This paper presents the design and realization of a compact microstrip patch filtenna for 5G mid-band (n78) applications. The proposed structure integrates a parallel-coupled bandpass filter with a rectangular microstrip patch antenna, operating at 3.5 GHz with a 400 MHz bandwidth (3.3–3.7 GHz). The Taconic TLY-5 substrate was used to achieve low dielectric loss and stable performance. Electromagnetic simulations optimized the design parameters for impedance matching, minimal return loss, and sufficient gain. A prototype was fabricated and experimentally validated, showing good agreement with simulations. Measured results indicate return loss better than –20 dB, gain of 4–6 dBi, and improved stopband rejection compared to a conventional patch antenna. By combining filtering and radiation functions into a single device, the proposed filtenna reduces circuit complexity, enhances spectral selectivity, and improves overall efficiency. These results highlight its suitability for compact and high-performance 5G wireless communication systems.