JP4105726B2 - Band stop filter - Google Patents
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- JP4105726B2 JP4105726B2 JP2006021640A JP2006021640A JP4105726B2 JP 4105726 B2 JP4105726 B2 JP 4105726B2 JP 2006021640 A JP2006021640 A JP 2006021640A JP 2006021640 A JP2006021640 A JP 2006021640A JP 4105726 B2 JP4105726 B2 JP 4105726B2
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本発明は、帯域阻止フィルタに係り、特に、より広帯域の周波数帯域を阻止することが可能な帯域阻止フィルタに関する。 The present invention relates to a band rejection filter, and more particularly to a band rejection filter capable of blocking a wider frequency band.
地上波デジタルテレビの中継局等において、例えば、受信設備では、隣接チャネルへの妨害波の除去、また、送信設備では、電力増幅器から出力される３次ＩＭ波の除去のために、帯域阻止フィルタが使用される。
図１４は、従来の帯域阻止フィルタの回路構成を示す図である。
図１４に示す帯域阻止フィルタは、例えば、同軸線路１０と接地との間に、λ／４の間隔をおいて、容量素子（Ｃ）とインダクタンス素子（Ｌ）から成る直列共振回路を複数接続したものである。（例えば、下記特許文献１参照）
FIG. 14 is a diagram showing a circuit configuration of a conventional band rejection filter.
In the band rejection filter shown in FIG. 14, for example, a plurality of series resonant circuits composed of a capacitive element (C) and an inductance element (L) are connected at an interval of λ / 4 between the
しかしながら、前述した従来の帯域阻止フィルタでは、同軸線路１０に、容量素子（Ｃ）とインダクタンス素子（Ｌ）から成る直列共振回路を接続するための分岐結合部（図１４のＢに示す部分）の構造が複雑であるばかりか、阻止する周波数帯域が狭帯域であるという問題点があった。
本発明は、前記従来技術の問題点を解決するためになされたものであり、本発明の目的は、分岐結合部を必要とせず、より広帯域の周波数帯域を阻止することが可能な帯域阻止フィルタを提供することにある。
本発明の前記ならびにその他の目的と新規な特徴は、本明細書の記述及び添付図面によって明らかにする。
However, in the conventional band rejection filter described above, a branch coupling portion (portion indicated by B in FIG. 14) for connecting a series resonant circuit composed of a capacitive element (C) and an inductance element (L) to the
The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a band rejection filter that does not require a branch coupling unit and can block a wider frequency band. Is to provide.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.
本願において開示される発明のうち、代表的なものの概要を簡単に説明すれば、下記の通りである。
前述の目的を達成するために、本発明は、第１ないし第４の端子を有するハイブリッド回路と、帯域通過フィルタとから成る帯域阻止フィルタであって、前記帯域通過フィルタは、前記ハイブリッド回路の第２の端子と第３の端子との間に接続され、前記ハイブリッド回路の第１の端子を、帯域阻止フィルタの入力端子となし、前記ハイブリッド回路の第４の端子を、帯域阻止フィルタの出力端子としたことを特徴とする。
また、本発明では、前記ハイブリッド回路の第２の端子と第３の端子との間に、ｎ（ｎ≧２）個の帯域通過フィルタを接続したことを特徴とする。
Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
In order to achieve the above-mentioned object, the present invention provides a band rejection filter comprising a hybrid circuit having first to fourth terminals and a bandpass filter , wherein the bandpass filter is the first of the hybrid circuits. 2 is connected between the second terminal and the third terminal , the first terminal of the hybrid circuit is made the input terminal of the band rejection filter, and the fourth terminal of the hybrid circuit is made the output terminal of the band rejection filter. It is characterized by that.
In the present invention, n (n ≧ 2) band-pass filters are connected between the second terminal and the third terminal of the hybrid circuit.
本願において開示される発明のうち代表的なものによって得られる効果を簡単に説明すれば、下記の通りである。
本発明の帯域阻止フィルタによれば、分岐結合部を必要とせず、より広帯域の周波数帯域を阻止することが可能となる。
The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
According to the band rejection filter of the present invention, it is possible to block a wider frequency band without requiring a branch coupling unit.
