1291809 九、發明說明： 【發明所屬之技術領域】 本發明提供一種電視調諧器 尤指一種雙重轉換電視調諧器。 【先前技術】 在電視祕當巾，調雜（tune相成柄常在整體成本中佔 有不小的比重。爾著個人電腦技術不斷進步，將電視的功能整 合_人賴祕歧其他㈣子裝置，故對繼職本降低的 考篁愈顯重要。舰論上來講，職器包含有兩個主要的组件。 第-個組件係用來執行高頻至中頻（或是射頻至中頻）的轉換； 第二個組制制來執射駐基躺轉換。 近成年來吊見的消費性電子裝置中常見的作法是將調譜器當 成獨立的兀件，連接於一顯示器，但調諧器本身並不是顯示器 内建的-料。如續述，電視觸料以是絲造於電路版上， 後才被裝《在個人電職統當中，故個人電腦亦可以具有電視 的功犯。逆樣的㈣器可以將—射頻電視訊號轉變成—基頻（或 低頻）視1峨然後再將基頻（或低頻）視訊訊號傳送至個人 電腦内的其他元件，以進行視訊處理的工作。 1291809 用—來執行射頻至帽職㈣路組件通常會需—频電路，以 及大量的如紐、電容、電晶體料離散的元件。絲執行中頻 至基頻轉換的電路組件則通常需—積體電路、—些濾波器元件、 一系列的觸及㈣元件、以及其他額相外部元件，因此整個 調譜器實際上會具有相當的複雜度。糾，現今可⑽電視調譜 益多半還是設計成可以在出薇之前藉由手_方式進行調譜工 作。以手_方式進行_工刺通常會縣歓的成本，而成 為整個調諧器成本中不小的一部分。 在技術進展的過程中，發展出來的表面較渡波器（Mace 贿sticwavefUter，SAWfllter)對機器的發展提供了極大的助 益’許多需要經由手動校調的電感與電容都可以自調譜器中移 除’並且對接收峨喊波效能可以在使用較小的體積與較低的 成本下，達到更佳的效果。然而，表面聲波舰器係設置於陶究 基底（ceramicsubstrate)之上，並無法與剩下的主動電路一同積 體化在-⑨晶元上，在設計巾鋪必須是離_組件，而使得調 譜器的體積難以縮小。-般而言，#調諧器被使用於電視機中時， 調譜器的大小JM；是非常重要’因為電視機通常都具有相當大的 體積。但是當織妓被使用在其他電子錢㈣，體積^變成 了一個非常重要的考量因素了。 1291809 第1圖為3知之調諧器1〇〇的示意圖（由美國第5,737,〇35 號專利案件所揭露）。然而，由於調諧器議中必須使用特殊的鏡 像排斥型混波器來作為第二混波器應，調譜器綱整體的成本會 文得車乂回另外’第一本地振盪器1〇4可與第一混波器撤一同 用來對自$入射頻訊號中選擇出的一特定的通道進行上轉換 (p convert)這思味了弟一本地振|器必須是一個可變頻率 的本地振盪器，具有一較大的操作頻率範圍。而由於在第一本地 振蓋to 104之操作頻率趟圍内的相位雜訊（沖&5^n〇ise)必須符合 一特定的相位雜訊限制（通常是-84 dBC/Hz),此時必須使用複數 個具有較小頻率範圍的壓控振盪器（VC0)以降低相位雜訊。這 亦會對增加電視調諧器1〇〇的複雜度與整體成本。 【發明内容】 因此本發明的一個目的在於提供一種雙重轉換電視調諧器，以 降低整體系統成本。 根據本發明一申請專利範圍，係揭露一種電視調諧器，包含 有：一第一混波器，用來將一接收射頻訊號轉換成一中頻訊號； 一帶通濾波器，耦合於該第一諧波混波器，用來對該中頻訊號進 行濾波以產生一帶通訊號；一第二諧波混波器，耦合於該帶通濾 波器’用來直接將該帶通訊號轉換成一同相基頻訊號；以及一第 1291809 三諧波混波裔’搞合於禮帶通濾、波器，用來直接將該帶通訊號轉 換成一正交基頻訊號。 根據本發明又一申清專利範圍’係揭露一種方法，用來處理一 接收射頻訊號’该方法包含有以下步驟··對該接收射頻訊號進行 混波以產生一中頻訊號；對該中頻訊號進行濾波以產生一帶通訊 號；對該帶通訊號進行混波以產生一同相基頻訊號；以及對該帶 通訊號進行混波以產生一正交基頻訊號。 【實施方式】 請參閱第2圖，第2圖為本發明一實施例之雙重轉換（d〇ubie conversion)電視調諧器200的示意圖。本實施例中的電視調譜器 200包含有：一低雜訊放大器202，一第一諧波混波器204，一第 一本地振盪器206，一帶通濾波器210，一第二本地振盪器212， 一第二譜波混波器214，一第一同相基頻放大器216，一同相低通 濾波器218, 一第二同相基頻放大器220, 一第三諧波混波器222， 一第一正交基頻放大器224，一正交低通濾波器226，以及一第二 正交基頻放大器228。 一接收射頻訊號RF_IN係經由低雜訊放大器202進行放大，而 耦合至第一諧波混波器204的一輸入端。雖然在本實施例中係使 1291809 白波此波的來作為混波器2〇4，然❿，以其他麵的混波器作為 :波為2G4亦是可行的作法。至於諧波混波器的操作方式與架構 睛茶考於2004年4月申請的台灣第〇93 j_94號專利申請案件「被 動邊波混波器」（Passive Harmonic Mixer )。 於本貝把例中’弟一本地振盪器206係操作於一可變的第一頻 率’並可提供一 〇。相位延遲的參考訊號以及一 9〇。相位延遲的參 考訊號。依據帶通濾波器21〇頻寬内的中心頻率，第一諧波混波 器204的輸出在接收射頻訊號中位於122〇廳2或丨㈣應冗之處 具有一所欲之通道。帶通濾、波器21〇的輸出會被摩馬合至第二諧波 混波器214的輸入端與第三譜波混波器222的輸入端。第二本地 振盪器212係操作於—固定的第二頻率（當輸人頻率為·顧2 時，该第二頻率為61〇MHz ;當輸入頻率為i〇9〇MHz時，該第二 頻率則為545MHz)，可以提供一 〇。相位延遲的參考訊號、一 45。 相位延遲的參考訊號，一 90。相位延遲的參考訊號，以及一 135。 相位延遲的參考訊號。第二諧波混波器214所輪出的係為一同相 (in-phase)基頻訊號，第三諧波混波器222所輸出的則是一正交 (quadrature)基頻訊號。第一同相基頻放大器216、同相低通濾 波态218、以及第二同相基頻放大器220可對同相基頻訊號進行滤 波及放大，以供電視接收器之後級進行處理。同樣的，第一正交 基頻放大器224、正交低通濾波器226、以及第二正交基頻放大器 1291809 228可對正交基頻訊號進行濾波及放大，以供電視接收器之後級進 行處理。經過整合後，第二同相放大器所輸出的I訊號與第二正交 放大器所輸出的Q訊號可以形成一基頻視訊訊號，然後可再被傳 送至其他視訊處理元件進行處理。 由於使用了一諧波架構（harmonic architecture)，第一本地振盪 器206所輸出之〇。相位延遲的參考訊號與9〇。相位延遲的參考訊 號的頻率範圍乃介於635MHz與1040MHz之間（這是在使用中心 頻率為1220MHZ的表面聲波濾波器21〇時的情形這樣的頻率 範圍是第1圖所示習知電視調諧器的一半，這也表示了，本發明 在對第一本地振盪器206設計時VC〇的架構可以大為簡化就可以 達成相同的相位雜訊限制（通常是一84 dBC/Hz)。基於上述兩個原 因’本發明對電視調諧器的設計的確可以大為簡化，且在電視調 谐裔200的成本也會大為降低。 至於電視調諧器200的第二級係構成一直接轉換接收器 (DCR)。由f通濾、波益210所輸出的帶通訊號（baruj pass signai) 會被直接轉換至基頻。上述的直接轉換架構包含有一同相（〗）路 徑與一正交（Q)路徑，用來直接將帶通訊號轉換成基頻訊號。由 於使用到了直接轉換的架構，在本實施例中並沒有第二中頻的存 在。