KR20100071152A - Isolator for maintaing high isolation characteristic and communication having the same - Google Patents

Abstract

PURPOSE: An isolator with high separation properties and a communication device including the isolator are provided to offer high separation properties regardless of the change of the load characteristic. CONSTITUTION: A first isolator(133) includes 1 ~ 3 ports. The first isolator receives a transmission signal. A second isolator includes the 1-3 ports. The second isolator receives a phase-shifted transmission signal having phase difference of 90° with the phase of a transmission signal. A signal combiner(139) shifts the phase of a second signal to 90° through the second port of the second isolator. A signal combiner produces a combining signal from the first signal inputted through the second signal of the first isolator and the shifted second signal.

Description

Isolator for maintaing high isolation characteristic and communication having the same

Embodiments of the inventive concept relate to wireless communication technology, and more particularly, to an isolator having high isolation characteristics, and a communication device including the isolator.

With the development of semiconductor technology, a variety of types of communication devices and technologies for terminals incorporating various functions are required. Thus, a system having a transmission / reception structure for processing a transmission / reception signal without separating transmission / reception frequency bands from a transmission / reception terminal, namely There is a growing trend for applications of communication devices in which the distinction between the transmitting and receiving ends is not clear.

One of the biggest problems raised in this transmission / reception structure is a problem regarding transmission / reception isolation. In general, a communication device may use an isolator to distribute a signal from a transceiver to a transmission signal and a reception signal.

As communication devices become smaller and lighter with the recent rapid development of mobile communication technology, the demand for miniaturization and thinning of components constituting the communication device is inevitable.

Accordingly, the technical problem to be achieved by the present invention is to provide an isolator having a high isolation characteristic and a communication device including the isolator regardless of a change in load characteristics.

In addition, an object of the present invention is to provide an isolator and a communication device including the isolator to reduce the leakage signal flowing into the transmitter and the receiver.

In order to accomplish the above technical problem, an isolator includes a first isolator including a first port for receiving a transmission signal, a second port, and a third port connected to a first feeder; A second isolator comprising a first port for receiving a phase shifted transmission signal having a phase difference of 90 ° from the phase of the transmission signal, a second port, and a third port connected to a second feeder; ; And a phase shift of the second signal input through the second port of the second isolator by 90 °, and a phase shifted second signal and a first signal input through the second port of the first isolator. A signal combiner for generating a combined signal from the apparatus.

In the reception operation, the first signal is a first reception signal received through the first power supply unit, and the second signal is a second reception signal received through the second power supply unit, and in the transmission operation, the first signal is A first leakage signal including at least a portion of the transmission signal and the second signal is a second leakage signal including at least a portion of the phase shifted transmission signal. Each of the first isolator and the second isolator may be a circulator, a 90 ° hybrid, or a directional coupler.

In order to accomplish the above technical problem, an isolator may include a first isolator including a first port for receiving a transmission signal, a second port, and a third port that may be connected to a power supply unit; A second isolator including a first port for receiving a phase shifted transmission signal having a phase difference of 90 ° from a phase of the transmission signal, a second port, and a third port connected to the power supply unit; And a phase shift of the second signal input through the second port of the second isolator by 90 °, and a phase shifted second signal and a first signal input through the second port of the first isolator. And a signal combiner for generating the combined signal from.

A circular polarization patch antenna, a quadrifilar spiral antenna, a quadrifilar helix antenna, a monopole antenna, a dipole antenna, or a micro strip patch antenna may be connected to the feeder.

Communication device for achieving the technical problem is a first feeder and a second feeder; A transmitter for generating a transmission signal; A signal separator for generating a first transmission signal having a phase equal to a phase of the transmission signal and a second transmission signal having a phase difference of 90 ° from a phase of the transmission signal; A first isolator including a first port for receiving the first transmission signal, a second port, and a third port connected to the first feeder; A second isolator including a first port for receiving the second transmission signal, a second port, and a third port connected to the second feeder; And a phase shift of the second signal input through the second port of the second isolator by 90 °, the phase shifted second signal and the first signal input through the second port of the first isolator. And a signal combiner for generating a combined signal from and transmitting the generated combined signal to a receiver.