以下、図面を参照して本発明の実施例を詳細に説明する。
なお、実施例を説明するための全図において、同一機能を有するものは同一符号を付け、その繰り返しの説明は省略する。
図１は、本発明の実施例の帯域阻止フィルタの回路構成を示すブロック図である。
本実施例の帯域阻止フィルタは、λ／４結合形３ｄＢハイブリッド回路（以下、単に、ハイブリッド回路という）（Ｈ）と、帯域通過フィルタ（ＢＰＦ）とを有する。
ここで、帯域通過フィルタ（ＢＰＦ）の第１の入出力端子（Ｔ１Ｂ）は、ハイブリッド回路（Ｈ）の第２の端子（Ｔ２）に、帯域通過フィルタ（ＢＰＦ）の第２の入出力端子（Ｔ２Ｂ）は、ハイブリッド回路（Ｈ）の第３の端子（Ｔ３）に接続される。即ち、帯域通過フィルタ（ＢＰＦ）は、ハイブリッド回路（Ｈ）の第２の端子（Ｔ２）と第３の端子（Ｔ３）との間に接続される。
そして、ハイブリッド回路（Ｈ）の第１の端子（Ｔ１）が、帯域阻止フィルタの入力端子となり、ハイブリッド回路（Ｈ）の第４の端子（Ｔ４）が、帯域阻止フィルタの出力端子となる。
なお、図１、および後述する各図において、ハイブリッド回路（Ｈ）の第２の端子（Ｔ ２ ）と帯域通過フィルタ（ＢＰＦ）の第１の入出力端子（Ｔ １Ｂ ）との間の距離を（Ｄ１）、ハイブリッド回路（Ｈ）の第３の端子（Ｔ ３ ）と帯域通過フィルタ（ＢＰＦ）の第２の入出力端子（Ｔ ２Ｂ ）との間の距離を（Ｄ２）とするとき、Ｄ１とＤ２とを等しく（Ｄ１＝Ｄ２）して、ハイブリッド回路（Ｈ）の第２の端子（Ｔ ２ ）と帯域通過フィルタ（ＢＰＦ）の第１の入出力端子（Ｔ １Ｂ ）との間を伝搬する信号の位相と、ハイブリッド回路（Ｈ）の第３の端子（Ｔ ３ ）と帯域通過フィルタ（ＢＰＦ）の第２の入出力端子（Ｔ ２Ｂ ）との間を伝搬する信号の位相を同じにしている。
ハイブリッド回路の〔Ｓ〕マトリクスは、下記（１）式で表される。この〔Ｓ〕マトリクスを使用し、図１に示すハイブリッド回路（Ｈ）の第１の端子（Ｔ１）に、Ｅｉｎの入力電圧を印加したときに、ハイブリッド回路（Ｈ）の各端子に出力される電圧（Ｅ１〜Ｅ４）は、下記（２）式で求めることができる。
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In all the drawings for explaining the embodiments, parts having the same functions are given the same reference numerals, and repeated explanation thereof is omitted.
FIG. 1 is a block diagram showing a circuit configuration of a band rejection filter according to an embodiment of the present invention.
The band rejection filter of the present embodiment includes a λ / 4 coupled 3 dB hybrid circuit (hereinafter simply referred to as a hybrid circuit) (H) and a band pass filter (BPF).
Here, the first input / output terminal (T 1B ) of the band pass filter (BPF) is connected to the second input / output terminal of the band pass filter (BPF) to the second terminal (T 2) of the hybrid circuit (H). (T 2B ) is connected to the third terminal (T 3 ) of the hybrid circuit (H). That is, the band pass filter (BPF) is connected between the second terminal (T 2 ) and the third terminal (T 3 ) of the hybrid circuit (H).
Then, the first terminal (T 1 ) of the hybrid circuit (H) is an input terminal of the band rejection filter, and the fourth terminal (T 4 ) of the hybrid circuit (H) is an output terminal of the band rejection filter. .
