JP5549496B2

JP5549496B2 - Wireless receiver

Info

Publication number: JP5549496B2
Application number: JP2010205916A
Authority: JP
Inventors: 章加藤
Original assignee: Murata Manufacturing Co Ltd
Current assignee: Murata Manufacturing Co Ltd
Priority date: 2010-09-14
Filing date: 2010-09-14
Publication date: 2014-07-16
Anticipated expiration: 2030-09-14
Also published as: JP2012065037A

Description

本発明は、無線受信装置に関し、特に、複数のフィルタ部の前段に、信号を増幅する増幅器を備える無線受信装置に関する。 The present invention relates to a wireless reception device, and more particularly, to a wireless reception device including an amplifier that amplifies a signal in front of a plurality of filter units.

近年、一つのアンテナで、ＶＨＦ帯からＵＨＦ帯までの広い周波数帯域の信号を受信することが可能な無線受信装置が開発されている。特許文献１及び特許文献２には、ＶＨＦ帯からＵＨＦ帯までの広い周波数帯域の信号を受信することが可能な無線受信装置が開示されている。特許文献１及び特許文献２に開示されている無線受信装置では、アンテナで受信した信号を、低い周波数帯域の信号を通すフィルタ部と、高い周波数帯域の信号を通すフィルタ部とを用いてＶＨＦ帯の信号とＵＨＦ帯の信号とに分け、チューナ部でそれぞれの周波数帯域の信号を同調させる。 In recent years, wireless receivers that can receive signals in a wide frequency band from the VHF band to the UHF band with a single antenna have been developed. Patent Literature 1 and Patent Literature 2 disclose a wireless reception device capable of receiving signals in a wide frequency band from the VHF band to the UHF band. In the wireless receivers disclosed in Patent Document 1 and Patent Document 2, a signal received by an antenna is transmitted through a VHF band using a filter unit that passes a signal in a low frequency band and a filter unit that passes a signal in a high frequency band. And the UHF band signal, and the tuner unit tunes each frequency band signal.

特開平４−３０６９２１号公報JP-A-4-306921 実開昭６０−１８６７３５号公報Japanese Utility Model Publication No. 60-186735

しかし、アンテナで受信した信号が弱い場合、無線受信装置は、フィルタ部の前段に増幅器を設けて、信号を増幅する必要がある。フィルタ部の前段に増幅器を設ける場合、負荷であるフィルタ部と接続される条件によっては、増幅器に帰還回路を設けなくとも、増幅器内部で所定量以上の信号が正帰還するため、増幅器が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができないという問題があった。特に、増幅器に正帰還する信号の量が増えると、不安定性が増加して増幅器が発振する可能性が生じる。なお、特許文献１及び特許文献２では、フィルタ部の前段に増幅器を設けた無線受信装置の構成は開示されていない。 However, when the signal received by the antenna is weak, the wireless reception device needs to amplify the signal by providing an amplifier in front of the filter unit. When an amplifier is provided in front of the filter unit, depending on the conditions connected to the filter unit that is a load, a predetermined amount or more of the signal is positively fed back in the amplifier without providing a feedback circuit in the amplifier. There has been a problem that a signal cannot be stably amplified within a range of frequencies that can be amplified. In particular, when the amount of the signal that is positively fed back to the amplifier increases, the instability increases and the amplifier may oscillate. Note that Patent Literature 1 and Patent Literature 2 do not disclose the configuration of a wireless reception device in which an amplifier is provided in front of the filter unit.

本発明は、斯かる事情に鑑みてなされたものであり、フィルタ部の前段に増幅器を備え、増幅器が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる無線受信装置を提供することを目的とする。 The present invention has been made in view of such circumstances, and includes a wireless amplifier capable of stably amplifying a signal within a frequency range in which the amplifier is provided in front of the filter unit and the amplifier can amplify the signal. An object is to provide a receiving apparatus.

上記目的を達成するために第１発明に係る無線受信装置は、アンテナで受信した信号を増幅する増幅器と、該増幅器に接続され、前記増幅器が前記信号を増幅することができる周波数の範囲内において、それぞれ異なる所定の周波数の範囲の前記信号を通過させることができる周波数帯域を有する、並列接続された複数のフィルタ部と、複数の前記フィルタ部のそれぞれに接続され、前記フィルタ部を通過した前記信号を同調させることが可能な複数のチューナ部とを備え、前記増幅器が前記信号を増幅することができる周波数の範囲内に含まれる二つの前記所定の周波数の範囲を第１周波数の範囲、第２周波数の範囲とした場合、複数の前記フィルタ部は、前記第１周波数の範囲の前記信号を通過させることができる第１周波数帯域を有する第１フィルタ部と、前記第２周波数の範囲の前記信号を通過させることができる第２周波数帯域を有する第２フィルタ部とを有し、前記第１フィルタ部の上限側の遮断周波数と、前記第２フィルタ部の下限側の遮断周波数とが一致、又は前記第１フィルタ部の上限側の遮断周波数が前記第２フィルタ部の前記第２周波数帯域に、及び前記第２フィルタ部の下限側の遮断周波数が前記第１フィルタ部の前記第１周波数帯域にそれぞれ含まれており、前記遮断周波数における複数の前記フィルタ部の合成インピーダンスが、前記増幅器の負荷インピーダンス以下になる。 In order to achieve the above object, a wireless receiver according to a first aspect of the present invention includes an amplifier that amplifies a signal received by an antenna, and a frequency that is connected to the amplifier and that the amplifier can amplify the signal. A plurality of filter units connected in parallel, each having a frequency band capable of passing the signals in different predetermined frequency ranges, and connected to each of the plurality of filter units and passing through the filter unit A plurality of tuner units capable of tuning a signal, and the two predetermined frequency ranges included in a frequency range in which the amplifier can amplify the signal are defined as a first frequency range, a first frequency range, and a second frequency range. When the frequency range is two, the plurality of filter units have a first frequency band that can pass the signal in the first frequency range. A first filter unit, and a second filter unit having a second frequency band through which the signal in the range of the second frequency can pass, the cutoff frequency on the upper limit side of the first filter unit, The cutoff frequency on the lower limit side of the second filter unit matches, or the cutoff frequency on the upper limit side of the first filter unit is in the second frequency band of the second filter unit, and on the lower limit side of the second filter unit A cutoff frequency is included in each of the first frequency bands of the first filter unit, and a combined impedance of the plurality of filter units at the cutoff frequency is equal to or less than a load impedance of the amplifier .

第１発明では、第１フィルタ部の上限側の遮断周波数と、第２フィルタ部の下限側の遮断周波数とが一致、又は第１フィルタ部の上限側の遮断周波数が第２フィルタ部の第２周波数帯域に、及び第２フィルタ部の下限側の遮断周波数が第１フィルタ部の第１周波数帯域にそれぞれ含まれている第１フィルタ部及び第２フィルタ部の前段に増幅器を備えることで、第１フィルタ部及び第２フィルタ部から増幅器に正帰還する信号の量が所定量以下となるように第１フィルタ部及び第２フィルタ部の合成インピーダンスの値を抑えることができ、増幅器が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。
また、遮断周波数における複数のフィルタ部の合成インピーダンスが、増幅器の負荷インピーダンス以下になる複数のフィルタ部の前段に増幅器を備えているので、フィルタ部から増幅器に正帰還する信号の量が所定量以下となり、増幅器が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。 In the first invention, the cutoff frequency on the upper limit side of the first filter unit matches the cutoff frequency on the lower limit side of the second filter unit, or the cutoff frequency on the upper limit side of the first filter unit is the second of the second filter unit. By providing an amplifier in front of the first filter unit and the second filter unit in which the cutoff frequency at the lower limit side of the second filter unit is included in the frequency band and the first frequency band of the first filter unit, respectively, The value of the combined impedance of the first filter unit and the second filter unit can be suppressed so that the amount of the positive feedback signal from the first filter unit and the second filter unit to the amplifier is less than a predetermined amount, and the amplifier amplifies the signal. The signal can be stably amplified within the range of frequencies that can be obtained.
Further, since the combined impedance of the plurality of filter units at the cutoff frequency is equal to or lower than the load impedance of the amplifier, an amplifier is provided in front of the plurality of filter units. Thus, the signal can be stably amplified within a frequency range in which the amplifier can amplify the signal.

