 . The frequency divider  450  is used to decrease the output frequency of the multi-bands VCO  1100  and the frequency decreased by the frequency divider  450  is able to compare with the input reference frequency. 
         [0050]      FIG. 5  is a view showing that the main structure of a tuner  200  with single conversion with IF. The tuner  200  is a heterodyne tuner or a broadband tuner, such as digital TV tuner. As shown in  FIG. 5 , the tuner  200  includes a filter  101 , a low noise amplifier (LNA)  102 , a mixer  106 , a filter  112 , a phase lock loop  1140  and a multi-bands VCO  1100 . The multi-bands VCO  1100  includes a voltage detector  1110 , a logic controller  1120 , a multiplexer  1160 , a plurality of oscillator  115   n  (n=1, 2, 3 . . . ) with different oscillated ranges, and a plurality of capacitor tanks  1130 . Each one of the capacitor tanks is connected to an oscillator  115   n  (n=1, 2, 3 . . . ). Each one of the capacitor tanks includes a plurality of capacitors C N  (N=1, 2, 3 . . . ). Each one of the capacitors in the capacitor tank includes a switch S N  (N=1, 2, 3 . . . ) used to control the capacitor value of the capacitor tank in accordance with the digital signals provided by the logic controller  1120 . Besides, the tuner  200  of the present invention further includes a power manage module. The power manage module includes a power detector  210  and a power manage device  220 . In addition, the filter  101  and the filter  112  can be a SAW filter. 
         [0051]    When the antenna (not shown) of the tuner  200  receives the radio frequency (such as frequency 2˜4 GHz) and transmits the radio frequency to the low noise amplifier  102 . The low noise amplifier  102  will amplifier the frequency and the frequency will be transmitted to the mixer  106 . The mixer  106  will mix the radio frequency and the oscillated frequency of the multi-bands VCO  1100  and output a oscillated frequency, such as mixing with a natural frequency or a central frequency. The phase lock loop  1140  will detect the different between the input radio frequency and the inner oscillated frequency and output a voltage with phase synchronizing to the oscillated frequency. The voltage detector  1110  of the multi-bands VCO  1100  will output a voltage in accordance with the loop filter  430  to choose a best oscillator. For example, when the loop filter  430  transmits a voltage in the first wave, such as 2˜2.5 GHz, the voltage detector  1110  can choose the oscillator  1151 . The voltage detector  1110  will transmit the voltage to the logic controller  1120 . The logic controller  1120  will output a digital controlled signal to control the number of the capacitors C N . In the present embodiment, the capacitor tanks can be divided into 16 sub-bands. Each of the capacitor is within 30˜32 MHz frequency range. Besides, the capacitor tanks  1130  can increase or decrease the capacitor value to adjust the oscillated frequency of the oscillator  1151 . The oscillator  1151  can be adjusted in optimum condition. Especially, the frequency device  1150  is adjusted in optimum phase noise, and the output is transmitted from the multiplexer  1160  to the mixer  106 . 
         [0052]    In one preferred embodiment of the present invention, the power detector  210  also detects the power level of the radio frequency of the first wave. The power level value will be transmitted to the power manage device  220 . For example, the power manage device  220  is a power/current mode controller. In other words, the power detector  210  will transmit the power level to the low noise amplifier  102  to adjust the power operation of the noise amplifier. 
         [0053]    When the power mange device  220  receives the power level, the power manage device  220  will determine the value of the power level. When the input power lever is a large signal, such as more than 50 dbm, the power manage device  220  will set the tuner in a max current mode controlling condition and output a current control signal to the low noise amplifier, such as output a current control signal with minimum gain. Besides, in the preferred embodiment of the present invention, there is an automatic gain control circuit  230  disposed between the power detector  210  and the low noise amplifier  102 . The power detector  210  will transmit the power level to the automatic gain control circuit  230  and the automatic gain control circuit  230  will transmit the signal to the low noise amplifier  102 . Therefore, the low noise amplifier  102  can be operated at the better power level. Besides, the power manage device  220  is able to be directly connected to the lower noise amplifier  102 , the mixer  106 , the multi-bands VCO  1100  and any other circuit device (not shown), as shown in  FIG. 5 . Therefore, when the power manage device  220  receives the power lever detected by the power detector  210 , the power manage device  220  will adjust the current of the lower noise amplifier and/or the mixer  106  in accordance with the power lever and adjust the current operating condition of other circuit devices to form the optimum condition of those circuits with the low noise amplifier  102 . Besides, at the same period, the power manage device  220  will control the current of the low noise amplifier  102  in accordance with the frequency of the oscillator to avoid the signal gain is large enough to overflow to the mixer  106  or local oscillator and the frequency shift problem is occurred. Obviously, according to the power detector  210  and the power manage device  220  in the power manage module, the tuner  200  of the present invention can operate in the optimum power consumption and the optimum condition when the input power is a large signal. 
