Rigol vb1020 vswr standing wave measuring bridge for dsa815 dsa815 tg rigol vb1020 p the rigol vb1020 vswr is a standing wave measuring bridge for dsa815 dsa815 tg the vb1020 is used together with rigol dsa series spectrum analysers with tracking generators to make s11 measurements return loss reflection coefficient vswr p p the vswr bridge connects directly onto the front of rigol dsa series spectrum analysers with tracking generators to improve the test accuracy and to avoid the n