Elastic wave device

An elastic wave device comprising:

• a piezoelectric substrate;
• a pair of reflectors disposed on the piezoelectric substrate along a propagation direction of an elastic wave;
• first to fifth comb electrode pairs disposed in order between the pair of reflectors;
• a first adjacence portion where the first comb electrode pair and the second comb electrode pair are adjacent to each other;
• a second adjacence portion where the second comb electrode pair and the third comb electrode pair are adjacent to each other;
• a third adjacence portion where the third comb electrode pair and the fourth comb electrode pair are adjacent to each other;
• and
• a fourth adjacence portion where the fourth comb electrode pair and the fifth comb electrode pair are adjacent to each other,
• wherein each of the first to fifth comb electrode pairs has a signal comb electrode and a ground comb electrode facing each other,
• the signal comb electrode of the second comb electrode pair and the signal comb electrode of the fourth comb electrode pair are connected together in parallel, and connected to an unbalanced signal terminal,
• the signal comb electrode of the third comb electrode pair is divided into a first region and a second region along the propagation direction of an elastic wave,
• a ground comb electrode of the first region of the third comb electrode pair and a ground comb electrode of the second region are electrically connected together in series via a series connection point,
• a signal comb electrode of the first region of the third comb electrode pair is connected in parallel to the signal comb electrode of the first comb electrode pair, and connected to a first balanced signal terminal,
• a signal comb electrode of the second region of the third comb electrode pair is connected in parallel to the signal comb electrode of the fifth comb electrode pair, and connected to a second balanced signal terminal,
• the ground comb electrodes of the first to fifth comb electrode pairs are connected to a ground electrode,
• at least one of a first connection electrode finger connecting the ground comb electrode of the first comb electrode pair to the ground comb electrode of the second comb electrode pair at the first adjacence portion, and a second connection electrode finger connecting the ground comb electrode of the second comb electrode pair to the ground comb electrode of the third comb electrode pair at the second adjacence portion is further provided,
• at least one of a third connection electrode finger connecting the ground comb electrode of the third comb electrode pair to the ground comb electrode of the fourth comb electrode pair at the third adjacence portion, and a fourth connection electrode finger connecting the ground comb electrode of the fourth comb electrode pair to the ground comb electrode of the fifth comb electrode pair at the fourth adjacence portion is provided, and
• at least one of the first connection electrode finger and the second connection electrode finger is formed from an even number of electrode fingers, and at least one of the third connection electrode finger and the fourth connection electrode finger is formed from an odd number of electrode fingers.