KR100411877B1 - Method For Automatic Measurement and Correction of DTV Tuner - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a digital broadcast tuner automatic measurement and correction method and a computer readable recording medium having recorded thereon a program for realizing the method.

2. The technical problem to be solved by the invention

The present invention relates to a digital broadcast tuner comprising a double frequency conversion function, a tracking filter and a tuner controller, wherein the exact frequency between an active tracking filter for frequency band division and a voltage controlled oscillator (VCO) for dual frequency conversion is provided. Automated measurement and calibration method for digital broadcast tuners for performing mapping and accurately correcting frequency behavior abnormalities due to changes in characteristics of components (varactor diodes, inductors and capacitors) used in tracking filters due to environmental changes such as temperature rise And a computer readable recording medium having recorded thereon a program for realizing the above method.

3. Summary of Solution to Invention

In the method of automatically measuring and calibrating a digital broadcasting tuner, the present invention uses a vector network analyzer connected to a digital broadcasting tuner and an external computer to measure frequency characteristics according to frequency tuning voltages of an active traffic filter for each frequency band and control voltage control. A first step of calculating a coefficient value for each frequency band by using an approximation function for frequency mapping with an oscillator (VCO) and storing the count value in a storage device of a tuner controller; The tuner controller performs frequency mapping on the active traffic filter using coefficient values of the corresponding frequency band stored in the storage device according to the control signal for each digital broadcasting channel from the external computer, and performs the frequency mapping through the spectrum analyzer. A second step of outputting a result; And a third step of the tuner controller correcting an abnormal frequency operation by updating a coefficient value of a corresponding frequency band stored for frequency mapping in the storage device in response to a frequency correction request from the external computer.

4. Important uses of the invention

The present invention is used in digital broadcast tuners and the like.

Description

Method for Automatic Measurement and Correction of DTV Tuner

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital broadcast tuner automatic measurement and correction method and a computer readable recording medium having recorded thereon a program for realizing the method, in particular comprising a double frequency conversion function, a tracking filter and a tuner controller. On the computer-readable recording medium recording the digital broadcasting tuner automatic measurement and correction method and the program for realizing the above method for accurately and automatically processing the frequency error correction caused by environmental changes such as frequency mapping and temperature in the digital broadcasting tuner. It is about.

In general, the basic condition of a widely available analog TV receiver is to be able to select the desired TV channel automatically, and to interfere with the interference, video signals, and intermediate frequency bits (which can degrade TV quality or cause TV blindness). IF Beat: Intermediate Frequency Beat (hereinafter referred to as "IF Beat") and spurious signals must be able to work correctly. The conditions of the analog broadcast TV receiver are equally applicable to the digital broadcast TV (hereinafter referred to as "DTV").

In the case of the DTV tuner currently under development, the effects of such signals (interference signals, video signals, IF Beat, spurious signals) can be classified into two categories.

The first is that the TV channel being watched cannot be operated normally due to the saturation of the low noise amplifier and mixer of the tuner prestage (frequency band divider) due to the large interference signal of adjacent bands. The second case is that the inter-modulation caused by two or more large interference signals in the adjacent band is present in the pass band of the watching TV channel, thereby deteriorating the TV reception sensitivity. Several methods have been proposed to solve the above two problems.

1 is a diagram illustrating an embodiment of a conventional DTV tuner including a dual frequency conversion function.

As shown in Fig. 1, the conventional DTV tuner with dual frequency conversion function has no tracking filter at the tuner pre-end, so the TV channel is selected only by the phase-locked loop, so that additional frequency mapping is possible. No device is required, and double frequency conversion allows suppression of spurious components by video signal, IF Beat and local power. However, such a structure is desired when receiving multi-channel broadcast signals simultaneously. It is impossible to suppress other strong broadcast interference signals, which reduces the operating area of the receiver, and the low noise amplifier and the mixer may enter a power saturation state, thereby degrading the performance of the receiver. In conclusion, while the DTV tuner of FIG. 1 has much room to deteriorate the performance of a TV receiver, there are few devices whose frequency characteristics change according to environmental changes, and thus, the DTV tuner is efficient for mass production and maintenance.

FIG. 2 is a diagram illustrating a configuration of a DTV tuner including a conventional dual frequency conversion function and a band division filter, and a band division (VHF_LOW, VHF_HIGH UHF) function and a band having a fixed frequency at a tuner front end in the structure of FIG. Add a pass filter.

