Introduction
Antennas are essential components in wireless communication systems, allowing for the transmission and reception of electromagnetic waves. One type of antenna commonly used in wireless systems is the microstrip antenna, which is known for its low profile and ease of fabrication. In this blog, we will design and simulate a compact circularly polarized inset-fed circular microstrip antenna for the 5 GHz band.
Design and Simulation of Compact Circularly Polarized Inset-Fed Circular Microstrip Antenna
The antenna is designed and simulated using our virtual prototyping electromagnetic software, HFWorks, which is a high-frequency electromagnetic simulation software based on the Finite Element Method (FEM). The material used for the antenna is Rogers TMM-3, which has a relative permittivity of 3.27. This material is commonly used in microstrip antenna design due to its low loss and stable performance over a wide range of frequencies.
The antenna is designed to have left-hand circular polarization, which is useful in applications such as satellite communication and GPS systems.
Geometry of the Antenna
The designed antenna is a compact circularly polarized antenna with only one input port and input signal. With careful design, it is possible to create two output signals with 90 degree phase difference from only one input port. Hence, the polarized channel separation of the system is maintained.
One of the critical factors that impact the performance of the antenna is the feeding method used. In our design, three different feeding methods - quarter-wave transformer, proximity coupled feed, and inset feed - are chosen and simulated in order to provide the best matching for the antenna. The quarter-wave transformer feeding method provides impedance transformation and isolation, while the proximity coupled feed uses a small gap between the feedline and the radiating patch to achieve a broad bandwidth. The inset feed is also known for its wide bandwidth and simple design.
Reflection Coefficient (S11) of the Proposed Antenna
From the above plot, we can observe that the antenna resonates at 5.72 GHz with a bandwidth of 60 MHz (5.57 GHz - 5.69 GHz).
3D Radiation Pattern (5.72 GHz)
The antenna has a maximum delivered gain of 7.92 dB at the resonant frequency of 5.72 GHz.
