Based on the GaAs substrate Enhanced/Depletion-mode pseudomorphic High Electron Mobility Transistor (E/D pHEMT) process, a three-bit adjustable 1 400 ps Digital-Controlled Delay (DCD) chip operating in the 0.5~6 GHz frequency range has been developed. The chip measures 3.60 mm×4.00 mm ×0.07 mm and integrates a three-bit digital-controlled delay line and a 3-bit parallel port drive circuit. Within the 0.5~6 GHz range, the DCD chip exhibits insertion loss of less than 11 dB, with insertion loss variation of less than ±0.5 dB. The Voltage Standing Wave Ratio (VSWR) for both input and output is less than 1.5 across all states. The 1 400 ps delay error can be internally adjusted to ±4 ps, achieving a delay quantity at the nanosecond level. By incorporating additional adjustable units and bonding cut-off methods, the delay accuracy is enhanced to 3‰. The chip features broadband operation, high precision, large delay quantity, and a compact size, making it well-suited for applications in antenna systems.