另外在這個實施例中，本發明係使用了兩個諧波混波器，其 11 12918091291809 IX. Description of the Invention: [Technical Field] The present invention provides a television tuner, especially a dual conversion television tuner. [Prior technology] In the TV secret towel, tune (tune phase handle often occupies a large proportion in the overall cost. The personal computer technology continues to improve, the function of the TV integration _ people rely on the other (four) sub-device Therefore, the examination of the reduction of succession is becoming more and more important. In terms of ship theory, the server contains two main components. The first component is used to perform high frequency to intermediate frequency (or RF to intermediate frequency). The second group of systems to perform the base-based conversion. A common practice in consumer electronic devices that has been hoisted in adulthood is to use the spectrometer as a separate component that is connected to a display, but the tuner It is not built-in in the display itself. As mentioned in the continuation, the TV touch is made on the circuit board, and then it is installed in the personal electric system. Therefore, the personal computer can also have the conviction of TV. The (4) device can convert the RF TV signal into a fundamental frequency (or low frequency) and then transmit the fundamental (or low frequency) video signal to other components in the personal computer for video processing. Use - to perform RF Cap-type (four)-channel components usually require frequency-frequency circuits, as well as a large number of discrete components such as nucleus, capacitors, and transistors. The circuit components that perform intermediate-frequency to fundamental-frequency conversion usually require integrated circuits and filters. Components, a series of touches (4) components, and other front-phase external components, so the entire spectrometer will actually have considerable complexity. Correction, nowadays (10) TV tuning is mostly designed to be used before the Weiwei Hand _ way to do the spectrum work. The hand _ way _ work thorns usually cost the county, and become a part of the overall tuner cost. In the process of technological progress, the development of the surface is better than the wave filter ( Mace bribe sticwavefUter, SAWfllter) has greatly contributed to the development of the machine 'many of the inductors and capacitors that need to be manually calibrated can be removed from the self-adjusting spectrum' and the performance of receiving shouting waves can be used in smaller Better results with lower volume and lower cost. However, the surface acoustic wave system is placed on the ceramic substrate and cannot be with the rest. The dynamic circuit is integrated on the -9-element, and the design of the towel must be away from the _ component, making the volume of the tuners difficult to shrink. - Generally, when the # tuner is used in a television set, The size of the spectrometer JM; is very important 'because TV sets usually have a considerable size. But when woven plaque is used in other electronic money (four), volume ^ becomes a very important consideration. 