The electromagnetic spectrum is a series of frequencies ranging from radio waves to microwaves, visible light, X-rays, and gamma rays. As the wavelength of the electromagnetic radiation shortens, the waves have a higher frequency—how quickly electromagnetic waves follow each other—and therefore more energy.

 

Radiofrequency is a type of electromagnetic wave that originates in the lower range of the electromagnetic spectrum whereas microwave is one of the higher radiofrequency divisions. RF refers to radio frequencies lower than 1 gigahertz, and microwave refers to radio frequencies from 1 gigahertz to 300 gigahertz.

 

Military RF an Microwave systems

Different parts of the spectrum serve different military purposes. Radio transmissions have relatively low data rates—particularly in the very low frequency range. However, they are able to travel long distances and pass through solid objects like buildings and trees, and are often
used for communications equipment. Microwaves have higher throughput—data upload and download rates—than radio waves and therefore are able to transmit more data, but are more limited in range and can be disrupted by solid objects. Hence, microwaves are often used for radars and satellite communications. Infrared waves, which emit energy, can be used for intelligence and targeting data because they are closely associated with heat sources.

 

The military uses the entire spectrum to support intelligence and military operations. These applications range from using very low frequency radio waves to communicate with submarines underwater, to microwaves as a continuous datalink between aircraft, and to lasers in the infrared and ultraviolet ends of the spectrum to dazzle satellite sensors and destroy drones. The majority of military communications capabilities use radio waves, microwaves, and infrared frequencies. Nearly every modern weapons system—airplanes, satellites, tanks, ships, and radios—depends on the spectrum to function. These applications can be combined to provide an overall military capability, such as command and control or electronic warfare.

 

In general, communications systems use radio and microwave frequencies; however, emerging communications technologies use lasers—transmitting light, instead of radio waves, between antennas. Radios use different frequencies depending on the range and amount of data they are
required to transmit. Ground-based radios are typically used at short ranges, limited by the line of sight. These short ranges span no more than 50 miles. In general, militaries use satellites to communicate over longer distances.

 

Another application of the spectrum is using radio or microwave frequencies to develop a picture of the battle space by providing the location of friendly and enemy forces. The most common application is radar, however recently light detection and ranging (LIDAR) systems are also used. Both technologies send out a signal that is then reflected back to sensors to determine the distance, speed, and potentially altitude of an object. Radars operate on different radio and microwave frequencies, depending on their purpose.

 

Lower-band frequencies provide a larger picture of the battle space, although, due to the amount of clutter or radar return (how much radio signal is returned to the radar), these systems are not able to provide targetquality pictures. Higher-band frequencies provide target quality pictures, yet lack the same effective range. Radar and LIDAR systems are commonly associated with air
defense, military aviation, artillery, and space systems.

 

Signals intelligence (SIGINT) systems primarily collect spectrum emissions. These passive systems—systems that do not emit their own signal—can listen to radio and radar frequencies or observe heat signatures of personnel, missiles, aircraft, artillery, and vehicles.

 

Radio frequency (RF) systems are used to power vital military electronics applications such as intelligence, surveillance, and reconnaissance (ISR) systems; communications systems; and electronic warfare (EW) suites. These systems must be extremely reliable and continually offer high performance – in very demanding, confined, and variable environments on the ground, in the air, and at sea. Each of these applications has unique requirements, driving development of custom RF interconnect solutions to address specific challenges. While safety comes first in the design of any of these complex military RF systems, performance must also be flawless.

 

Radar is primarily used in intelligence, surveillance, and reconnaissance (ISR) therefore radar is highly pulsed; quick transmission and efficient analysis of the data received prevents adversaries from locating positions.

 

For example, EW systems perform numerous mission-critical functions, including defense against attacks and providing enhanced situational awareness. These systems use RF signals to locate and identify potential threats, landscape features, and more, and include ground-based radar, antimissile defense, guidance systems, and similar applications. Each of these applications depends entirely on continuous real-time transmission of data with high accuracy.

 

EW systems are also continuously evolving to counter the proliferation of spread spectrum based communication systems, multimode, and Low Probability of Intercept (LPI) radars, smart weapons and missiles in warfare,  increased surveillance through Aerostats, AEW&C aircrafts, unmanned air vehicles (UAV) and satellite based communication and radar.