また、第２発明に係る無線受信装置は、第１発明において、前記第１周波数の範囲がＶＨＦ帯、前記第２周波数の範囲がＵＨＦ帯をそれぞれ含む。 In the wireless receiver according to the second invention, in the first invention, the first frequency range includes a VHF band, and the second frequency range includes a UHF band.

第２発明では、第１周波数の範囲がＶＨＦ帯、第２周波数の範囲がＵＨＦ帯をそれぞれ含むので、ＶＨＦ帯及びＵＨＦ帯の信号を受信することが可能な無線受信装置を提供することができる。 In the second invention, since the first frequency range includes the VHF band and the second frequency range includes the UHF band, it is possible to provide a radio receiving apparatus capable of receiving signals in the VHF band and the UHF band. .

また、第３発明に係る無線受信装置は、第１又は第２発明において、前記増幅器が前記信号を増幅することができる周波数の範囲内に含まれる三つの前記所定の周波数の範囲を第１周波数の範囲、第２周波数の範囲、第３周波数の範囲とした場合、複数の前記フィルタ部は、前記第１周波数の範囲の前記信号を通過させることができる第１周波数帯域を有する第１フィルタ部と、前記第２周波数の範囲の前記信号を通過させることができる第２周波数帯域を有する第２フィルタ部と、前記第３周波数の範囲の前記信号を通過させることができる第３周波数帯域を有する第３フィルタ部とを備え、前記第１フィルタ部の上限側の遮断周波数と、前記第２フィルタ部の下限側の遮断周波数とが、及び前記第２フィルタ部の上限側の遮断周波数と、前記第３フィルタ部の下限側の遮断周波数とがそれぞれ一致、又は前記第１フィルタ部の上限側の遮断周波数が前記第２フィルタ部の前記第２周波数帯域に、前記第２フィルタ部の下限側の遮断周波数が前記第１フィルタ部の前記第１周波数帯域に、前記第２フィルタ部の上限側の遮断周波数が前記第３フィルタ部の前記第３周波数帯域に、及び前記第３フィルタ部の下限側の遮断周波数が前記第２フィルタ部の前記第２周波数帯域にそれぞれ含まれている。 According to a third aspect of the present invention, in the first or second aspect, the three predetermined frequency ranges included in the frequency range in which the amplifier can amplify the signal are set to the first frequency range. The first filter unit having a first frequency band in which a plurality of the filter units can pass the signal in the first frequency range when the range, the second frequency range, and the third frequency range are set. A second filter unit having a second frequency band that can pass the signal in the range of the second frequency, and a third frequency band that can pass the signal in the range of the third frequency A third filter unit, a cutoff frequency on the upper limit side of the first filter unit, a cutoff frequency on the lower limit side of the second filter unit, and a cutoff frequency on the upper limit side of the second filter unit, The cut-off frequency on the lower limit side of the third filter unit coincides with each other, or the cut-off frequency on the upper limit side of the first filter unit is in the second frequency band of the second filter unit, and the lower limit side of the second filter unit Is the first frequency band of the first filter unit, the upper cutoff frequency of the second filter unit is the third frequency band of the third filter unit, and the lower limit of the third filter unit Side cut-off frequencies are included in the second frequency band of the second filter unit, respectively.

第３発明では、第１フィルタ部の上限側の遮断周波数と、第２フィルタ部の下限側の遮断周波数とが、及び第２フィルタ部の上限側の遮断周波数と、第３フィルタ部の下限側の遮断周波数とがそれぞれ一致、又は第１フィルタ部の上限側の遮断周波数が第２フィルタ部の第２周波数帯域に、第２フィルタ部の下限側の遮断周波数が第１フィルタ部の第１周波数帯域に、第２フィルタ部の上限側の遮断周波数が第３フィルタ部の第３周波数帯域に、及び第３フィルタ部の下限側の遮断周波数が第２フィルタ部の第２周波数帯域にそれぞれ含まれている第１フィルタ部、第２フィルタ部及び第３フィルタ部の前段に増幅器を備えることで、第１フィルタ部、第２フィルタ部及び第３フィルタ部から増幅器に正帰還する信号の量が所定量以下となるように第１フィルタ部、第２フィルタ部及び第３フィルタ部の合成インピーダンスの値を抑えることができ、増幅器が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。 In the third invention, the cutoff frequency on the upper limit side of the first filter unit, the cutoff frequency on the lower limit side of the second filter unit, the cutoff frequency on the upper limit side of the second filter unit, and the lower limit side of the third filter unit Or the cutoff frequency on the upper limit side of the first filter unit is in the second frequency band of the second filter unit, and the cutoff frequency on the lower limit side of the second filter unit is the first frequency of the first filter unit. The cut-off frequency on the upper limit side of the second filter unit is included in the third frequency band of the third filter unit, and the cut-off frequency on the lower limit side of the third filter unit is included in the second frequency band of the second filter unit. By providing an amplifier in front of the first filter unit, the second filter unit, and the third filter unit, the amount of signal that is positively fed back to the amplifier from the first filter unit, the second filter unit, and the third filter unit can be increased. Less than quantitative Thus, the value of the combined impedance of the first filter unit, the second filter unit, and the third filter unit can be suppressed, and the signal can be stably amplified within the frequency range in which the amplifier can amplify the signal. .

また、第４発明に係る無線受信装置は、第３発明において、前記第１周波数の範囲がＶＨＦ帯ローバンド、前記第２周波数の範囲がＶＨＦ帯ハイバンド、前記第３周波数の範囲がＵＨＦ帯をそれぞれ含む。 According to a fourth aspect of the present invention, in the third aspect , the first frequency range is a VHF band low band, the second frequency range is a VHF band high band, and the third frequency range is a UHF band. Includes each.

第４発明では、第１周波数の範囲がＶＨＦ帯ローバンド、第２周波数の範囲がＶＨＦ帯ハイバンド、第３周波数の範囲がＵＨＦ帯をそれぞれ含むので、ＶＨＦ帯ローバンド、ＶＨＦ帯ハイバンド及びＵＨＦ帯の信号を受信することが可能な無線受信装置を提供することができる。 In the fourth invention, since the first frequency range includes the VHF band low band, the second frequency range includes the VHF band high band, and the third frequency range includes the UHF band, the VHF band low band, the VHF band high band, and the UHF band It is possible to provide a wireless receiver capable of receiving the above signals.

本発明に係る無線受信装置は、第１フィルタ部の上限側の遮断周波数と、第２フィルタ部の下限側の遮断周波数とが一致、又は第１フィルタ部の上限側の遮断周波数が第２フィルタ部の第２周波数帯域に、及び第２フィルタ部の下限側の遮断周波数が第１フィルタ部の第１周波数帯域にそれぞれ含まれている第１フィルタ部及び第２フィルタ部の前段に増幅器を備えることで、第１フィルタ部及び第２フィルタ部から増幅器に正帰還する信号の量が所定量以下となるように第１フィルタ部及び第２フィルタ部の合成インピーダンスの値を抑えることができ、増幅器が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。
また、遮断周波数における複数のフィルタ部の合成インピーダンスが、増幅器の負荷インピーダンス以下になる複数のフィルタ部の前段に増幅器を備えているので、フィルタ部から増幅器に正帰還する信号の量が所定量以下となり、増幅器が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。 In the wireless reception device according to the present invention, the cutoff frequency on the upper limit side of the first filter unit matches the cutoff frequency on the lower limit side of the second filter unit, or the cutoff frequency on the upper limit side of the first filter unit is the second filter. An amplifier is provided in front of the first filter unit and the second filter unit in which the cut-off frequency on the lower frequency side of the second filter unit is included in the first frequency band of the first filter unit. Thus, the value of the combined impedance of the first filter unit and the second filter unit can be suppressed so that the amount of the signal positively fed back from the first filter unit and the second filter unit to the amplifier is equal to or less than a predetermined amount. Can stably amplify the signal within a frequency range where the signal can be amplified.
Further, since the combined impedance of the plurality of filter units at the cutoff frequency is equal to or lower than the load impedance of the amplifier, an amplifier is provided in front of the plurality of filter units. Thus, the signal can be stably amplified within a frequency range in which the amplifier can amplify the signal.

