KR100784149B1 - Dual type time division duplex transmitting/receiving device - Google Patents

Abstract

A dual type TDD(Time Division Duplex) transceiver is provided to obtain a sufficient isolation between an Rx path and a Tx path without a switch or a hybrid and to suppress an internal resonance state. A dual type TDD transceiver comprises the first device(350) and the second device(360), which independently receive Tx signals and Rx signals. The first device(350) and the second device(360) are connected to each other so that an Rx signal inputted to the first device(350) and an Rx signal inputted to the second device(360) respectively are outputted to a port of the second device(360) and a port of the first device(350). The first device(350) comprises the first isolation unit coupled to a port, to which a Tx signal is inputted, and the second isolation unit coupled to a port, to which an Rx signal is inputted. The second device(360) comprises the third isolation unit coupled to a port, to which an Rx signal is inputted, and the fourth isolation unit coupled to a port, to which a Tx signal is inputted. The first through fourth isolation units respectively comprise circulators(400-406).

Description

Dual Type Time Division Duplex Transmitting and Receiving Device

1 is a view showing an example of a conventional dual type TDD transceiver.

2 is a diagram showing the configuration of another conventional TDD transceiver;

3 is a diagram illustrating a connection state of a dual type time division transceiver according to an embodiment of the present invention.

4 is a diagram illustrating a detailed configuration of a dual type TDD transceiver according to an embodiment of the present invention.

FIG. 5 is a diagram showing a simulation waveform when a circuit is configured as shown in FIG. 8; FIG.

FIG. 6 is a diagram illustrating a reception path output waveform in a dual type TDD transceiver according to an exemplary embodiment of the present invention implemented as shown in FIG. 4.

FIG. 7 is a view illustrating a received signal waveform output from a dual type TDD transceiver as shown in FIG. 9.

8 is a diagram illustrating a circuit configuration of a TDD transmission and reception apparatus in which a reception path is ideally implemented.

9 is a diagram illustrating a circuit configuration when an RF switch or a hybrid is not installed in a conventionally operating dual type TDD transceiver.

The present invention relates to a time division multiplexing device, and more particularly, to a dual type time division multiplexing device for improving isolation.

As frequency acquisition becomes a big problem in wireless communication, a time division duplex (TDD) method that enables communication with a single frequency is receiving more attention.

The TDD scheme operates in a transmission mode and a reception mode over time. Frequency division duplex using different frequency bands in the uplink and the downlink for bidirectional communication. Compared to the FDD) method, the single frequency can be operated. In addition, since the TDD scheme uses an asymmetric match between transmission and reception time slots, the TDD scheme has a technical characteristic suitable for transmission of an application such as the Internet.

That is, the TDD scheme enables high-speed processing without using one antenna and using only half the frequency of the FDD scheme, thereby providing a service at a relatively low cost.

The TDD scheme is widely used in a relay apparatus for relaying a portable Internet signal and an OFDM modulated RF signal between a base station and a terminal.

In particular, a TDD transceiver for a repeater or the like is often implemented in a dual type. In this case, the dual type refers to a type in which two identical high frequency circuit units are configured to reduce a signal error.

1 is a diagram illustrating an example of a conventional dual type TDD transceiver.

Referring to FIG. 1, a conventional dual type TDD transceiver includes a first device 150 and a second device 160, and each device includes a first circulator 100 and a second circulator 102. , RF switch 104, band pass filter 106, and amplifier 108.

In FIG. 1, when the TDD transmission / reception system is in a transmission mode, a transmission signal is input to port 1 and transmitted to the RF switch 104 through the first circulator 100. At this time, the first circulator 100 functions to isolate the signal so that the signal is transmitted to the RF switch 104 and not to the amplifier 108.

When the TDD transceiver is in the transmit mode, the RF switch is not open and the transmit signal is output to port 2 through the second circulator 102. In this case, the second circulator 102 functions to isolate the signal so that the transmission signal is transmitted only to port 2 and not to the band pass filter 106.

