⚡ electrical engineering

A Quatre-Lobed Arc-Slotted Microstrip Patch Antenna for Ku-Band Applications at 14.45 GHz

This paper presents a compact, 8 mm × 8 mm quatre-lobed arc-slotted microstrip patch antenna designed for Ku-band applications at 14.45 GHz, which achieves a broad impedance bandwidth of 14.05–15.10 GHz, a reflection coefficient of −18.5 dB, and a maximum gain of 6.27 dBi, making it a practical solution for satellite and wireless communication systems.

Original authors: Omar Saraereh

Published 2026-07-13

📖 5 min read🧠 Deep dive

CC BY 4.0

Original authors: Omar Saraereh

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

Imagine you're trying to catch a specific radio signal in a crowded room, but the signal is hiding in a very tricky spot: the Ku-band, specifically at 14.45 GHz. This is the kind of frequency used for satellite internet and high-speed wireless links. Usually, catching this signal requires a big, clunky antenna, or a very expensive, high-tech one that costs a fortune to build.

But what if you could build a tiny, flat antenna that fits on a standard circuit board, costs almost nothing, and still catches that signal perfectly? That's exactly what Omar Saraereh from Hashemite University has simulated in this study.

The "Four-Petal" Trick

Think of a standard microstrip antenna like a simple, flat square pancake. It's cheap and easy to make, but it has a problem: it's picky. It only likes one very narrow slice of the frequency spectrum. If you try to tune it slightly off, it stops working. It's like a radio that only plays one station, and if you turn the dial even a tiny bit, you get static.

To fix this, the researcher didn't just make a bigger pancake. Instead, he carved a special pattern into it. He took a standard square patch and cut out a central square hole and added four curved, arc-shaped slots around the edges.

Imagine a flower with four petals (a "quatre-lobed" shape), but instead of being solid, the petals have little curved cuts in them. This design is like a maze for electricity. When the signal hits the antenna, the electricity (current) has to travel along these curved paths. Because the path is longer and more winding than a straight line, the antenna can "resonate" (vibrate happily) at the right frequency without needing to be physically huge.

The "Cheap Material" Challenge

Here is the twist: The researcher didn't use a super-expensive, high-tech material. He used FR-4, which is the same material found in almost every cheap circuit board you've ever seen (like in a toy or a remote control).

Usually, using this "cheap" material at such high speeds (14.45 GHz) is a bad idea because it eats up energy and makes the signal weak. The paper argues against the idea that you must use expensive materials to get good results at these speeds. Instead, the study suggests that if you design the shape of the antenna just right, you can make the cheap material work surprisingly well.

What the Simulations Showed

The researcher didn't build a physical prototype to test in a lab; instead, he used a powerful computer program called HFSS to simulate the antenna in a virtual world. In these simulations, the results looked very promising:

The Sweet Spot: The antenna hit its target frequency of 14.45 GHz perfectly.
The "Catch": It grabbed the signal so well that the "reflection" (the signal bouncing back instead of going out) was very low, measuring -18.5 dB. Think of this as the antenna saying, "I want this signal, and I'm taking it all!"
The Range: Because of those clever curved slots, the antenna didn't just work at one exact number. It worked across a range of 1.05 GHz (from 14.05 GHz to 15.10 GHz). That's a wide net for catching signals, which is a big deal for a tiny antenna.
The Power: It sent out a signal with a gain of 6.27 dBi. In antenna language, this is a solid, directional beam, like a flashlight shining straight ahead rather than a lightbulb glowing in all directions.
The Shape: The signal shot straight out (broadside) with a stable pattern, meaning it didn't get messy or point in weird directions.

What It's NOT

It's important to know what this paper doesn't claim. The researcher didn't say this is the most powerful antenna in the world. He didn't claim it works better than complex, multi-layer antennas that are stacked like sandwiches. In fact, the study argues against the idea that you need those complex, expensive, multi-layer designs to get good performance. This design proves you can keep it simple, single-layer, and cheap.

Also, the paper doesn't say this antenna is ready to be put into your phone tomorrow. It explicitly states these are simulation results. The numbers (-18.5 dB, 6.27 dBi) are what the computer calculated, not what a physical ruler measured on a real object in a lab.

The Bottom Line

This paper suggests that by carving a specific "four-petal" pattern with curved slots into a tiny, cheap circuit board, you can create an antenna that is perfectly tuned for 14.45 GHz. It offers a wide range of frequencies, a strong signal, and a stable direction, all without needing expensive materials or complex stacking.

