Manufacturing method of 225MHz-678MHz high-suppression low-loss electrically tunable filter

The invention discloses a manufacturing method of a 225MHz-678MHz high-suppression low-loss electrically tunable filter, and belongs to the technical field of electrically tunable filters, the method comprises the following steps: layout of a PCB (Printed Circuit Board): the PCB is provided with two layers, and each layer of the PCB is grounded through a large area; the filters arranged on the PCB are arranged in a bilateral symmetry mode, blocking capacitors are arranged in radio frequency input and output pins of the filters, and hollow coils are made of enameled wires. The size of the electrically tunable filter is reduced, and when the insertion loss is smaller than or equal to 4dB, the positive and negative 10% suppression of any center frequency of 225MHz-678MHz is larger than or equal to 13dBc, and the far-end suppression at the double position of the center frequency is larger than or equal to 40dB; the Q value can reach 250 to 300. 本发明公开了一种225MHz~678MHz高抑制低损耗电调滤波器的制造方法，属于电调滤波器技术领域，该方法为：PCB电路板布局：PCB电路