A radio frequency self-checking device for FDD microwave communication systems

Abstract

The utility model discloses a radio frequency self -checking device for FDD microwave communication system, including coupling circuit, frequency conversion circuit, frequency source circuit and controller, the coupling circuit is equipped with a two -way radio frequency port for with the two -way connection of external duplexer's tuning terminal, the through output port of coupling circuit is connected with the radio frequency input port of frequency conversion circuit, the intermediate frequency output port of frequency conversion circuit is connected with the coupling input port of coupling circuit, the local oscillator port of frequency conversion circuit is connected with the output port of frequency source circuit, it belongs to communication field, through this self -checking device, the signal of transmitting channel in system is frequency conversion to the signal of receiving channel, and sends back receiving channel and carries out the signal processing effect.

Description

Technical Field

[0001] This utility model relates to a radio frequency self-testing device for FDD microwave communication systems in the field of communications, and is applicable to the self-testing application of radio frequency signals in microwave communication using frequency division multiplexing mode in the field of wireless communication. Background Technology

[0002] In modern wireless communication systems, communication systems with automatic detection capabilities can promptly identify system faults and accurately pinpoint the problem, facilitating troubleshooting and maintenance, and improving the overall reliability and security of the communication system. For equipment installed outdoors at high altitudes, this significantly reduces the difficulty of maintenance and troubleshooting. Therefore, radio frequency self-testing devices used in microwave communication systems play a crucial role in the system. Utility Model Content

[0003] The purpose of this invention is to provide a radio frequency (RF) self-test device for FDD microwave communication systems. Based on the operating characteristics of frequency division duplex (FDM) mode, where the transmitted and received signals operate at different frequencies simultaneously, this self-test device utilizes this system characteristic to convert the simultaneously existing transmitted channel signals to the received channel signals and send them back to the received channel for signal processing. During this process, the self-test device retains only one RF interface to achieve the RF self-test function. This device simplifies and facilitates the connection and application of the entire outdoor unit, improves the reliability and stability of the outdoor communication unit's inspection and maintenance, and makes maintenance and self-testing easier, thereby identifying abnormalities in antennas, duplexers, and other equipment throughout the channel.

[0004] The purpose of this utility model is achieved as follows: A radio frequency self-test device for an FDD microwave communication system includes a coupling circuit, a frequency conversion circuit, a frequency source circuit, and a controller; The coupling circuit is provided with a bidirectional RF port for bidirectional connection to the tuning terminal of an external duplexer; the direct output port of the coupling circuit is connected to the RF input port of the frequency converter circuit; the intermediate frequency output port of the frequency converter circuit is connected to the coupling input port of the coupling circuit; and the local oscillator port of the frequency converter circuit is connected to the output port of the frequency source circuit. The duplexer is bidirectionally connected to the coupling circuit via a tuning terminal.

[0005] Furthermore, the main body of the coupling circuit is a coupler; the frequency conversion circuit includes a first amplifier and a mixer; the frequency source circuit includes a frequency synthesizer and a second amplifier. The bidirectional port of the coupler is connected to the duplexer via a tuning terminal; the coupling port of the coupler is connected to the first input terminal of the mixer; the output terminal of the mixer is connected to the input terminal of the first amplifier, and the output terminal of the first amplifier is connected to the input port of the coupler. The second input terminal of the mixer is connected to the output terminal of the second amplifier, and the input terminal of the second amplifier is connected to the output terminal of the frequency synthesizer; the controller is connected to the input terminal of the frequency synthesizer.

[0006] Compared with the prior art, the present invention has the following advantages: 1. This utility model contains only one radio frequency port, which realizes the input and output of the received frequency signal and the transmitted frequency signal, thereby completing the radio frequency self-loop function.

[0007] 2. This utility model includes the detection of transmitted and received signals at the antenna port, realizing the abnormal detection of the duplexer; 3. This utility model includes a power detection function, which can simultaneously detect the transmission capability of the equipment; 4. This utility model can be extended to the self-test of the FDD system for transmitting and receiving channels in multiple frequency bands. It can be connected to an external multiplexer and has a wide frequency band range in its internal circuitry, thus enabling self-testing of multiple receiving and transmitting frequency band signals. Attached Figure Description

[0008] Figure 1 This is a principle block diagram of an embodiment of the present utility model.

[0009] Figure 2 This is a circuit schematic diagram of an embodiment of the present invention. Detailed Implementation

[0010] The present invention will be further described below with reference to the embodiments, which are intended only to better understand the content of the present invention. Therefore, the specific embodiments given do not limit the protection scope of the present invention. In addition, only the parts related to the present invention are shown in the accompanying drawings, not the entire structure.

[0011] This embodiment includes a coupling circuit 1, a frequency conversion circuit 2, a frequency source circuit 3, a control circuit 4, and a power supply 5. The signal from the transmitting channel passes through an external duplexer, and the transmitting frequency signal is input to the common port of the self-test device at the tuning port of the duplexer. After entering the self-test device, the transmitting frequency signal first enters the main channel port of the coupling circuit 1, and is output to the frequency conversion circuit 2 via the main channel of the coupling circuit 1. Simultaneously, the frequency source circuit 3 outputs a local oscillator signal to the frequency conversion circuit 2. The frequency conversion circuit 2 converts the transmitting signal to the receiving signal frequency, and the received signal output by the frequency conversion circuit 2 is input to the coupling port 1 of the coupler. The received signal is then output to the coupling port of the coupler via the main channel of the coupler 1. The tuning probe inputs the received signal into the duplexer, and after receiving filtering by the duplexer, it enters the receiving channel for down-conversion output, thus completing the RF self-loop of the signal from the transmitting channel to the receiving channel. The frequency source circuit 3 provides the local oscillator signal to the frequency conversion circuit 2 to achieve frequency conversion. Control circuit 4 provides frequency control signals to frequency source circuit 3. Power supply circuit 5 provides power to the entire circuit, mainly to frequency source 3 and control circuit 4.