本発明の実施の形態１に係る無線受信装置の構成を示すブロック図である。It is a block diagram which shows the structure of the radio | wireless receiver which concerns on Embodiment 1 of this invention. 図１に示す無線受信装置のシミュレーションで得られたフィルタ部の信号の周波数と信号の強度との関係を示したグラフである。3 is a graph showing the relationship between the signal frequency and the signal strength of the filter unit obtained by the simulation of the wireless receiver shown in FIG. 1. 図１に示す無線受信装置のシミュレーションで得られた信号の周波数とフィルタ部の合成インピーダンスとの関係を示したグラフである。3 is a graph showing the relationship between the frequency of a signal obtained by simulation of the wireless receiver shown in FIG. 1 and the combined impedance of the filter unit. 本発明の実施の形態１に係る別の構成の無線受信装置のシミュレーションで得られたフィルタ部の信号の周波数と信号の強度との関係を示したグラフである。It is the graph which showed the relationship between the frequency of the signal of the filter part and signal strength which were obtained by simulation of the radio | wireless receiver of another structure which concerns on Embodiment 1 of this invention. 本発明の実施の形態１に係る別の構成の無線受信装置のシミュレーションで得られた信号の周波数とフィルタ部の合成インピーダンスとの関係を示したグラフである。It is the graph which showed the relationship between the frequency of the signal obtained by simulation of the radio | wireless receiver of another structure which concerns on Embodiment 1 of this invention, and the synthetic | combination impedance of a filter part. 本発明の実施の形態２に係る無線受信装置の構成を示すブロック図である。It is a block diagram which shows the structure of the radio | wireless receiver which concerns on Embodiment 2 of this invention. 図６に示す無線受信装置のシミュレーションで得られたフィルタ部の信号の周波数と信号の強度との関係を示したグラフである。7 is a graph showing the relationship between the signal frequency and the signal strength of the filter unit obtained by the simulation of the wireless reception device shown in FIG. 6. 図６に示す無線受信装置のシミュレーションで得られた信号の周波数とフィルタ部の合成インピーダンスとの関係を示したグラフである。7 is a graph showing the relationship between the frequency of a signal obtained by simulation of the wireless reception device shown in FIG. 6 and the combined impedance of the filter unit.

以下、本発明の実施の形態について、図面を参照しながら詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

（実施の形態１）
図１は、本発明の実施の形態１に係る無線受信装置の構成を示すブロック図である。図１に示す無線受信装置１は、ＶＨＦ帯及びＵＨＦ帯の信号を受信することができるアンテナ２が接続され、特にＶＨＦ帯ハイバンド（２０７．５ＭＨｚ〜２２２ＭＨｚ）のマルチメディア放送及びＵＨＦ帯（４７０ＭＨｚ〜７７０ＭＨｚ）のテレビ放送の信号を受信することができる。なお、本発明の実施の形態１では、ＶＨＦ帯ハイバンドを、単にＶＨＦ帯として説明する。 (Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a radio reception apparatus according to Embodiment 1 of the present invention. The radio receiver 1 shown in FIG. 1 is connected to an antenna 2 capable of receiving signals in the VHF band and the UHF band. In particular, the VHF band high band (207.5 MHz to 222 MHz) multimedia broadcast and the UHF band (470 MHz). ˜770 MHz) can be received. In the first embodiment of the present invention, the VHF band high band will be described simply as the VHF band.

無線受信装置１は、アンテナ２で受信した信号を増幅する増幅器１１、増幅器１１に接続されたフィルタ部１２、１３、フィルタ部１２、１３のそれぞれに接続されたチューナ部１４、１５を備えている。フィルタ部１２、１３は並列接続されている。なお、無線受信装置１を携帯電話機に組み込む場合は、図示していないが、アンテナ２と増幅器１１との間に、携帯電話機の送信信号の周波数（例えば８００ＭＨｚ）を減衰させるトラップフィルタ部を挿入しても良い。 The wireless reception device 1 includes an amplifier 11 that amplifies a signal received by the antenna 2, filter units 12 and 13 connected to the amplifier 11, and tuner units 14 and 15 connected to the filter units 12 and 13, respectively. . The filter units 12 and 13 are connected in parallel. When the wireless receiver 1 is incorporated in a mobile phone, although not shown, a trap filter unit that attenuates the frequency (for example, 800 MHz) of the transmission signal of the mobile phone is inserted between the antenna 2 and the amplifier 11. May be.

増幅器１１は、ＶＨＦ帯及びＵＨＦ帯を含む周波数の範囲の信号を増幅することができる。増幅器１１は、信号を増幅する際に、信号に付加される雑音が小さい低雑音増幅器（ＬＮＡ）である。さらに、増幅器１１は、外部から制御信号を供給することで、動作、不動作（スルー動作）を切り替えたり、信号の増幅度を変更（例えば１０ｄＢを２０ｄＢに変更）したりすることができる。 The amplifier 11 can amplify a signal in a frequency range including the VHF band and the UHF band. The amplifier 11 is a low noise amplifier (LNA) that has a small noise added to a signal when the signal is amplified. Furthermore, the amplifier 11 can switch between operation and non-operation (through operation) by supplying a control signal from the outside, and can change the amplification degree of the signal (for example, change 10 dB to 20 dB).

フィルタ部１２（第１フィルタ部）は、ＶＨＦ帯を含む所定の周波数の範囲（第１周波数の範囲）の信号を通過させることができる第１周波数帯域を有するローパスフィルタである。例えば、フィルタ部１２は、定Ｋ型フィルタを組み合わせたＴ型回路で、直列接続された二つのコイル（各２６．５ｎＨ）と、二つのコイルの接点と接地端子との間に設けられたコンデンサ（２１．２ｐＦ）とで構成されている。フィルタ部１３（第２フィルタ部）は、ＵＨＦ帯を含む所定の周波数の範囲（第２周波数の範囲）の信号を通過させることができる第２周波数帯域を有するハイパスフィルタである。例えば、フィルタ部１３は、定Ｋ型フィルタを組み合わせたＴ型回路で、直列接続された二つのコンデンサ（各１０．６ｐＦ）と、二つのコンデンサの接点と接地端子との間に設けられたコイル（１３．３ｎＨ）とで構成されている。なお、フィルタ部１２、１３は、定Ｋ型フィルタを組み合わせたＴ型回路に限定されるものではなく、所定の周波数の範囲の信号を通過させることができる周波数帯域を有する回路であれば、何れの回路構成であっても良い。 The filter unit 12 (first filter unit) is a low-pass filter having a first frequency band that can pass a signal in a predetermined frequency range (first frequency range) including the VHF band. For example, the filter unit 12 is a T-type circuit combined with a constant K-type filter, and is a capacitor provided between two coils connected in series (each 26.5 nH) and a contact between the two coils and a ground terminal. (21.2 pF). The filter unit 13 (second filter unit) is a high-pass filter having a second frequency band that can pass a signal in a predetermined frequency range (second frequency range) including the UHF band. For example, the filter unit 13 is a T-type circuit in which a constant K-type filter is combined, and two capacitors (10.6 pF each) connected in series, and a coil provided between the contact point of the two capacitors and the ground terminal (13.3 nH). The filter units 12 and 13 are not limited to a T-type circuit in which a constant K-type filter is combined, and any filter circuit having a frequency band that can pass a signal in a predetermined frequency range can be used. The circuit configuration may be as follows.

さらに、フィルタ部１２の第１周波数帯域と、フィルタ部１３の第２周波数帯域とは、それぞれ異なる所定の周波数の範囲の信号を通過させることができる。また、フィルタ部１２の上限側の遮断周波数（通過した信号の強度が半減する周波数）が、フィルタ部１３の第２周波数帯域に含まれている。逆に、フィルタ部１３の下限側の遮断周波数が、フィルタ部１２の第１周波数帯域に含まれている。 Further, the first frequency band of the filter unit 12 and the second frequency band of the filter unit 13 can pass signals having different predetermined frequency ranges, respectively. Further, the cutoff frequency on the upper limit side of the filter unit 12 (the frequency at which the intensity of the signal that has passed through is halved) is included in the second frequency band of the filter unit 13. Conversely, the cutoff frequency on the lower limit side of the filter unit 13 is included in the first frequency band of the filter unit 12.

