L-Band Variable-Delay-Time YIG-YAG-YIG and YAG-YIG-YAG Delay Lines

Two types of YIG variable-delay-time microwave delay lines are described. These are the YIG-YAG-YIG and YAG-YIG-YAG configurations, both of which provide ∼2 μs of variable delay in L-band. Two-port operation is achieved in both of these devices with leakage of the undelayed pulse between input and output being attenuated more than 100 dB. These are completely self-contained devices with internal permanent magnets and terminals for connecting a control signal to vary the delay time. Insertion loss, bandwidth, and VSWR data are presented as well as curves showing delay variation with control current. A comparison of these two types of delay lines is also presented, pointing out the advantages and disadvantages of each type.