Note that in each drawing Figure 1, and described below, the distance between the first input and output terminals of the second terminal of the hybrid circuit (H) (T 2) and the band pass filter (BPF) (T 1B) (D1) When the distance between the third terminal (T 3 ) of the hybrid circuit (H) and the second input / output terminal (T 2B ) of the bandpass filter (BPF) is (D2), D1 And D2 are equal (D1 = D2) and propagated between the second terminal (T 2 ) of the hybrid circuit (H ) and the first input / output terminal (T 1B ) of the bandpass filter (BPF). And the phase of the signal propagating between the third terminal (T 3 ) of the hybrid circuit (H) and the second input / output terminal (T 2B ) of the bandpass filter (BPF) are made the same. ing.
The [S] matrix of the hybrid circuit is expressed by the following equation (1). Using this [S] matrix, when an input voltage of Ein is applied to the first terminal (T1) of the hybrid circuit (H) shown in FIG. 1, it is output to each terminal of the hybrid circuit (H). The voltages (E 1 to E 4 ) can be obtained by the following equation (2).
前述の（２）式から分かるように、図１に示すハイブリッド回路（Ｈ）の第１の端子（Ｔ１）に、Ｅｉｎの入力電圧を印加したときに、ハイブリッド回路（Ｈ）の第２の端子（Ｔ２）から、Ｅｉｎ／√２（＝Ｅ２）の電圧が、また、第３の端子（Ｔ３）から、−ｊＥｉｎ／√２（＝Ｅ３）の電圧が出力される。
今、帯域通過フィルタ（ＢＰＦ）の通過帯域を（ｆｏ±Δｆ；ｆｏは中心周波数）とするとき、図２に示すように、この通過帯域内の周波数においては、ハイブリッド回路（Ｈ）の第２の端子（Ｔ２）から出力された、Ｅｉｎ／√２の電圧は、帯域通過フィルタ（ＢＰＦ）を通過して、ハイブリッド回路（Ｈ）の第３の端子（Ｔ３）に入力され、同様に、第３の端子（Ｔ３）から出力された、−ｊＥｉｎ／√２の電圧は、帯域通過フィルタ（ＢＰＦ）を通過して、ハイブリッド回路（Ｈ）の第２の端子（Ｔ２）に入力される。
このとき、ハイブリッド回路（Ｈ）の各端子に出力される電圧（Ｅ１Ｂ〜Ｅ４Ｂ）は、下記（３）式で求めることができる。
As can be seen from the above equation (2), when the input voltage of Ein is applied to the first terminal (T 1 ) of the hybrid circuit (H) shown in FIG. from the terminal (T 2), the voltage of the Ein / √2 (= E 2) is also the third terminal (T 3), the voltage of -jEin / √2 (= E 3) is outputted.
Now, assuming that the passband of the bandpass filter (BPF) is (fo ± Δf; fo is the center frequency), as shown in FIG. 2, the second frequency of the hybrid circuit (H) is obtained at a frequency within this passband. The voltage of Ein / √2 output from the terminal (T 2 ) of the second signal passes through the band-pass filter (BPF) and is input to the third terminal (T 3 ) of the hybrid circuit (H). The voltage of −jEin / √2 output from the third terminal (T 3 ) passes through the band pass filter (BPF) and is input to the second terminal (T 2 ) of the hybrid circuit (H). Is done.
At this time, the voltages (E 1B to E 4B ) output to each terminal of the hybrid circuit (H) can be obtained by the following equation (3).