As shown in FIG. 2, the conventional DTV tuner including the dual frequency conversion function and the band division filter is capable of suppressing broadcast signals outside the divided band but cannot suppress the signals within the divided band. This is almost the same as the DTV tuner of FIG. Like the DTV tuner of FIG. 1, the DTV tuner having this structure has much room for deterioration of receiver performance. However, the DTV tuner is somewhat efficient in mass production and maintenance due to the fact that there are few elements whose frequency characteristics change due to environmental changes.

3 is a diagram illustrating an embodiment of a DTV tuner including a dual frequency conversion function, a tracking filter, and a tuner controller to which the present invention is applied. Not only is it possible to suppress interference signals that can degrade the quality of a TV channel or cause a condition in which the TV broadcast itself is impossible, but dual frequency conversion makes it possible to operate independently of video signals and IF Beat components. Such a DTV tuner requires frequency mapping between an active tracking filter for frequency band division and a voltage controlled oscillator (VCO) for dual frequency conversion. Therefore, the DTV tuner as described above has to be equipped with an additional tuner controller to enable automatic selection of TV channels, and the structure thereof becomes very complicated. In addition, a large number of devices that can change frequency characteristics according to environmental changes are included. It is difficult to mass-produce and maintain.

As described above with reference to the DTV tuner of FIGS. 1 to 3, since there is no structure having excellent reception performance and efficient mass production and maintenance, an appropriate trade-off is required. Since the broadcast standard is a transitional very poor radio wave environment in which digital broadcasting must be transmitted in a mixed manner with the existing analog method, the initial requirement of digital broadcasting that can provide high quality can be called reception performance. Thus, the DTV tuner as shown in FIG. 3 is used. However, it can be said that the time required for a method for efficiently processing frequency error correction during mass production and maintenance is required.

For reference, the DTV tuner device will be described in more detail as follows.

First, as a prior patent related to the DTV tuner device, a "wideband frequency automatic channel selection device and method using frequency mapping approximation function" (Republic of Korea Patent Publication "10-2001-0046208", 2001.06.05 publication) is as follows. .

This patent relates to an automatic channel selection device and method for automatically selecting a wideband frequency channel using a frequency mapping function, which is caused by out-of-band interference signals of a broadcast channel being viewed. It is possible to suppress various phenomena, and as a result, improve the operating range of the receiver. Also, automatic frequency selection and frequency error correction of DTV channels are independent of image signals and IF Beat components that may be introduced when receiving multiple channels. It is possible to improve the performance of the receiver compared to the conventionally proposed structure. However, it basically uses double frequency conversion, and its structure and measuring method vary greatly depending on the use of a tracking filter at the tuner front end. In other words, when the broadcasting frequency band is divided into three bands (VHF_LOW, VHF_HIGH UHF) using the dual frequency conversion and the tuning filter at the front end of the tuner, intermodulation and crossover caused by receiver linearity expansion and out-of-band interference signals are processed. The modulation and saturation characteristics are improved, but the structure is complicated, a tuner controller for frequency mapping between the tuner pre-end and the first voltage controlled oscillator (VCO) is required, and additional software (S / W) is required.

Accordingly, in a digital broadcast tuner including a dual frequency conversion function, a tracking filter, and a tuner controller, accurate frequency mapping is performed between an active tracking filter for frequency band division and a voltage controlled oscillator (VCO) for dual frequency conversion. A method for accurately and automatically processing frequency error correction caused by a change in characteristics of components (varactor diodes, inductors, and capacitors) used in a tracking filter due to environmental changes such as temperature rise is essential.

SUMMARY OF THE INVENTION The present invention has been proposed to meet the above demands, and has been disclosed in the digital broadcasting tuner including a double frequency conversion function, a tracking filter, and a tuner controller, wherein the active tracking filter and the dual frequency for frequency band division are provided. Performs accurate frequency mapping between voltage controlled oscillators (VCOs) for conversion, and eliminates frequency operation abnormalities due to changes in the characteristics of components (varactor diodes, inductors, and capacitors) used in tracking filters due to environmental changes such as temperature rise. It is an object of the present invention to provide a method for automatically measuring and correcting a digital broadcast tuner for correcting and a computer-readable recording medium recording a program for realizing the method.

1 is a configuration diagram of one embodiment of a conventional DTV tuner (Tuner) including a dual frequency conversion function.

