Figure 5

Experimental maximum amplitudes at the input voltage of 75 V and 125 V. (a,b) Peak amplitudes at the fundamental frequency using (a) the aluminium PC transducer with \({\rm{\Lambda }}\) = 8.1 mm and the ABS one with \({\rm{\Lambda }}\) = 2.1 mm, and using (b) the aluminium PC transducer with \({\rm{\Lambda }}\) = 5.7 mm and the ABS one with \({\rm{\Lambda }}\) = 1.4 mm. (c,d) Peak amplitudes the second harmonic frequency using (c) the aluminium PC transducer with \({\rm{\Lambda }}\) = 8.1 mm and the ABS one with \({\rm{\Lambda }}\) = 2.1 mm, and using (d) the aluminium PC transducer with \({\rm{\Lambda }}\) = 5.7 mm and the ABS one with \({\rm{\Lambda }}\) = 1.4 mm. In every figure, the black square and blue triangle markers indicate the aluminium and ABS PC waveguides at 75 V, whereas the red circle and purple inverted triangle markers correspond to the aluminium and ABS PC structures at 125 V.