このように、ハイブリッド回路（Ｈ）の第１の端子（Ｔ１）から入力された入力信号の中で、帯域通過フィルタ（ＢＰＦ）の通過帯域内の信号は、ハイブリッド回路（Ｈ）の第１の端子（Ｔ１）に逆流し、ハイブリッド回路（Ｈ）の第４の端子（Ｔ４）から出力されない。
また、図３に示すように、帯域通過フィルタ（ＢＰＦ）の通過帯域外の周波数において、ハイブリッド回路（Ｈ）の第２の端子（Ｔ２）から出力された、Ｅｉｎ／√２の電圧は、帯域通過フィルタ（ＢＰＦ）の電圧反射係数（ΓＢ）によって反射され、ハイブリッド回路（Ｈ）の第２の端子（Ｔ２）に再入力され、同様に、第３の端子（Ｔ３）から出力された、−ｊＥｉｎ／√２の電圧は、帯域通過フィルタ（ＢＰＦ）の電圧反射係数（ΓＢ）によって反射され、ハイブリッド回路（Ｈ）の第３の端子（Ｔ３）に再入力される。
このとき、ハイブリッド回路（Ｈ）の各端子に出力される電圧（Ｅ１Γ〜Ｅ４Γ）は、下記（４）式で求めることができる。
Thus, among the input signals input from the first terminal (T 1 ) of the hybrid circuit (H), the signal in the pass band of the band pass filter (BPF) is the first signal of the hybrid circuit (H). The terminal flows backward to the terminal (T 1 ) and is not output from the fourth terminal (T 4 ) of the hybrid circuit (H).
Also, as shown in FIG. 3, at a frequency outside the pass band of the band pass filter (BPF), the voltage of Ein / √2 output from the second terminal (T 2 ) of the hybrid circuit (H) is Reflected by the voltage reflection coefficient (Γ B ) of the bandpass filter (BPF), re-input to the second terminal (T 2 ) of the hybrid circuit (H), and similarly output from the third terminal (T 3 ). is, the voltage of -jEin / √2 is reflected by the voltage reflection coefficient of the bandpass filter (BPF) (Γ B), is re-input to the third terminal of the hybrid circuit (H) (T 3).
At this time, the voltages (E 1Γ to E 4Γ ) output to each terminal of the hybrid circuit (H) can be obtained by the following equation (4).
このように、ハイブリッド回路（Ｈ）の第１の端子（Ｔ１）から入力された入力信号の中で、帯域通過フィルタ（ＢＰＦ）の通過帯域外の信号は、ハイブリッド回路（Ｈ）の第１の端子（Ｔ４）から出力される。
即ち、図１に示す帯域阻止フィルタは、ハイブリッド回路（Ｈ）の第１の端子（Ｔ１）に入力された入力信号の中で、帯域通過フィルタ（ＢＰＦ）の通過帯域内の信号を減衰させて、ハイブリッド回路（Ｈ）の第４の端子（Ｔ４）から出力させる。
本実施例の帯域阻止フィルタでは、従来の帯域阻止フィルタのように、分岐結合部を必要としないので信頼性を向上させることが可能である。また、阻止する周波数帯域は、帯域通過フィルタ（ＢＰＦ）の通過帯域により決定されるので、従来の帯域阻止フィルタよりも、より広帯域の周波数帯域を阻止することが可能となる。
なお、図４に示すように、ハイブリッド回路（Ｈ）の第２の端子（Ｔ２）と、第３の端子（Ｔ３）に、同一の特性を備える帯域通過フィルタ（ＢＰＦａ，ＢＰＦｂ）をそれぞれ接続しても、本実施例の帯域阻止フィルタと同様の特性を得ることが可能である。
しかしながら、本実施例の帯域阻止フィルタは、図４に示す帯域阻止フィルタと比して、帯域通過フィルタが１個で済むので、コストを低減することが可能である。また、図４において、Ｒは無反射終端器である。
Thus, among the input signals input from the first terminal (T 1 ) of the hybrid circuit (H), the signal outside the pass band of the band pass filter (BPF) is the first signal of the hybrid circuit (H). Are output from the terminal (T 4 ).
That is, the band rejection filter shown in FIG. 1 attenuates the signal in the pass band of the band pass filter (BPF) among the input signals input to the first terminal (T 1 ) of the hybrid circuit (H). Te, is output from the fourth terminal of the hybrid circuit (H) (T 4).
In the band rejection filter of the present embodiment, unlike the conventional band rejection filter, the branch coupling part is not required, so that the reliability can be improved. Further, since the frequency band to be blocked is determined by the pass band of the band pass filter (BPF), it is possible to block a wider frequency band than the conventional band blocking filter.
As shown in FIG. 4, bandpass filters (BPFa, BPFb) having the same characteristics are provided on the second terminal (T 2 ) and the third terminal (T 3 ) of the hybrid circuit (H), respectively. Even if connected, it is possible to obtain the same characteristics as the band rejection filter of the present embodiment.