2 is a diagram illustrating a configuration of a DTV tuner including a conventional dual frequency conversion function and a band division filter.

3 is a diagram illustrating an embodiment of a DTV tuner including a dual frequency conversion function, a tracking filter, and a tuner controller to which the present invention is applied.

Figure 4 is an embodiment explanatory diagram of the initialization process of the digital broadcast tuner automatic measurement and correction method according to the present invention.

5 is a diagram illustrating an embodiment of a frequency mapping measurement process in a normal operation state of a digital broadcasting tuner automatic measurement and correction method according to the present invention;

Figure 6 is a flow diagram of an embodiment of the frequency mapping and measurement process of the digital broadcast tuner automatic measurement and correction method according to the present invention.

7 is a diagram illustrating an embodiment of an output waveform of 8-VSB modulation according to the present invention.

8 is an exemplary explanatory diagram of an output characteristic of a tuner measured in a normal state according to the present invention.

9 is a diagram illustrating an embodiment of an optimization process for frequency error correction in a digital broadcast tuner automatic measurement and correction method according to the present invention;

* Description of the symbols for the main parts of the drawings 30: DTV tuner 31: Frequency band divider 311: Band pass filter 312: Active tracking filter 32: Frequency up adjuster 33: Frequency down adjuster 34: Dual frequency controller 341: First phase synchronization Loop 342: second phase locked loop 35: tuner controller

900: 8-VSB Modulator 903: Spectrum Analyzer

904: Power Supply 905: Notebook

906: GPIB

In order to achieve the above object, the present invention provides a digital broadcast tuner automatic measurement and correction method, the frequency characteristics according to the frequency tuning voltage of the active traffic filter for each frequency band using a vector network analyzer and an external computer connected to the digital broadcast tuner. A first step of measuring a value, calculating a coefficient value for each frequency band by using an approximation function for frequency mapping with a voltage controlled oscillator (VCO), and storing the calculated coefficient value in a storage device of a tuner controller; The tuner controller performs frequency mapping on the active traffic filter using coefficient values of the corresponding frequency band stored in the storage device according to the control signal for each digital broadcasting channel from the external computer, and performs the frequency mapping through the spectrum analyzer. A second step of outputting a result; And a third step of the tuner controller correcting an abnormal frequency operation by updating a coefficient value of a corresponding frequency band stored in the storage device for frequency mapping in response to a frequency correction request from the external computer.

In addition, the present invention, in the digital broadcasting tuner automatic measurement and correction system equipped with a processor, by using a vector network analyzer and an external computer connected to the digital broadcasting tuner frequency characteristics according to the frequency tuning voltage of the active traffic filter for each frequency band A first function of measuring, counting coefficient values for each frequency band by using an approximation function for frequency mapping with a voltage controlled oscillator (VCO), and then storing them in a storage device of a tuner controller; The tuner controller performs frequency mapping on the active traffic filter using coefficient values of the corresponding frequency band stored in the storage device according to the control signal for each digital broadcasting channel from the external computer, and performs the frequency mapping through the spectrum analyzer. A second function of outputting a result; And a program for the tuner controller to update a coefficient value of a corresponding frequency band stored in the storage device for frequency mapping in response to a frequency correction request from the external computer, thereby realizing a third function of correcting an abnormal frequency operation. Provide a computer-readable recording medium for recording.

Currently, for analog broadcasting and digital broadcasting The most difficult part in mass production of a TV receiver is the efficient manufacture of the tuner, and the abnormal operation of the tuner (the frequency characteristic change is most) accounts for most of the causes of the TV receiver failure. Therefore, if the operation abnormality (error) caused by the change in the frequency characteristic of the tuner can be efficiently compensated, the time and cost required for the manufacture and maintenance of the tuner can be greatly reduced.

The present invention relates to the frequency tuning voltage on the structural characteristics (including dual frequency conversion + tracking filter) of the tuner for terrestrial DTV receivers currently commercially developed to correct an operation abnormality (error) caused by such a change in the frequency characteristic of the tuner. Tuner malfunction and use due to environmental changes that may occur during the realization of frequency mapping between the active tracking filter and the voltage-controlled oscillator (VCO), in particular the frequency characteristics of components (such as varactor diodes) with temperature rise. We present a method that can efficiently and accurately compensate for frequency variations due to manufacturing errors of components (inductors, capacitors, and varactor diodes).

