Diversification in communication bands was accomplished in order to meet the growing demands of users in the area of Satellite Communication (SatCom) technology and respectively the L-Band (1-2 GHz), S-Band (2-4 GHz), C-Band (4-8 GHz), X-Band (8-12 GHz), Ku-Band (12-18 GHz) and Ka-Band (18-40 GHz) bands were used. Utilization of new communication bands such as the Q-Band (30-50 GHz), V-Band (50-75 GHz) and E-Band (60-90 GHz) is expected in the near future to fulfill increasing band width demands.
As the frequency of the utilized band increases due to a physical phenomenon, the signal weakens during rain and loss impact caused by the water vapor/vaporization in the atmosphere (the absorption of the water has a fatal impact over satellite communication) increases. Since there is always water in the atmosphere whether in solid, liquid or in gas forms, the effects of water are constantly taken into consideration in all calculations made for communication systems.
In addition to the dish/parabolic antennas, activities are being conducted regarding the active or passive phased array ‘flat’ (flat array/paneled) antenna based on liquid crystal technology for the SatCom terminals stationed at Unmanned Air Vehicles (UAV).
However, as the data requirement demanded by the UAV’s to be downloaded is quite high (it could increase up to 20 – 40 megabytes of data rate per second depending on the user’s demand) and as phased array technology does not yet own the data rate defined as broad band, dish antennas are preferred more for UAV platforms.
With the launch of the communication satellites to be stationed at LEO (Low Earth Orbit) and MEO (Medium Earth Orbit) orbits in 2020 and afterwards, data transmission in higher capacities will be available on account of the developments to occur in phased array or low profile antenna technology and therefore the utilization of these types of antennas will be more common in the UAV SatCom market.
There are still SatCom systems with the flat paneled antennas in utilization for UAVs, yet these products offer a 256kb data rate per second to their users even under the best circumstances.
Ku-Band SatCom was procured in recent years within the scope of the SatCom system requirement of the ANKA-S UAVs. However, as this product bears strategic importance, it is projected that its existing foreign dependency will result in a critical vulnerability in terms of the operational performance of the ANKA UAV Platform and foreign market expansion.
As a complete solution, CTech Company displayed the prototype of the Ku-Band National UAV SatCom System composed of indigenous design and production antenna and modem, developed to eliminate the aforesaid foreign dependency, at the SAHA Expo 2018 Fair held in Istanbul on 13 – 15 September 2018. It has been learned that seamless and uninterrupted (even during rain) performance at a10 megabyte data rate could be achieved with the National UAV SatCom terminal.
CTech Company launched its activities to develop an indigenous SatCom modem in 2016 initially with Turkish Aerospace (TUSAŞ) which is currently its shareholder. Additionally, in the beginning of 2017, within the scope of a resolution it adopted CTech launched the production activities of the SatCom antenna within the country through utilizing the equities of the company. As may be recalled, Turkish Aerospace became the shareholder of CTech in the beginning of 2018 (26 January 2018).
CTech signed a contract towards the utilization of the National UAV SatCom System in ANKA-S UAV platforms with Turkish Aerospace in 2018. According to the contract, CTech will be accomplishing the delivery of two Ku-Band National UAV SatCom Systems to Turkish Aerospace at the first stage. Then, Turkish Aerospace will be additionally ordering the National UAV SatCom Systems from CTech to be utilized in these platforms as it receives additional ANKA-S orders.
There are Ku-Band transponders at TürkSat 3A (Ku-Band), 4A (X-Band, Ku-Band and Ka-Band) and 4B (C-Band, Ku-Band and Ka-Band) communication satellites. The Ku-Band transponders will exist on the new communication satellites (Ku-Band in TürkSat 5A, both Ku-Band and Ka-Band in 5B, X-Band and Ku-Band in TürkSAT 6A) as well. Where Ku-Band remains as a commercial/civil communication band, the X-Band is utilized only for military communication purposes.
With the assistance of the technological know-how and experiences it acquired in SatCom terminals used in mobile platforms, CTech simultaneously started to work on the Ka–Band version of the National UAV SatCom System.
A UAV is capable of executing a tactical operation in a circle/area with a 150 km radius in normal circumstances over its data link. CTech’s Ku-Band National UAV SatCom System will own a communication capability covering a very wide region extending from the West of Europe to the east of Kazakhstan within its satellite coverage area when it is integrated with the ANKA UAV. This indicates a crucial range increase in terms of both command and image/voice communication capabilities. On account of the beyond line of sight (BLOS) communication capability to be acquired through the National SatCom System, elevation to strategic operation level from the tactical level will be achieved with the ANKA UAV without foreign dependency.
Even though the Ku-Band satellite terminals are being used for commercial/civil band communication, the National UAV SatCom terminal has an encrypted module placed onto the modem for encrypted communication as well. Moreover, upon request, the user will have the chance to integrate their own encryption system to the terminal/modem.
In order to render the satellite communication system more resistant to jamming and rejection, CTech developed the Secure SatCom System in line with NATO STANAG 4606 standards. The Secure SatCom technology, which is in a way an electronically protected communication system developed specially for the Turkish Armed Forces (TAF), remains only in a few companies in the world besides CTech. According to a representative of the company, the satellite communication system became more resistant against jamming, rejection, wiretapping and recording on account of the Secure SatCom System with the structure enabling utilization in land, at sea and in the air. According to the information we acquired, the system is still under production and the delivery of the Secure SatCom to the TAF will be starting from 2019 onwards. The TAF will be initially using the Secure SatCom System in land and naval platforms. Development of the Secure SatCom system for UAVs remains on the product road map regarding the satellite communication of CTech.
The CTech National UAV SatCom terminal manufactured with compatibility to the Ku-Band SatCom System presently available on the ANKA-S UAV has a dish antenna with an 18-inch (45.72 cm) diameter and a data rate of 10 megabytes per second. The National UAV SatCom terminal could be utilized for all UAVs manufactured in Turkey requiring satellite communication capability and on other similar air platforms. The company continues its negotiations with the relevant UAV manufacturers to this end as well. With the help of direct drive technology, the angular error rate of the National UAV SatCom terminal is lower compared with other products.
CTech plans to initiate the delivery of the National UAV SatCom terminals, the tests of which are currently ongoing, to Turkish Aerospace in the first quarter of 2019. Within this context, the System Integration Laboratory Unit will be delivered during the first stage, and while Turkish Aerospace engineers test the system before its integration to the ANKA UAV in the laboratory environment, CTech will complete the system qualification process and then deliver the products to Turkish Aerospace.