When the TDD transceiver is in the reception mode, the reception signal is input to port 2, and the reception signal is input to the band pass filter 106 through the second circulator 102. The second circulator 102 functions to isolate the received signal so that the received signal is sent to the band pass filter 106 rather than the RF switch 104.

The band pass filter 106 passes only a frequency signal of a predetermined band among the received RF signals.

The signal passing through the band pass filter 106 is amplified by the amplifier 108. The amplified signal is transmitted to port 1 through the first circulator 100, and the first circulator 100 isolates the signal so that the signal is not transmitted to the RF switch.

In the dual type TDD transceiver, the first device 150 and the second device 160 operate the same independently.

The most problematic problem in such a TDD transceiver is isolation of the signal when operating in the transmission mode and the reception mode. In particular, the self-resonance phenomenon caused by signal isolation is degraded.

The self resonance phenomenon refers to a phenomenon in which a received signal amplified by the amplifier 108 is not isolated from the first circulator 100 and is input back to the band pass filter 106 through the second circulator 102.

At this time, when the amplification degree of the amplifier 108 is greater than the isolation degree of the circulators 100 and 102, this self resonance phenomenon is further intensified.

Conventionally, the occurrence of such a self resonance phenomenon is suppressed by using the RF switch 104. When the RF switch 104 is in the reception mode, the RF switch 104 is open and prevents a signal that is not isolated from the first circulator 100 from being transmitted to the second circulator 102.

In the related art, such a hybrid switch, rather than an RF switch, has been used to suppress the occurrence of self resonance.

2 is a diagram illustrating the configuration of another conventional TDD transceiver. As shown in FIG. 2, hybrids 200, 202, and 204 are provided, and the self-resonance phenomenon in which the received signal amplified using the hybrids 200, 202, and 204 is retracted is suppressed.

That is, conventionally, as in the case of FIGS. 1 and 2, the isolation between transmission and reception is secured by using a switch or a hybrid and the self-resonance phenomenon is suppressed. However, the high loss and poor spurious characteristics of the switch and the hybrid are always problematic. Became. In addition, there was a problem in that a significant cost in packaging a switch, which is a carrier, in order to use a low loss switch.

In order to solve the problems of the prior art as described above, the present invention is to propose a time-division multiplexing transmission / reception apparatus capable of securing sufficient isolation between a reception path and a transmission path and suppressing self-resonance without using a switch or a hybrid. do.

Another object of the present invention is to propose a dual type time division multiplexing transmission / reception apparatus which secures isolation between a reception path and a transmission path by processing signals independently and independently.

It is still another object of the present invention to propose a time division multiplexing and transmitting device capable of securing sufficient isolation between a reception path and a transmission path at a lower cost.

In order to achieve the above object, according to an aspect of the present invention, in the dual type TDD transmission and reception apparatus, including a first device and a second device for receiving the transmission signal and the received signal independently, the first A dual type in which the first device and the second device are connected to each other such that a received signal input to a device is output to a port of the second device, and a received signal input to the second device is output to a port of the first device. A TDD transceiver is provided.

The first apparatus includes first isolation means coupled to a port through which a transmission signal is input and second isolation means coupled to a port through which a received signal is input, and wherein the second device is coupled to a port through which the received signal is input. And third isolation means and fourth isolation means coupled to the port to which the transmission signal is input.

The first to fourth isolation means may include a circulator.

The first device may include: a first band pass filter configured to pass only a frequency signal of a predetermined band with respect to a received signal input to the first device; And a first amplifier for amplifying the signal passing through the first band pass filter, wherein the received signal amplified by the first amplifier is output to a port to which the transmission signal of the second device is input.

