**1. Introduction**

With the II World War, especially radar and military communication technologies gained thoughtful importance, and studies on antenna design, analysis and measurement caught a great momentum. Particularly, low volume antennas were needed for installation in air and naval combat vehicles. By the development of digital computers aftermath of the war, antenna design and analysis began to be carried to the computer environment to realize analytical and computational electromagnetic techniques. This era accelerated development process of antennas like other communication elements.

Nowadays, studies on microwave integrated circuits and components, which are frequently used in communication systems designed to operate at high frequencies, are going ahead at a dizzying pace. In addition, theoretical and experimental studies focusing on solid-state devices and planar transmission lines have greatly contributed to the development of microwave integrated circuits and components and expanded their use. In the light of these developments, interest to antennas, particularly for planar ones, has increased and thus, in order to reduce the cost and also volume occupied by microwave and RF systems, printed antennas are generally preferred to use them with high frequency circuits in the same plane.

As is well known, the space race of humankind started with the first artificial satellite *Sputnik-1* which was developed and placed into orbit by the USSR in 1957. A model of Sputnik-1 is shown in **Figure 1**. In the same year, *Sputnik-2* placed a living being into orbit of Earth for the first time. In the following year, the USA

#### **Figure 1.**

*The Sputnik-1 with monopole antennas (image courtesy of NASA/NSSDCA).*

joined this race with *Explorer-1*. The Explorer-1 was placed into an orbit with a perigee of 360 km and apogee of 2535 km as mentioned in [1]. It had a cosmic ray sensor, an internal temperature sensor, a temperature sensor on the cone nose, and a microphone to detect the micro-meteoroid effect. Its most important task was to detect high-energy atomic particles with a cosmic ray sensor. The sensor therefore contained a Geiger-Müller tube. There were two transmitters at 108 and 108.03 MHz. It transmitted the relevant data to the station with those modules. As can be seen from **Figure 2**, the fiberglass slot antenna is positioned toward the nose of the vehicle. In addition, four flexible monopoles are placed in the middle of the vehicle. Its most important achievement was the discovery of the generations of Van Allen belt around the world. Afterward, this discovery was confirmed by Explorer-3 spacecraft [1].

By 2017, there were 4635 satellites orbiting the planet for different purposes based on the published Index of Objects Launched into Outer Space maintained

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elevation angles.

*Antennas for Space Applications: A Review DOI: http://dx.doi.org/10.5772/intechopen.93116*

evolving around the world.

by the United Nations Office for Outer Space Affairs (*UNOOSA*). According to the report of 2019, while this chapter was being written, about 5000 satellites have been

In recent years, especially antennas used in satellite communication systems are expected to have low volume, lightweight, low cost, high gain and directivity. Since the antennas used here are the last elements of the transmitting and receiving systems, they enable the connection of both sides over the space. They must be therefore suitable to the structure on which they are used, both electrically and physically. In addition, the gain and radiation pattern characteristics must be considered together with the general approaches used in the design of these antennas. The characteristics of the printed circuit antennas in meeting these criteria are more appropriate. Another important feature is that it is compatible with printed circuit technology and can be produced as a persistence of RF and high frequency circuit topology. Another advantage of printed circuit antennas is that they can be easily mounted on non-planar surfaces or manufactured using flexible printed circuit boards. In order to realize matching circuits, in very small areas inductive, resistive and capacitive surface mount device (SMD) components can be used with the printed circuit technology. Similarly, the frequency tuning of the antennas can be achieved electrically and mechanically in a variety of ways, which makes it

Depending on the orbit around the world in general, space vehicles and satellites

• Scientific research and exploring for solar system, deep space and others,

• Manned space flights-for now generally in LEO for example International

There are also telemetry/telecommand (TM/TC) communication units in different frequency bands, global positioning systems and other telecommunication modules for transmitting and receiving the RF signals in launch vehicle, respectively. Consequently, suitable antennas should be designed and utilized according to

One of the most needed satellites is LEO satellite. LEO satellites orbit between 160 and 1600 km from the Earth's surface. These satellites are usually small compared to communication GEO satellites, easy to launch and put into orbit. They can be used for different purposes. For ground monitoring purposes, satellite constellation can be placed into orbit and used for voice, fax and data communications. In addition, due to the limited surface area and volume available on the satellite, the antenna must be as small as possible in weight and volume. Finally, considering the limited power budget of the satellite, it is important that the antenna may have a passive and conical radiation pattern to direct the electromagnetic energy to low

particularly advantageous for the printed circuit antennas.