In a receiving operation, the first signal is a first receiving signal received through the first feeding part, and the second signal is a second receiving signal received through the second feeding part, and in the transmitting operation the first signal. The signal is a first leakage signal including at least a portion of the transmission signal and the second signal is a second leakage signal including at least a portion of the second transmission signal. The communication device further includes an antenna connected between the first feed part and the second feed part.

The isolator for achieving the technical problem is a first isolator for transmitting a transmission signal to the first feeder during transmission; A second isolator for transmitting a signal having a phase difference of 90 ° from the phase of the transmission signal to the second feeder during the transmission; And shifts the phase of the second leakage signal output from the second isolater by 90 ° during the transmission, and combines the phase-shifted second leakage signal and the first leakage signal output from the first isolater to the receiver. It includes a signal combiner to. The first feed part and the second feed part may be connected to each other.

The communication apparatus for achieving the technical problem is a signal separator for generating a first transmission signal having a phase equal to the phase of the transmission signal and a second transmission signal having a phase difference of 90 degrees with the phase of the transmission signal; A first isolator for transmitting the first transmission signal to the first antenna during transmission; A second isolator for transmitting the second transmission signal to a second antenna during the transmission; And a 90 ° shift in phase of the second leakage signal output from the second isolator at the time of transmission, and combining the phase-shifted second leakage signal and the first leakage signal output from the first isolator. And a signal combiner for transmitting the signal to the receiver. The first antenna and the second antenna may be connected to each other.

The communication device may be an RFID reader, a radar, an electromagnetic wave diagnosis device, or a mobile communication device.

Since the isolator according to the embodiment of the present invention can maintain a high isolation characteristic regardless of a change in load characteristic, there is an effect of stably separating and outputting signals having different frequencies.

In addition, since the isolator according to the embodiment of the present invention can remove the leakage signal generated from the internal circuit of the isolator or the communication device and the interference signal from the outside by using the signal separator and the signal combiner to receive the communication device as much as possible. There is an effect that can improve the sensitivity and input and output characteristics.

In addition, the isolator according to an embodiment of the present invention can provide an isolator of the form optimized according to the appearance and operating environment of the communication device has the effect that the communication device can be miniaturized and light weight.

Specific structural to functional descriptions of embodiments according to the inventive concept disclosed in the specification or the application are only illustrated for the purpose of describing embodiments according to the inventive concept, and according to the inventive concept. The examples may be embodied in various forms and should not be construed as limited to the embodiments set forth herein or in the application.

Embodiments in accordance with the concepts of the present invention can make various changes and have various forms, so that specific embodiments are illustrated in the drawings and described in detail in this specification or application. It should be understood, however, that it is not intended to limit the embodiments according to the concepts of the present invention to specific forms of disclosure, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.

Terms such as first and / or second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another, for example, without departing from the scope of rights in accordance with the inventive concept, and the first component may be called a second component and similarly The second component may also be referred to as the first component.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between. Other expressions describing the relationship between components, such as "between" and "immediately between," or "neighboring to," and "directly neighboring to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. As used herein, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof that is described, and that one or more other features or numbers are present. It should be understood that it does not exclude in advance the possibility of the presence or addition of steps, actions, components, parts or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined herein. Do not.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a schematic block diagram of a general communication device. Referring to FIG. 1, the communication device 10 may include a transmitter 20, a receiver 30, an isolator 35, and an antenna 40.

The transmitter 20 generates a transmission signal capable of supplying operating power and transmission data. The antenna 40 may transmit a transmission signal output from the transmitter 20 to the outside or receive a reception signal transmitted from the outside. At this time, the transmitter 20 and the receiver 30 may be equipped with an isolator (35) in front of the antenna 40 in order to share one antenna (40).

The isolator 35, which may be implemented as a circulator, includes a first port connected to the transmitter 20, a second port connected to the receiver 30, and a third port connected to the antenna 40. The input signal can be distributed or transmitted with directionality. That is, when the signal is input to any one of a plurality of input and output terminals, the isolator 35 transfers the input signal only to a specific terminal and does not transfer the remaining signal to the other terminal to change the transmission direction of the transmission signal and the reception signal. Can be controlled.

