Antenna Radome for SATCOM User Mobile Terminals

Status

Completed
Status date

2019-02-25
Activity Code

7-.017

Objectives

The objective of this activity is to survey existing radome designs and identify relevant performance characteristics applicable to radomes used by mobile satellite ground user terminal antennas operating in Ku-band and Ka-band in different mobile environments.

The activity consists in the identification of shortcomings in current radome designs and in the exploration of improved designs to mitigate these shortcomings while trying to minimize the cost. The improved designs has to be verified by defining, building and testing one representative radome Engineering Model suitable for ground terminal to demonstrate the viability of the approach.

TeS Teleinformatica e Sistemi s.r.l., carried out a study on Antenna Radomes for mobile applications (land, maritime and aeronautical) identifying the different performance characteristics applicable to the antenna radomes for mobile user terminal antennas operating in Ku-band and Ka-band. The study activity required to highlight the main short comings in the state of this radome products and to explore possible improvements in the design and development areas. After a deep review of the state of the art of radome for mobile user terminal a set of radome design improvements at sample level have been achieved by TeS for both Ku and in the Ka frequency band. In addition to the state of the art radome materials a quite new material (PP-PP Self Reinforced Polypropylene) has been investigated for radome application as well as the possibility the use of Frequency Selective Surfaces radome solutions. Some of their potentialities are to provide radio-transparency in the Ka band (RX and TX simultaneously) to make use of chip material and to allow significant radome weight reduction while the main shortcomings for such solutions are the technology and the manufacturing processes not completely yet mature for the commercial market.

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Challenges

In this study, a picture of the present state-of-the-art situation of radomes for mobile application is identified so as to focalize on criticalities and performance that need to be improved in each specific application (land, maritime and aicraft).

Investigation on possible solutions are explored considering both electromechanical and cost aspect of the radome design, comparing different common and uncommon radome wall configurations and materials.Especially for the newborn Ka and even more the near future Ku/Ka band mobile applications, the challenge is to identify innovative solutions able to provide an RF transparent radome able to withstand the mechanical stress of the specific application with an eye on the cost that always need to be kept reasonable.

Benefits

The main expected benefits are:

1) The identification of suitable radome materials, layup configurations, design strategy and manufacturing process able to improve the state of the art of the present commercial satellite antenna radomes for mobile application operating in both Ku and Ka frequency bands.

2) The demonstration, by means of a new EM radome, of the expected overall improvements in terms electrical, mechanical and cost performance goals. Particular attention is paid to the Ka band frequency band where a very limited number of COTS radome solutions are present especially in the more stringent mobile environments.

Features

Satellite communication are now offering European and Global wide band data services in the Ka-Band frequencies for a high rate two-way mobile satellite communication link. This new trend reflects into more stringent radome requirements necessary to balance robustness, electrical performances at Ka Band. Radome design and development at such frequencies asks for innovative investigation in terms of material selection and design techniques.

Standard multilayer radome design at Ka band (and Ku/Ka band) could suffer the shortcoming of a reduced mechanical performance due to the small thickness of the layers involved in the layup.

Such thickness reduction is related to the shorter wavelength involved at Ka Band, thus typical sandwich stratifications would not have the necessary mechanical robustness to withstand the mobile environment, therefore, more complex layup solutions need to be considered.

In the latter case, a solution has been considered and aimed to provide the minimum required stiffness and mechanical strength, but the reduced thickness of the materials involved stays small and special attention has to be paid for both the tolerances and the technological process. A very interesting design solution, first at sample level, has been found by TeS aimed to the realization of a dual band Ku/Ka band maritime radome able to provide good electrical and mechanical performance while maintaining acceptable the overall manufacturing costs.

The multiband Ku Ka band radome solution has been then selected, among the proposed solutions, as the candidate one for the Engineering Model (EM) development of this research study. The EM radome has been verified during a detailed design phase, approved in the CDR meeting and then developed according to the identified manufacturing process. The final test on the EM radome has confirmed very good performance and the validity of the experimental results already achieved at sample level. One of the most important outcome in this Ku/Ka multilayer solution is the understanding of complex unwanted phenomena (occurred during the manufacturing process) that otherwise degrade significantly the radome performance if suitable countermeasures are not taken.

The possibility of a proper diagnostic on the manufactured radome samples and the electrical model retuning of these, allow the radome designer to refine the very first layup stratification to finally match the wanted electrical performance.