I recently use HMC703 to drive CHC2442 ( a 24GHz transceiver by UMS ) generating FMCW waves. But there is a strange phenomenon, that at the beginning of a ramp, the tuning voltage (Vtune) outputted by HMC703 always accompany with a glitch (see the photo below). The HMC703 is triggered by an external trigger signal (the yellow wave in the photo), and the bandwidth of loop filter is 200kHz, which is adequate for VCO to hop back to 24GHz.
Would you please offer me any suggestion on this weird problem? Thanks in advance.