For example, the isolator 35 outputs the transmission signal to the third port and transmits the transmission signal to the antenna 40 while blocking the second port so that the transmission signal input to the first port does not flow into the receiver 30, or The reception signal may be output to the second port and transmitted to the reception unit 30 while blocking the first port so that the reception signal input to the third port does not flow into the transmission unit 20.

The isolator 35 exhibits a high transmit / receive isolation characteristic of about 30 dB when the port to which the load is connected such as the antenna 40 rather than the transmitter 20 and the receiver 30 is ideally matched. This means that even when the antenna 40 and the isolator 35 are perfectly matched, a leakage signal attenuated by up to 30 dB at the transmitter 20 may flow into the receiver 30.

Therefore, if the isolation degree of the isolator 35 is not sufficiently secured, that is, the isolation between the input and output terminals is not properly performed, the received signal to be input to the receiver 20 flows into the transmitter 30 or the antenna 40 Through the transmission signal to be transmitted to the receiver 30 may be leaked signal may occur.

In addition, in the communication device 10, signal reflection and interference effects may occur due to an impedance mismatch of transmission line impedance and impedances of components (eg, an isolator and an antenna) inside the circuit. The reflected signal flows into the transmitter and / or receiver, or acts as noise on the transmission line, resulting in increased signal distortion.

Conventional communication device 10 has a significant magnitude of leakage signal and / or reflection signal due to the limited isolation characteristics of isolator 35 itself and signal reflection in a load such as antenna 40, such leakage signal. And / or the reflected signal acts as noise in each of the receiver 30 or the transmitter 20 and reduces the strength of the signal, thereby reducing the reception sensitivity.

2 is a schematic block diagram of a communication device including an isolator according to an embodiment of the present invention. Referring to FIG. 2, the communication device 100, which may be implemented as a radar, an RFID reader, an electromagnetic wave diagnosis device, or a mobile communication device, includes a transmitter 110, a receiver 120, and an isolator 130 -X. can do. In addition, the communication device 100 may further include a first feeder 135 and a second full class 138. According to an embodiment, the first feed part 135 and the second feed part 138 may be connected to each other.

For example, the transmitter 110, the receiver 120, and the isolator 130 -X may be implemented as one circuit, for example, one chip. In some embodiments, the isolator 130 -X may include a first feed unit 135 and a second feed unit 138. Also, according to an embodiment, each of the first feed part 135 and the second feed part 138 may be implemented as a feed circuit or a feed point.

The communication device 100 according to the embodiment of the present invention includes at least two feed units 135 and 138. Each of the two feed parts 135 and 138 may be connected with a load such as an antenna or a termination resistor.

When at least one antenna is connected to each of the first feed part 135 and the second feed part 138, the communication device 100 may be a wireless communication device capable of performing wireless communication with the outside. Here, the antenna may be implemented as a circularly polarized patch antenna, a quadrifilar spiral antenna, a quadrifilar helix antenna, a monopole antenna, a dipole antenna, or a micro strip patch antenna.

For convenience of description, the first feeder 135 is connected to the first antenna (not shown) and the second feeder 138 is connected to the second antenna (not shown) in the communication device 100. An example will be described. In this case, the first antenna 135 and the second antenna 138 may be connected to each other, but the present invention is not limited thereto.

The transmitter 110 generates a transmission signal capable of supplying operating power and / or transmission data. Each of the first antenna (not shown) and the second antenna (not shown) may transmit signals having a circular polarization direction to the outside or may receive signals having a circular polarization direction transmitted from the outside.

Isolator 130-X, X = 1 or 2 may include a transmit signal separator (or signal separator) 131, a first isolator 133, a second isolator 137, and a signal combiner 139. Can be. Each of the first isolator 133 and the second isolator 137 may be implemented as a 3-port passive element.

The transmission signal separator 131 includes an input terminal, a first output terminal, and a second output terminal connected to the transmitter 110, and separates the transmission signal output from the transmitter 110 into two signals having different phases. can do.

When operating as a signal separator, the transmission signal separator 131 receives a transmission signal output from the transmission unit 110 and has a first transmission signal having the same phase as that of the transmission signal, and a phase of 90 ° with the transmission signal. A second transmission signal having a difference may be generated, and each of the generated first transmission signal and the second transmission signal may be output through each of the first output terminal and the second output terminal.

