L波段收发信机的研究

【作者】 孔良；

【导师】 杨涛；

【作者基本信息】 电子科技大学 ， 电磁场与微波技术， 2008， 硕士

【摘要】 本文根据课题指标提出了L波段收发信机的设计方案,完成了中心频率为1GHz、带宽为85MHz信号的接收和发射,并根据系统功能要求为毫米波收发信机提供9GHz的本振信号。为滤除杂波,设计了一个发夹型带通滤波器,其中心频率为8.9GHz,带宽为380MHz,在8GHz和10GHz处的抑制大于40dBc。在正交解调芯片的基带滤波器设计中,采用将滤波器的地设置为电平为1V的“浮地”,即将系统地和滤波器的地分离的方法,减小了地噪声的干扰。本文将该收发信机分为三个部分加以研究,主要包括:本振部分、发射上变频部分和接收部分。在本振部分,采用锁相环加倍频链的方式获得所需要的9GHz本振信号,功率为18.85dBm,相位噪声为-72.58dBc/Hz@1kHz,-79.29dBc/Hz@10kHz。发射上变频部分根据指标要求选择合适的芯片,产生发射中心频率为1GHz,带宽为85MHz的信号,其电平为-2dBm。接收部分采用两级放大器级联、零中频接收、自动增益控制的结构,实现了最大接收增益51dB,AGC动态范围＞45dB,信号I/Q解调的性能。测试完成后,对测试中发现的问题进行了分析,同时给出了一些改进措施及设计中需要注意的问题,为以后的设计制作提供一些可借鉴的经验。更多还原

【Abstract】 According to the target, we present a design scheme which achieves transmission and receiving signal of center frequency 1GHz, band width 85MHz and the local oscillation signal of 9GHz. In order to filter other spur, we design a hairpin band-pass filter, which has the center frequency of 8.9 GHz, the band width of 380 MHz and rejection greater than 40 dBc at 8 GHz and 10 GHz. In the Quadrature demodulator chip, we set the base-band filter’s "floating" ground to 1 V to reduce the noise.The transceiver comprises three parts: local oscillation circuit, transmitting circuit and receiving circuit. In the local oscillation circuit, we use phase-locked loop and frequency multiplication chain to generate the 9GHz local oscillation signal with power of 18.85dBm and phase noise of -72.58dBc/Hz@1kHz, -79.29dBc/Hz@10kHz. In the transmitting circuit, we choose the appropriate chip to realize transmitting signal of center frequency 1GHz, band width 85MHz and power of -2dBm. In order to reach the design requirements, there are the two-cascade amplifying technologies, zero-if receiver and automatic gain controls in receiving circuit. This study realize the maximum receive gain of 51dB, most greatly dynamic range >45dB and the signal I/Q demodulation.The transceiver has been measured and some improving advice is presented based on experiment. All of these can provide important experience for later research on this area.更多还原