JPH0641206U - Circulator - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a circulator with high isolation. [Configuration] power inputted from the first terminal, isolation from a second terminal, and the circulator C ₁ -C ₃ for outputting as the insertion loss from the third terminal and three connections. Since the isolation output from the circulator C ₁ is used as the input of the circulator C ₂ and the insertion loss output from the circulator C ₁ is used as the input of the circulator C ₃ , a high isolation can be output. . 【effect】

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a circulator suitable for use in a high frequency circuit such as an FM-CW radar.

[0002]

[Prior art]

 As is well known, in a high frequency circuit such as a radio wave radar, a circulator in which a plurality of input terminals are irreversible is used in the circuit. FIG. 3 is a plan view showing an example of a general circulator 1. In this figure, reference numeral 2 is a substrate, and a ferrite 3 is embedded in the central portion thereof. On the substrate 2, strip lines 4, 5 and 6 having a width of several mm are formed to join the ferrite 3 in a Y shape. Further, a permanent magnet (not shown) is arranged on the lower surface of the substrate 2 at a position facing the ferrite 3. Therefore, when a direct current (static) magnetic field is applied to the ferrite 3 which is the intersection of the Y-shaped strips by this permanent magnet, a phase shift occurs in the ferrite 3 and, as a result, the circulator 1 operates as follows. . That is, the power input to the terminal 7 is output from the terminal 8, the power input from the terminal 8 is output from the terminal 9, and the power input from the terminal 9 is output to the terminal 7. Circulation operation Will be realized.

In order to utilize such a circulation operation, the circulator 1 has played a role as a “duplexer” described below in a circuit in the radio radar. Here, the duplexer function (circulation operation) in the circuit will be described with reference to the schematic configuration of the conventional radio radar shown in FIG. In this figure, 10 is a transmitter, which supplies a high frequency signal fo to the circulator 1. When the high frequency signal fo is input to the circulator 1, it is output from the terminal 8 via the terminal 7 of the circulator 1. Here, between terminals 7 and 8, 0. There is an insertion loss of 5 dB.

The high-frequency signal fo output from the terminal 8 in this manner is radiated from the antenna 11 to the space, and the reflected wave fr reflected by hitting the target object is received again from the antenna 11. Then, the circulator 1 outputs the reflected wave fr to the terminal 9 via the terminal 8 and transmits the reflected wave fr to the receiver 12. Here, there is an isolation (separation degree) of about 20 dB between the terminal 7 and the terminal 9, and this isolation attenuates the high frequency signal fo that wraps around to the receiver 12 side. That is, since the circulator 1 serves as a duplexer that captures the reflected wave fr while outputting the high frequency signal fo, it is possible to share one antenna 11 for transmission and reception, and as a result, the radar uses the high frequency signal fo. The target object is detected by receiving the reflected wave fr while transmitting the. Moreover, the circulator 1 having such a function can protect the transmitter 10 from reflection due to the mismatch of the antenna 11.

[0005]

[Problems to be solved by the device]

 By the way, in the above-mentioned conventional circulator 1, since the isolation is about 20 dB, a part of the electric power output from the transmitter 10 spills into the receiver 12, which hinders the reception of the receiver 12. As a result, it was a factor that deteriorated the reception sensitivity. Therefore, in order to prevent the high frequency signal fo from affecting the reflected wave fr, the circulator 1 having a high isolation characteristic is required. However, since such a circulator 1 has a complicated structure, a large size, and a high price, a circulator having a simple structure and high isolation is desired. The present invention has been made under such a background, and an object thereof is to realize a circulator capable of supplying high isolation with a simple configuration.

[0006]

[Means for Solving the Problems]

 The circulator according to the present invention outputs the power supplied to the first terminal from the second terminal, the power supplied to the second terminal from the third terminal, and the first terminal to the third terminal. A first to a third circulation means for isolating a path toward the first circulation means, and connecting the second terminal of the first circulation means and the first terminal of the second circulation means with each other; A second terminal of the second circulating means and a second terminal of the third circulating means, and a first terminal of the third circulating means and a third terminal of the first circulating means. The first terminal of the first circulating means, the second terminal of the second circulating means, and the third terminal of the third circulating means are respectively connected to the first to third terminals. It is characterized by being an output terminal.

[0007]

[Action]

 According to the above structure, the isolation between the first circulating means and the isolation between the third circulating means is added between the first input / output terminal and the third input / output terminal. . This results in a high isolation circulator.

