Amplifiers are developed to amplify weak signals. They are available in various types to fulfil different requirements of users. Let’s discuss the types and their uses –

Low Noise Amplifier (LNA)

It performs the same function of amplifying the signals from very low power and without significantly degrading its signal-to-noise ratio. It is named LNA after this specialty. A conventional amplifier increases both the signal and noise received in the input. It is majorly used in medical instruments, radio communications systems, and electronic equipment, etc.

Amplifiers RF

These devices amplify the varying input signals and produce the output with larger amplitude with varying signals in the same way as in input. They are available in different types such as Low noise, Pulse, Bi-directional, Multi-carrier, and Buffer. Its applications include defence components, electromagnetic compatibility (EMC) testing, medical diagnostics, and communications testing.

Microwave Amplifiers

Microwave amplifiers or Traveling wave tube amplifiers (TWTAs) are designed for high power amplification at low microwave frequencies. They are used to amplify across a broad spectrum of frequencies. However, usually. Its applications are Passive Intermodulation Testing (PIM), Intermodulation Testing (IM), and Adjacent Channel Power Testing. It is also used for Multi-tone testing, Power handling, EM Immunity Testing, and High Signal Level Testing, etc.

Solid State Power Amplifier (SSPA)

SSPA is the alternative to applications using Traveling Wave Tube (TWT) Amplifiers currently. It is preferred because of its high performance and reliability, and most importantly it is cost effective. It is used in Airborne, Missile, Radars, and Communications.

You can buy any of them based on your requirements. All the types in various variants are available online at the Raditek’s website www.raditek.com

A Block Upconverter or BUC is used in both Commercial and Military Markets for transferring data a from a ground-based unit to a satellite and then redirect to another ground-based unit. It makes the BUC an essential device for communication broadcast systems like the Internet, television as well as for weather systems. It is a most used device for government agencies as it is perfect at long distance communications.

Block Up Converter uses phase-locked loop local oscillators and optionally uses an external frequency of 10 MHz to maintain the correct transmitted frequency. It converts frequencies from L-band to any of the required bands like S, C, X Ku and Ka band.

There are two other separate bands consisting of electromagnetic waves. These two bands are 40 – 60 GHz for tracking, 1 – 2 GHz for communication.

C band is used for long-distance communications like TV and Internet broadcasting systems. Various bands are used in radars including Ku-band referring to the frequencies under the K band and Ka-band refers to the frequencies above K band.

You can find a wide range of types and variants of Block Up Converter on the Raditek web site www.raditek.com Read the description carefully before ordering the product and you can also contact 1-408-266-7404 in case of any colarification. You must ensure ordering a high-quality Block Upconverter to ensure desired efficiency and longevity of your satcom communication.

Waveguide circulators are devices with three ports developed to create isolation between transmitted and received signals. These are commonly used for electronically steered antenna (AESA) arrays, telecommunications applications, and satellite communications etc.

A waveguide isolator is a modified circulator having one port terminated with a matched impedance. Both the devices are typically used for preventing high powered transmitter outputs interfering with sensitive receiver circuitry. It efficiently does so by separating received signals at the input of the antenna from the transmitter’s signals.

Most of the circulators that are based on passive ferromagnetic technologies are coaxial or waveguide packaged devices. These types of circulators work best in their frequency range of operation by providing very high isolation. As compared to cavity duplexers being used for in-building telecommunications installations and base stations.

Both of these are used in the applications ranging from hundreds of megahertz to tens of gigahertz, it makes them perfect for operations in radar and communication bands. Many factors limit the frequency bandwidth of operation of a circulator like the geometry of the magnetic material used, the impedance matching network of the circulator, and the design of the transmission line along with manufacturing techniques and the types of ferrite.

The performance of waveguide circulators and isolators is measured on the parameters of isolation, bandwidth, and insertion loss etc. Other important factors that should be considered are power handling, size, interconnect technology, and temperature range.