For example, the transmission signal separator 131 outputs the transmission signal as the first transmission signal to the first isolator 133 through the first output terminal, and phase shifts the transmission signal by φ (eg, φ = 90 °). The post-phase shifted signal may be output as the second transmission signal to the second isolator 137 through the second output terminal.

Here, the first transmission signal and the second transmission signal are signals having different phases, that is, signals having a predetermined phase difference φ, and the phase difference φ of the first transmission signal and the second transmission signal is substantially 90 °. Can be.

The first isolator 133 includes a first port connected to the transmission signal separator 131, a second port connected to the signal combiner 139, and a third port connected to the first feeder 135. The signal input to either terminal can be output only to a specific terminal.

In the transmission operation, the first isolater 133 outputs the first transmission signal to the third port while blocking the second port so that the first transmission signal input to the first port does not flow into the receiver 120. The first reception signal may be output to the second port while blocking the first port so that the first reception signal input to the third port does not flow into the transmitter 110 during the reception operation.

At this time, most of the first transmission signal is output to the first feeder 135 through the third port, but at least a part of the first transmission signal leaks from the first isolator 133 and receives the receiver through the second port ( 120). Hereinafter, at least a part of a signal leaking from the first containment 133, for example, the first transmission signal output to the receiver 120 during a transmission operation, is referred to as a 'first leakage signal'.

The second isolator 137 includes a first port connected to the transmission signal separator 131, a second port connected to the signal combiner 139, and a third port connected to the second feeder 138. The signal input to either terminal can be output only to a specific terminal.

In the transmission operation, the second isolator 137 outputs the second transmission signal to the third port while blocking the second port so that the second transmission signal input to the first port does not flow into the receiver 120 or The second reception signal may be output to the second port while blocking the first port so that the second reception signal input to the third port may not flow into the transmitter 110 during the reception operation.

At this time, most of the second transmission signal is output to the second feeder 138 through the third port, but at least a part of the second transmission signal leaks from the second isolator 137 and receives the receiver through the second port ( 120). Hereinafter, a signal leaking from the second isolator 137, for example, at least a part of the second transmission signal flowing to the receiver 120 during a transmission operation is referred to as a 'second leakage signal'.

The signal combiner 139 includes a first input terminal connected to the first isolator 133, a second input terminal connected to the second isolator 137, and an output terminal connected to the receiver 120. According to the operation mode of 100, the first signal output from the first isolator 133 and the second signal output from the second isolator 137 are received, and any one of the received first signal and the second signal After adjusting the phase of the combined signal may be generated or the combined signal may be generated as it is from the first signal and the second signal.

Here, in the receiving operation, the first signal may be the first receiving signal, the second signal may be the second receiving signal, and in the transmitting operation, the first signal may be the first leakage signal and the second signal may be the second leakage signal. In the transmission operation, that is, when the first leakage signal output from the first isolator 133 and the second leakage signal output from the second isolator 137 are input to the signal combiner 139, the signal combiner 139 is used. May shift the phase of the second leakage signal to generate a phase-shifted second leakage signal, and combine the generated second leakage signal with the first leakage signal to generate a combined signal.

Here, the signal combiner 139 controls the phase of the first leakage signal and the phase of the second leakage signal to have a predetermined phase difference φ. The signal combiner 139 makes the difference φ between the phase of the first leakage signal and the phase of the second leakage signal substantially 90 °. Thus, the signal combiner 139 includes a phase controller for controlling the phase of the second leakage signal.

For example, the signal combiner 139 receives the first leakage signal and the second leakage signal, shifts the received second leakage signal by 90 °, and then combines the phase-shifted second leakage signal and the first leakage signal. do.

In the signal combiner 137, the difference between the phase of the phase-shifted second leakage signal and the phase of the first leakage signal becomes substantially 180 °. Thus, the first leakage signal output from the first isolator 133. The signal combiner 139 may be canceled by canceling each other by a second leakage signal having a phase opposite to that of the first leakage signal.

In the receiving operation, that is, the signal combiner 139 combines the first received signal output from the first isolater 133 and the second received signal output from the second isolater 137 and receives the combined signal combined with the receiver ( 120). For example, the signal combiner 139 may generate a combined signal by combining the first received signal and the second received signal having a phase difference of 90 degrees with the phase of the first received signal.