1291809 3 Schematic diagram of the tuner 1 (disclosed by the US Patent No. 5, 737, No. 35). However, since the tuner must use a special mirror-repellent type mixer as the second mixer, The overall cost of the spectrometer will be transcribed. The first local oscillator 1〇4 can be used together with the first mixer to perform a specific channel selected from the incoming RF signal. P convert This is a local oscillator that has a variable frequency and has a large operating frequency range. Since the phase noise (punch & 5^n〇ise) within the operating frequency range of the first local oscillating to 104 must conform to a specific phase noise limit (usually -84 dBC/Hz), this A number of voltage controlled oscillators (VC0) with a small frequency range must be used to reduce phase noise. This will also increase the complexity and overall cost of the TV tuner. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a dual conversion television tuner to reduce overall system cost. According to a patent application of the present invention, a television tuner includes: a first mixer for converting a received RF signal into an intermediate frequency signal; and a band pass filter coupled to the first harmonic a mixer for filtering the intermediate frequency signal to generate a band communication number; a second harmonic mixer coupled to the band pass filter for directly converting the band communication signal to an in-phase fundamental frequency The signal; and a 1291809 three-harmonic mixed-wave family' engages in a ritual pass filter and a wave device for directly converting the band communication signal into an orthogonal fundamental frequency signal. According to another aspect of the present invention, a method for processing a received RF signal is disclosed. The method includes the following steps: - mixing the received RF signal to generate an intermediate frequency signal; The signal is filtered to generate a band communication number; the band communication signal is mixed to generate an in-phase baseband signal; and the band communication number is mixed to generate an orthogonal baseband signal. [Embodiment] Please refer to FIG. 2, which is a schematic diagram of a dual conversion (D〇ubie conversion) TV tuner 200 according to an embodiment of the present invention. The TV spectrometer 200 in this embodiment includes: a low noise amplifier 202, a first harmonic mixer 204, a first local oscillator 206, a bandpass filter 210, and a second local oscillator. 212, a second spectral wave mixer 214, a first in-phase baseband amplifier 216, a non-inverting low pass filter 218, a second in-phase baseband amplifier 220, and a third harmonic mixer 222, A first quadrature baseband amplifier 224, an orthogonal low pass filter 226, and a second quadrature baseband amplifier 228. A receive RF signal RF_IN is amplified by a low noise amplifier 202 and coupled to an input of the first harmonic mixer 204. Although in the present embodiment, the wave of 1291809 white wave is used as the mixer 2〇4, it is also possible to use the mixer of the other surface as the wave 2G4. As for the operation mode and architecture of the harmonic mixer, the tea application was filed in April 2004 in Taiwan's No. 93 j_94 patent application "Passive Harmonic Mixer". In the example of Benbe, the "one local oscillator 206 operates at a variable first frequency" and provides a 〇. The phase delay reference