[0012] This device can achieve the radio frequency self-test function of FDD signal by simply connecting the tuning probe port reserved in the duplexer to the self-test device.

[0013] The entire RF self-test device, because it is used in a frequency division duplex system, has the transmit signal and the receive signal existing simultaneously and at different frequencies at the tuning port of the duplexer. The self-test device can convert the input transmit signal to the frequency of the receive signal and output it to the external duplexer at the same port.

[0014] Reference Figure 1 The present invention includes a coupling circuit, a frequency conversion circuit, a frequency source circuit, a control circuit, and a power supply circuit. Figure 1 This is a block diagram illustrating the principle of an embodiment of the present utility model. Figure 2 This is the circuit schematic diagram of this utility model.

[0015] This invention is specifically implemented as follows: the tuning port of the multiplexer is connected to the input / output port of the coupling circuit in the self-test device. The through port of the coupling circuit is connected to the input port of the frequency converter circuit; the coupling port of the coupling circuit is connected to the output port of the frequency converter circuit; the local oscillator input port of the frequency converter circuit is connected to the output port of the frequency source; the output port of the control circuit is connected to the control input port of the local oscillator circuit. The power supply circuit is connected to the power input ports of all other circuits.

[0016] In this invention, the coupling circuit serves to directly output the transmit signal from the duplexer to the frequency converter circuit, and simultaneously output the receive signal, which has been frequency-converted to the receiving frequency by the frequency converter circuit, to the coupling port of the coupling circuit and then to the duplexer. The signal then passes through the receiving filter circuit of the duplexer to the receiving link of the channel, thus completing the self-test of the entire device.

[0017] The function of the frequency conversion circuit in this invention is to convert the simultaneously existing different frequency transmission signals in the FDD system into receiving signals, complete the frequency conversion, and realize the self-transmission and self-reception of the equipment.

[0018] In this invention, the frequency source circuit converts the transmit signal frequency of the FDD system into the receive signal frequency, providing a difference frequency local oscillator signal source.

[0019] The working principle of this utility model is as follows: The working principle of the RF self-test device for FDD microwave communication system in this utility model is as follows: Figure 2 As shown. When the system starts its self-test, the signal sent from the transmitting channel is output to its tuning port via a duplexer. The tuning port outputs the transmitted signal to the RF port of the self-test device. The input transmitted signal is directly output to the RF port of the frequency converter circuit via a coupler. A local frequency source generates a local oscillator signal and outputs it to the local oscillator port of the frequency converter circuit. The transmitted signal frequency and the local oscillator signal frequency are mixed to output the received frequency signal. The received signal is output to the amplifier circuit for signal amplification. The amplified received frequency signal is input through the coupling port of the coupler and coupled out to the unique RF port of the self-test device. The received signal output from the self-test device is input through the tuning terminal of the duplexer. The received signal is filtered in the duplexer and outputs the received frequency signal to enter the system's receiving channel. This completes the entire process of the transmitted channel signal looping back to the receiving channel for system self-test.

[0020] Since both received and transmitted signals need to be input and output through coupling circuits in the self-test device.

[0021] This device achieves self-testing using only a single RF port. Compared to traditional loopback modules with two RF ports and duplexers with two RF ports, this self-testing device requires only one RF port, and the corresponding duplexer only needs one RF port for connection. This significantly reduces the system size and lowers costs. The simple connection method makes it convenient for equipment located outdoors for extended periods, improving reliability and maintainability.

[0022] This device is suitable for FDD mode communication systems. When there are multiple receiving and transmitting frequency bands, the self-test device is also applicable. The self-test device can be extended according to the operating frequency of the external multiplexer, thus matching frequency division multiplexing communication systems applied to multiple operating frequency bands.

Claims

1. A radio frequency self-test device for an FDD microwave communication system, characterized in that, It includes a coupling circuit (1), a frequency conversion circuit (2), a frequency source circuit (3), and a controller (4); The coupling circuit (1) is provided with a bidirectional radio frequency port for bidirectional connection with the tuning terminal of an external duplexer; the direct output port of the coupling circuit (1) is connected to the radio frequency input port of the frequency converter circuit (2); the intermediate frequency output port of the frequency converter circuit (2) is connected to the coupling input port of the coupling circuit (1); the local oscillator port of the frequency converter circuit (2) is connected to the output port of the frequency source circuit (3). The duplexer is bidirectionally connected to the coupling circuit via a tuning terminal.

2. The radio frequency self-test device for an FDD microwave communication system according to claim 1, characterized in that, The main body of the coupling circuit is a coupler; the frequency conversion circuit includes a first amplifier and a mixer; the frequency source circuit includes a frequency synthesizer and a second amplifier. The bidirectional port of the coupler is connected to the duplexer via a tuning terminal; the coupling port of the coupler is connected to the first input terminal of the mixer; the output terminal of the mixer is connected to the input terminal of the first amplifier, and the output terminal of the first amplifier is connected to the input port of the coupler. The second input terminal of the mixer is connected to the output terminal of the second amplifier, and the input terminal of the second amplifier is connected to the output terminal of the frequency synthesizer; the controller is connected to the input terminal of the frequency synthesizer.

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