The second device may include: a second band pass filter configured to pass only a frequency signal of a predetermined band with respect to a received signal input to the second device; And a second amplifier for amplifying the signal passing through the second band pass filter, wherein the received signal amplified by the second amplifier is output to a port to which the transmission signal of the first device is input.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the dual type time division multiplexing and transmission apparatus for improving the isolation according to the present invention.

3 is a diagram illustrating a connection state diagram of a dual type time division transceiver according to an embodiment of the present invention.

Referring to FIG. 3, unlike the time division transmitting and receiving device operating independently in the conventional dual type, the first device 350 and the second device 360 are independently connected to each other.

The first device 350 is provided with a port 1 and a port 2, and a transmission signal is input to the port 1 and a reception signal is input to the port 2. In addition, the second device 360 is provided with a port 3 and a port 4, and a port 3 receives a transmission signal to the reception signal port 4.

The first circulator 400 is connected to port 1, the second circulator 402 is connected to port 2, the third circulator 404 is connected to port 3, and the fourth circulator is connected to port 4. 406 is connected.

The first transmission path 300 of the transmission signal input through the port 1 is formed between the port 1 to the port 2 as in the prior art. In addition, a second transmission path 304 of the transmission signal input through port 4 is also formed between port 4 and port 3.

However, a first receive path 302 of the received signal input through port 2 is formed between port 2 and port 4. In addition, a second receive path 306 of the received signal input through port 3 is formed between port 3 and port 1.

That is, although a conventionally received signal input to port 2 is output to port 1, according to a preferred embodiment of the present invention, a received signal input to port 2 is output to port 4, and a conventionally received signal input to port 3 Although is output to the port 4, according to a preferred embodiment of the present invention, the received signal input to the port 3 is output to the port 1.

In other words, according to the preferred embodiment of the present invention, the received signal input to the first device 350 is output from the second device 360, and the received signal input to the second device 360 is directed to the first device. The output is 360. As such, in the dual type TDD transceiver, changing the reception signal path does not provide sufficient isolation when the reception signal is separated from the transmission path by using a circulator or other isolation means so that the amplified reception signal is returned to the reception path. This is to minimize the distortion of the signal generated by the self-resonance.

As described above, the dual type TDD transceiver which is connected in a dependent manner by changing the reception path is isolated by more isolation means until the received signal introduced into the transmission path is introduced back into the reception path due to insufficient isolation. Compared to the dual type TDD transceiver, self resonance can be suppressed more efficiently.

FIG. 3 illustrates only a connection state of a dual type TDD transceiver according to a preferred embodiment of the present invention for the convenience of description. Advantages and detailed operations of the present invention will be described in more detail with reference to FIG. 4.

4 is a diagram illustrating a detailed configuration of a dual type TDD transceiver according to an embodiment of the present invention.

Referring to FIG. 4, a dual type TDD transceiver according to an embodiment of the present invention includes a first device 350 and a second device 360, and the first device 350 includes a first circulator 400. ), A second circulator 402, a first band pass filter 408, and a first amplifier 410, wherein the second device 360 includes a third circulator 404, a fourth circulator 406, a second band pass filter 412, and a second amplifier 414.

As shown in FIG. 4, the first device 350 and the second device 360 are connected to each other and operate dependently. As shown in FIG. 3, the received signal input to port 2 of the first device 350 is output to port 4 of the second device, and the received signal input to port 3 of the second device 360 is first. Output to port 1 of the device.

First, operation in the case where a transmission signal is input to port 1 of the first device will be described.

When a transmission signal is input to port 1 of the first device 350, the transmission signal is transmitted through the first transmission path 300 by the first circulator 400. The first transmission path 300 is not provided with an RF switch or a hybrid for disconnecting a signal as in the prior art.

The transmission signal transmitted through the first transmission path 300 is output to the port 2 by the second circulator 402. Although the first circulator 400 or the second circulator 402 does not sufficiently isolate the transmission signal, the transmission signal may be output to port 2 through another path, but the dual type TDD transmission / reception according to the preferred embodiment of the present invention. According to the apparatus, the transmitted signal entering the other path is introduced into port 2 after the signal is isolated through more circulators, so that the likelihood of affecting the transmitted signal output to port 2 is significantly reduced.