         [0054]    When the input power lever is a small signal, such as less than 10 dbm, the power manage device  220  will set the tuner in a min current mode controlling condition and output a current control signal to the low noise amplifier  102 , such as output a current control signal with maximum gain. In the preferred embodiment of the present invention, there is an automatic gain control circuit  230  disposed between the power detector  210  and the low noise amplifier  102 . The power detector  210  will transmit the power level to the automatic gain control circuit  230  and the automatic gain control circuit  230  will transmit the signal to the low noise amplifier  102 . Therefore, the low noise amplifier  102  can be operated at the better power level. Besides, the power manage device  220  is able to be directly connected to the lower noise amplifier  102 , the mixer  106 , the multi-bands VCO  1100  and any other circuit device (not shown), as shown in  FIG. 5 . Therefore, when the power manage device  220  receives the power lever detected by the power detector  210 , the power manage device  220  will adjust the current of the lower noise amplifier and/or the mixer  106  in accordance with the power lever and adjust the current operating condition of other circuit devices to form the optimum condition of those circuits with the low noise amplifier  102 . Obviously, according to the power detector  210  and the power manage device  220  in the power manage module, the tuner  200  of the present invention can operate in the optimum power consumption and the optimum condition when the input power is a large signal. 
         [0055]    When the input power level is between 10 dbm and 50 dbm, such as 30 dbm, the power detector  210  won&#39;t change the gain of the low noise amplifier  102 . The regular standard of the low noise amplifier is operated, such as the gain is changed in a linear range. Similarly, the power manage device  220  will adjust the current of the low noise amplifier  102  and/or the mixer  106  in accordance with the current power lever and also adjust the operative condition of the other circuit devices. These circuit devices and the low noise amplifier  102  are in optimum condition. Therefore, the tuner  200  is able to operate at the optimum power consumption and the optimum condition. 
         [0056]    As the description above, when the low noise amplifier  102  will amplifier the radio signal of the first wave with the suitable power lever in accordance with the controlled signal of the automatic controlled circuit  230 . At final, the filer  112  will filer unnecessary channels to complete the tune function of the tuner. 
         [0057]    Besides, it should be noted that the multi-bands VCO  1100 , the power manage module, the low noise amplifier  102  and the mixer  106  are able to be composed together and formed a frequency conversion apparatus  300 . The multi-bands VCO  1100  and the mixer  106  are formed together to be a frequency synthesizer used to up-conversion or down-conversion. The input signal is limited to be a radio frequency (such as input is an intermediate frequency), as shown in  FIG. 6 . 
         [0058]      FIG. 7  is a view showing a dual conversion with IF tuner  500 . As shown in  FIG. 7 , the tuner  500  includes two signal conversion units serially connected to each other. The pre-conversion unit and the post-conversion unit respectively include a radio/intermediate frequency mixer  106   a,  a filter  112 , a multi-bands VCO  1100 , a phase lock loop  1140  and a power manage module. The multi-bands VCO  1100  includes a voltage detector  1110 , a logic controller  1120 , a multiplexer  1160 , a plurality of oscillator  115   n  (n=1, 2, 3 . . . ) with different oscillated ranges, and a plurality of capacitor tanks  1130 . Each one of the capacitor tanks is connected to a oscillator  115   n  (n=1, 2, 3 . . . ). Each one of the capacitor tanks includes a plurality of capacitors C N  (N=1, 2, 3 . . . ). Each one of the capacitors in the capacitor tank includes a switch S N  (N=1, 2, 3 . . . ) used to control the capacitor value of the capacitor tank in accordance with the digital signals provided by the logic controller  1120 . The power manage module includes a power detector  210  and a power manage device  22 . Optionally, there is an automatic gain controller  230  disposed between the power detector  210  and the power manage device  220 . Besides, the pre-conversion unit can be formed a up-conversion unit in accordance with the multi-bands VCO  1100 , for example the oscillated frequency of the multi-bands VCO is 1 GHz-2 GHz. The pose-conversion unit can be formed a down-conversion unit by setting a specific oscillated frequency of the local oscillator  110   b.    