signal and a 9 〇. Reference signal for phase delay. Depending on the center frequency within the bandwidth of the bandpass filter 21, the output of the first harmonic mixer 204 has a desired path in the received RF signal at 122 〇 2 or 丨 (4). The output of the band pass filter, wave 21 会 is coupled to the input of the second harmonic mixer 214 and the input of the third spectral wave mixer 222 by the horse. The second local oscillator 212 operates on a fixed second frequency (the second frequency is 61 〇 MHz when the input frequency is 顾 2; the second frequency is when the input frequency is i 〇 9 〇 MHz) It is 545MHz) and can be provided. Phase delay reference signal, a 45. The phase delay reference signal, a 90. The phase delay reference signal, and a 135. Phase delay reference signal. The second harmonic mixer 214 rotates in an in-phase fundamental frequency signal, and the third harmonic mixer 222 outputs a quadrature fundamental frequency signal. The first in-phase baseband amplifier 216, the in-phase low-pass filter state 218, and the second in-phase baseband amplifier 220 can filter and amplify the in-phase baseband signal for processing by the television receiver. Similarly, the first quadrature baseband amplifier 224, the quadrature low-pass filter 226, and the second quadrature baseband amplifier 1291809 228 can filter and amplify the quadrature baseband signal for later stages of the television receiver. deal with. After integration, the I signal output by the second non-inverting amplifier and the Q signal output by the second quadrature amplifier can form a fundamental video signal, which can then be transmitted to other video processing components for processing. The output of the first local oscillator 206 is due to the use of a harmonic architecture. The phase delay reference signal is 9〇. The frequency range of the phase-delayed reference signal is between 635MHz and 1040MHz (this is the case when the surface acoustic wave filter 21中心 with a center frequency of 1220 MHz is used. The frequency range is the conventional television tuner shown in FIG. In half, this also means that the design of the VC〇 in the design of the first local oscillator 206 can be greatly simplified to achieve the same phase noise limitation (usually a 84 dBC/Hz). The reason for the invention is that the design of the television tuner can be greatly simplified, and the cost of the television tuner 200 is also greatly reduced. As for the second stage of the television tuner 200, a direct conversion receiver (DCR) is constructed. The baruj pass signai output by the f-pass filter and the wave benefit 210 is directly converted to the base frequency. The above direct conversion architecture includes an in-phase (〗) path and an orthogonal (Q) path. To directly convert the band communication signal into a baseband signal. Since the direct conversion architecture is used, there is no second intermediate frequency in this embodiment. In addition, in this embodiment, the present invention is The two harmonic mixers, which 111,291,809