However, since the band rejection filter of the present embodiment requires only one band pass filter as compared with the band rejection filter shown in FIG. 4, the cost can be reduced. In FIG. 4, R is a non-reflection terminator.
図５は、本実施例の帯域阻止フィルタの一例の伝送特性を示すグラフであり、横軸は周波数（ＭＨｚ）でメモリ間隔は１０ＭＨｚ、中心周波数は５００ＭＨｚ、縦軸は減衰量（ｄＢ）でメモリ間隔は５ｄＢである。
この図５は、図１に示すハイブリッド回路（Ｈ）の第４の端子（Ｔ４）から出力される出力信号の減衰特性を示す図である。
また、図６は、本実施例の帯域阻止フィルタの一例の反射特性を示すグラフであり、横軸は周波数（ＭＨｚ）でメモリ間隔は１０ＭＨｚ、中心周波数は５００ＭＨｚ、縦軸は減衰量（ｄＢ）でメモリ間隔は５ｄＢである。
この図６は、図１に示すハイブリッド回路（Ｈ）の第１の端子（Ｔ１）に反射される信号の減衰特性を示す図である。
また、図７は、図５、図６の特性を示す帯域阻止フィルタに使用された６次同軸共振器型帯域通過フィルタの伝送特性（減衰特性）を示すグラフであり、横軸は周波数（ＭＨｚ）でメモリ間隔は１０ＭＨｚ、中心周波数は５００ＭＨｚ、縦軸は減衰量（ｄＢ）でメモリ間隔は１０ｄＢである。
さらに図８は、図５、図６の特性を示す帯域阻止フィルタに使用された６次同軸共振器型帯域通過フィルタの反射特性を示すグラフであり、横軸は周波数（ＭＨｚ）でメモリ間隔は１０ＭＨｚ、中心周波数は５００ＭＨｚ、縦軸は減衰量（ｄＢ）でメモリ間隔は５ｄＢである。
これらの図から分かるように、本実施例の帯域阻止フィルタの阻止帯域は、ハイブリッド回路（Ｈ）の第２の端子（Ｔ２）と第３の端子（Ｔ３）との間に接続される帯域通過フィルタの通過帯域と同じになることが分かる。
FIG. 5 is a graph showing the transmission characteristics of an example of the band rejection filter of this embodiment. The horizontal axis is frequency (MHz), the memory interval is 10 MHz, the center frequency is 500 MHz, and the vertical axis is the attenuation amount (dB). The interval is 5 dB.
FIG. 5 is a diagram showing the attenuation characteristic of the output signal output from the fourth terminal (T 4 ) of the hybrid circuit (H) shown in FIG.
FIG. 6 is a graph showing the reflection characteristics of an example of the band rejection filter of this embodiment. The horizontal axis is frequency (MHz), the memory interval is 10 MHz, the center frequency is 500 MHz, and the vertical axis is attenuation (dB). And the memory interval is 5 dB.
FIG 6 is a diagram showing the attenuation characteristics of the reflected signal being the first terminal (T 1) of the hybrid circuit (H) shown in FIG.
FIG. 7 is a graph showing transmission characteristics (attenuation characteristics) of a sixth-order coaxial resonator type bandpass filter used in the band rejection filter having the characteristics shown in FIGS. 5 and 6, and the horizontal axis represents frequency (MHz). ), The memory interval is 10 MHz, the center frequency is 500 MHz, the vertical axis is the attenuation (dB), and the memory interval is 10 dB.
FIG. 8 is a graph showing the reflection characteristics of the 6th-order coaxial resonator type bandpass filter used in the band rejection filter having the characteristics shown in FIGS. 5 and 6. The horizontal axis is the frequency (MHz) and the memory interval is 10 MHz, center frequency is 500 MHz, the vertical axis is attenuation (dB), and the memory interval is 5 dB.
As can be seen from these figures, the stop band of the band stop filter of the present embodiment is connected between the second terminal (T 2 ) and the third terminal (T 3 ) of the hybrid circuit (H). It turns out that it becomes the same as the pass band of a band pass filter.
