Engineering Implementation of Pulse RF Modulator
WU Jun-chen · Radio Engineering of China · 2007
The basic principles of PLL frequency modulation are introduced.The low jitter transmission of pulse signals is realized by direct RF-modulation based on PLL frequency modulation.Pretreated pulse signals are input to the tuning port of the VCO to modulate the carrier signal.The carrier signal is generated by ADF4360-2 of ADI Corporation.The LO signal is generated by Si4133 of Si Lab.The modulated carrier signal and the LO signal are mixed to generate the IF signal.After filtering and amplifying,the mixed signal is output to the outdoor equipment.Experiments prove that this design can realize the low jitter modulation of pulse signals and meet design requirements well.The 3σ jitter of demodulated pulse signals is less than 20ns.