         [0059]    Because the tuner  500  with dual conversion with IF includes two single conversion units serially connected to each other. The pre-conversion unit includes a low noise amplifier  102 , a radio/intermediate frequency mixer  106   a,  a multi-bands VCO  1100 , a phase lock loop  1140  and a power manage module. Because the operative procedure of the signal conversion unit is the same as the embodiments described in  FIG. 5  and  FIG. 6 , the detail description of the single conversion unit is omitted. It should be noted that the two signal conversion units are operated by the multi-bands VCO  1100 , the phase lock loop  1140  and the power manage module. In the practical design, only the pre-conversion unit (up-conversion unit) is added with the multi-bands VCO  1100 , the phase lock loop  1140  and the power manage module. Alternatively, the pose-conversion unit (down-conversion unit) is added with multi-bands VCO  1100 , the phase lock loop  1140  and the power manage module. Certainly, there is no power manage module in the pre-conversion unit (up-conversion unit) and the power manage module is in the post-conversion unit (down-conversion unit). The embodiments in the previous description are included in the present invention, it is not limited herein. 
         [0060]    Besides the power manage device is added in the operation of the adjusting of the tuner, in order to let the tuner of the present invention with better performance, there is a input resistance added in the low noise amplifier to automatically adjust the value of the input radio frequency. The detail description is in the following chapter. 
         [0061]      FIG. 8A  is a view showing the low noise amplifier of the present invention. As shown in  FIG. 8A , the low noise amplifier  1  includes a first active component  10 , a second active component  12  and a plurality of adjustable attenuation device  20 ,  22 . Each one of the active component in the low noise amplifier  1  includes a first end, a second end and a third end. In the present embodiment, the active components are BJT and the first end is a base end, the second end is the emitter end and the third end is a collector end. Besides, the adjustable attenuation devices  20 ,  22  are components with two ends, such as resistance, inductance, capacitance, diode and any combination above. The adjustable attenuation devices can be the component with three ends, such as BJT, FET, MOSFET or CMOS. 
         [0062]    Please still referring to  FIG. 8A , the base ends of the first active component  10  and the second active component  12  are connected to the input end and used to receive the broadband radio frequency fed from the antenna of the tuner. When the first adjustable attenuation device  20  is a two ends component, the first end is connected to the base end of the first active component  10  and the second end is connected to the emitter end of the second active component  12 . Besides, the second adjustable attenuation device  22  is a two ends component too, the first end is connected to the base end of the first active component  10  and the second end is connected to the emitter end of the second active component  12 . Obviously, the voltage (V B1 ) of the base end of the first active component  10  and the voltage V E2  of the emitter end of the second active component  12  are adjusted or changed by changing the impedance of the adjustable attenuation device  22 . Therefore, when the gains of the first active component and the second active component in the low noise amplifier of the present invention are adjusted, such as adjusting the gain o f the low noise amplifier by a power manage device, the input impedance of the low noise amplifier  1  is changeable in a small range, for example the input impedance is changeable within the 50±2Ω. Therefore, the tuner and the low noise amplifier can maintain in the optimum compatible impedance condition. Certainly, before the input signal is transmitted from the antenna of the tuner to the low noise amplifier  1 , the input signal is optionally transmitted to amplifier circuit (not shown), such as an automatic gain controlled circuit. 
         [0063]    Besides, in order to adjust the input impedance, the adjustable attenuation device  20  and  22  can be the adjustable component, such as adjustable resistance, adjustable inductance, adjustable capacitance and so on. The third end (such as collector end) of the first active component  10  and the second active component  12  is connected to the two ends component (not shown) to be the load of the low noise amplifier  1 . The two ends component is resistance, inductance, capacitance, diode or any combinations above. 
         [0064]    Now referring to  FIG. 8B ,  FIG. 8B  is a view showing another embodiment of the low noise amplifier in the present invention. The base ends of the first active component  10  and the second active component  12  are connected to the input end and used to receive the broadband radio frequency fed from the antenna of the tuner. When the first adjustable attenuation device  20  is a three ends component, such as a BJT, the third end (such as collector) is connected to the base end of the second active component  12  and the second end (such as emitter) is connected to the emitter of the first active component  10  and the first end (such as base) is connected to a voltage control end V ctl2  used to adjust voltage. 