• Satellites with low earth orbiting (LEO) satellites

• High elliptical orbiting (HEO) satellites

• Geostationary (GEO) satellites,

Space Station (ISS).

• Satellites with middle earth orbiting (MEO) satellites

• In addition, space launch vehicles can be added to this list.

planned mission for the space launch vehicles similar to the satellites.

can be divided into six main groups:

#### *Antennas for Space Applications: A Review DOI: http://dx.doi.org/10.5772/intechopen.93116*

*Advanced Radio Frequency Antennas for Modern Communication and Medical Systems*

joined this race with *Explorer-1*. The Explorer-1 was placed into an orbit with a perigee of 360 km and apogee of 2535 km as mentioned in [1]. It had a cosmic ray sensor, an internal temperature sensor, a temperature sensor on the cone nose, and a microphone to detect the micro-meteoroid effect. Its most important task was to detect high-energy atomic particles with a cosmic ray sensor. The sensor therefore contained a Geiger-Müller tube. There were two transmitters at 108 and 108.03 MHz. It transmitted the relevant data to the station with those modules. As can be seen from **Figure 2**, the fiberglass slot antenna is positioned toward the nose of the vehicle. In addition, four flexible monopoles are placed in the middle of the vehicle. Its most important achievement was the discovery of the generations of Van Allen belt around the world. Afterward, this discovery was confirmed by

*The Sputnik-1 with monopole antennas (image courtesy of NASA/NSSDCA).*

By 2017, there were 4635 satellites orbiting the planet for different purposes based on the published Index of Objects Launched into Outer Space maintained

*The Explorer-1 with its turnstile antenna for VHF communication (image courtesy of NASA).*

**140**

**Figure 2.**

Explorer-3 spacecraft [1].

**Figure 1.**

by the United Nations Office for Outer Space Affairs (*UNOOSA*). According to the report of 2019, while this chapter was being written, about 5000 satellites have been evolving around the world.

In recent years, especially antennas used in satellite communication systems are expected to have low volume, lightweight, low cost, high gain and directivity. Since the antennas used here are the last elements of the transmitting and receiving systems, they enable the connection of both sides over the space. They must be therefore suitable to the structure on which they are used, both electrically and physically. In addition, the gain and radiation pattern characteristics must be considered together with the general approaches used in the design of these antennas. The characteristics of the printed circuit antennas in meeting these criteria are more appropriate. Another important feature is that it is compatible with printed circuit technology and can be produced as a persistence of RF and high frequency circuit topology. Another advantage of printed circuit antennas is that they can be easily mounted on non-planar surfaces or manufactured using flexible printed circuit boards. In order to realize matching circuits, in very small areas inductive, resistive and capacitive surface mount device (SMD) components can be used with the printed circuit technology. Similarly, the frequency tuning of the antennas can be achieved electrically and mechanically in a variety of ways, which makes it particularly advantageous for the printed circuit antennas.

Depending on the orbit around the world in general, space vehicles and satellites can be divided into six main groups:


There are also telemetry/telecommand (TM/TC) communication units in different frequency bands, global positioning systems and other telecommunication modules for transmitting and receiving the RF signals in launch vehicle, respectively. Consequently, suitable antennas should be designed and utilized according to planned mission for the space launch vehicles similar to the satellites.

One of the most needed satellites is LEO satellite. LEO satellites orbit between 160 and 1600 km from the Earth's surface. These satellites are usually small compared to communication GEO satellites, easy to launch and put into orbit. They can be used for different purposes. For ground monitoring purposes, satellite constellation can be placed into orbit and used for voice, fax and data communications. In addition, due to the limited surface area and volume available on the satellite, the antenna must be as small as possible in weight and volume. Finally, considering the limited power budget of the satellite, it is important that the antenna may have a passive and conical radiation pattern to direct the electromagnetic energy to low elevation angles.

