Abstract: With the rapid advancement of automotive intelligence, connectivity, and electrification, vehicle-mounted wireless communication technologies now serve as a critical enabler for vehicle to everything connectivity. The antenna placement and individual performance significantly impact the communication capabilities of 2/3/4/5G, DSRC, V2X, and GNSS systems. Thus, accurate evaluation of wireless communication performance is essential for OEMs. This paper investigates the key factors influencing the communication networks of intelligent connected vehicles (ICVs). Through circuit design and simulation verification, we analyze antenna positioning and standalone performance, proposing an integrated antenna system solution for ICVs. Experimental results show that in the B1 low-frequency band, the antenna's receiving sensitivity improved by approximately 3 dB, while in the high-frequency band, the sensitivity increased by about 2 dB. This study provides valuable insights for the optimized design and engineering development of antennas in intelligent connected vehicles.