Ka波段频率合成器设计

提出了一种Ka波段低杂散、捷变频频率合成器设计方案。该方案采用直接数字合成(DDS)+直接上变频的频率合成模式,DDS1产生360~600 MHz低杂散中频信号,DDS2产生波形信号。经过4次上变频、分段滤波、放大后,该方案实现了宽带、低杂散、捷变频频率合成器的设计,为系统提供本振信号、激励信号等。根据设计方案,制作了实物。实测该频率合成器输出杂散小于-75 dBc,频率切换时间小于200 ns,带宽2 GHz,步进1 MHz,35 GHz载波处相噪约-95 dBc/Hz@1kHz。该频率合成器不仅可广泛应用于雷达、对抗、通信等领域,也为其他类似需求频率合成器提供了参考。

Design of Ka-band Frequency Synthsizer

A design scheme of Ka-band low-clutter frequency synthesizer of frequency agility is proposed in this paper.The scheme adopts the frequency synthesizer mode of direct digital synthesis(DDS)+direct up conversion.The 360~600 MHz intermediate frequency(IF)signal with low clutter is created by DDS1,and the signal of transmitting waveform is created by DDS2.In the scheme,a low clutter broadband frequency synthesizer of frequency agility is realized after 4 times up conversion,segment filtering and amplification,which provides local oscillator(LO)signal,exciting signal,etc.According to the design scheme,the real synthesizer is made.Measured results show that:the output clutter is less than-75 dBc,frequency switch time is less than 200 ns,bandwidth is 2 GHz,step is 1 MHz and the phase noise is about-95 dBc/Hz@1 kHz at 35 GHz carrier wave.This synthesizer not only can be applied to radar,electronic countermeasure,communication,etc.,but also offers a reference for other synthesizers with similar requirements.