Antennas used in LEO-type satellites can be divided into three types: payload data transmission (PDT) antennas for downloading high-density data to the ground station or inter satellite link (ISL) communication, payload antennas for special missions like mobile communication, GNSS services or remote sensing operations and TM/TC antennas to control the satellite and receive health parameters to monitor its functionality. The frequency ranges allocated for LEO satellites vary according to the characteristics of the payload on the satellite, but are determined by International Telecommunication Union (ITU).

After a LEO satellite is launched, it must be brought to desired position or orbit in order to fulfill the function of the satellite or be required to stabilize tumbling. This phase is called as Launch and Early Orbiting Phase (LEOP). In this case, hemispherical or omnidirectional antennas are very beneficial and used for the transmitting and receiving TM/TCs since they have wide coverage capability [2]. Antennas having directional or shaped conical radiation pattern are preferred in order to transmit telemetry and payload data to the ground station after it has been commissioned. Since line of sight (LOS) communication time interval is limited over one ground station, it is desirable to use this interval in the most efficient manner. This can be acquired by starting downlink and uplink communication at low elevation angles of the satellite. Because it will provide more time to download high-density payload data from the satellite. Therefore, at lower elevation angles of the satellite, a higher antenna gain is required, whereas in the case where the satellite is at higher elevation angle with respect to ground station, the antenna gain may be relatively lower so as to maintain link margin positively.

### **2. Antennas exposed to effects of space environment**

In space not only functionality should be taken into consideration but also durability and reliability of antennas should be taken into account. Consequently, in design phase of antennas to be used in space applications, environmental conditions are decisive factors. Materials to be used on space antennas should meet requirements based on space qualifications and factors [3]. These factors can be listed under two main subjects: *effects due to the launching activity* and *space environment.*

#### **2.1 Launch phase**

During launch of spacecraft, acoustic vibrations, shocks, mechanical stress based on static loads, dynamic loads and sudden atmospheric pressure fall occur and those effects should be taken into account in the course of antenna design step. In addition, in commissioning phase pyrotechnical shocks are generated while deploying solar panels and payloads like deployable antennas. All of those may affect objects, for example antennas, detached to surface of spacecraft, adversely.

#### **2.2 Space environment**

After LEOP, antennas will be exposed to harsh space environment. Those can be listed as vacuum, high temperature changes regarding nonconductive thermal feature of vacuum typically between −150 and 150°C, outgassing or material sublimation which can create contamination for payloads especially on lens of cameras, ionizing or cosmic radiation (beta, gamma, and X-rays), solar radiation, atomic oxygen oxidation or erosion due to atmospheric effect of low earth orbiting.

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*Antennas for Space Applications: A Review DOI: http://dx.doi.org/10.5772/intechopen.93116*

tions can be listed as:

• sine vibration,

be listed as:

materials

Hardware

• thermal qualification,

• random vibration or acoustic,

• quasi-static acceleration,

• stiffness measurement, and

• low outgassing compatibility [4].

• ECSS-E-ST-32-08C—materials

• ECSS-E-ST-10-03C—testing

processes, mechanical parts and assemblies

• Outgassing Data for Selecting Spacecraft Materials

• NASA-STD-7001—Payload Vibroacoustic Test Criteria

• NASA-STD-7002B—Payload Test Requirements

• NASA-STD-7003—Pyroshock Test Criteria

which have been published by NASA.

which have been published by ESA and

GSFC Flight Programs and Projects

**2.3 Verification for launch and environmental effects**

In order to verify that antennas can perform functionally in space environment and withstand launch effect mentioned above, some tests should be performed as addition to functional tests before mission started. These environmental verifica-

To verify the modules, requirements and tests have been defined by NASA and ESA in their published standards. For space programs, the related requirements and tests are prepared based on those standards. Some important and general ones can

• ECSS-Q-ST-70-02—thermal vacuum outgassing test for the screening of space

• ECSS-Q-ST-70-71C Rev.1—materials, processes and their data selection

• ECSS-Q-ST-70-04C—thermal testing for the evaluation of space materials,

• GSFC-STD-7000A—General Environmental Verification Standard (GEVS) for

• NASA-STD-5001—Structural Design and Test Factors of Safety for Spaceflight