That is, the present invention performs accurate frequency mapping between a dual frequency conversion function, an active tracking filter for frequency band division, and a voltage controlled oscillator (VCO) for dual frequency conversion, and a tracking filter according to environmental changes such as a temperature rise. By precisely and automatically correcting the frequency error due to the change of characteristics of the components (varactor diode, inductor and capacitor) used in the system, it is possible to realize an automatic digital tuner measurement system for the tuner, which is very efficient for the aspect and maintenance of the tuner.

In particular, when the device of the present invention is applied to a DTV tuner, interference suppression of interference signals that may degrade the quality of a TV channel to be watched or cause a state in which TV broadcasting itself is impossible through the automatic selection function of a desired TV channel is prevented. In addition to suppressing the video signal and the IF Beat component, the frequency error correction function according to the operating environment can be accurately performed.

That is, the intermodulation, cross-modulation and saturation characteristics caused by the interference signals can be suppressed by using the active tracking filter 312 of the tuner front end (frequency band division), and the image signal and the IF Beat component are The suppression is possible by the dual frequency conversion in the frequency uplink adjusting unit 32 and the frequency downlink adjusting unit 33. The frequency mapping between the active tracking filter 312 for frequency band division and the voltage controlled oscillator (VCO) for dual frequency conversion, which is a structural disadvantage, is processed using the tuner controller 35, and the environment such as temperature The frequency change of the active tracking filter 312 according to the change can be processed by using a measuring device for frequency correction, which can improve the performance of the terrestrial digital broadcasting receiver, as well as time and cost in the actual commercial product development and maintenance. You can save.

The digital broadcast tuner to which the present invention is applied should include the following functions.

First, convert the received input frequency (50 ~ 810MHz) to the final intermediate frequency (44MHz).

Second, active tracking filtering is performed for band division selection of the wideband input frequency and low noise amplification.

Third, it performs channel frequency tuning function.

Fourth, it performs reception gain control through AGC (Automatic Gain Control) adjustment signal.

Fifth, it performs video signal removal and channel out-of-band signal filtering.

As described above, since the DTV tuner is the most important RF module that determines the reception performance of the TV, the frequency characteristics are influenced by environmental influences such as error and temperature due to the characteristics of components such as inductors and varactor diodes used in the tracking filter. If this changes, you should be able to adjust it. In addition, it should be developed to minimize the time required for the development of commercial products. In the following description, frequency mapping and errors according to environmental changes (errors of components due to frequency and temperature characteristics) of the digital broadcasting tuner according to the present invention. In the measurement method for correction, the description is divided into three steps, that is, an initialization process, a normal operation process (frequency mapping process), and an optimization process (calibration process).

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, an initialization process for frequency mapping will be described with reference to FIG. 3. FIG. 3 is a diagram illustrating an embodiment of a DTV tuner including a dual frequency conversion function, a tracking filter, and a tuner controller to which the present invention is applied. In FIG. 3, the frequency mapping between the active tracking filter 312 and the first voltage controlled oscillator (VCO) 340 is shown in FIG.

FIG. 4 is a diagram illustrating an embodiment of an initialization process in a digital broadcast tuner automatic measurement and correction method according to the present invention.

Input / output terminals 410 and 412 of the frequency band divider 31 including the active tracking filter 312 are connected to the vector network analyzer 403 to connect the power supply line 413 with the power supply 404. The frequency output characteristic is measured when the tracking filter tuning voltage is applied. In addition, the connection lines 414, 415, 416, including the General Purpose Interface Bus (GPIB) 406 and the Notebook 405, allow the tuning voltage, which exhibits optimal frequency characteristics, to be automatically stored in the notebook 405.

That is, as illustrated in FIG. 4, the frequency characteristics of the active tracking filter 312 (between 0 and 30V) of each frequency band are measured using the vector network analyzer 403. In the actual measurement, the bandwidth of the "VHF_LOW" band is about 10MHz, the bandwidth of the "VHF_HIGH" band is about 20MHz, and the bandwidth of the "UHF" band is about 30MHz, and DC provides symmetrical band characteristics at the center frequency of the TV channel. After applying the value, these DC values are stored in the notebook 405.

The DC values for each TV channel of the frequency bands measured in this way are each obtained using software (S / W) built into the notebook 405 (using an approximation function for frequency mapping in Equation 1 below). Find the coefficient value for each frequency band. For example, the coefficient values of [Equation 1] calculated in the channels of three frequency bands (VHF_LOW, VHF_HIGH, and UHF) total 18 (3 × 6 (count values of A0 to A5)). Here, the approximation function for frequency mapping is a 5th order polynomial, and the equation of DC value for each TV channel of each frequency band is shown in Equation 1 below.