図９は、本発明の実施例の帯域阻止フィルタの変形例を示すブロック図である。図９に示す帯域阻止フィルタは、ハイブリッド回路（Ｈ）の第２の端子（Ｔ２）と第３の端子（Ｔ３）との間に、それぞれ通過帯域が異なる２つの帯域通過フィルタ（ＢＰＦ１、ＢＰＦ２）を接続したものである。
図１０も、本発明の実施例の帯域阻止フィルタの変形例を示すブロック図である。図１０に示す帯域阻止フィルタは、第２の端子（Ｔ２）と第３の端子（Ｔ３）との間に帯域通過フィルタ（ＢＰＦ１〜ＢＰＦｎ）を接続したｎ個のハイブリッド回路（Ｈ１〜Ｈｎ）を縦続接続したものである。
図１１も、本発明の実施例の帯域阻止フィルタの変形例を示すブロック図である。図１１に示す帯域阻止フィルタは、第２の端子（Ｔ２）と第３の端子（Ｔ３）との間に、少なくともｎ個の帯域通過フィルタ（ＢＰＦ１１〜ＢＰＦ１ｎ，ＢＰＦ２，ＢＰＦｍ１〜ＢＰＦｍｎ）を接続したｎ個のハイブリッド回路（Ｈ１〜Ｈｎ）を縦続接続したものである。
FIG. 9 is a block diagram showing a modification of the band rejection filter according to the embodiment of the present invention. The band rejection filter shown in FIG. 9 includes two bandpass filters (BPF1, BPF1,...) Having different passbands between the second terminal (T 2 ) and the third terminal (T 3 ) of the hybrid circuit (H). BPF2) is connected.
FIG. 10 is also a block diagram showing a modification of the band rejection filter according to the embodiment of the present invention. The band rejection filter shown in FIG. 10 includes n hybrid circuits (H1 to Hn) in which bandpass filters (BPF1 to BPFn) are connected between the second terminal (T 2 ) and the third terminal (T 3 ). ) In cascade.
FIG. 11 is also a block diagram showing a modification of the band rejection filter of the embodiment of the present invention. The band rejection filter shown in FIG. 11 includes at least n band pass filters (BPF11 to BPF1n, BPF2, BPFm1 to BPFmn) between the second terminal (T 2 ) and the third terminal (T 3 ). N connected hybrid circuits (H1 to Hn) are cascade-connected.
なお、図９に示すように、本発明の実施例の帯域阻止フィルタにおいて、帯域通過フィルタとしては、帯域阻止フィルタの通過帯域において、帯域通過フィルタの入力インピーダンスが高いものを使用する必要がある。
即ち、本実施例の帯域阻止フィルタにおいて、図１２に示すような回路構成の帯域通過フィルタを使用する場合、入力側（または、出力側）の容量素子（Ｃ１）とインダクタンス素子（Ｌ１）から成る並列共振回路、あるいは、出力側（または、入力側）の容量素子（Ｃ２）とインダクタンス素子（Ｌ３）から成る並列共振回路は、帯域阻止フィルタの通過帯域において、低インピーダンスとなり回路が短絡状態に近くなるので好ましくない。
これに対して、図１３に示すような回路構成の帯域通過フィルタでは、入力側（または、出力側）の容量素子（Ｃ１）とインダクタンス素子（Ｌ１）から成る直列共振回路、あるいは、出力側（または、入力側）の容量素子（Ｃ２）とインダクタンス素子（Ｌ３）から成る直列共振回路は、帯域阻止フィルタの通過帯域において、高インピーダンスとなるので、本実施例の帯域阻止フィルタに最適である。
以上、本発明者によってなされた発明を、前記実施例に基づき具体的に説明したが、本発明は、前記実施例に限定されるものではなく、その要旨を逸脱しない範囲において種々変更可能であることは勿論である。
As shown in FIG. 9, in the band rejection filter of the embodiment of the present invention, it is necessary to use a bandpass filter having a high bandpass filter input impedance in the passband of the band rejection filter.
