The invention discloses a lightweight, low-cost and high-density electric connector, which can provide impedance controlling, high-speed and low-disturbance communication as well as low insertion loss even if no shielding is arranged between the joints. A signal joint (S) and a ground joint (G) in the connector can be scaled down in proportion and arranged in opposite, so that a high field (H) isgenerated in a gap between the joints which produces differential signal pairs and a low field (L) is produced near an adjacent signal pair by the differential signals in a first differential pair.