Relay

[0016] Example: such as figure 1 , 2 , 3, the input signal is input from input terminal 1, passes through matcher 2 to unidirectional bandpass surface acoustic wave filter 3, then reaches matcher 4, passes through matcher 4 to PA (Power Amplifier, power amplifier) ​​5, from PA5 The output signal passes through the matcher 6, the one-way band-pass surface acoustic wave filter 7, and the matcher 8 is output from the output port 9. The unidirectional bandpass surface acoustic wave filter 3 is composed of a substrate 31 and an input transducer 32 and an output transducer 33 on the substrate 31. The input transducer 32 is composed of electrodes 321 and finger strips 322. PA is a two-stage amplifier, 1stage51 and 2stage52 respectively.

[0017] The bandpass surface acoustic wave filter and PA in the present invention can adopt existing technical solutions. In the example of the present invention, a lithium niobate band-pass surface acoustic wave filter is used to achieve filtering. In the example of the present invention, the PA is a PA designed by Suzhou Inno Motion Company, and the number is INXGB25402300941. The PA is composed of HBT transistors, with a gain G of 30dB and a bandwidth of 80MHz. Among them, the size of the first level is 320um 2 , The second level size is 2500 um 2. The main function of the first stage is to amplify the signal, adjust the input impedance, and realize automatic gain control; the second stage further amplifies the signal to ensure a sufficiently high gain. The present invention is not limited to the specific models described in the text, and other band-pass surface acoustic wave filters and PAs that meet the requirements are also included.