         [0065]    Obviously, the voltage (V B1 ) of the base end of the first active component  10  and the voltage V E2  of the emitter end of the second active component  12  are adjusted or changed by adjusting the voltage of the voltage controlled end V ctl1  of the adjustable attenuation device  20  to change the impedance of the adjustable attenuation device  20 . Similarly, the voltage (V B2 ) of the base end of the second active component  12  and the voltage V E1  of the emitter end of the first active component  10  are adjusted or changed by adjusting the voltage of the voltage controlled end V ctl1  of the adjustable attenuation device  20  to change the impedance of the adjustable attenuation device  20 . Therefore, when the gains of the first active component and the second active component in the low noise amplifier of the present invention are adjusted, such as adjusting the gain of the low noise amplifier by a power manage device, the input impedance of the low noise amplifier  1  is changeable in a small range, for example the input impedance is changeable within the 75±5Ω. Therefore, the tuner and the low noise amplifier can maintain in the optimum compatible impedance condition. Certainly, before the input signal is transmitted from the antenna of the tuner to the low noise amplifier  1 , the input signal is optionally transmitted to amplifier circuit (not shown), such as a automatic gain controlled circuit. 
         [0066]    Besides, in order to adjust the input impedance, the adjustable attenuation device  20  and  22  can be BJT, FET, MOSFET or CMOS. In the preferred embodiment, the voltage value of the voltage controlled end V ctl1 -V ctl2  can be chosen to be zero voltage. The third end (such as collector end) of the first active component  10  and the second active component  12  is connected to the two ends component (not shown) to be the load of the low noise amplifier  1 . The two ends component is resistance, inductance, capacitance, diode or any combinations above. 
         [0067]    Besides, the first adjustable attenuation device  20  and  22  shown in  FIG. 8A  and  FIG. 8B  of the present invention can be a plurality of components being parallel to each other. In other words, the first adjustable attenuation device  20  and the second adjustable attenuation device  22  can be formed by a plurality of adjustable attenuation devices being parallel connection. 
         [0068]      FIG. 9A  is a view showing the low noise amplifier in another embodiment of the present invention. As shown in  FIG. 9A , the low noise amplifier  2  includes a first active component  30 , a second active component  32  and a plurality of adjustable attenuation device  40 ,  42 . The active components  30  and  32  are FET, MOSFET, CMOS, and so on. The first end is a gate end, the second end is the source end and the third end is a drain end. Besides, the adjustable attenuation devices  40 ,  42  are components with two ends, such as resistance, inductance, capacitance, diode and any combination above. Besides, the adjustable attenuation devices  40 ,  42  are components with three ends, such as BJT, FET, MOSFET, CMOS and so on. 
         [0069]    Obviously, the circuit structure in  FIG. 9A  is the same as the structure shown in  FIG. 8A  and  FIG. 8B . The first active component is replaced from BJT to FET, MOSFET or CMOS. In the present embodiment, the NMOS is chosen to be the active component. 
         [0070]    Please still referring to  FIG. 9A , the gate ends of the first active component  30  and the second active component  32  are connected to the input end and used to receive the broadband radio frequency fed from the antenna of the tuner. When the first adjustable attenuation device  40  is a two ends component, the first end is connected to the gate end (V G1 ) of the first active component  30  ant the second end is connected to the source end (V S2 ) of the second active component  32 . 
         [0071]    Besides, as the second adjustable attenuation device  42  is a two ends component too, the first end is connected to the gate end (V G2 ) of the second active component  32  and the second end is connected to the source end (V S2 ) of the first active component  30 . Obviously, when the gain of the low noise amplifier in the present invention is adjusted (such as a power manage module used to adjust the gain of the low noise amplifier), the input impedance of the low noise amplifier  2  can be adjusted within a small range, such as the impedance is within 50±2Ω, by the connection of the first adjustable attenuation device  40  and the second adjustable attenuation device  42 . 
         [0072]    Therefore, the tuner and the low noise amplifier can maintain in the optimum compatible impedance condition. Certainly, before the input signal is transmitted from the antenna of the tuner to the low noise amplifier  2 , the input signal is optionally transmitted to amplifier circuit (not shown), such as a automatic gain controlled circuit. 
         [0073]    Besides, in order to adjust the input impedance, the adjustable attenuation device  40  and  42  can be the adjustable component, such as adjustable resistance, adjustable inductance, and adjustable capacitance and so on. The third ends (such as drain ends) of the first active component  30  and the second active component  32  are connected to the two ends component (not shown) to be the load of the low noise amplifier  2 . The two ends component is resistance, inductance, capacitance, diode or any combinations above. 