As such, the signal combiner 139 cancels or combines the first signal and the second signal input during an operation mode of the communication device 100, for example, during a transmission operation or a reception operation, and outputs them to the receiver 120. Can be.

Each of the transmission signal separator 131 and the signal combiner 139 according to an embodiment of the present invention may output all the devices capable of separating and outputting one input signal into at least two, or combining and outputting at least two input signals into one. Include. For example, according to an embodiment, each of the transmit signal separator 131 and the signal combiner 137 has a 90 ° hybrid (90 ° Hybrid (130-1 in FIG. 3)) or a Wilkinson power devider / coupler and a delay. It may be implemented as a combination of delays (130-2 in FIG. 4).

Accordingly, the various isolators 130-1 or 130-2 to be described herein include a transmission signal separator 131 and a signal implemented in different forms according to the operating environment and / or appearance of the communication device 100. The combiner 139, the first isolator 133, and the second isolator 137 may be included.

In this case, each of the transmission signal separator 131 and the signal combiner 139 according to an embodiment of the present invention preferably uses a combination of a 90 ° hybrid and Wilkinson power divider and a delay unit in a symmetrical structure. In addition, each of the first isolator 133 and the second isolator 137 has a symmetrical structure of a circulator, a directional coupler or a 90 ° hybrid to have the same isolation characteristics. It is preferable to arrange and use.

3 is a circuit diagram of a communication device including an isolator according to an embodiment of the present invention. Referring to FIG. 3, each of the transmission signal separator 131 and the signal combiner 139 is implemented as a 90 ° hybrid, and each of the first isolator 133 and the second isolator 137 is implemented as a circulator. The present invention is not limited thereto.

The 90˚ hybrid includes a first terminal, a second terminal connected to the terminating resistor (50Ω), a third terminal, and a fourth terminal, and may operate as a signal separator or a signal combiner depending on the direction of the input signal. .

That is, the 90˚ hybrid divides one input signal input to the first terminal into two signals, and shifts one of the two signals by 90 ° from the phase of the other signal, and thus phases 90 ° from each other. Generate two signals with difference. The magnitude of each of the two generated signals may be 1/2 of the magnitude of the input signal.

In addition, when 90 ° hybrid is used in reverse, the 90 ° hybrid has a phase of any one of two input signals input to each of the third and fourth terminals by 90 ° than the phase of the other signal. By shifting, the phase shifted signal and the remaining signal may be synthesized to generate a signal corresponding to the sum of the two signals.

The circulator includes a plurality of input / output terminals, and when a signal is input to any one of the plurality of input / output terminals, the circulator transmits a signal to only one of the left or right terminals and blocks the transmission of the signal to the other terminal. The signal is directed and transmitted as if the signal rotates in the direction.

4 is a circuit diagram of a communication device including an isolator according to another embodiment of the present invention. Referring to FIG. 4, the isolator 130-2 includes a signal separator 131, a first isolator 133, a second isolator 137, and a signal combiner 139. In the embodiment of FIG. 4, each of the transmission signal separator 131 and the signal combiner 139 is implemented as a combination of a Wilkinson power divider (or Wilkinson power combiner) and a delay unit widely used as an in-phase divider (or in-phase combiner). Each of the first isolator 133 and the second isolator 137 will be described as an example of an isolator implemented as a directional coupler.

Each of the transmit signal separator 131 and the signal combiner 139 includes a Wilkinson power divider (or separator) and a delay. The Wilkinson power divider is a power divider mainly used in an RF band or a microwave frequency band. The Wilkinson power divider may divide and output an input signal into at least two signals.

Also, if the Wilkinson power divider is used in reverse, it can be used as a Wilkinson power combiner. That is, when at least two signals are input to the Wilkinson power combiner, the Wilkinson power combiner may combine the at least two signals into one signal to obtain an output having the combined power of the at least two signals.

The delay unit is connected between the Wilkinson power divider and the first isolator 137, and receives any one of the output signals of the Wilkinson power divider and shifts the phase by Φ. At this time, the delay unit has a phase difference of 90 ° between the phase of the input signal and the phase of the output signal.