An operation when the reception signal is input to the second port will be described below.

When a received signal is input to the second port, the second circulator 402 isolates the signal so that the received signal is transmitted to the first receive path 302. The first band pass filter 408 passes only signals of a predetermined frequency band among the received signals. The bandwidth and center frequency of the band pass filter can be adjusted by adjusting the capacitor and inductor values.

The received signal passing through the first band pass filter 408 is amplified by the amplifier 410. The amplifier 410 is preferably a low noise amplifier that amplifies the RF signal with low noise.

The signal amplified by the amplifier is isolated by the fourth circulator 406 and output to port 4. The received signal received through the port 2 may not be sufficiently isolated by the second circulator 402, and thus may be transmitted to the first circulator 400 through the first transmission path 300, and the first circulator 400 may receive the received signal. May not be sufficiently isolated and may be output to port 1. In the reception mode, there is a possibility that the received signal inputted to the port 3 is outputted to the port 1 and the signal is distorted. However, the received signal inputted to the port 3 is amplified by the second amplifier 414 and transmitted to the port 1. Since the received signal entering the port 1 through the first path is isolated twice by two circulators 400 and 402 without being amplified, and then the incoming signal is introduced into the port 1, there is a great possibility of distortion of the signal. small.

In addition, after the received signal inputted to the port 2 is amplified by the first amplifier 410, the isolation may not be sufficiently performed in the fourth circulator 406, thereby causing a magnetic resonance phenomenon. However, according to the dual type TDD resonator according to the preferred embodiment of the present invention, when the signal is introduced into the second transmission path 304 because the isolation is not sufficiently performed in the fourth circulator, the introduced signal is a third circulator. Only after passing through the three circulators of the 404 and the first circulator 400 and the second circulator 402 is output back to the port 4. Therefore, the signal isolation is not performed by only one circulator, but the signal is isolated by three circulators as in the prior art. Therefore, even if an additional device such as a switch or a hybrid is not used, the self-resonance phenomenon can be sufficiently suppressed. Can be.

Next, the operation in the case where a transmission signal is input to the port 4 will be described. The operation in the case where the transmission signal is input to the port 4 is the same as the case in which the transmission signal is input to the port 1.

The transmission signal input to the port 4 is isolated by the fourth circulator 406 and transmitted to the second transmission path 304, and is isolated by the third circulator 404 and output to the port 3. The second transmission path 304 is not provided with an RF switch or a hybrid for disconnecting the signal.

Although the third circulator 404 or the second circulator 406 does not sufficiently isolate the transmission signal, the transmission signal may be output to port 3 through another path, but the dual type TDD transmission and reception according to the preferred embodiment of the present invention. According to the device, the transmitted signal entering the other path is introduced into port 3 after the signal is isolated through more circulators, so that the likelihood of affecting the transmitted signal output to port 3 is significantly reduced.

Next, the case where the received signal is input to the port 3 will be described. Receiving through the port 3 is the same as when the above-described reception signal is input.

When the received signal is input to port 3, the signal is transmitted by the third circulator to the fourth path 306, filtered by the second band pass filter 412, and amplified by the second amplifier 414. do. The amplified signal is output to port 1 through the first circulator 400.

The received signal received at port 3 may not be sufficiently isolated by the third circulator 404 and may be transmitted to the fourth circulator 406 through the second transmission path 304, and the fourth circulator 406 May not be isolated enough to output to port 4. In the reception mode, there is a possibility that the received signal inputted to the port 2 is outputted to the port 4 and the signal is distorted, but the received signal inputted to the port 2 is amplified by the first amplifier 410 and transmitted to the port 4, Since a received signal entering the port 4 through the second transmission path 304 is isolated twice by two circulators 404 and 406 without being amplified, and then the incoming signal enters the port 4, signal distortion may occur. The probability is very small.