図２は、図１に示す無線受信装置１のシミュレーションで得られたフィルタ部１２、１３の信号の周波数と信号の強度との関係を示したグラフである。図３は、図１に示す無線受信装置１のシミュレーションで得られた信号の周波数とフィルタ部１２、１３の合成インピーダンスとの関係を示したグラフである。図２では、フィルタ部１２を通過した信号の周波数と信号の強度との関係を波形Ｌ、フィルタ部１３を通過した信号の周波数と信号の強度との関係を波形Ｈとしてそれぞれ示している。波形Ｌは、フィルタ部１２が略４０ＭＨｚ〜略３２０ＭＨｚ（フィルタ部１２の第１周波数帯域）の信号を通過させ、上限側の遮断周波数が略３２０ＭＨｚとなることを示している。波形Ｈは、フィルタ部１３が略２８０ＭＨｚ〜（フィルタ部１３の第２周波数帯域）の信号を通過させ、下限側の遮断周波数が略２８０ＭＨｚとなることを示している。なお、遮断周波数は、強度が５００ｍＶの信号がフィルタ部１２、１３を通過して信号の強度が半減（２５０ｍＶ）する周波数である。なお、無線受信装置１のシミュレーションには、回路シミュレーションでは一般的なＳＰＩＣＥ（ＳｉｍｕｌａｒｉｏｎＰｒｏｇｒａｍｗｉｔｈＩｎｔｅｇｒａｔｅｄＣｉｒｃｕｉｔＥｍｐｈａｓｉｓ）のＡＣ解析を用いている。 FIG. 2 is a graph showing the relationship between the signal frequency and the signal strength of the filter units 12 and 13 obtained by the simulation of the wireless reception device 1 shown in FIG. FIG. 3 is a graph showing the relationship between the frequency of the signal obtained by the simulation of the wireless receiver 1 shown in FIG. 1 and the combined impedance of the filter units 12 and 13. In FIG. 2, the relationship between the frequency of the signal passing through the filter unit 12 and the signal strength is shown as a waveform L, and the relationship between the frequency of the signal passing through the filter unit 13 and the signal strength is shown as a waveform H. The waveform L indicates that the filter unit 12 passes a signal of about 40 MHz to about 320 MHz (the first frequency band of the filter unit 12), and the cutoff frequency on the upper limit side is about 320 MHz. A waveform H indicates that the filter unit 13 passes a signal of approximately 280 MHz to (the second frequency band of the filter unit 13), and the cutoff frequency on the lower limit side is approximately 280 MHz. The cut-off frequency is a frequency at which a signal having an intensity of 500 mV passes through the filter units 12 and 13 and the signal intensity is halved (250 mV). Note that the simulation of the wireless reception device 1 uses a general SPICE (Simulation Program with Integrated Circuit Emphasis) AC analysis in the circuit simulation.

図２では、フィルタ部１２の第１周波数帯域（略４０ＭＨｚ〜略３２０ＭＨｚ）と、フィルタ部１３の第２周波数帯域（略２８０ＭＨｚ〜）とは、それぞれ異なる所定の周波数の範囲の信号を通過させることができる。また、フィルタ部１２の上限側の遮断周波数（略３２０ＭＨｚ）が、フィルタ部１３の第２周波数帯域に含まれている。逆に、フィルタ部１３の下限側の遮断周波数（略２８０ＭＨｚ）が、フィルタ部１２の第１周波数帯域に含まれている。 In FIG. 2, the first frequency band (approximately 40 MHz to approximately 320 MHz) of the filter unit 12 and the second frequency band (approximately 280 MHz to) of the filter unit 13 pass signals having different predetermined frequency ranges. Can do. Further, the upper cutoff frequency (approximately 320 MHz) of the filter unit 12 is included in the second frequency band of the filter unit 13. Conversely, the cut-off frequency (approximately 280 MHz) on the lower limit side of the filter unit 13 is included in the first frequency band of the filter unit 12.

フィルタ部１２、１３の遮断周波数、周波数帯域を図２に示した遮断周波数、周波数帯域にすることで、信号の周波数とフィルタ部１２、１３の合成インピーダンスとの関係は図３に示すようになり、フィルタ部１２、１３の合成インピーダンスを、増幅器１１で信号を増幅することができる周波数の範囲（例えば、０Ｈｚ〜２．０ＧＨｚ）内において、増幅器１１の負荷インピーダンスである５０Ω以下にすることができる。合成インピーダンスが、増幅器１１の負荷インピーダンス以下になるフィルタ部１２、１３の前段に増幅器１１を備えているので、フィルタ部１２、１３から増幅器１１に正帰還する信号の量を所定量以下にすることができ、増幅器１１が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。なお、フィルタ部１２、１３から増幅器１１に正帰還する信号の所定量は、無線受信装置１を実際に動作させた場合に増幅器１１の動作が不安定となるフィルタ部１２、１３の合成インピーダンスから類推される信号の量である。無線受信装置１の回路構成により、フィルタ部１２、１３から増幅器１１に正帰還する信号の所定量は異なる。 By setting the cutoff frequency and frequency band of the filter units 12 and 13 to the cutoff frequency and frequency band shown in FIG. 2, the relationship between the signal frequency and the combined impedance of the filter units 12 and 13 is as shown in FIG. The combined impedance of the filter units 12 and 13 can be set to 50 Ω or less which is the load impedance of the amplifier 11 within a frequency range (for example, 0 Hz to 2.0 GHz) in which the signal can be amplified by the amplifier 11. . Since the amplifier 11 is provided in front of the filter units 12 and 13 where the combined impedance is equal to or lower than the load impedance of the amplifier 11, the amount of the signal that is positively fed back from the filter units 12 and 13 to the amplifier 11 is set to a predetermined amount or less. Thus, the signal can be stably amplified within a frequency range in which the amplifier 11 can amplify the signal. The predetermined amount of the signal that is positively fed back from the filter units 12 and 13 to the amplifier 11 is based on the combined impedance of the filter units 12 and 13 that cause the operation of the amplifier 11 to become unstable when the wireless reception device 1 is actually operated. This is the amount of signal that can be inferred. Depending on the circuit configuration of the wireless reception device 1, the predetermined amount of the signal that is positively fed back from the filter units 12 and 13 to the amplifier 11 varies.

また、フィルタ部１２、１３の合成インピーダンスが、増幅器１１の負荷インピーダンスより大きくなると、フィルタ部１２、１３から増幅器１１に正帰還する信号の量が増えるが、所定量より大きくならなければ増幅器１１の動作が不安定になることも、増幅器１１が発振することもない。例えば、第１周波数帯域を有するフィルタ部１２と、第２周波数帯域を有するフィルタ部１３とは、それぞれ異なる所定の周波数の範囲の信号を通過させることができる。また、フィルタ部１２、１３の遮断周波数同士が一致する場合であっても、フィルタ部１２、１３から増幅器１１に正帰還する信号の量が所定量以下となるようにフィルタ部１２、１３の合成インピーダンスの値を抑えることができ、増幅器１１が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。 Further, when the combined impedance of the filter units 12 and 13 becomes larger than the load impedance of the amplifier 11, the amount of signals that are positively fed back from the filter units 12 and 13 to the amplifier 11 increases. The operation does not become unstable and the amplifier 11 does not oscillate. For example, the filter unit 12 having the first frequency band and the filter unit 13 having the second frequency band can pass signals having different predetermined frequency ranges. Further, even when the cutoff frequencies of the filter units 12 and 13 coincide with each other, the synthesis of the filter units 12 and 13 is performed so that the amount of the positive feedback signal from the filter units 12 and 13 to the amplifier 11 is equal to or less than a predetermined amount. The impedance value can be suppressed, and the signal can be stably amplified within the frequency range in which the amplifier 11 can amplify the signal.

図４は、本発明の実施の形態１に係る別の構成の無線受信装置１のシミュレーションで得られたフィルタ部１２、１３の信号の周波数と信号の強度との関係を示したグラフである。図５は、本発明の実施の形態１に係る別の構成の無線受信装置１のシミュレーションで得られた信号の周波数とフィルタ部１２、１３の合成インピーダンスとの関係を示したグラフである。なお、別の構成の無線受信装置１は、フィルタ部１２が、直列接続された二つのコイル（各３４．０ｎＨ）と、二つのコイルの接点と接地端子との間に設けられたコンデンサ（３０．０ｐＦ）とで構成され、フィルタ部１３が、直列接続された二つのコンデンサ（各８．０ｐＦ）と、二つのコンデンサの接点と接地端子との間に設けられたコイル（１０．０ｎＨ）とで構成されている点以外、図１に示す無線受信装置１と同じである。 FIG. 4 is a graph showing the relationship between the signal frequency and the signal strength of the filter units 12 and 13 obtained by the simulation of the wireless reception device 1 having another configuration according to the first embodiment of the present invention. FIG. 5 is a graph showing the relationship between the signal frequency and the combined impedance of the filter units 12 and 13 obtained by the simulation of the wireless reception device 1 having another configuration according to the first embodiment of the present invention. In the wireless receiver 1 having another configuration, the filter unit 12 includes two coils (34.0 nH each) connected in series, and a capacitor (30 provided between the contact point of the two coils and the ground terminal). 0.0pF), and the filter unit 13 includes two capacitors connected in series (each 8.0 pF), and a coil (10.0 nH) provided between the contact point of the two capacitors and the ground terminal. 1 is the same as the wireless reception device 1 shown in FIG.

