The dual harmonic interdigital transducers (DHIDT)

In order to increase the operating frequency, many authors have addressed in different methods to overcome the difficulty of submicron processes in fabrications. Due to the great success that the quasi-harmonic interdigital transducers (QHIDT) have got, this paper presents a structure, called the harmonic dual interdigital transducers (DHIDT), in which the operating frequency of the transducers is at both the third harmonic of the element and the harmonics of the array. It is more suitable for the high frequency SAW devices because of its wider width of the transducer fingers, excellent sidelobes rejection characteristics and lower loss. The theoretical spectra of two DHIDTs are discussed in this paper. The experimental results are also shown in this paper and are in good agreement with the theoretical results