A kind of high frame rate (HFR) 2D and 3D imaging method was developed in 1997. Because only one transmission is required to construct an image, this method can reach an ultra high frame rate (about 3750 volumes or frames per second for biological soft tissues at a depth of 200 mm). Compared with conventional delay-and-sum (dynamic focusing) method, the new method uses the fast Fourier transform (FFT) algorithm. This may simplify the imaging system dramatically. But as the HFR method needs a special weighting on the received signal, the imaging system is still a little complicated. For example, a large number of amplifiers with different gains are required. In this paper, a more general HFR method is presented in the view of angular spectrum. Based on the study, the weighting process is replaced by Fourier transform. Computer simulation, which uses experimental data, is performed to verify the method. Results show that images constructed have the same high quality as the original HFR method while the system implementation of the method could be greatly simplified.