[0008]

【Example】

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a circulator C according to an embodiment of the present invention. The circulator C shown in this figure has a configuration in which three circulators C ₁ , C ₂ , and C ₃ having the same configuration as the circulator 1 shown in FIG. 3 are connected. Here, when the terminal 1 of each of the circulators C _{1 to} C ₃ is used as an input end, the magnetic field applied to the ferrite 3 is adjusted so that isolation is produced at each terminal 3 and insertion loss is produced at each terminal 2. That is, in each of the circulators C _{1 to} C ₃ , the insertion loss between the terminals 1 and 2 is 0.5 dB, and the isolation between the terminals 1 and 3 is 20 dB.

According to such a circulator C, first, when the power P ₁ is applied to the terminal 1 of the circulator C ₁ , isolation of 20 dB is obtained at the terminal 3 and insertion of 0.5 dB at the other terminal 2. Loss appears. Next, when the output of the terminal 2 of the circulator C ₁ to terminal 1 of the circulator C ₂ is supplied, the insertion loss 0.5dB between terminal 1 of the circulator C ₂ are added, resulting in the circulator C ₁ The electric power P ₁ supplied to the terminal 1 of is a loss of 1 dB and is output from the terminal ₂ of the circulator C ₂ . On the other hand, in between the terminals 1 and 3 in the circulator C _3, similarly to the isolation of the circulator C ₁ described above, because it is 20 dB, between the terminals 1 and 3 of the circulator C ₃ of the circulator C ₁ is 40d It becomes B isolation. Thus, the circulator C combines the three Saki Regulator C ₁ -C ₃ all SANYO performing one circulation operation, the power P ₁ supplied to the terminal 1 of the circulator C ₁ is the circulator C is output from the _second terminal 2, power supplied to the terminal 2 of the circulator C ₂ is output from the terminal 3 of Saki Regulator C _3. Then, between the terminals 1 and 3 of the circulator C ₃ at this time circulator C ₁ becomes 40dB isolation.

The operation of the circulator C having the above-described configuration when used in a radio radar will be described below with reference to FIG. In this figure, each part corresponding to that in FIG. 4 is assigned the same reference numeral, and the description thereof is omitted. First, when the high frequency signal fo is supplied from the transmitter 10 to the circulator C, the power having a loss of 1 dB is output to the antenna 11 by the above-described circulation operation.

On the other hand, when the antenna 11 receives the reflected wave fr of the high frequency signal fo emitted from the radio wave radar, the circulator C transmits the reflected wave fr to the receiver 12. Also in this case, the reflected wave fr receives an insertion loss of 1.0 dB and is input to the receiver 12. By combining the circulator C ₁ -C _3, and the high-frequency signal fo reflected wave fr, because a 40dB isolation, double isolation is achieved as compared with the prior art. Therefore, even if the insertion loss is twice as large as that in the conventional case, the influence of the transmission power on the reception power can be relatively reduced. Thus, in this circulator C, high isolation can be realized with a simple configuration in which the existing circulators C _{1 to} C ₃ are connected.

[0012]

[Effect of device]

 As described above, according to the present invention, the electric power supplied to the first terminal is output from the second terminal, the electric power supplied to this second terminal is output from the third terminal, and A first to third circulation means for isolating a path from a terminal to the third terminal, and connecting the second terminal of the first circulation means and the first terminal of the second circulation means. And connecting the third terminal of the second circulating means and the second terminal of the third circulating means, and connecting the first terminal of the third circulating means to the first terminal of the first circulating means. A first terminal of the first circulating means, a second terminal of the second circulating means, and a third terminal of the third circulating means. ~ Since it is the third input / output terminal, the first circulation is between the first input / output terminal and the third input / output terminal. Becomes Isolation and third isolation and obtained by adding the characteristics of the circulation means of the means, the circulator of high isolation can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a circulator according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a part of the radio wave radar according to the embodiment.

FIG. 3 is a block diagram showing a configuration example of a conventional circulator.

FIG. 4 is a block diagram showing a part of the radio wave radar according to the embodiment.

[Explanation of symbols]

C ...... circulator _{C 1, C 2, C 3} ...... circulator

Claims (1)

[Scope of utility model registration request] 1. The power supplied to the first terminal is output from the second terminal, the power supplied to the second terminal is output from the third terminal, and the power is directed from the first terminal to the third terminal. The first circulation device is provided with first to third circulation means having paths isolated, and the second circulation circuit is connected to the second terminal of the first circulation means and the first terminal of the second circulation means. A third terminal of the means and a second terminal of the third circulating means are connected, and a first terminal of the third circulating means and a third terminal of the first circulating means are connected. And a first terminal of the first circulating means, a second terminal of the second circulating means, and a third terminal of the third circulating means as first to third input / output terminals, respectively. A circulator that is characterized by