Here, X is the center frequency (CENTER FREQUENCY (TV channels)), A0, A1, A2, A3, A4, A5 represent approximation coefficients.

The calculated total 18 frequency band coefficient values are transferred from the notebook 405 to the tuner controller 35 as shown in FIG. 5 and stored in the EEPROM (Electrically Erasable and Programmable ROM) of the tuner controller 35. This is used as the initial value of the tuner operation.

Next, a normal operation process using frequency mapping is as follows.

First, a measurement apparatus and method for frequency mapping in the normal operation of the tuner through an initialization process for frequency mapping will be described with reference to FIGS. 5 and 6.

FIG. 5 is an exemplary diagram illustrating a frequency mapping measurement process in a normal operating state of a digital broadcasting tuner automatic measurement and correction method according to the present invention.

As shown in FIG. 5, the measurement apparatus for frequency mapping is composed of a DTV tuner 30, an 8-VSB modulator 500, a tuner controller 35, a spectrum analyzer 503, and a notebook 504.

First, when the DTV channel signal is applied to the DTV tuner 30 from the 8-VSB (Vestigial Side Bands) modulator 500 through the signal line 510, the output of the active tracking filter 312 of the DTV tuner 30 is increased in frequency. In the adjusting section 32 and the frequency down-regulating section 33, two phase locked loops (PLLs) 341 and 342 are frequency-mixed in turn, and a final intermediate frequency (IF) of 44 MHz is transmitted through the signal line 512. It is output to the analyzer 503. In addition, the notebook computer 503 uses an IIC-BUS signal (PLL data and clock signal) containing frequency information capable of driving two phase locked loops (PLLs) 341 and 342 in the DTV tuner 30. Tuner controller 35 is controlled to apply via 515.

At this time, the signal transmitted through the signal line 513 is tuned for applying the switching information and the frequency information stored in the EEPROM (Electrically Erasable Programmable Read Only Memory) of the tuner controller 35 to the active tracking filter of the DTV tuner 30. DC voltage.

On the other hand, the operation of the S / W stored in the EEPROM of the tuner controller 35 is the same as FIG.

FIG. 6 is a diagram illustrating an embodiment of a frequency mapping and measuring process in a digital broadcasting tuner automatic measurement and correction method according to the present invention.

First, the coefficients A0 to A5 of the 18 approximation functions obtained through the initialization process are stored in the EEPROM of the tuner controller 35 through the signal line 515 of the notebook 504 of FIG. After initializing the data of the microprocessor, memory and EEPROM of the controller 35 (601), IIC-BUS (PLL data and the frequency information from the external main microcontroller (here, using the notebook 504) and Clock signal) is applied to the tuner controller 35, the tuner controller 35 decodes (602) which frequency the IIC-BUS signal represents.

Subsequently, the microprocessor of the tuner controller 35 determines whether channel switching is necessary (603). If channel switching is necessary, the microprocessor of the tuner controller 35 sets the operation value of the first phase locked loop (1st PLL) 341 using the decoded frequency information. 604, a variable for band switching is obtained (605).

Subsequently, the corresponding frequency component value is calculated using the F (X) function of Equation 1 above (606), and the calculated value of F (X) is converted into D / A (Digital /) in the tuner controller 35. Analog) The calculated value of F (X) is then set 607 to analog values and provides this value to the corresponding frequency tuning voltage of the active tracking filter 312 (608). Thereafter, the process proceeds to a frequency decoding process 602 according to the input signal.

On the other hand, as a result of determining whether channel switching is necessary (603), if channel switching is not necessary, after performing a function (conversion of frequency characteristic data values stored in EEPROM) according to other commands (609), a frequency decoding process according to an input signal (602) Proceed to). That is, the signal applied to the 8-VSB modulator 500 (FIG. 7, DTV channel 14, tuner applied power: -50 dBm) in the normal state where the frequency characteristic of each band does not change is changed through FIG. 8 through the spectrum analyzer 503. Output characteristics such as (tuner output frequency: 44 MHz, output power: -12.5 dBm) are obtained.

Finally, the optimization process for frequency error correction is as follows.