The directional coupler is a device for receiving a signal at an input and for transmitting the received signal to another device, comprising a first transmission line and a second transmission line. The directional coupler may transmit or receive a signal between the transmitter 110 and the first feeder 135 or the transmitter 110 and the second feeder 138 through the first transmission line. The input signal may be output to the second transmission line by a coupling phenomenon.

The isolator 130-X; X = 1, 2, which can reliably separate signals having different frequencies in a communication device, is received according to the isolation characteristics of the isolator 130-X; X = 1, 2; At least part of the signal may leak through other terminals.

That is, in the first isolator 133, a first leakage signal is generated in which at least a portion of the first transmission signal flows toward the receiver 120 according to an isolation of the first isolator 133. In the second isolator 137, a second leakage signal may be generated in which at least a part of the second transmission signal flows toward the receiver 120 according to the isolation degree of the second isolator 137.

The isolation degree of the first isolator 133 is changed according to the load characteristics (reflection coefficient Γa) of the first antenna and is output from the first isolator 133 according to the isolation degree of the first isolator 133. 1 The amount of leakage signal also changes. In addition, the isolation of the second isolator 137 is changed according to the load characteristics (reflection coefficient (Γb)) of the second antenna and is output from the second isolator 137 according to the isolation of the second isolator 137. The amount of the second leakage signal also changes.

In the conventional isolator 35, when the load characteristic of the antenna 40 changes, the amount of the leakage signal output from the isolator 35 increases rapidly, and the leakage signal is transmitted to the transmitter 20 or the receiver 30. By lowering the noise, the reception sensitivity was lowered.

However, the isolator 130 -X, X = 1, 2 according to the embodiment of the present invention has the same load characteristics when the load characteristics Γa of the first antenna and the load characteristics Γb of the second antenna are the same. The first leakage signal output from the first isolator 133 and the second leakage signal output from the first isolator 137 are the same, even though the load characteristics of the second antenna are variably changed. Can be offset.

That is, the isolators 130-X, X = 1, 2 cancel the first leakage signal and the second leakage signal generated by the two isolators 133 and 137 existing therein to cancel each other. Therefore, since the leakage signal flowing into the transmitter 110 and the receiver 120 can be blocked, the isolation characteristic is not affected by the load characteristic change.

If the load characteristic Γa of the first antenna and the load characteristic Γb of the second antenna are not the same, the isolators 130 -X, X = 1, 2 are output from the first isolator 133. Since only the leakage signal corresponding to the difference between the first leakage signal and the second leakage signal output from the second isolator 137 is transmitted to the transmitter 110 or the receiver 120, the load characteristics compared to the conventional isolator 35 This has the effect of reducing the impact on change.

In addition, at least a portion of the first received signal output from the first isolator 133 may be reflected by the impedance mismatch between the first antenna and the first isolator 133 to be returned to the first isolator 133. . Similarly, at least a part of the second received signal output from the second isolator 137 may also be reflected by the impedance mismatch between the second antenna and the second isolator 137 to be returned to the second isolator 137. .

When the reflected signal is introduced into the receiver 120 or the transmitter 110, the reflected signal acts as a noise like the leaked signal, thereby deteriorating the input / output characteristics of the communication device 100. However, the isolator 130-X, X = 1, 2 according to the embodiment of the present invention transmits the transmitted signal separator 131 and the reflected signal in the same way as to remove the first leakage signal and the second leakage signal. And / or may be canceled or reduced using the signal combiner 139.

In addition, in the isolator 130-X according to an embodiment of the present invention, the transmission signal and / or the reception signal are transmitted through internal circuits and are signaled by impedances βa and βb on transmission lines (PathA and PathB in FIG. 3). Even if distortion occurs, this can also be canceled or reduced using the transmission signal separator 131 and / or the signal combiner 139 in the same way as removing the first and second leakage signals, so that the occurrence on the transmission line The distortion signal can be blocked.

As described above, the isolators 130-X, X = 1, 2 according to the embodiment of the present invention are insensitive to load characteristic changes, and thus high isolation even when the loads are not matched with the respective isolators 133 and 137. Has the effect of maintaining the characteristics.