図４に示す波形Ｌは、フィルタ部１２が略４０ＭＨｚ〜略３００ＭＨｚ（フィルタ部１２の第１周波数帯域）の信号を通過させ、上限側の遮断周波数が略３００ＭＨｚとなることを示している。波形Ｈは、フィルタ部１３が略３００ＭＨｚ〜（フィルタ部１３の第２周波数帯域）の信号を通過させ、下限側の遮断周波数が略３００ＭＨｚとなることを示している。 A waveform L shown in FIG. 4 indicates that the filter unit 12 passes a signal of approximately 40 MHz to approximately 300 MHz (the first frequency band of the filter unit 12), and the cutoff frequency on the upper limit side is approximately 300 MHz. The waveform H indicates that the filter unit 13 passes a signal of approximately 300 MHz to (the second frequency band of the filter unit 13), and the cutoff frequency on the lower limit side is approximately 300 MHz.

図４に示すように、フィルタ部１２の第１周波数帯域（略４０ＭＨｚ〜略３００ＭＨｚ）と、フィルタ部１３の第２周波数帯域（略３００ＭＨｚ〜）とは異なる周波数帯域で、フィルタ部１２、１３の遮断周波数（略３００ＭＨｚ）同士が一致している。 As shown in FIG. 4, the first frequency band (approximately 40 MHz to approximately 300 MHz) of the filter unit 12 and the second frequency band (approximately 300 MHz to) of the filter unit 13 are different in frequency bands. The cutoff frequencies (approximately 300 MHz) match.

フィルタ部１２、１３の遮断周波数、周波数帯域を図４に示した遮断周波数、周波数帯域にすることで、信号の周波数とフィルタ部１２、１３の合成インピーダンスとの関係は図５に示すようになり、フィルタ部１２、１３の合成インピーダンスを、略２５０ＭＨｚ〜略３６０ＭＨｚの周波数帯域を除く増幅器１１で信号を増幅することができる周波数の範囲内において、増幅器１１の負荷インピーダンスである５０Ω以下にすることができる。また、略２５０ＭＨｚ〜略３６０ＭＨｚの周波数帯域においては、増幅器１１の負荷インピーダンスである５０Ωより大きくなり、特に、略３００ＭＨｚの周波数では、フィルタ部１２、１３の合成インピーダンスが略２７０Ωと最大値となる。しかし、過去の経験において、フィルタ部１２、１３の合成インピーダンスが十倍程度であっても、増幅器１１が発振することなく正常に動作していたことから、フィルタ部１２、１３から増幅器１１に正帰還する信号の量を所定量以下にすることができるフィルタ部１２、１３の合成インピーダンスの値であると推測できる。そのため、フィルタ部１２、１３の遮断周波数（略３００ＭＨｚ）同士を一致させた場合であっても、増幅器１１が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。 By setting the cutoff frequency and frequency band of the filter units 12 and 13 to the cutoff frequency and frequency band shown in FIG. 4, the relationship between the signal frequency and the combined impedance of the filter units 12 and 13 is as shown in FIG. The combined impedance of the filter units 12 and 13 is set to 50Ω or less which is the load impedance of the amplifier 11 within a frequency range in which the signal can be amplified by the amplifier 11 excluding the frequency band of about 250 MHz to about 360 MHz. it can. Moreover, in the frequency band of about 250 MHz to about 360 MHz, it becomes larger than 50Ω which is the load impedance of the amplifier 11, and in particular, in the frequency of about 300 MHz, the combined impedance of the filter units 12 and 13 becomes a maximum value of about 270Ω. However, in past experience, even if the combined impedance of the filter units 12 and 13 is about ten times, the amplifier 11 was operating normally without oscillating. It can be estimated that this is the value of the combined impedance of the filter units 12 and 13 that can reduce the amount of the signal to be fed back to a predetermined amount or less. Therefore, even when the cutoff frequencies (approximately 300 MHz) of the filter units 12 and 13 are matched, the signal can be stably amplified within the frequency range in which the amplifier 11 can amplify the signal. .

次に、チューナ部１４は、フィルタ部１２を通過したＶＨＦ帯の信号を同調させることが可能な回路である。チューナ部１４で同調させたマルチメディア放送の信号に対して所定の処理を行うことで、図示していない表示装置でマルチメディア放送を視聴することができる。チューナ部１５は、フィルタ部１３を通過したＵＨＦ帯の信号を同調させることが可能な回路である。チューナ部１５で同調させたテレビ放送の信号に対して所定の処理を行うことで、図示していない表示装置でテレビ放送を視聴することができる。 Next, the tuner unit 14 is a circuit capable of tuning a VHF band signal that has passed through the filter unit 12. By performing predetermined processing on the multimedia broadcast signal tuned by the tuner unit 14, the multimedia broadcast can be viewed on a display device (not shown). The tuner unit 15 is a circuit that can tune the UHF band signal that has passed through the filter unit 13. By performing predetermined processing on the TV broadcast signal tuned by the tuner unit 15, the TV broadcast can be viewed on a display device (not shown).

以上のように、本発明の実施の形態１に係る無線受信装置１は、複数のフィルタ部１２、１３の遮断周波数同士が一致、又は一つのフィルタ部１２（１３）の遮断周波数が近傍する他のフィルタ部１３（１２）の第２（第１）周波数帯域に含まれている複数のフィルタ部１２、１３の前段に増幅器１１を備えているので、フィルタ部１２、１３から増幅器１１に正帰還する信号の量が所定量以下となるようにフィルタ部１２、１３の合成インピーダンスの値を抑えることができ、増幅器１１が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。また、増幅器１１が発振することを防止することができる。 As described above, the wireless reception device 1 according to Embodiment 1 of the present invention is such that the cutoff frequencies of the plurality of filter units 12 and 13 are the same, or the cutoff frequency of one filter unit 12 (13) is close. Since the amplifier 11 is provided in front of the plurality of filter units 12 and 13 included in the second (first) frequency band of the filter unit 13 (12), positive feedback from the filter units 12 and 13 to the amplifier 11 is provided. The value of the combined impedance of the filter units 12 and 13 can be suppressed so that the amount of the signal to be performed is equal to or less than the predetermined amount, and the signal can be stably amplified within the frequency range in which the amplifier 11 can amplify the signal. be able to. Further, it is possible to prevent the amplifier 11 from oscillating.

なお、本発明の実施の形態１に係る無線受信装置１は、増幅器１１が信号を増幅することができる周波数の範囲は、ＶＨＦ帯を含む所定の周波数の範囲（第１周波数の範囲）と、ＵＨＦ帯を含む所定の周波数の範囲（第２周波数の範囲）との二つの所定の周波数の範囲を含む場合に限定されるものではなく、ＶＨＦ帯、ＵＨＦ帯を含まない二つの所定の周波数の範囲を含む場合であっても良い。 Note that, in the wireless reception device 1 according to Embodiment 1 of the present invention, the frequency range in which the amplifier 11 can amplify the signal is a predetermined frequency range including the VHF band (first frequency range); The present invention is not limited to the case where the two predetermined frequency ranges including the predetermined frequency range including the UHF band (second frequency range) are included, but the two predetermined frequencies not including the VHF band and the UHF band. It may be a case including a range.