         [0074]    Now referring to  FIG. 9B ,  FIG. 9B  is a view showing another embodiment of the low noise amplifier in the present invention. The gate ends of the first active component  30  and the second active component  32  in the low noise amplifier  2  are connected to the input end and used to receive the broadband radio frequency fed from the antenna of the tuner. When the first adjustable attenuation device  40  is a three ends component, such as a NMOS, the third end (such as drain end) is connected to the gate end (V G1 ) of the first active component  30  and the second end (such as source end) is connected to the source end (V S2 ) of the second active component  32  and the first end (such as gate end) is connected to a voltage control end Vctl 1  used to adjust voltage. Besides, when the second adjustable attenuation device  42  is a three ends component (such as a NMOS), the third end (such as drain end) is connected to the gate end (V G2 ) of the second active component  32  and the second end (such as source end) is connected to the source end (V S1 ) of the first active component  30  and the first end (such as gate end) is connected to a voltage control end V ctl2  used to adjust voltage. Obviously, the voltage (V G1 ) of the gate end of the first active component  30  and the voltage V S2  of the source end of the second active component  12  are adjusted or changed to be a fixed voltage value and the voltage of the voltage controlled end Vctl 1  of the first adjustable attenuation device  40  is changed to a suitable voltage value, then the impedance of the adjustable attenuation device  20  is adjustable. Similarly, the voltage (V S1 ) of the source end of the first active component  30  and the voltage (V G2 ) of the gate end of the second active component  32  are adjusted or changed and the voltage of the voltage controlled end V ctl2  of the adjustable attenuation device  42  is adjusted, then the impedance of the adjustable attenuation device  42  is adjustable. Therefore, according to the connection of the adjustable attenuation device  40  or  42 , the input impedance of the low noise amplifier  2  is changeable in a small range, for example the input impedance is changeable within the 75±5Ω. Therefore, the tuner and the low noise amplifier can maintain in the optimum compatible impedance condition. Certainly, before the input signal is transmitted from the antenna of the tuner to the low noise amplifier  2 , the input signal is optionally transmitted to amplifier circuit (not shown), such as a automatic gain controlled circuit. 
         [0075]    Besides, in order to adjust the input impedance, the adjustable attenuation device  40  and  42  can be BJT, FET, MOSFET or CMOS. In the preferred embodiment, the voltage value of the voltage controlled end V ctl1 -V ctl2  can be chosen to be zero voltage. The third ends (such as drain ends) of the first active component  30  and the second active component  32  are connected to the two ends component (not shown) to be the load of the low noise amplifier  2 . The two ends component is resistance, inductance, capacitance, diode or any combinations above. 
         [0076]    Besides, the first adjustable attenuation device  40  and  42  shown in  FIG. 9A  and  FIG. 9B  of the present invention can be a plurality of components being parallel to each other. In other words, the first adjustable attenuation device  40  and the second adjustable attenuation device  42  can be formed by a plurality of adjustable attenuation devices being parallel connection. 
         [0077]      FIG. 10  is a view showing another embodiment of the low noise amplifier in the present invention. As shown in  FIG. 10 , the low noise amplifier  3  includes a first active component  30 , a second active component  32 , a third active component  34 , a forth active component  36  and a plurality of adjust attenuation device  40  and  42 . The adjustable attenuation devices can be BJT, FET, MOSFET or CMOS. The first end is a gate end, the second end is the source end and the third end is a drain end. Besides, the adjustable attenuation devices  40 ,  42  are components with two ends, such as resistance, inductance, capacitance, diode and any combination above. Besides, the adjustable attenuation devices  40 ,  42  are components with three ends, such as BJT, FET, MOSFET, CMOS and so on. 
         [0078]    Obviously, the circuit structure of the embodiment shown in  FIG. 10  is the same as the circuit shown in  FIG. 9A  and  FIG. 9B . In  FIG. 10 , the active components  34  and  36  are respectively connected to the active components  30  and  32  shown in  FIG. 9A  and  FIG. 9B . The third end (drain) of the active component  30  is connected to the second end (source) of the active component  34 . Besides, the third end (drain) of the active component  34  is connected to a load device and the first end (gate) of the active component  34  is connected to the ground. The object to add an active component  34  and an active component  36  is to increase the output impedance of the low noise amplifier. 
         [0079]    Obviously, the circuit structure in  FIG. 10  is the same as the structure shown in  FIG. 8A  and  FIG. 8B . The active component is a BJT, FET, MOSFET or CMOS. Because the circuit structure and the operated procedure are similar to the description above, the detail description is omitted herein. 
         [0080]    Besides, it should be noted that the low noise amplifier circuit described above can be formed on the wafer by the highly improved development of the semiconductor package technique. The tuner is able to be on die. The low noise amplifier of the present invention is able to replace the low noise amplifier  102  in the tuner  100  (as shown in  FIG. 1A  to  FIG. 1D ). By a suitable bias design, the tuner with the low noise amplifier of the present invention is in good impedance compatibility and the ability of the noise control in the circuit is increased.