That is, in the band rejection filter of the present embodiment, when a band pass filter having a circuit configuration as shown in FIG. 12 is used, it comprises an input side (or output side) capacitive element (C1) and an inductance element (L1). The parallel resonant circuit or the parallel resonant circuit composed of the output side (or input side) capacitive element (C2) and the inductance element (L3) has a low impedance in the pass band of the band rejection filter, and the circuit is close to a short circuit state. This is not preferable.
On the other hand, in the bandpass filter having the circuit configuration as shown in FIG. 13, a series resonant circuit including a capacitive element (C1) and an inductance element (L1) on the input side (or output side), or the output side ( Alternatively, the series resonant circuit including the capacitive element (C2) and the inductance element (L3) on the input side has a high impedance in the pass band of the band rejection filter, and is optimal for the band rejection filter of this embodiment.
As mentioned above, the invention made by the present inventor has been specifically described based on the above embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Of course.
Ｈ，Ｈ１〜Ｈｎ λ／４結合形３ｄＢハイブリッド回路
ＢＰＦ，ＢＰＦａ，ＢＰＦｂ，ＢＰＦ１，ＢＰＦ２，ＢＰＦ１１〜ＢＰＦ１ｎ，ＢＰＦｍ１〜ＢＰＦｍｎ帯域通過フィルタ
Ｃ，Ｃ１〜Ｃ３ 容量素子
Ｌ，Ｌ１〜Ｌ３ インダクタンス素子
Ｒ 無反射終端器
H, H1 to Hn λ / 4 coupled 3 dB hybrid circuit BPF, BPFa, BPFb, BPF1, BPF2, BPF11 to BPF1n, BPFm1 to BPFmn Bandpass filter C, C1 to C3 Capacitance element L, L1 to L3 Inductance element R Non-reflective Terminator
Claims (2)
前記帯域通過フィルタは、前記ハイブリッド回路の第２の端子と第３の端子との間に接続され、
前記ハイブリッド回路の第１の端子を、帯域阻止フィルタの入力端子となし、
前記ハイブリッド回路の第４の端子を、帯域阻止フィルタの出力端子としたことを特徴とする帯域阻止フィルタ。 A band rejection filter comprising a hybrid circuit having first to fourth terminals and a bandpass filter ,
The band pass filter is connected between a second terminal and a third terminal of the hybrid circuit;
The first terminal of the hybrid circuit is not an input terminal of a band rejection filter,
A band rejection filter, wherein the fourth terminal of the hybrid circuit is an output terminal of a band rejection filter.
2. The band rejection filter according to claim 1, wherein n (n ≧ 2) band-pass filters are connected between the second terminal and the third terminal of the hybrid circuit.
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| US8264298B2 (en) * | 2009-10-01 | 2012-09-11 | Unidyne, Inc. | Filtering device and a method for filtering a signal |
| US8421554B2 (en) * | 2009-10-01 | 2013-04-16 | Ubidyne, Inc. | Filtering device for filtering RF signals and method for filtering RF signals |
| US8339216B2 (en) * | 2009-10-01 | 2012-12-25 | Ubidyne, Inc. | Duplexer and method for separating a transmit signal and a receive signal |
| JP2013074496A (en) * | 2011-09-28 | 2013-04-22 | Onkyo Corp | Branch circuit |
| EP2693560B1 (en) * | 2012-08-02 | 2016-12-28 | Alcatel Lucent | Filter assembly |
| EP2960981B1 (en) * | 2013-02-19 | 2018-07-25 | Osaka Prefecture University Public Corporation | Waveguide-type image rejection filter, single-sideband receiver utilizing same |
| EP2814172A1 (en) * | 2013-06-10 | 2014-12-17 | Alcatel Lucent | Filter for RF applications |
| JP2016066884A (en) * | 2014-09-24 | 2016-04-28 | 住友電気工業株式会社 | Filter device |
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| CN104966864A (en) * | 2009-11-02 | 2015-10-07 | 株式会社Kmw | Radio frequency filter |
| CN104966864B (en) * | 2009-11-02 | 2018-03-06 | 株式会社 Kmw | Radio-frequency filter |
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