（実施の形態２）
図６は、本発明の実施の形態２に係る無線受信装置の構成を示すブロック図である。図６に示す無線受信装置３は、ＶＨＦ帯ローバンド、ＶＨＦ帯ハイバンド及びＵＨＦ帯の信号を受信することができるアンテナ２が接続され、特に、ＶＨＦ帯ローバンド（９０ＭＨｚ〜１０８ＭＨｚ）のマルチメディア放送、ＶＨＦ帯ハイバンド（２０７．５ＭＨｚ〜２２２ＭＨｚ）のマルチメディア放送及びＵＨＦ帯（４７０ＭＨｚ〜７７０ＭＨｚ）のテレビ放送の信号を受信することができる。そのため、本発明の実施の形態２に係る無線受信装置３は、実施の形態１に係る無線受信装置１に、ＶＨＦ帯ローバンドの信号を受信するための構成が追加されている。 (Embodiment 2)
FIG. 6 is a block diagram showing a configuration of a radio reception apparatus according to Embodiment 2 of the present invention. The radio receiver 3 shown in FIG. 6 is connected to an antenna 2 that can receive signals in the VHF band low band, the VHF band high band, and the UHF band. In particular, the VHF band low band (90 MHz to 108 MHz) multimedia broadcast, It is possible to receive VHF band high band (207.5 MHz to 222 MHz) multimedia broadcast signals and UHF band (470 MHz to 770 MHz) television broadcast signals. Therefore, a configuration for receiving a VHF band low-band signal is added to radio reception apparatus 3 according to Embodiment 2 of the present invention in addition to radio reception apparatus 1 according to Embodiment 1.

無線受信装置３は、アンテナ２で受信した信号を増幅する増幅器３１、増幅器３１に接続されたフィルタ部３２、３３、３４、フィルタ部３２、３３、３４のそれぞれに接続されたチューナ部３５、３６、３７を備えている。フィルタ部３２、３３、３４は並列接続されている。なお、無線受信装置３を携帯電話機に組み込む場合は、図示していないが、アンテナ２と増幅器３１との間に、携帯電話機の送信信号の周波数（例えば８００ＭＨｚ）を減衰させるトラップフィルタ部を挿入しても良い。 The wireless receiver 3 includes an amplifier 31 that amplifies a signal received by the antenna 2, filter units 32, 33, and 34 connected to the amplifier 31, and tuner units 35 and 36 connected to the filter units 32, 33, and 34, respectively. , 37. The filter units 32, 33, and 34 are connected in parallel. When the wireless receiver 3 is incorporated in a mobile phone, although not shown, a trap filter unit that attenuates the frequency (for example, 800 MHz) of the transmission signal of the mobile phone is inserted between the antenna 2 and the amplifier 31. May be.

増幅器３１は、ＶＨＦ帯ローバンド、ＶＨＦ帯ハイバンド及びＵＨＦ帯を含む周波数の範囲の信号を増幅することができる。増幅器３１は、信号を増幅する際に、信号に付加される雑音が小さい低雑音増幅器（ＬＮＡ）である。さらに、増幅器３１は、外部から制御信号を供給することで、動作、不動作（スルー動作）の切替、信号の増幅度の変更（例えば１０ｄＢを２０ｄＢに変更）をすることができる。 The amplifier 31 can amplify signals in a frequency range including a VHF band low band, a VHF band high band, and a UHF band. The amplifier 31 is a low noise amplifier (LNA) that adds little noise to the signal when amplifying the signal. Further, the amplifier 31 can switch between operation and non-operation (through operation) and change the signal amplification degree (for example, change from 10 dB to 20 dB) by supplying a control signal from the outside.

フィルタ部３２（第１フィルタ部）は、ＶＨＦ帯ローバンドを含む所定の周波数の範囲（第１周波数の範囲）の信号を通過させることができる第１周波数帯域を有するローパスフィルタである。例えば、フィルタ部３２は、定Ｋ型フィルタを組み合わせたＴ型回路で、直列接続された二つのコイル（各５３ｎＨ）と、二つのコイルの接点と接地端子との間に設けられたコンデンサ（４２．４ｐＦ）とで構成されている。フィルタ部３３（第２フィルタ部）は、ＶＨＦ帯ハイバンドを含む所定の周波数の範囲（第２周波数の範囲）の信号を通過させることができる第２周波数帯域を有するバンドパスフィルタである。例えば、フィルタ部３３は、定Ｋ型フィルタを組み合わせたπ型回路で、直列接続された二つのコイル（各３９．８ｎＨ）及び二つのコンデンサ（各１５１．６ｐＦ）と、二つのコンデンサの接点と接地端子との間に設けられたコイル（１５．２ｎＨ）及びコンデンサ（６３．６ｐＦ）とで構成されている。フィルタ部３４（第３フィルタ部）は、ＵＨＦ帯を含む所定の周波数の範囲（第３周波数の範囲）の信号を通過させることができる第３周波数帯域を有するハイパスフィルタである。例えば、フィルタ部３４は、定Ｋ型フィルタを組み合わせたＴ型回路で、直列接続された二つのコンデンサ（各１２．７ｐＦ）と、二つのコンデンサの接点と接地端子との間に設けられたコイル（１５．９ｎＨ）とで構成されている。なお、フィルタ部３２、３４は、定Ｋ型フィルタを組み合わせたＴ型回路に限定されるものではなく、所定の周波数の範囲の信号を通過させることができる回路であれば、何れの回路構成であっても良い。フィルタ部３３は、定Ｋ型フィルタを組み合わせたπ型回路に限定されるものではなく、所定の周波数の範囲の信号を通過させることができる回路であれば、何れの回路構成であっても良い。 The filter unit 32 (first filter unit) is a low-pass filter having a first frequency band that can pass a signal in a predetermined frequency range (first frequency range) including the VHF band low band. For example, the filter unit 32 is a T-type circuit in which a constant K-type filter is combined, and two coils connected in series (each 53 nH) and a capacitor (42) provided between the contact point of the two coils and the ground terminal. .4 pF). The filter unit 33 (second filter unit) is a bandpass filter having a second frequency band that can pass a signal in a predetermined frequency range (second frequency range) including the VHF band high band. For example, the filter unit 33 is a π-type circuit combined with a constant K-type filter, and includes two coils (39.8 nH each) and two capacitors (151.6 pF each) connected in series, and a contact point between the two capacitors. It consists of a coil (15.2 nH) and a capacitor (63.6 pF) provided between the ground terminal. The filter unit 34 (third filter unit) is a high-pass filter having a third frequency band that can pass a signal in a predetermined frequency range (third frequency range) including the UHF band. For example, the filter unit 34 is a T-type circuit in which a constant K-type filter is combined, and two capacitors (12.7 pF each) connected in series, and a coil provided between a contact point of the two capacitors and a ground terminal. (15.9 nH). The filter units 32 and 34 are not limited to a T-type circuit in which a constant K-type filter is combined. Any circuit configuration may be used as long as the circuit can pass a signal in a predetermined frequency range. There may be. The filter unit 33 is not limited to a π-type circuit combined with a constant K-type filter, and may be any circuit configuration as long as it can pass a signal in a predetermined frequency range. .

さらに、第１周波数帯域を有するフィルタ部３２と、第２周波数帯域を有するフィルタ部３３、第３周波数帯域を有するフィルタ部３４とは、それぞれ異なる所定の周波数の範囲の信号を通過させることができる。また、フィルタ部３２の上限側の遮断周波数（通過した信号の強度が半減する周波数）が、フィルタ部３３の第２周波数帯域に含まれている。逆に、フィルタ部３３の下限側の遮断周波数が、フィルタ部３２の第１周波数帯域に含まれている。さらに、フィルタ部３３の上限側の遮断周波数が、フィルタ部３４の第３周波数帯域に含まれている。逆に、フィルタ部３４の下限側の遮断周波数が、フィルタ部３３の第２周波数帯域に含まれている。 Furthermore, the filter unit 32 having the first frequency band, the filter unit 33 having the second frequency band, and the filter unit 34 having the third frequency band can pass signals having different predetermined frequency ranges, respectively. . Further, the cutoff frequency on the upper limit side of the filter unit 32 (the frequency at which the intensity of the signal that has passed through is halved) is included in the second frequency band of the filter unit 33. Conversely, the cutoff frequency on the lower limit side of the filter unit 33 is included in the first frequency band of the filter unit 32. Further, the cutoff frequency on the upper limit side of the filter unit 33 is included in the third frequency band of the filter unit 34. On the contrary, the cutoff frequency on the lower limit side of the filter unit 34 is included in the second frequency band of the filter unit 33.

