Unidirectional magnetostatic forward volume wave transducers

A unidirectional transducer for magnetostatic forward volume waves (MSFVW) is described in this paper. This transducer consists of two conventional microstrip couplers in parallel respectively driven by 90° out of phase microwave signals. The operation of a unidirectional transducer (UDT) has been theoretically predicted using impedance characteristics of microstrips. This unidirectional behavior has been experimentally checked on epitaxial YIG films and 20 dB of directivity has been obtained. Low insertion loss delay line (close to 10 dB) has been achieved by use of UDT for launching and receiving MSFVW in S-band.