Investigation of coplanar waveguide fed SWB antenna with controllable stop band characteristics

This study presents a coplanar waveguide (CPW)-fed monopole antenna engineered for super-wideband (SWB) applications. The antenna is designed to resonate at frequencies ranging from 2.44 GHz to over 25 GHz. The prototype is built on an F4B substrate with dimensions of 34 × 36 mm² and a thickness of 1 mm. The distance from the ground to the feed line is calibrated at 0.20 mm for good impedance matching. The suggested antenna demonstrates an average gain of 4.90 dB and a maximum peak gain of 6.0 dB, making it suitable for high-performance applications. Incorporating a rectangular complementary ring resonator into the radiator produces a band-notched function, thereby minimizing interference from specific frequency bands. A varactor diode is included in the complementary ring resonator to modify the interference band to lower frequencies within the ultra-wideband spectrum. The prototype is experimentally evaluated for SWB applications, both with and without a notched band. The empirical and simulated results demonstrate a robust association, thereby confirming the validity of the approach. The proposed antenna presents a compact and versatile solution for SWB applications, effectively mitigating interference from overlapping frequency bands. The reconfigurable notch feature, enabled by the varactor diode, provides a significant advantage over fixed-notch systems by allowing dynamic adjustment to different interference conditions. This study demonstrates a significant improvement in SWB antenna design, offering enhanced performance, compactness, and versatility for modern wireless communication systems, radar applications, and portable devices.