Trapezoidal Antenna with Reconfigurable Frequency for Wireless Communication Systems

This paper presents a low-profile, trapezoidal-shaped, frequency-reconfigurable antenna, consisting of a trapezoidal radiating element surrounded by a 2 mm wide line and a rectangular ground plane with two L-shaped slots designed to operate in the microwave frequency band. The antenna is fed by a microstrip line. The substrate used is Rogers RT5880, with a relative permittivity of 2.2 and a tangent loss of 0.0009. To enable switching between different operating states, four PIN diodes are strategically inserted into the antenna's radiating top surface. The proposed Sub-6 GHz antenna operates in five states, covering six different frequency bands. The standing wave ratio (VSWR) of the presented antenna is less than 2 for all operating bands. The efficiency of the designed antenna is 90%, and the gain varies between 3 and 8.5 dBi across the corresponding operating frequency ranges. The proposed structure is simulated using the Computer Simulation Technology Microwave Studio (CST MWS) simulator. Due to its compact dimensions and compatibility with multiple wireless standards, including fourth and fifth-generation (5G) technology, the antenna is well-suited for integration into portable devices.