While the computer simulations look great, the real test would be building it and seeing if it works just as well in the real world. But for now, this "four-petal" design offers a very exciting, low-cost blueprint for future satellite and wireless systems.

Technical Summary: A Quatre-Lobed Arc-Slotted Microstrip Patch Antenna for Ku-Band Applications

Problem Statement
Microstrip patch antennas are widely used in wireless applications due to their low profile, ease of fabrication, and compatibility with printed circuit board (PCB) technologies. However, they face inherent limitations, particularly narrow impedance bandwidth and performance degradation at higher frequencies (such as the Ku-band) due to dielectric and conductor losses. While slotting techniques and geometric perturbations can enhance bandwidth, many existing solutions rely on complex multilayer structures, array configurations, or intricate feeding networks that compromise manufacturability and compactness. Furthermore, achieving stable broadside radiation and strong impedance matching simultaneously on low-cost, lossy substrates like FR-4 remains a design challenge.

Methodology
The study presents the design and simulation of a single-layer, compact microstrip patch antenna operating at 14.45 GHz within the Ku-band (12–18 GHz).

Geometry: The radiating element features a "Quatre-Lobed Arc-Slotted" configuration. The design begins with a central circular region (radius 2 mm) and incorporates four lobed structures (radius 0.5 mm) arranged symmetrically. Key geometric modifications include a central square slot (2 mm × 2 mm) and surrounding arc-shaped slots. These slots are designed to alter surface current paths, effectively increasing the electrical length without increasing the physical footprint, thereby controlling resonance and enhancing bandwidth.
Substrate and Materials: The antenna is fabricated on an FR-4 epoxy substrate (8 mm × 8 mm × 0.8 mm). FR-4 was selected for its low cost and compatibility with standard PCB manufacturing, despite its higher dielectric loss compared to specialized microwave laminates.
Feeding: A microstrip line feed (2.1 mm × 0.3 mm) is employed with a lumped port excitation to facilitate impedance matching and dominant mode excitation.
Simulation: Full-wave electromagnetic simulations were conducted using the High Frequency Structure Simulator (HFSS). The model included finite conductivity and dielectric loss to accurately represent high-frequency behavior. Adaptive meshing was used to ensure convergence, and radiation boundaries were applied to simulate free-space conditions.

Key Contributions
The paper outlines four primary contributions:

Novel Geometry: The design of a Quatre-Lobed Arc-Slotted microstrip patch specifically optimized for 14.45 GHz operation.
Bandwidth Enhancement: Achievement of a strong impedance match with a 10 dB impedance bandwidth of approximately 1.05 GHz (14.05–15.10 GHz), which is notably wider than many conventional single-layer patch designs.
Performance Metrics: Realization of a peak gain of 6.27 dBi with a stable broadside radiation pattern, demonstrating effective radiation performance despite the use of a lossy FR-4 substrate.
Practicality: Demonstration that a single-layer, compact structure can achieve significant bandwidth and stable radiation without the need for multilayer stacking, complex feeding networks, or external matching circuits.

Results

Impedance Matching: The antenna achieved a reflection coefficient ( $S_{11}$ ) of −18.5 dB at the center frequency of 14.45 GHz. The Voltage Standing Wave Ratio (VSWR) at resonance was calculated to be approximately 1.27.
Bandwidth: The 10 dB impedance bandwidth spans from 14.05 GHz to 15.10 GHz, covering a range of 1.05 GHz.
Radiation Characteristics: The antenna exhibits a broadside radiation pattern (main lobe along the +Z axis) with a realized gain of 6.27 dBi. The radiation pattern is stable with minimal distortion, and back radiation is suppressed due to the ground plane.
Efficiency: The radiation efficiency was estimated to be between 88% and 90% at the operating frequency, indicating that conductor and dielectric losses were effectively managed through the geometric design.

Significance and Claims
The paper claims that the proposed design offers a practical and deployable solution for Ku-band applications, including satellite communication systems and high-frequency wireless links. The significance of the work lies in its ability to balance electrical performance with structural simplicity. By utilizing a symmetric, arc-slotted geometry, the design successfully manages current path control and impedance balance on a low-cost FR-4 substrate. The authors assert that this approach provides a viable trade-off between profile, cost-effectiveness, and performance stability, avoiding the complexity of multilayer or array-based solutions while maintaining a wide operational bandwidth and stable radiation patterns suitable for integration into compact wireless systems.