Low-Cost Compact Hairpin Filter Integrated with a Diamond Antenna for Wireless and 5G Sub-6 GHz Applications

In order to simplify the complex wireless communication system while maintaining good electrical performance and reducing the cost, a new compact design has been developed that combines two essential components of the wireless communication chain, the filter and the antenna, into a single multifunctional device capable of radiating and filtering. This filtering antenna, also known as a filtenna, was designed and manufactured for use in 5G sub-6 GHz and wireless applications at the n77-band (3.3–4.2 GHz). The structure consists of a hairpin filter made up of three folded U-shaped resonators integrated with a monopole antenna having a diamond-shaped radiating element. The strength of our work is that we were able to create a compact, small, and low-cost design while achieving good electrical performance. The simulated and measured results are compatible, the reflection coefficient showed a good impedance matching for both resonance frequencies 3.57 GHz and 4.10 GHz (|S₁₁|≤ − 10 dB), as well as a voltage standing wave ratio less than 2. Several other results will be presented and discussed later in this article. The software used for the simulation is High-Frequency Structure Simulator (ANSYS HFSS) which employs the finite element approach. A prototype of the filtenna (filtering Antenna) was fabricated and measured using the vector network analyzer 3656D.