MESHED STACKED LTCC ANTENNAS TO PROPEL UAE SPACE EXPLORATION MISSIONS INTO THE FUTURE

Professor Mahmoud Al Ahmad, at the Department of Electrical Engineering at the United Arab Emirates University recently published a research entitled “Meshed Stacked LTCC Antenna for Space Application” with the aim of studying how different mesh configurations of stacked meshed patch antennas can change the performance, frequency and efficiency of LTCC antennas for space application.

The study looked into several forms of meshing, one where both patches were mesh, another where only the top patch was meshed, and one where only the bottom patch was meshed, and finally one where both patches are continuous solid metal. The study carried out was different from previous studies which only concentrated on single layer patch designs.

Al Ahmad explained to Innovation@ UAE magazine, the importance of the study is due to the growing dependence on Geostationary (GEO) satellites for global HD televisions, data transfer and internet applications which have resulted in increased demand for higher data rates and more efficient frequency usage.

Meshing and Antennas

Firstly, what is meshing? To understand this, we first need to understand the two types of light weight printed circuit antennas being used today. The first type is Microstrip antennas which essentially consist of metallization on a grounded substrate. Given that they are low-profile, and light weight they can be made conformal and are easily integrated into integrated circuits.

They are used in many areas in aerospace and communication systems and have become indispensable components for transmission and reception of electromagnetic energy.

Microstrip antennas can be further segregated into what is called, “Microstrip patch antennas” which have been reported to be implemented using meta-materials for enhanced performance. Metallization is implemented with a continuous metal (conducting) surface. An alternative to this is using meshed antennas.

Meshed antennas are made of a meshed configuration of the conducting surfaces. Meshing can be applied to the patches, the ground plane or both. When the meshing is applied to the patch, the metallization continues to serve as an effective radiator.

The importance of meshed antennas is that they are inexpensive, and easily made through screen printing, ink jet printing or using off the shelf meshed conductors.

Study Findings

The results of the study showed that the stacked mesh performance in terms of the resonant frequency, return loss, gain and radiation efficiency can be comparable to that of a typical, continuous metal stacked design. Both patches are 20.86 mm × 21.46 mm. The maximum absolute gain and radiation efficiency of the solid stacked patch were 5.05 dBi (Decibels relative to isotropic (dBi) is a unit of measurement that describes how much power an antenna transmits in a single direction when compared to an isotropic radiator, which transmits in all directions at once) and 91.6% while those of the meshed stacked patch were 5.22 dBi and 91.8% respectively.

In addition, the measurements of stacked meshed design showed that the antenna was resonant at 2.52 GHz (GHz, short for gigahertz, is a unit of frequency equal to one billion hertz. It is commonly used to measure computer processing speed, alternating current, and electromagnetic (EM) frequencies) with a reflection coefficient in dB of −23.69 dB. It has a 40 MHz −10 dB impedance bandwidth (1.5%) from 2.50 GHz to 2.54 GHz. The antenna exhibited a maximum measured gain of +5 dBi and cross polarization of 10 dB at boresight. An equivalent circuit model for the design was also proposed. The antenna was intended for space application, and therefore it was implemented using Low Temperature CoFired Ceramic (LTCC) technology as the LTCC properties can withstand the harsh environment of space.

Therefore, research found that although the meshed lines increase the line impedance and therefore can result in increased losses, this can be mitigated by careful mesh selection. Lastly, the meshed design allows for better bonding between the LTCC tape layers.

Importance for Earth applications

Al Ahmad explained to Innovation@UAE magazine, the importance of the study is due to the growing dependence on Geostationary (GEO) satellites for global HD televisions, data transfer and internet applications which have resulted in increased demand for higher data rates and more efficient frequency usage.

As he explains,” GEO satellites, which orbit at an altitude of 36,800 km, are now required to handle higher transmission frequencies, particularly in the millimeter-wave range, to meet this escalating demand. Additionally, the emergence of Low Earth Orbit (LEO) satellite constellations, situated between 700 km and 1500 km above Earth and numbering in the hundreds or thousands, is set to create a global network that extends beyond internet access to broader applications like the Internet of Things (IoT) and vehicle-to-vehicle communication.”

He adds,” This evolution calls for a radical transformation in satellite technology, emphasizing smaller, lighter satellites with reduced production times and costs. Traditional waveguide technologies are being replaced by 3D-multilayer lightweight technologies that utilize various carrier materials to meet new system requirements. Among these materials, LTCC stands out. LTCC, known for its multilayer dielectric integration and packaging capabilities, can accommodate up to 40 layers of multilayer circuits on sintered ceramic carriers, making it highly suitable for new satellite technologies.”

Importance for Space

In terms of meshed stacked LTCC antennas, these are crucial in space exploration because they serve as a primary means for communication, sensing, navigation, and data transmission between spacecraft and earth.

Al Ahmad believes that their importance becomes even more profound as we delve deeper into space.

He states, “The decision to conduct a study on meshed stacked LTCC antennas was driven by the need to advance space communication systems. LTCC technology is celebrated for its ability to withstand extreme conditions, making it an ideal choice for the harsh environment of space. The meshed stacked design of these antennas represents a significant technological advancement, promising enhanced performance while reducing weight, a critical factor in space missions. This innovative approach aims to meet the increasing complexity and requirements of modern space missions, offering a blend of durability, efficiency, and reduced mass, all of which are essential in the demanding realm of space exploration.”

He gives an example of how this could be utilized in space. For example, using meshed stacked antennas, scientists could deploy a spacecraft that is lighter but with the same communication efficiency, as well as resilience in the harsh conditions of space.

This would entail cost savings and enhanced mission efficiency, which are critical in the field of space exploration.

Benefits for UAE Space exploration

Al Ahmad believes that the stacked meshed antennas represent more than just mere components but are a signal for the dawn of a new epoch in space communication and exploration.

While this is still an emergent technology, its prospects for future space missions are vast. Al Ahmad states, “The United

Arab Emirates (UAE), with its bold vision for space exploration, is poised to lead in embracing these advanced technologies. The integration of LTCC antennas could be a game-changer for the UAE, revolutionizing its approach to various aspects of space exploration, from satellite communications to deep space ventures and scientific research.”

For Al Ahmad as the need for advanced communication systems in space escalates, the integration of meshed stacked LTCC antennas into upcoming missions becomes ever more crucial.

The UAE, with its visionary approach to space exploration by embracing these state-of-the-art antennas could significantly refine the UAE›s strategy in space exploration, opening new horizons in satellite communication, the Internet of Things (IoT), and more.