采用SAW和PLL技术的扩频通信信道模块

SS Communication Channel Module Using SAW and PLL Technology

通过采用锁相环 (PL L)技术实现了射频载波的跳频扩频 (FHSS) ,跳变载波相噪小于 - 98d Bc/ Hz@1k Hz,杂散抑制大于 70 d B,收发端隔离度大于 10 5 d B;声表面波 (SAW)匹配滤波器保证了 2 0 Mbps的直接序列扩频 (DSSS)信号的实时解扩 ,SAW固定延迟线实现了延迟差分解调与解码。导出采用 2阶有源比例积分器作为PL

HFSS of RF carrier is implemented by PLL technology, with phase noise <-98 dBc/Hz @1 kHz, spur suppression > dB, isolation between transmitter and receiver >105 dB. The 10 Mbps DSSS signal is despreaded with Surface Acoustic Wave (SAW) matching filter. The intermediate frequency correlating peaks were demodulated and decoded with SAW stable delay line. The mathematical relation between phase margin and loop attenuation in PLL frequency synthesizer adopting the active 2 order scale integrator as loop low pass filter is deduced.