Читать книгу The Physics and Technology of Diagnostic Ultrasound: A Practitioner's Guide - Robert Gill - Страница 29

1 Consider a 5 MHz transmit pulse with a duration of 1 μsec.How many cycles are transmitted?Sketch the spectrum for this pulse.

2 Now consider a 10 MHz pulse with a duration of 0.5 μsec.Sketch the spectrum for this pulse.Compare this to your answer for question 1.Which pulse will give the best image resolution?

3 An L3-7 probe has a bandwidth extending from 3 MHz to 7 MHz (i.e. it can process frequencies in this range). What is the shortest possible pulse duration that can be transmitted using this probe?