In addition, after the received signal input to the port 3 is amplified by the second amplifier 410 may not be sufficiently isolated from the first circulator 400 may cause a magnetic resonance phenomenon. However, according to the dual type TDD resonator according to the preferred embodiment of the present invention, even if a signal is introduced into the first transmission path 300 because the isolation is not sufficiently performed in the first circulator, the received signal is still in the second circulator. Since the output is outputted to Port 1 only after passing through three circulators of the 402 and the fourth circulator 406 and the third circulator 404, a plurality of signals cannot be installed even if a switch or a hybrid is not provided separately. Isolation can effectively suppress the magnetic resonance phenomenon.

Hereinafter, the signal waveform and the performance output from the dual type TDD transceiver according to an embodiment of the present invention will be described.

First, a waveform generated when a reception path is an ideally implemented dual type TDD transceiver is described. 8 is a diagram illustrating a circuit configuration of a TDD transceiver device having an ideal reception path. In a TDD transceiver apparatus having an ideal implementation of a reception path, a reception signal is transmitted only to a reception path as shown in FIG. 8, and is configured not to flow through another path.

FIG. 5 is a diagram illustrating a simulation waveform when a circuit is configured as shown in FIG. 8.

6 is a diagram illustrating a reception path output waveform in a dual type TDD transceiver according to an exemplary embodiment of the present invention implemented as shown in FIG. 4.

As shown in FIG. 6, the dual type TDD transceiver according to the preferred embodiment of the present invention can confirm that the reception path is almost the same as the waveform output from the TDD transceiver.

The output waveform of the dual type TDD transceiver according to a preferred embodiment of the present invention is compared with the output waveform of a conventional independently operated dual type TDD transceiver without an RF switch or hybrid. FIG. 9 is a diagram illustrating a circuit configuration when an RF switch or a hybrid is not installed in a conventionally operated dual type TDD transceiver. FIG. 7 is a reception signal output from the dual type TDD transceiver. It is a figure which shows a waveform.

As shown in FIG. 7, when the conventional independently operating dual type transmission / reception apparatus does not include an RF switch or a hybrid, the signal is distorted due to self resonance when compared with the waveform of the ideal case of FIG. 5. You can check it.

As described above, according to the preferred embodiment of the present invention, the dual type TDD transceiver is independently connected independently and independently, thereby ensuring sufficient isolation between the reception path and the transmission path without using a switch or a hybrid and causing self-resonance. There is an advantage that can be suppressed.

Claims (5)

In the dual type TDD transceiver, A first device and a second device for receiving the transmission signal and the received signal independently, The received signal inputted to the first device is outputted to the port of the second device, and the received signal inputted to the second device is outputted to the port of the first device so that the first device and the second device are mutually different. Connected dual type TDD transceiver. The method of claim 1, The first apparatus includes first isolation means coupled to a port through which a transmission signal is input and second isolation means coupled to a port through which a received signal is input, and wherein the second device is coupled to a port through which the received signal is input. And a fourth isolation means coupled to the third isolation means and a port to which the transmission signal is input. The method of claim 2, And the first to fourth isolating means comprises a circulator. The method of claim 1, The first device, A first band pass filter configured to pass only a frequency signal of a predetermined band with respect to the received signal input to the first device; And A first amplifier for amplifying the signal passing through the first band pass filter, And a received signal amplified by the first amplifier is output to a port to which the transmission signal of the second device is input. The method of claim 1, The second device, A second band pass filter configured to pass only a frequency signal of a predetermined band with respect to the received signal input to the second device; And A second amplifier for amplifying the signal passing through the second band pass filter, And a received signal amplified by the second amplifier is output to a port to which the transmission signal of the first device is input.

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