A highly dispersive dual-concentric-core pure silica photonic crystal fiber is designed with a maximum chromatic dispersion value of about -9500\text{ps}/\left(\text{nm \hspace{0.17em} km}\right) around the 1.56\text{\hspace{0.17em} μm} wavelength region and a full width at half-maximum (FWHM) of \text{55 \hspace{0.17em} nm} . The change in the dispersion–bandwidth product as a function of period is carefully studied by using the plane wave expansion method. The coupled mode theory matches well with the plane wave expansion method that was used to simulate the chromatic dispersion. This kind of a photonic crystal fiber structure is suitable for high-dispersion application in phased array antenna systems based on photonic crystal fiber arrays.