Lattice phase equaliser
（重定向自Lattice filter）
![Lattice filter topology](/Images/godic/202501/23/Lattice_filter,_general.svg1844.png")
![A prototype lattice filter which passes low frequencies without phase shifting](/Images/godic/202501/23/Lattice_filter,_prototype.svg1844.png")
![Prototype lattice filter response ranging from 0 radians at low frequencies to -π radians at high frequencies](/Images/godic/202501/23/Lattice_prototype_response1844.PNG")
![Lattice filter transformed from the prototype to operate at 10 kHz midpoint and 600Ω terminations](/Images/godic/202501/23/Lattice_filter,_10kHz,_600R.svg1844.png")
A lattice phase equaliser or lattice filter is an example of an all-pass filter. That is, the attenuation of the filter is constant at all frequencies but the relative phase between input and output varies with frequency. The lattice filter topology has the particular property of being a constant-resistance network and for this reason is often used in combination with other constant resistance filters such as bridge-T equalisers. The topology of a lattice filter, also called an X-section is identical to bridge topology. The lattice phase equaliser was invented by Otto Zobel. using a filter topology proposed by George Campbell.