In addition, the isolator 130-1 according to an embodiment of the present invention is a leakage signal and / or a reflection signal generated by the limited isolation characteristics of the conventional isolator 35 itself and signal reflection at a load such as an antenna. There is an effect to reduce.

FIG. 5A is a graph illustrating isolation characteristics according to changes in load characteristics in the conventional isolator illustrated in FIG. 1, and FIG. 5B is diagram illustrating changes in load characteristics in an isolator according to an embodiment of the present disclosure illustrated in FIG. 2. Graph showing isolation characteristics.

For convenience of description, the conventional isolator 35 shows the isolation characteristic of the circulator as an example, and the isolator 130 -X, X = 1, 2 according to the embodiment of the present invention is an isolator (Fig. 3). The isolation characteristic of 130-1) is described as an example.

In general, the isolator 35 is connected to a load (for example, an antenna) having an arbitrary matching state, and the isolation of the isolator 35 is ideally matched with the isolator 35. When matched, it has the highest isolation characteristics. However, in reality, the load characteristic of the antenna 40 is very sensitive to changes in the external environment, and when the load characteristic is changed, no match is made at the terminal to which the isolator 35 and the antenna 40 are connected. The segregation characteristics of the transceivers rapidly collapse.

The isolation of a conventional isolator 35, such as a circulator, exhibits a high isolation characteristic of about 25 dB when ideally matched with the load (e.g., antenna) (i.e., Γ = -∞; c). However, when the reflection coefficient of the antenna changes to Γ = -9.54dB (b), Γ = -3.52dB (a) according to the load characteristics, the isolation characteristic of the circulator drops rapidly to about 10dB and 4dB, respectively. As described above, the conventional isolator 35 is inevitably affected by the load characteristics that change depending on the surrounding situation of the antenna 40 to be connected, and thus, it is necessary to provide a substantially low isolation level.

However, the isolator 130-X, X = 1, 2 according to the embodiment of the present invention uses the transmission signal separator 133 and / or the signal combiner 137 even if the leakage signal increases as the load characteristic changes. By canceling the leakage current, a high isolation characteristic of about 30 dB or more insensitive to the load characteristic change can be maintained.

That is, the isolation of the isolators 130-X, X = 1, 2 according to an embodiment of the present invention is ideally matched to the load (e.g., antenna) (i.e., Γa = Γb = -∞; (c ') The isolation characteristics of the antenna are about 55dB, and the reflection coefficient of the antenna changes to Γa = Γb = -9.54dB (b ') and Γa = Γb = -3.52dB (a') as the load characteristics change. In addition, the isolation characteristics of the isolator according to the embodiment of the present invention can maintain a high isolation characteristics compared to the conventional isolator 35 to about 40dB, 30dB, respectively.

Accordingly, the isolator 130-X, X = 1, 2 according to an embodiment of the present invention stably isolates the transmitter 110 and the receiver 120 from each other even in a communication device in which the load characteristics are seriously changed like a mobile terminal. Since it is possible to improve the reception sensitivity, it is possible.

In addition, the isolator 130-X, X = 1, 2 according to the embodiment of the present invention can provide the isolator of the type optimized according to the appearance and operating environment of the communication device, thereby miniaturizing the communication device 100. And there is an effect that can be reduced in weight.

The communication device 100 according to the embodiment of the present invention is a wireless communication device, a wireless computer, a personal digital assistance (PDA), a cellular telephone, a portable multimedia player (PMP), a mobile communication device (mobile) communication device, a satellite communication device, an RFID reader, an RFID system including the RFID reader and an RFID tag, a frequency-modulated continuous wave radar, a high frequency radar, a distance measuring radar, or an electromagnetic wave Diagnostic devices and the like.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

The detailed description of each drawing is provided in order to provide a thorough understanding of the drawings cited in the detailed description of the invention.

1 shows a schematic block diagram of a general communication device.

2 is a schematic block diagram of a communication device including an isolator according to an embodiment of the present invention.

3 is a circuit diagram of a communication device including an isolator according to an embodiment of the present invention.

4 is a circuit diagram of a communication device including an isolator according to another embodiment of the present invention.

Figure 5a is a graph showing the isolation characteristics according to the load characteristics change in the conventional isolator.

5B is a graph illustrating isolation characteristics according to load characteristic changes in an isolator according to an embodiment of the present invention.