When the frequency characteristics of a normal DTV tuner are changed due to environmental influences such as temperature, or the newly manufactured tuner is measured through a normal operation process using the frequency mapping, and as a result of errors in component manufacturing, as shown in FIG. If a result other than the measurement result appears, the following frequency error correction process is performed. That is, for example, if the frequency characteristic is changed due to environmental influences such as temperature, and the 8-VSB signal is measured at the left or right side without being located at the center (center frequency of 44 MHz), as shown in FIG. 9. Similarly, the measurement device is configured to obtain the desired frequency characteristics by modifying the frequency tuning voltage applied to the active tracking filter of the DTV tuner.

Since the present invention includes all of the measurement apparatus of FIGS. 4, 5 and 6, the 8-VSB modulator 900, the DTV tuner 30, the tuner controller 35, the spectrum analyzer 903, the power supply 904 , Notebook 905, GPIB 906.

The optimization process for frequency error correction is performed as follows.

First, the signal of each DTV channel is applied to the DTV tuner 30 through the 8-VSB modulator 900 to measure the degree of change of frequency characteristics through a normal operation process using the frequency mapping. At this time, the tuner controller 35 receives the IIC-BUS signal applied through the signal line 915 of the notebook 905 in response to the frequency correction request from the notebook 905, so that only the frequency information of the PLL is received by the DTV tuner 30. Is applied through the signal line 912, and the tuning voltage of the tuner tracking filter is applied through the signal line 914 of the power supply 904. In order to obtain the output characteristics as shown in FIG. 8, the spectrum analyzer (903, 44 MHz ± 3 MHz) is set by changing the applied DC value of the power supply 904 to a step of 0.05 V in the range of ± 0.5 V of the tuning voltage value for each TV channel. The output characteristic of the marking (marked at) is measured. At this time, the output frequency characteristic displayed on the screen of the spectrum analyzer 903 changes according to the applied tuning DC voltage. When the output characteristics of the tuner are the minimum of the gain variation of the 8-VSB output signal at ± 3 MHz at the center frequency of 44 MHz, that is, select a DC voltage value exhibiting the output characteristic that is most similar to that of FIG. (905). The stored DC voltage values are calculated through the software built into the notebook 405, and the frequency mapping coefficient values (18 in total) of Equation 1 are updated, and then the frequency band coefficient values received through the signal line 915 are updated. By changing and storing the initial frequency mapping coefficient values already stored in the EEPROM of the tuner controller 35 upon request, the changed frequency characteristics can be corrected accurately. On the other hand, the frequency for the active tracking filter of the DTV tuner 30 can be corrected. The tuning voltage is applied via the signal line 913 of the tuner controller 35 rather than the power supply 904. The method according to the optimization process through the frequency error correction is performed after performing a function according to other commands (609, the frequency characteristic data value stored in the EEPROM) (609), and repeats the normal process (601 ~ 608) of FIG. Check if there is any frequency error correction.

In conclusion, when the measurement apparatus of FIG. 9 proposed in the present invention is used, frequency calibration of a normal DTV tuner and frequency calibration for frequency error correction according to environmental changes are easily performed, thereby improving performance of the DTV tuner. Not only is it possible to manufacture it, but it is also very efficient because it saves time and cost for maintenance of commercial product development and breakdown.

The method of the present invention as described above may be implemented as a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.). Since this process can be easily implemented by those skilled in the art will not be described in more detail.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, the present invention provides a digital broadcast tuner including a double frequency conversion function, a tracking filter, and a tuner controller, wherein the active tracking filter for frequency band division and the voltage controlled oscillator (VCO) for dual frequency conversion are provided. It is effective to accurately and automatically handle frequency error correction according to environmental changes such as accurate frequency mapping and temperature between them. Therefore, when the apparatus of the present invention is applied to a DTV tuner, the interference signal suppression may be performed through the automatic selection function of the desired TV channel, which may degrade the quality of the TV channel to be watched or cause the TV broadcast itself to be impossible. Not only is it possible to operate regardless of the video signal and IF Beat component, and it is also possible to accurately perform the frequency error correction function according to the operating environment.

In addition, the present invention can effectively reduce the frequency error in response to changes in the frequency characteristics of the tracking filter due to environmental changes, thereby greatly reducing the time and effort required for commercial product development and maintenance.

