一种V/U频段零中频发射信道小型化设计

针对V/U频段,提出了一种宽带发射机的前端设计方法,其中包括射频信道设计、频率合成器的设计以及基带电路设计。鉴于小型化的设计思想,射频前端采用零中频发射机架构,通过合理的滤波、放大等信号处理,输出1 dB压缩点为16 dBm。频率合成器采用集成VCO的锁相环芯片ADF4351,为满足高速跳频通信体制,采用兵乓环高速换频,实现单边带相位噪声优于-125 dBc/Hz@100 kHz,频率切换时间小于10μs。基带电路采用正交调制器LTC5598和12位双通道DA转换器AD9716,可实现最大带宽为40 MHz的I/Q双路同时调制。通过FPGA或DSP基带处理,可广泛用于V/U小型化发射机设计。

Miniaturization Design of Zero-IF Transmission Channel in V/U Band

A front-end design method for wideband transmitters operating at V/U band is proposed,including the RF channel design,frequency synthesizer design and baseband circuit design.In view of the miniaturized design concept,the RF front-end adopts a zero-IF transmitter structure,and through reasonable filtering,amplification and other signal processing,the output 1 dB compression point of 16 dBm is obtained.The frequency synthesizer adopts the phase-locked loop chip ADF4351 with integrated VCO.In order to meet requirements of the high-speed frequency hopping communication system,the high-speed frequency shifting of the ping-pong ring is adopted,and the single-sideband phase noise is better than-125 dBc/Hz@100 kHz,and the frequency switching time is less than 10 μs.The baseband circuit uses the quadrature modulator LTC5598 and the 12-bit dual-channel DA converter AD9716 to achieve I/Q dual simultaneous modulation with a maximum bandwidth of 40 MHz.The proposed method can be widely used in V/U miniaturized transmitter design by FPGA or DSP baseband processing.