 

Military radio frequency (RF) systems must be designed to withstand the rigors of the often-harsh environments in which they will be used, while at the same time achieving extremely high performance for mission-critical applications.

 

Since these systems often operate under severe environmental conditions, two of the most important considerations in choosing optimal RF interconnect solutions include the use of low-smoke, zero-halogen cable and connectors and the use of assemblies optimized for high phase stability even at high temperature.

 

Test equipment for evaluating the RF/microwave performance levels of mil/aero systems and their components covers a wide range of frequencies and functions due to the diversified nature of military electronic systems. An analyzer that can digitize and accurately display the key parameters of a radar pulse may not be the best choice for deciphering the characteristics of a secure radio communications system.

 

Measurement and testing systems

Greater complexity in military electronic systems requires more capabilities in the measurement equipment used to test those systems. Consequently, various market studies predict healthy growth for at least the next five years for test equipment aimed at specific markets within military electronics, such as mobile radio testing and aviation test equipment.

 

Mobile radios are being designed smaller and lighter with multiple frequency bands and modulation formats, while aviation testing must account for the increased use of robotic and automated systems as well as RF/microwave and digital electronics systems.

 

In the case of mobile radios, single models are being designed with multiple modulation formats, switchable bandwidths, and increased frequency ranges that must be covered by candidate test instruments. Aviation testing involves a wide range of measurements, from characterizing communications and GPS radios to checking brakes, hydraulic systems, and vacuum integrity. Increasing use of military unmanned aerial vehicles (UAVs) is a main driver behind the expected growth in demand for electronic test equipment aimed at aviation systems.

 

There are many forms of microwave measurements

• Transmission and reflection parameters (small-signal)
• Large-signal parameters (gain compression, load-pull, etc)
• Frequency generation and conversion
• Waveform analysis (time and frequency domains)
• Noise figure and noise parameters
• Signal purity
• Antenna patterns

 

Some of the TE tools of the microwave trade include:

• • sweep oscillators and synthesizers
  • network analyzers (vector and scalar)
  • frequency counters and meters
  • noise figure meters and test sets
  • power meters
  • spectrum analyzers
  • high-speed digitizing oscilloscopes
  • detectors
  • curve tracers
  • impedance tuners
  • RF and DC probes

 

Generating Signals

Signal generators for military applications must cover an enormous amount of ground in terms of frequency and waveform type, given the range of signal formats used—from radar pulses to complex modulated millimeter-wave (mmWave) signals in secure communications systems. Rather than rely on a conventional swept-frequency signal generator, military systems testers are turning more to arbitrary waveform generators (AWGs). AWGs have the capability to almost randomly program different waveform formats over a defined frequency range.

 

Analyzing Spectrum

Spectrum and signal analyzers, important tools in any military electronics test solution, are also commonly found in rack-mount enclosures as well as in portable and modular packages.

 

Environmental challenges and phase stability

Phase is a key parameter for detection and measurement in many military RF systems such as radar, missile defense, EW, and many other systems that rely on continuous transmission and reception of RF signals with high accuracy and consistent speeds, regardless of temperature. The phase behavior of coaxial cable assemblies can adversely affect system performance when phase tracking is required and, as a result, phase must be extremely stable in the components within those RF systems.

 

For example, the electronically steered antennas used in many military RF applications use antennas with an array of radiating elements to steer antenna beams rather than physically moving an antenna. Beam-steering for transmission or reception is performed by adjusting the phase of the individual antenna elements in the array. The antenna array elements are each fed by high-frequency transmission lines; the accuracy of the signal phase presented to each array element depends on the phase accuracy and stability of the cable assemblies.

 

Military electronics systems are exposed to extreme and highly variable environmental conditions, such as corrosive salt spray in the ocean or high temperatures in the desert. For effective performance, the RF signals within those systems should travel through any coaxial cables with minimal delays and loss regardless of these environmental factors. As coaxial cables are subjected to cold and hot temperature extremes, their phase characteristics change as a function of temperature, with changes in the phase tracking or matching between cables. Even a small phase-tracking error between cables used in a phase-critical application, such as for a phased-array antenna, can adversely affect antenna performance.

 

Market

RF test equipment market is expected to increase around 1-2$ billion during the forecast period 2021-2031 with 3-7% CAGR.

