信号匹配单元是异频双工电台，基站发射部分的主要配件，其作用是将发射和接收讯号相隔离，保证接收和发射都能同时正常工作。
The signal matching unit is the main accessory of the transmission part of the base station and the different frequency duplex station, and its function is to isolate the transmitting and receiving signals to ensure that the receiving and transmitting can work normally at the same time.
信号匹配单元是一个分布参数的腔体滤波器，其频率响应曲线决定于腔体的分布参数我们要求无线对讲系统中信号匹配单元应在 -30℃－ 60℃的温度范围内具有相当的频率稳定度，不至于影响无线对讲机的通讯效果，也就是说信号匹配单元的频率响应曲线应在相应的温度范围内保持其要求的频谱位置和曲线形状。
The signal matching unit is a cavity filter with distribution parameters, and its frequency response curve is determined by the distribution parameters of the cavity, and we require that the signal matching unit in the wireless intercom system should have considerable frequency stability in the temperature range of -30 °C - 60 °C, so as not to affect the communication effect of the wireless walkie-talkie, that is to say, the frequency response curve of the signal matching unit should maintain its required spectrum position and curve shape within the corresponding temperature range.
信号匹配的隔离度是指两个等效带阻滤波器的阻带衰减量，除一些特定的场合外，一般双工器的接收通道和发射通道中的阻带的衰减量，也即双工器的接收端和发射端至天线端的隔离度相当的。带阻滤波器既能将微弱的接受信号藕合进来，又能将较大的发射功率馈送到天线上去，且两者各自完成其功能而不相互影响，在双工电台中起到收发共用天线的作用。
The isolation of signal matching refers to the attenuation of the stopband of the two equivalent band-stop filters, except for some specific occasions, the attenuation of the stopband in the receiving channel and the transmit channel of the general duplexer, that is, the isolation degree of the receiving end and the transmitting end to the antenna end of the duplexer is comparable. The band-stop filter can not only combine the weak receiving signal, but also feed the larger transmitting power to the antenna, and the two complete their functions without affecting each other, and play the role of transmitting and receiving common antennas in duplex stations.
信号匹配单元采用1U标准全铝机箱，面板拉丝处理，加厚结构和把手，减少机柜不必要的空间占用。设备可承受200W高功率输入高可靠性。采用新型结构设计增强了通带外抑制度，增加了三个端口隔离器。
The signal matching unit adopts a 1U standard all-aluminum chassis with brushed panels, thickened structure and handles to reduce unnecessary space occupation of the cabinet. The device can withstand 200W high power input and high reliability. The new structural design enhances the out-of-band rejection and adds three port isolators.
| 型号/Model | LR040GSG |
|---|---|
| 系统适应/System adaptation | DPMR,DMR,PDT,NXDN，TETRA |
| 频率范围(MHz)/Frequency Range (MHz) | 400-440MHz，450-490MHZ |
| 工作带宽/Working bandwidth | VHF:±1MHZ UHF:±2MHZ |
| 双工间隔/Duplex spacing | VHF:5.7MHZ UHF:10MHZ |
| 带外抑制/Out-of-band inhibition | +2.5MHz，>45dB;+5MHz，>75dB |
| 隔离度/Isolation | >75dB |
| 带内波动/In-band fluctuations | ≤0.5dB |
| 插入耗损( dBm)/Insertion Wear (dBm) | ≤1.8dB |
| 驻波比/VSWR | 1.25:1 |
| 最大功率/Maximum power | 200w |
| 阻抗/impedance | 50Q |
| 接口类型/Interface type | N型/Type N |
| 温度范围/Temperature range | -25℃+55℃ |
| 滤波方式/filtering | 双向带内滤波/Bidirectional in-band filtering |
| 防水防尘/Waterproof and dustproof | IP58 |