図７は、図６に示す無線受信装置３のシミュレーションで得られたフィルタ部３２〜３４の信号の周波数と信号の強度との関係を示したグラフである。図８は、図６に示す無線受信装置３のシミュレーションで得られた信号の周波数とフィルタ部３２〜３４の合成インピーダンスとの関係を示したグラフである。図７では、フィルタ部３２を通過した信号の周波数と信号の強度との関係を波形Ｌ、フィルタ部３３を通過した信号の周波数と信号の強度との関係を波形Ｂ、フィルタ部３４を通過した信号の周波数と信号の強度との関係を波形Ｈとしてそれぞれ示している。 FIG. 7 is a graph showing the relationship between the signal frequency and the signal intensity of the filter units 32 to 34 obtained by the simulation of the wireless reception device 3 shown in FIG. FIG. 8 is a graph showing the relationship between the frequency of the signal obtained by the simulation of the wireless reception device 3 shown in FIG. 6 and the combined impedance of the filter units 32 to 34. In FIG. 7, the relationship between the frequency of the signal that has passed through the filter unit 32 and the intensity of the signal is the waveform L, the relationship between the frequency of the signal that has passed through the filter unit 33 and the intensity of the signal is the waveform B, and The relationship between the signal frequency and the signal intensity is shown as a waveform H, respectively.

波形Ｌは、フィルタ部３２が略７５ＭＨｚ〜略１７５ＭＨｚ（フィルタ部３２の第１周波数帯域）の信号を通過させ、上限側の遮断周波数が略１７５ＭＨｚとなることを示している。波形Ｂは、フィルタ部３３が略１６５ＭＨｚ〜略２３５ＭＨｚ（フィルタ部３３の第２周波数帯域）の信号を通過させ、下限側の遮断周波数が略１６５ＭＨｚ、上限側の遮断周波数が略２３５ＭＨｚとなることを示している。波形Ｈは、フィルタ部３４が略２２５ＭＨｚ〜（フィルタ部３４の第３周波数帯域）の信号を通過させ、下限側の遮断周波数が略２２５ＭＨｚとなることを示している。なお、遮断周波数は、強度が５００ｍＶの信号がフィルタ部３２〜３４を通過して信号の強度が半減（２５０ｍＶ）する周波数である。 The waveform L indicates that the filter unit 32 passes a signal of about 75 MHz to about 175 MHz (the first frequency band of the filter unit 32), and the cutoff frequency on the upper limit side is about 175 MHz. The waveform B indicates that the filter unit 33 passes a signal of approximately 165 MHz to approximately 235 MHz (the second frequency band of the filter unit 33), the lower limit cutoff frequency is approximately 165 MHz, and the upper limit cutoff frequency is approximately 235 MHz. Show. The waveform H indicates that the filter unit 34 passes a signal of approximately 225 MHz to (the third frequency band of the filter unit 34), and the cutoff frequency on the lower limit side is approximately 225 MHz. The cut-off frequency is a frequency at which a signal having an intensity of 500 mV passes through the filter units 32 to 34 and the signal intensity is halved (250 mV).

図７に示すように、フィルタ部３２の第１周波数帯域（略７５ＭＨｚ〜略１７５ＭＨｚ）と、フィルタ部３３の第２周波数帯域（略１６０ＭＨｚ〜略２３５ＭＨｚ）と、フィルタ部３４の第３周波数帯域（略２２５ＭＨｚ〜）とは、それぞれ異なり、異なる周波数帯域を有するフィルタ部３２〜３４は、それぞれ異なる所定の周波数の範囲の信号を通過させることができる。また、フィルタ部３２の上限側の遮断周波数（略１７５ＭＨｚ）が、フィルタ部３３の第２周波数帯域に含まれている。逆に、フィルタ部３３の下限側の遮断周波数（略１６５ＭＨｚ）が、フィルタ部３２の第１周波数帯域に含まれている。さらに、フィルタ部３３の上限側の遮断周波数（略２３５ＭＨｚ）が、フィルタ部３４の第３周波数帯域に含まれている。逆に、フィルタ部３４の下限側の遮断周波数（略２２５ＭＨｚ）が、フィルタ部３３の第２周波数帯域に含まれている。 As shown in FIG. 7, the first frequency band (approximately 75 MHz to approximately 175 MHz) of the filter unit 32, the second frequency band (approximately 160 MHz to approximately 235 MHz) of the filter unit 33, and the third frequency band ( The filter units 32 to 34 having different frequency bands can pass signals having different predetermined frequency ranges. Further, the cutoff frequency (approximately 175 MHz) on the upper limit side of the filter unit 32 is included in the second frequency band of the filter unit 33. Conversely, the cutoff frequency (approximately 165 MHz) on the lower limit side of the filter unit 33 is included in the first frequency band of the filter unit 32. Further, the upper cutoff frequency (approximately 235 MHz) of the filter unit 33 is included in the third frequency band of the filter unit 34. Conversely, the cut-off frequency (approximately 225 MHz) on the lower limit side of the filter unit 34 is included in the second frequency band of the filter unit 33.

フィルタ部３２〜３４の遮断周波数、周波数帯域を図７に示した遮断周波数、周波数帯域にすることで、信号の周波数とフィルタ部３２〜３４の合成インピーダンスとの関係は図８に示すようになり、フィルタ部３２〜３４の合成インピーダンスを、増幅器３１で信号を増幅することができる周波数の範囲（例えば、０Ｈｚ〜２．０ＧＨｚ）内において、増幅器３１の負荷インピーダンスである５０Ω以下にすることができる。合成インピーダンスが、増幅器３１の負荷インピーダンス以下になるフィルタ部３２〜３４の前段に増幅器３１を備えることで、フィルタ部３２〜３４から増幅器３１に正帰還する信号の量を所定量以下にすることができ、増幅器３１が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。なお、フィルタ部３２〜３４から増幅器３１に正帰還する信号の所定量は、無線受信装置３を実際に動作させた場合に増幅器３１の動作が不安定となるフィルタ部３２〜３４の合成インピーダンスから類推される信号の量である。無線受信装置３の回路構成により、フィルタ部３２〜３４から増幅器３１に正帰還する信号の所定量は異なる。 By setting the cutoff frequency and frequency band of the filter units 32 to 34 to the cutoff frequency and frequency band shown in FIG. 7, the relationship between the signal frequency and the combined impedance of the filter units 32 to 34 is as shown in FIG. The combined impedance of the filter units 32 to 34 can be set to 50 Ω or less which is the load impedance of the amplifier 31 within a frequency range (for example, 0 Hz to 2.0 GHz) in which the signal can be amplified by the amplifier 31. . By providing the amplifier 31 in front of the filter units 32 to 34 where the combined impedance is equal to or lower than the load impedance of the amplifier 31, the amount of the signal that is positively fed back from the filter units 32 to 34 to the amplifier 31 can be reduced to a predetermined amount or less. Thus, the signal can be stably amplified within a frequency range in which the amplifier 31 can amplify the signal. Note that the predetermined amount of the signal that is positively fed back from the filter units 32 to 34 to the amplifier 31 is based on the combined impedance of the filter units 32 to 34 in which the operation of the amplifier 31 becomes unstable when the wireless reception device 3 is actually operated. This is the amount of signal that can be inferred. The predetermined amount of the signal that is positively fed back from the filter units 32 to 34 to the amplifier 31 differs depending on the circuit configuration of the wireless reception device 3.

また、フィルタ部３２〜３４の合成インピーダンスが、増幅器３１の負荷インピーダンスより大きくなると、フィルタ部３２〜３４から増幅器３１に正帰還する信号の量が増えるが、所定量より大きくならなければ増幅器３１の動作が不安定になることも、増幅器３１が発振することもない。例えば、第１周波数帯域を有するフィルタ部３２と、第２周波数帯域を有するフィルタ部３３と、第３周波数帯域を有するフィルタ部３４とは、それぞれ異なる所定の周波数の範囲の信号を通過させることができる。また、フィルタ部３２〜３４の遮断周波数同士が一致する場合であっても、フィルタ部３２〜３４から増幅器３１に正帰還する信号の量が所定量以下となるようにフィルタ部３２〜３４の合成インピーダンスの値を抑えることができ、増幅器３１が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。 Further, when the combined impedance of the filter units 32 to 34 becomes larger than the load impedance of the amplifier 31, the amount of the signal that is positively fed back from the filter units 32 to 34 to the amplifier 31 increases. The operation does not become unstable and the amplifier 31 does not oscillate. For example, the filter unit 32 having the first frequency band, the filter unit 33 having the second frequency band, and the filter unit 34 having the third frequency band may pass signals having different predetermined frequency ranges. it can. Further, even when the cutoff frequencies of the filter units 32 to 34 coincide with each other, the synthesis of the filter units 32 to 34 is performed so that the amount of the signal positively fed back from the filter units 32 to 34 to the amplifier 31 is equal to or less than a predetermined amount. The impedance value can be suppressed, and the signal can be stably amplified within the frequency range in which the amplifier 31 can amplify the signal.

