Multifunctional DMR radio frequency assembly

Abstract

The utility model provides a multifunctional DMR radio frequency assembly comprising a bridge connected with an input signal, the bridge is connected with a first signal output port through a circulator, the bridge is connected to an uplink and downlink selector through a frequency band selector, and the uplink and downlink selector outputs an uplink signal and a downlink signal. In the joint operation process of the 450MHz wireless train dispatching system and the DRTD system, the device can play a role in switching between two systems, can also support simultaneous use of the two systems, does not need manual intervention, and is good in reliability, convenient to maintain, high in efficiency and the like.

Description

Technical Field

[0001] The utility model relates to the field of repeater communication equipment, in particular to a multifunctional DMR radio frequency component. Background Art

[0002] The Digital Radio Dispatching Communication System (DRTD) is the primary communication system for future conventional railway systems. However, the existing 450MHz wireless train dispatching system still accounts for a significant portion of the system's coverage, necessitating a retrofit of the Digital Radio Dispatching Communication System (DRTD). This system must be compatible with the 450MHz wireless train dispatching system, ensuring no interruption or impact to existing train dispatching services during the wireless system upgrade. The existing 450MHz wireless train dispatching system must operate alongside the DRTD system, ensuring a smooth transition from the existing 450MHz wireless train dispatching system to the DRTD system. Utility Model Content

[0003] In order to solve the problems of the prior art, the utility model provides a multifunctional DMR radio frequency component. When a 450MHz wireless modulation system and a DRTD system are in common operation, the component can switch between the two systems and can also support the simultaneous use of the two systems without manual intervention, thereby having good reliability, convenient maintenance and high efficiency.

[0004] The utility model includes an electric bridge connected to an input signal, the electric bridge is connected to a first signal output port through a circulator, the electric bridge is connected to an uplink and downlink selector through a frequency band selector, and the uplink and downlink selector outputs an uplink signal and a downlink signal; wherein the circulator isolates 457MHz~459MHz frequency band signals and outputs 413.2MHz~414.2MHz frequency band and 467MHz~469MHz frequency band signals through the first signal output port; the frequency band selector isolates 413.2MHz~414.2MHz frequency band and 467MHz~469MHz frequency band, and separates 457MHz~459MHz frequency band; and the uplink and downlink selector screens uplink and downlink signals in the 457MHz~459MHz frequency band.

[0005] As a further improvement, the circulator and the band selector both have a 100W load.

[0006] The beneficial effects of the utility model are:

[0007] 1. The device is compatible with two working modes at the same time and can switch smoothly between the two modes;

[0008] 2. No additional control equipment is required.

[0009] 3. This product is small in size and has a modular design that makes it easy to disassemble and install, improves the production process, simplifies the assembly process, and facilitates mass production; it also has low energy consumption and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0011] Figure 1 This is a schematic diagram of the circuit structure of the utility model. DETAILED DESCRIPTION

[0012] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0013] A specific implementation of the utility model is as follows Figure 1 As shown:

[0014] 1. Use a built-in circulator to isolate the 457MHz~459MHz frequency band signal and output the 413.2MHz~414.2 MHz frequency band and the 467MHz~469MHz frequency band signal;

[0015] 2. Use the built-in frequency band selector to isolate the 413.2MHz~414.2MHz band from the 467MHz~469MHz band, and separate the 457MHz~459MHz band.

[0016] 3. A built-in uplink / downlink selector is used to filter the uplink and downlink signals in the 457MHz~459MHz frequency band, solving the problem of uplink signals in the 457MHz~459MHz frequency band interfering with downlink signals due to device reflections, and vice versa.

[0017] The multifunctional DMR RF module simultaneously inputs signals in the 450MHz and 413MHz frequency bands. The DRTD (Digital Radio Dispatching and Communication System) standard frequency band is 413.2MHz to 414.2MHz, and the 450MHz wireless train modulation frequency bands are 457MHz to 459MHz and 467MHz to 469MHz. 413.7MHz is the center frequency of the DRTD (Digital Radio Dispatching and Communication System) standard Type I repeater, while 458MHz and 468MHz are the center frequencies of the 450MHz wireless train modulation co- and inter-frequency transmissions.

[0018] How it works

[0019] The 413.7M / 458M and 468MHz signals are transmitted through the first port of the 3dB bridge in the dual-mode device to the second port of the circulator and directly to the transmitter. The 458MHz signal is absorbed by the load of the third port of the circulator to avoid causing a large echo. At the same time, the signal through the second port of the 3dB bridge selects 458MHz to the uplink and downlink selection switches to the transmitter port, and the downlink 458M signal is sent to the ANT (458) interface. Under this working condition, a low-level control signal is simultaneously output to the low-noise amplifier to turn off the low-noise amplifier to prevent the signal from self-excited and burning out the low-noise amplifier.

[0020] The uplink 458M signal is connected to the multifunctional DMR radio frequency component ANT (458) interface. The signal passes through the internal radio frequency switch (not controlled by default) and is sent to the RX (458) interface. This interface is connected to the low noise amplifier and then sent to the digital intermediate frequency board radio frequency input interface after amplification.

[0021] When the RF switch is switched, the corresponding indicator light can display the current working status.

[0022] The features are listed below:

[0023] Serial number Function (or module) name Functional Description 1 +5V Positive power supply 2 GND Grounding 3 MCU control signal 1 Multifunctional DMR radio frequency component uplink and downlink control level, 4 MCU control signal 2 Multifunctional DMR radio frequency component uplink and downlink control level 5 LNA off control signal Control the low noise amplifier switch state level 6 With light display function Display device working status indication

[0024] The performance list is as follows:

[0025] Serial number Performance Name Performance Description 1 Frequency range (MHz) 400~425 MHz, 450~470MHz 2 Uplink insertion loss (dB) ≤1.0 3 Insertion loss (dB) 413.2~414.2MHz: ≤1.5; 457~459MHz: ≤1.5; 467~469MHz: ≤1; 4 413 / 458 isolation (dB) ≥85 5 Port isolation (dB) ≥55 6 Input / output voltage standing wave ratio ≤1.25 7 Withstand power (W) ≥100 8 In-band flatness (dB) ≤0.5 9 Operating temperature -40～+57℃

[0026] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, the above is only a preferred implementation method of the present invention. Since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with this technical field is within the technical scope disclosed by this utility model. For ordinary technicians in this technical field, changes or replacements that can be easily thought of should be included in the protection scope of this utility model without departing from the principle of this utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims

1. A multifunctional DMR radio frequency component, characterized by: The system includes an electric bridge connected to an input signal, the electric bridge is connected to a first signal output port through a circulator, the electric bridge is connected to an uplink / downlink selector through a frequency band selector, and the uplink / downlink selector outputs an uplink signal and a downlink signal; wherein the circulator isolates the 457MHz~459MHz frequency band signal and outputs the 413.2MHz~414.2MHz frequency band and the 467MHz~469MHz frequency band signal through the first signal output port; the frequency band selector isolates the 413.2MHz~414.2MHz frequency band from the 467MHz~469MHz frequency band and separates the 457MHz~459MHz frequency band; and the uplink / downlink selector filters the uplink and downlink signals in the 457MHz~459MHz frequency band.

2. The multifunctional DMR radio frequency component according to claim 1, characterized in that: The circulator and band selector each have a 100W load.

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