Low-frequency oscillator and base station antenna

The invention provides a low-frequency oscillator with relatively small size and high radiation efficiency, and a base station antenna with the low-frequency oscillator. The low-frequency oscillator provided by the invention comprises a base, four supporting arms which upward extend from the base, and eight balancing arms which are arranged in a manner that two balancing arms vertically extend out of two sides of each supporting arm, wherein the two sides of the supporting arm are deviated from the base end. Each balancing arm is S-shaped and comprises a first unit segment and a second unit segment which are arc-shaped. One end of the first unit segment is connected with the supporting arm, and the other end is smoothly connected with the second unit segment. The curvature center of the first unit segment of the balancing arm and the center of the base are arranged at the same side of the balancing arm. The curvature center of the first unit segment of the balancing arm and the curvature center of the second unit segment of the balancing arm are arranged at different sides of the balancing arm.