中-個係位於同相⑴路獲中，另一個則為於正交⑼路徑中 因此，弟-本地振盧器212會固定操作於61略（這是在使用中 心頻率為122_的表面聲波驗_時的情形），這是第i 圖所不第二本地振盪器⑽操作頻率的—半。就其本身而論，在 習知的電視調譜器中’必須使用額外的頻率轉換級來將輸出的 Hout域轉換至細，耐本發_沒有這制需求。另 外’同相·慮波器218與正交低通渡波器226都可以是簡易型 的低通濾波器，可以製造於一積體電路上。第丨圖所示習知的電 視調諧ϋ係使關了麵歧龍4，聽具有鏡像财（_ rejection)的功能’通常都會概置在晶片之外，而藉由本發明將 直接轉換雜歸諧波毅11 _實施枝，整個電視觸器200 的複雜度與成本都可以大為降低。 本發明係在為波混波為中使用了直接轉換的架構以在使用單 一中頻的情形下，將一接收射頻訊號轉換成基頻訊號。此外，可 _ 變本地振盪器的頻率範圍亦可降為習知技術的一半。此外，僅需 使用較少的VC0數量，即可確保第一本地振盪器的相位雜訊會符 合相位雜訊位準的限制條件。另外，藉由使用了直接轉換的架構， 同相低通濾波器218與正交低通濾波器226都可以設置在晶片 上、而第二與第三諧波混波器輸出的訊號就是基頻視訊訊號，然 後基頻視訊訊號可以直接被傳送至其他的視訊處理單元，而不需 12 1291809 再經過第二中頻至基頻的轉換工作。 - 以上所述僅為本發明之較佳實施例，凡依本發明申請專利範圍 所做之均等變化與修飾，皆應屬本發明之涵蓋範圍。 一 【圖式簡單說明】 第1圖為習知技術一高度整合的電視調諧器的示意圖。 第2圖為本發明雙重轉換電視調諧器的實施例示意圖。 _ 【主要元件符號說明】 100、200 調諧器 101、202 低雜訊放大器 102 、 108 混波器 104、110、206、212 本地振盈器 106、210、114 帶通濾波器 112 、 116 中頻放大器 204 > 214 > 222 諧波混波器 216、220 同相基頻放大 218 同相低通濾波器 224 > 228 正交基頻放大器 226 正交低通遽波器 13The mid-single is located in the in-phase (1) way, and the other is in the orthogonal (9) path. Therefore, the disc-local vibrator 212 will be fixed at 61 (this is the surface acoustic wave test using the center frequency of 122_). In the case of _), this is the half of the operating frequency of the second local oscillator (10) in the i-th diagram. For its part, in the conventional television spectrometers, an additional frequency conversion stage must be used to convert the Hout field of the output to fine, which is not required for this system. Further, the in-phase filter 218 and the quadrature low-pass wave 226 may be simple low-pass filters and can be fabricated on an integrated circuit. The conventional TV tuning system shown in Figure 使 关 了 歧 , , , , , , , , , , , , , , , , , , , , _ _ _ _ _ _ ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' Bo Yi 11 _ implementation, the complexity and cost of the entire TV contactor 200 can be greatly reduced. The present invention employs a direct conversion architecture for wave mixing to convert a received RF signal into a baseband signal using a single intermediate frequency. In addition, the frequency range of the local oscillator can be reduced to half that of the prior art. In addition, using only a small number of VC0s ensures that the phase noise of the first local oscillator will meet the phase noise level constraints. In addition, by using a direct conversion architecture, both the in-phase low-pass filter 218 and the quadrature low-pass filter 226 can be placed on the wafer, and the signals output by the second and third harmonic mixers are the fundamental video. The signal and then the baseband video signal can be directly transmitted to other video processing units without the need for 12 1291809 to pass the second intermediate frequency to the base frequency conversion. The above is only the preferred embodiment of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of a highly integrated television tuner of the prior art. 2 is a schematic diagram of an embodiment of a dual conversion television tuner of the present invention. _ [Main component symbol description] 100, 200 tuner 101, 202 low noise amplifier 102, 108 mixer 104, 110, 206, 212 local oscillator 106, 210, 114 bandpass filter 112, 116 intermediate frequency Amplifier 204 > 214 > 222 Harmonic mixer 216, 220 Non-inverted fundamental frequency amplification 218 Non-inverting low-pass filter 224 > 228 Quadrature baseband amplifier 226 Orthogonal low-pass chopper 13