Filter, integrated passive device and electronic device

A filter, comprising:

• a first port, a second port, a first band-pass filter circuit, a second band-pass filter circuit, and a third band-pass filter circuit;
• wherein
• the first band-pass filter circuit is connected with the first port and configured to input a first signal with a frequency between a first frequency and a second frequency in an initial signal input from the first port to the second band-pass filter circuit;
• the second band-pass filter circuit is connected with the first band-pass filter circuit and configured to:
• receive the first signal, and input a second signal with a frequency between a third frequency and a fourth frequency in the first signal to the third band-pass filter circuit;
• and
• the third band-pass filter circuit is connected with the second band-pass filter circuit and configured to:
• receive the second signal, and input a third signal with a frequency between a fifth frequency and a sixth frequency in the second signal to the second port;
• wherein the first frequency and the fifth frequency are each greater than the third frequency, the sixth frequency and the fourth frequency are each greater than the second frequency, and the second frequency is greater than the first frequency.