Variable frequency filter and high-frequency front end circuit

A variable frequency filter comprising:

• an input terminal;
• an output terminal;
• a series arm resonant circuit comprising:
• a fixed capacitor having a fixed capacitance, and
• a variable capacitor, an inductor, and an elastic wave resonator connected in parallel with each other,
• wherein a first end of the series arm resonant circuit is connected to the input terminal and a second end of the series arm is connected to the output terminal;
• a first parallel arm resonant circuit having one end connected to the first end of the series arm resonant circuit and another end connected to ground;
• and
• a second parallel arm resonant circuit having one end connected to the second end of the series arm resonant circuit and another end connected to ground,
• wherein the first parallel arm resonant circuit and the second parallel arm resonant circuit each comprise a variable capacitor, an inductor, and an elastic wave resonator connected in series with each other, and
• wherein the fixed capacitor is connected to an end of the series arm resonant circuit that is connected to the parallel arm resonant circuit comprising the elastic wave resonator having the lowest impedance.