具有内外置天线切换功能的新型双射频低噪放大电路的设计

Design of a New Type of Double Radio Frequency Low Noise Amplifier Circuits with the Function of Inner and Outer Antenna Switching

介绍了一种工作于GPS的L1、L2频段和GLONASS的G1、G2频段,并具有内外置天线切换功能的新型双射频低噪放大电路,其中改进了低噪放大电路的结构,明显提高了其带外抑制量,使其具有更好的抗干扰能力,并采用了新型的内外置天线切换电路,解决了外置天线接口对内置天线信号的影响问题.仿真结果表明,该新型双射频低噪放大电路具有较低的噪声系数、较高的增益平坦度和带外抑制能力,并且稳定性很好.制作了该电路的印制板,并对其进行调试和测试,其主要技术参数的测试结果与仿真结果比较符合,从而验证了该新型双射频低噪放大电路所具有的良好特性,而且所制作的电路样品结构紧凑、占用PCB板面积较小,非常适合于手持式高精度定位接收机.

It introduces a new type of double radio frequency low noise amplifier circuits with the function of switching between inner and outer antenna using GPS L1 , L2 band＆amp;GLONASS G1 , G2 band.The low noise amplifier circuit structure was improved , and the amount of restraint outside the band increased ob-viously , making it have better ability to resist interference .The new type of circuits had the function of switching between inner and outer antenna to avoid the influence of the outer antenna port interface on the signals of the inner antenna .The simulation results show that this new type of double radio frequency low noise amplifier circuits have low noise figure , high gain flatness and the ability of out-of-band rejection . The circuit＆#39;s stability is good .A circuit sample was made , and then the debugging and testing were car-ried out.The main technical parameters of the measured results are in agreement with the simulation ones.The new type of double radio frequency low noise amplifier circuits have good characteristics .The sample circuit structure is compact , and the occupancy of PCB board area is lesser , which is very suit-able for hand-held high precision positioning receivers .