AN X-BAND ACOUSTOOPTIC VARIABLE DELAY-LINE FOR RADAR TARGET SIMULATION

The design and characterization of a 54-mu s, continuously-variable, a cousto-optic (AO) delay line developed for radar testing applications is presented, Design goals for the delay line include over 10 MHz of i nstantaneous bandwidth, 1.2 GHz of tunable bandwidth operating at X-ba nd, 45 dB of dynamic range, and electronically-controllable delay sele ction to simulate dynamic radar targets with radial range rates up to 500 m/s, In addition, the device was designed to have phase noise and spurious signal levels compatible with high performance radars, To ach ieve these goals, a 33-MHz center frequency variable delay line was co nstructed and coherent frequency translation was used to provide opera tion at S-band, Operating principles for this new intermediate frequen cy (LF) delay line are presented, and key component issues are discuss ed, A computer design and analysis tool is described that predicts del ay line performance. Experimental results are presented at both the IF and at X-band.