. Author manuscript; available in PMC: 2022 Jul 1.

Published in final edited form as: IEEE Trans Ultrason Ferroelectr Freq Control. 2021 Jun 29;68(7):2419–2431. doi: 10.1109/TUFFC.2021.3065952

TABLE I.

SUMMARY OF DF TRANSDUCER DESIGNS AND CHARACTERISTICS REPORTED IN LITERATURE.

Groups	Transducer Type	LF F₀(MHz)	LF Bandwidth ^a	HF F₀(MHz)	HF Bandwidth ^a
Bouakaz et al. [15]	Interleaved LF/HF array	1.1	77% (0.65 – 1.5 MHz)	3.3	82% (1.5 – 4.2 MHz)
Ferin et al. [17]	Parallel LF/HF arrays	3.5	90% (1.9 – 5.1 MHz)	7.5	90% (4.1 – 10.9 MHz)
Van Neer et al. [18]	Interleaved LF/HF array	~1	55% (at −10 dB)	3.7	50% (at −10 dB)
Hu et al. [19]	Parallel LF/HF arrays	1.5	~50%	5.4	73%
Li et al. [20]	Stacked LF/HF arrays	3.4	36.2% (2.78 – 4.0 MHz)	14.8	45.3% (11.45 – 18.15 MHz)
Lukács et al. [23]	Center HF element, outer LF ring	~2	60% (at −3 dB & 3 MHz)	30	100%
Chérin et al. [29]	Parallel LF elements/HF array	1.7	78%	21	52% (13 – 24 MHz)
This paper	Stacked LF/HF arrays	1.86	64.5% (1.2 – 2.4 MHz)	20.3	71% (13.3 – 27.8 MHz)

LF: low-frequency component; HF: high-frequency component; F₀: center frequency cited in references.

Fractional bandwidth is defined as: (upper – lower cutoff frequency)/F₀; reported at −6 dB unless noted otherwise.