Claims (15)

A first isolator including a first port for receiving a transmission signal, a second port, and a third port connected to the first feeder; A second isolator comprising a first port for receiving a phase shifted transmission signal having a phase difference of 90 ° from the phase of the transmission signal, a second port, and a third port connected to a second feeder; ; And Phase shift of the second signal input through the second port of the second isolator by 90 °, and from the phase shifted second signal and the first signal input through the second port of the first An isolator comprising a signal combiner for generating a combined signal. The method of claim 1, In the receiving operation, the first signal is a first received signal received through the first feeder and the second signal is a second received signal received through the second feeder, And the first signal is a first leakage signal including at least a portion of the transmission signal and the second signal is a second leakage signal including at least a portion of the phase shifted transmission signal in a transmission operation. The isolator of claim 1 wherein the signal coupler comprises a Wilkinson power coupler. The isolator of claim 1 wherein each of the first isolators and the second isolators is a circulator, a 90 ° hybrid, or a directional coupler. A first isolator including a first port for receiving a transmission signal, a second port, and a third port that can be connected to a feeder; A second isolator including a first port for receiving a phase shifted transmission signal having a phase difference of 90 ° from a phase of the transmission signal, a second port, and a third port connected to the power supply unit; And Phase shift of the second signal input through the second port of the second isolator by 90 °, and from the phase shifted second signal and the first signal input through the second port of the first An isolator comprising a signal combiner for generating a combined signal. The method of claim 5, wherein the isolator further comprises an antenna connected to the feeder, And said antenna is a circularly polarized patch antenna, a quadrifilar spiral antenna, a quadrifilar helix antenna, a monopole antenna, a dipole antenna, or a micro strip patch antenna. A first feed part and a second feed part; A transmitter for generating a transmission signal; A signal separator for generating a first transmission signal having a phase equal to a phase of the transmission signal and a second transmission signal having a phase difference of 90 ° from a phase of the transmission signal; A first isolator including a first port for receiving the first transmission signal, a second port, and a third port connected to the first feeder; A second isolator including a first port for receiving the second transmission signal, a second port, and a third port connected to the second feeder; And Phase shift of the second signal input through the second port of the second isolator by 90 °, and from the phase shifted second signal and the first signal input through the second port of the first And a signal combiner for generating a combined signal and transmitting the generated combined signal to a receiver. The method of claim 7, wherein In the receiving operation, the first signal is a first received signal received through the first feeder and the second signal is a second received signal received through the second feeder, In the transmitting operation, the first signal is a first leakage signal including at least a portion of the transmission signal and the second signal is a second leakage signal including at least a portion of the second transmission signal. The communication device according to claim 7 or 8, wherein the communication device further comprises an antenna connected between the first feed part and the second feed part. The method of claim 7 or 8, wherein the communication device, A first antenna connected to the first feeding part; And And a second antenna connected to the second feeder. A first isolator for transmitting a transmission signal to the first power supply unit during transmission; A second isolator for transmitting a signal having a phase difference of 90 ° from the phase of the transmission signal to the second feeder during the transmission; And Shifting the phase of the second leakage signal output from the second isolater by 90 ° during the transmission, combining the phase-shifted second leakage signal and the first leakage signal output from the first isolater, and transmitting to the receiver Isolator comprising a signal coupler for. 12. The separator of claim 11 wherein said first feed portion and said second feed portion are connected to each other. A signal separator for generating a first transmission signal having a phase equal to a phase of the transmission signal and a second transmission signal having a phase difference of 90 ° from the phase of the transmission signal; A first isolator for transmitting the first transmitted signal to the first antenna when transmitting; A second isolator for transmitting the second transmission signal to a second antenna during the transmission; And A combined signal generated by combining a phase-shifted second leakage signal outputted from the second isolator by 90 ° and combining a phase-shifted second leakage signal and the first leakage signal output from the first isolator at the time of transmission; Communication device including a signal combiner for transmitting to the receiving unit. The communication device according to claim 13, wherein the first antenna and the second antenna are connected to each other. The communication device according to claim 13, wherein the communication device is an RFID reader, a radar, an electromagnetic wave diagnosis device, or a mobile communication device.

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