なお、複数のフィルタ部３２〜３４の遮断周波数同士が一致する場合とは、具体的に、フィルタ部３２の上限側の遮断周波数（略１７５ＭＨｚ）が、フィルタ部３３の下限側の遮断周波数（略１６５ＭＨｚ）と一致、フィルタ部３３の上限側の遮断周波数（略２３５ＭＨｚ）が、フィルタ部３４の下限側の遮断周波数（略２２５ＭＨｚ）と一致している場合である。 Note that the case where the cutoff frequencies of the plurality of filter units 32 to 34 match each other specifically means that the cutoff frequency on the upper limit side of the filter unit 32 (approximately 175 MHz) is the cutoff frequency on the lower limit side of the filter unit 33 (approximately). 165 MHz), and the cutoff frequency (approximately 235 MHz) on the upper limit side of the filter unit 33 matches the cutoff frequency (approximately 225 MHz) on the lower limit side of the filter unit 34.

次に、チューナ部３５は、フィルタ部３２を通過したＶＨＦ帯ローバンドの信号を同調させることが可能な回路である。チューナ部３５で同調させたマルチメディア放送の信号に対して所定の処理を行うことで、図示していない表示装置でマルチメディア放送を視聴することができる。チューナ部３６は、フィルタ部３３を通過したＶＨＦ帯ハイバンドの信号を同調させることが可能な回路である。チューナ部３６で同調させたマルチメディア放送の信号に対して所定の処理を行うことで、図示していない表示装置でマルチメディア放送を視聴することができる。チューナ部３７は、フィルタ部３４を通過したＵＨＦ帯の信号を同調させることが可能な回路である。チューナ部３７で同調させたテレビ放送の信号に対して所定の処理を行うことで、図示していない表示装置でテレビ放送を視聴することができる。 Next, the tuner unit 35 is a circuit that can tune the VHF band low band signal that has passed through the filter unit 32. By performing predetermined processing on the multimedia broadcast signal tuned by the tuner unit 35, the multimedia broadcast can be viewed on a display device (not shown). The tuner unit 36 is a circuit that can tune the VHF band high band signal that has passed through the filter unit 33. By performing predetermined processing on the multimedia broadcast signal tuned by the tuner unit 36, the multimedia broadcast can be viewed on a display device (not shown). The tuner unit 37 is a circuit that can tune the UHF band signal that has passed through the filter unit 34. By performing predetermined processing on the television broadcast signal tuned by the tuner unit 37, the television broadcast can be viewed on a display device (not shown).

以上のように、本発明の実施の形態１に係る無線受信装置３は、フィルタ部３２の上限側の遮断周波数がフィルタ部３３の第２周波数帯域に、フィルタ部３３の下限側の遮断周波数がフィルタ部３２の第１周波数帯域に、フィルタ部３３の上限側の遮断周波数がフィルタ部３４の第３周波数帯域に、及びフィルタ部３４の下限側の遮断周波数がフィルタ部３３の第２周波数帯域にそれぞれ含まれている複数のフィルタ部３２〜３４の前段に増幅器３１を備えるので、フィルタ部３２〜３４から増幅器３１に正帰還する信号の量が所定量以下となるようにフィルタ部３２〜３４の合成インピーダンスの値を抑えることができ、増幅器３１が信号を増幅することができる周波数の範囲内において安定して信号を増幅することができる。また、増幅器３１が発振することを防止することができる。 As described above, in the radio reception device 3 according to Embodiment 1 of the present invention, the cutoff frequency on the upper limit side of the filter unit 32 is in the second frequency band of the filter unit 33, and the cutoff frequency on the lower limit side of the filter unit 33 is In the first frequency band of the filter unit 32, the cutoff frequency on the upper limit side of the filter unit 33 is in the third frequency band of the filter unit 34, and the cutoff frequency on the lower limit side of the filter unit 34 is in the second frequency band of the filter unit 33. Since the amplifier 31 is provided in front of each of the plurality of filter units 32 to 34 included therein, the filter units 32 to 34 are configured so that the amount of the signal positively fed back from the filter units 32 to 34 to the amplifier 31 is equal to or less than a predetermined amount. The value of the combined impedance can be suppressed, and the signal can be stably amplified within the frequency range in which the amplifier 31 can amplify the signal. Further, it is possible to prevent the amplifier 31 from oscillating.

なお、本発明の実施の形態２に係る無線受信装置３は、増幅器３１が信号を増幅することができる周波数の範囲を、ＶＨＦ帯ローバンドを含む所定の周波数の範囲（第１周波数の範囲）と、ＶＨＦ帯ハイバンドを含む所定の周波数の範囲（第２周波数の範囲）と、ＵＨＦ帯を含む所定の周波数の範囲（第３周波数の範囲）との三つの所定の周波数の範囲を含む場合に限定されるものではなく、ＶＨＦ帯ローバンド、ＶＨＦ帯ハイバンド、ＵＨＦ帯を含まない三つの所定の周波数の範囲を含む場合であっても、四つ以上の所定の周波数の範囲を含む場合であっても良い。 Note that, in the wireless reception device 3 according to Embodiment 2 of the present invention, the frequency range in which the amplifier 31 can amplify the signal is defined as a predetermined frequency range (first frequency range) including the VHF band low band. In the case of including three predetermined frequency ranges including a predetermined frequency range including the VHF band high band (second frequency range) and a predetermined frequency range including the UHF band (third frequency range). The present invention is not limited to the case of including three predetermined frequency ranges not including the VHF band low band, VHF band high band, and UHF band, but including four or more predetermined frequency ranges. May be.

１、３無線受信装置
２アンテナ
１１、３１増幅器
１２、１３、３２〜３４フィルタ部
１４、１５、３５〜３７チューナ部 1, 3 Radio receiver 2 Antenna 11, 31 Amplifier 12, 13, 32-34 Filter unit 14, 15, 35-37 Tuner unit

Claims

An amplifier for amplifying the signal received by the antenna;
A plurality of parallel-connected devices each having a frequency band that is connected to the amplifier and has a frequency band that allows the signal to pass through different predetermined frequency ranges within a frequency range in which the amplifier can amplify the signal. A filter section;
A plurality of tuner units connected to each of the plurality of filter units and capable of tuning the signal that has passed through the filter unit;
When the two predetermined frequency ranges included in the frequency range in which the amplifier can amplify the signal are the first frequency range and the second frequency range,
The plurality of filter units are
A first filter section having a first frequency band capable of passing the signal in the first frequency range;
A second filter unit having a second frequency band capable of passing the signal in the second frequency range;
Have
The cutoff frequency on the upper limit side of the first filter unit matches the cutoff frequency on the lower limit side of the second filter unit,
Alternatively, the cutoff frequency on the upper limit side of the first filter unit is in the second frequency band of the second filter unit, and the cutoff frequency on the lower limit side of the second filter unit is the first frequency band of the first filter unit. Each included in
The wireless reception device , wherein a combined impedance of the plurality of filter units at the cutoff frequency is equal to or less than a load impedance of the amplifier .

The radio receiving apparatus according to claim 1, wherein the first frequency range includes a VHF band, and the second frequency range includes a UHF band .

When the three predetermined frequency ranges included in the frequency range in which the amplifier can amplify the signal are a first frequency range, a second frequency range , and a third frequency range ,
The plurality of filter units are
A first filter section having a first frequency band capable of passing the signal in the first frequency range;
A second filter section having a second frequency band capable of passing the signal in the second frequency range ;
A third filter unit having a third frequency band capable of passing the signal in the range of the third frequency ,
The cutoff frequency on the upper limit side of the first filter unit, the cutoff frequency on the lower limit side of the second filter unit, the cutoff frequency on the upper limit side of the second filter unit, and the lower limit side of the third filter unit The cut-off frequency matches each other
Or the said second frequency band of the cut-off frequency of the upper side of the first filter section and the second filter unit, before Symbol the first frequency band of the cut-off frequency of the first filter portion of the lower side of the second filter portion Furthermore, the cutoff frequency on the upper limit side of the second filter unit is in the third frequency band of the third filter unit, and the cutoff frequency on the lower limit side of the third filter unit is the second frequency of the second filter unit. The radio reception apparatus according to claim 1, wherein the radio reception apparatus is included in each band .

The radio receiving apparatus according to claim 3, wherein the first frequency range includes a VHF band low band , the second frequency range includes a VHF band high band, and the third frequency range includes a UHF band .