Impact of Lower Substrate on Phase Modulation at High Frequency

It should be noted that the phase modulation function of the unit at high frequency is still determined by the outer circular patch diameter r1, as shown in Fig. 2. The two rings on the upper substrate serve as a reflective ground in relation to the upper circular patch. Therefore, the inclusion of the lower substrate with rings and circular patch has negligible effect on the reflective functionality created by the upper substrate.