Radiofrequency (RF) test equipment is used to compute signals at a higher frequency range than that supported by any other general test equipment. Along with standard measurement functionality, they also have specialized functions to determine the characteristics of an RF signal (radio waves transmitted within the frequency range of 3 hertz to 300 megahertz). Presently, the RF test equipment market is mainly driven by increasing communication applications of RF such as cellular, radio telecommunication, broadband, satellite, radar, and navigation.

 

The rising demand for internet connections and RF-enabled consumer electronics, such as laptops, mobile phones, tablets, microwave ovens, and televisions among others have also been encouraging the growth of the RF-enabled components. This, in turn, has been further strengthening the growth of RF testing equipment.

 

Huge adoption rates of smartphones and other modules have exceedingly increased data traffic. Data traffic and the number of the data centers are expanding due to the surging bandwidth consumption for a broad variety of applications and services resulting in increased data handling.
Mobile operators are continuously upgrading the quality of their services by monitoring and controlling the output power transmitted and analyzing interpreting them with the help of excellent sources. With LTE-A standard becoming a norm, sufficing consumers’ demand, ensuring greater coverage and providing quality services is the prime focus of firms in this sector.

 

As RF based Radar is a valuable tool used in many applications from traffic enforcement to air traffic control and military applications, hence growing advancements in the field will also generate the need for study market’s products. Wireless Gigabit(WiGig) is one of the latest and emerging technologies (IEEE 802.11ad) that works in the bandwidth of 60GHz and delivers up to 7 Gbit/s (20 times faster than IEEE 802.11n standard connection). The development in this market will also increase the speed and applications for the studied market.

 

The growing 5G adoption also brings huge opportunity into the market. But most vendors need to upgrade or develop testing equipment, which is compatible with the 5G technology. For instance, Rohde & Schwarz offers comprehensive over-the-air (OTA) test solutions to pave the way for mmWave and massive MIMO antennas. The emergence of Industrial Internet of Things (IIoT) and machine-to-machine (M2M) communication solutions is also expected to boost the growth further of the studied market, especially for telecommunications applications.

 

Owing to the demand of RF equipment surging worldwide in building communication technology in various industries and increasing presence of small and medium enterprises are the factors driving the market growth. Rising adoption of wireless devices is a key growth prospect.

 

Rising Applications from Automotive Industry

Automotive industry is continuously focussing on inserting technology in vehicles. RF electronic components in automobiles have resulted in much safer, efficient connected vehicles. RF applications when used in new vehicles need a thorough check up by testing transmitter and receiver systems. After the testing is done, vehicle is all set to provide technological comfort. Thus, rise of technology in automotive industries is escalating the sales of RF equipment system.

 

Limited spectrum and weather impact

Inconsistency of RF based wireless system, sometimes due to low network or due to climatic conditions can have a negative impact on its sales. Wireless communication need bandwidth, strong internet connection inspite of weather conditions. Furthermore, difficulty in installation and high costs are other factors that may inhibit the growth.

 

Key players include Fortive (US), Keysight (US), Yokogawa (Japan), Teledyne Technologies (US), Giga-tronics (US), Good Will Instruments (Taiwan), Anritsu (Japan), Teradyne Inc, Cobham PLC, Viavi Solutions, Inc

Recent developments by the manufacturers are:

• In June 2020, Keysight launched a new family of photovoltaic array simulators delivering 2000V and 20kW of power in a 3U format. The launch enables the engineers to maximise solar power conversion.
• Yokogawa Electric Corporation and Hirotsu Bio Science Inc. have announced their partnership 1 week ago. The partnership aims to expand the use of HBS’s N-NOSE cancer screening test service. The screening detects cancer utilizing the highly sensitive olfactory sensory functions of nematodes to detect cancer.
• Giga-tronics in August 2020 has announced the launch of new wide bandwidth RF playback solution for radar and electronic warfare applications particularly designed for military electronics applications. The launch is a part of company’s COMPASS platform (Coherent MultiChannel Playback Acquisition Streaming System).

 

Regional Outlook

Asia Pacific is projected to be holding the largest market share owing to vast population. India is the biggest market for smart phone companies driving the growth of RF equipments in the region. Connectivity solution providers such as Huawei, MediaTek, Sony, etc are based in Asia only. Owing to presence of solution providers and research and development team in Asia is expected to drive the growth during the forecast period too.

 

References and Resources also include:

https://militaryembedded.com/radar-ew/rf-and-microwave/powering-high-performance-ultrareliable-rf-systems-in-military-electronics

 

 

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