Claims (7)

In the digital broadcast tuner automatic measurement and correction method, Using a vector network analyzer and an external computer connected to the digital broadcast tuner, the frequency characteristics of each active frequency filter are measured according to the frequency tuning voltage of the active traffic filter, and each function is approximated using an approximation function for frequency mapping with a voltage controlled oscillator (VCO). A first step of calculating a count value for each frequency band and storing the count value in a storage device of the tuner controller; The tuner controller performs frequency mapping on the active traffic filter using coefficient values of the corresponding frequency band stored in the storage device according to the control signal for each digital broadcasting channel from the external computer, and performs the frequency mapping through the spectrum analyzer. A second step of outputting a result; And A third step of the tuner controller correcting an abnormal frequency operation by updating a coefficient value of a corresponding frequency band stored for frequency mapping in the storage device in response to a frequency correction request from the external computer; Tuner automatic measurement and correction method for digital broadcasting comprising a. The method of claim 1, The first step is, In order to measure the frequency characteristics according to the frequency tuning voltage of the active tracking filter for each frequency band by using a vector network analyzer and an external computer connected to the digital broadcasting tuner, a voltage value providing symmetrical band characteristics at the center frequency of the channel is active. A fourth step of applying the result to a traffic filter and storing the result in the external computer; A fifth step of the external computer calculating coefficient values for each frequency band by using an approximation function for frequency mapping with the voltage controlled oscillator (VCO) from the stored voltage values; And A sixth step in which the tuner controller receives the calculated coefficient values for each frequency band from the external computer and stores them in the storage device as initial values; Tuner automatic measurement and correction method for digital broadcasting comprising a. The method of claim 2, In the fifth step of calculating a coefficient value for each frequency band by using an approximation function, An automatic measurement and correction method for a digital broadcast tuner, which is calculated by the following equation. F (X) = A0 + A1X + A2X ² + A3X ³ + A4X ⁴ + A5X ⁵ Where X is the center frequency (CENTER FREQUENCY) and A0, A1, A2, A3, A4, and A5 represent approximate coefficients. The method according to any one of claims 1 to 3, The second step, A seventh step of receiving, by the tuner controller, a control signal (phase synchronization loop data and a clock signal) including frequency information from the external computer; An eighth step of the tuner controller decoding frequency information according to the received control signal and determining whether channel switching is necessary; As a result of the determination of the eighth step, if the channel switching is necessary, the operation value of the first phase synchronization loop is set using the decoded frequency information, the variable for band switching is obtained, and the corresponding frequency stored in the storage device. A ninth step of performing frequency mapping on the active traffic filter using coefficient values of a band and outputting the result through the spectrum analyzer; And As a result of the determination of the eighth step, if channel switching is not necessary, frequency mapping is performed on the active traffic filter using coefficient values of the corresponding frequency band stored in the storage device, and the result is output through the spectrum analyzer. Tenth step Tuner automatic measurement and correction method for digital broadcasting comprising a. The method of claim 4, wherein The third step, An eleventh step of the tuner controller changing the frequency tuning voltage value from the reference tuning voltage value in a predetermined step and applying the frequency tuning voltage value to the active traffic filter according to a frequency correction request from the external computer; A twelve step of the tuner controller correcting an abnormal frequency operation by updating a coefficient value of a corresponding frequency band stored for frequency mapping in the storage device according to a request for updating a frequency band coefficient value from the external computer; And A thirteenth step in which the tuner controller applies a frequency tuning voltage value corresponding to the coefficient value of the updated frequency band to the active traffic filter, and outputs the result through the spectrum analyzer to provide a frequency correction result; Tuner automatic measurement and correction method for digital broadcasting comprising a. Digital broadcast tuner automatic measurement and correction system with a processor, Using a vector network analyzer and an external computer connected to the digital broadcast tuner, the frequency characteristics of each active frequency filter are measured according to the frequency tuning voltage of the active traffic filter, and each function is approximated using an approximation function for frequency mapping with a voltage controlled oscillator (VCO). A first function of calculating a count value for each frequency band and storing the count value in a storage device of the tuner controller; The tuner controller performs frequency mapping on the active traffic filter using coefficient values of the corresponding frequency band stored in the storage device according to the control signal for each digital broadcasting channel from the external computer, and performs the frequency mapping through the spectrum analyzer. A second function of outputting a result; And A third function of correcting a frequency operation abnormality by the tuner controller updating a coefficient value of a corresponding frequency band stored for frequency mapping in the storage device in response to a frequency correction request from the external computer; A computer-readable recording medium having recorded thereon a program for realizing this. delete