A 8 GHz microwave substrate integrated waveguide power amplifier using complementary split ring resonators

This paper introduces a design for a microwave substrate integrated waveguide (SIW) power amplifier (PA) for modern wireless communications. The amplifier design incorporates complementary split ring resonator (CSRR) structures integrated within the SIW to achieve low-loss characteristics and miniaturization through a below cut-off frequency operation approach. The designed PA operates at 8 GHz and exhibits good performance, which are measured output power Pout of 35.51 dBm, a maximum power added efficiency PAE of 47.2% and a power gain of 12.51 dB. The final circuit occupies just a compact size of 41 x 15.7 mm2 benefiting from using the CSRR structure. The proposed PA employs a low-cost QFN packaged GaN HEMT device from Qorvo and it was designed and fabricated on a cost-effective RO4003C substrate. The simulated results agree well with the measured ones validating the accuracy of the design. With promising measured results, the proposed PA can be a potential candidate for using in the modern wireless communication systems.