You can find a wide range of waveguide isolators and circulators catering to your different needs on the Raditek website www.raditek.com

Microwave Amplifiers are used to amplify microwave signals. They are used in all Microwave Terrestrial Radio links, Satellite Communications and throughout the Electromagnetic Compatibility (EMC) testing industry.

There are four types of Microwave Amplifiers, and you must choose the one according to your needs.

Low Noise Amplifiers

LNA or Low Noise Amplifiers increases the power of the signal and minimize the additional noise. They are designed to produce over 40 dB of signal gain with less than 1 dB of noise magnitude.

Linear Signal Amplifier

The Linear Signal Amplifier is the “gain block” of the system. It is a generic amplifier. So, there is no determining factor of the power gain in the system.

Driver Amplifier

Driver Amplifier provides maximum system performance while being discrete. They are used in state of the art electronic warfare, and instrumentation. Testing and measurement applications also possess driver amplifiers.

Power Amplifiers

Power amplifiers offer the final gain in the output signal as it boosts the signal which is already at a relatively high-level. The noise figure in it is not critical because noise output is heavily attenuated along with the signal.

These are four types of microwave amplifiers used for various objectives and in different applications. You can buy all of these from Raditek Inc.

Picture and voice quality in television and the download speed of the internet highly depends on the Coaxial Coupler. So, it becomes necessary to buy a well-performing coupler to get high definition quality picture and sound.

The most important thing to look for is to ensure that the connector is compatible with Dish Network, Wi-Fi radios, off-air antenna systems, and wireless LAN Devices as well as with Cable Internet Svc (including Cox, Charter, and Comcast, etc.). It should have been manufactured from superior quality, weather resistant material possessing extremely low signal attenuation.

It should be easy to use so that even a novice can install without requiring to cut, splice or tools. You can find one coupler for both indoor and outdoor use. You must also know which coax cable you have to connect like RG58, RG59, FG6, and RG11 coaxial cable. These cables might be with wall plates for outdoor and for indoor use.

You must also check the signal loss in the coupler as the signal loss is inevitable. Signal consistently degrade while passing through be it any device. What you can do is it to ensure the least signal loss. There is high-quality Coaxial Coupler available ensuring least signal loss and excellent quality audio, video.

You must look for all these qualities before buying a coupler online. Do ask the manufacturer about the specifications and warranty on the product as the products manufactured with the high-quality material are durable giving consistent throughout their life.

A circulator is a three port device. It is essentially a passive device, but can exhibit some characteristics that make it almost behave as if it were active. An isolator is a two port device having an input and an output, it is simply a circulator whose third port has been terminated.

Circulators and Isolators provide unique transmission paths, allowing RF energy to pass in one direction with little (insertion) loss, but with high loss (isolation) in the other direction.

Isolators and circulators can exist as Stripline, Coaxial, Microstrip, or Waveguide type, and can be rated for powers from milliwatts to Megawatts. Raditek can provide superb stripline isolators to 18GHz, Microstrip ones to 60 GHz. Coaxial to 50Ghz and Waveguide to 110GHz.

A typical use of a circulator would be as a duplexer, connecting a transmitter to Port 1, antenna to port 2 and receiver to port 3. This provides simultaneous transmission and reception of signals.

A very common use for isolators is at the output of a power amplifier. Forward power is passed with a minimal insertion loss. Reverse power resulting from disconnect at the output (removing the connection to antenna), will (with no isolator installed) flow back to the output FET/LDMOS etc. and likely damage or destroy it/them. With the isolator installed, any reflected power will flow into the isolator’s load and be safely dissipated as heat (as long as the load is rated to handle the power, and is properly heat sunk, so that the load temperature stays <100C).

Typical parameters could be 0.25dB insertion loss, 22dB isolation and VSWR on the ports of 1.2:1 over a 5% percentage bandwidth.

The Raditek isolators and circulators are believed to have the best performance in the marketplace, within constraints and compromises of physical size, power, and RF performance.

Block Upconverter (BUC) converts a band of frequencies. It is used to convert the frequency from lower to higher. BUC is used in the transmission of satellite signals. BUCs are used to convert L band to Ku band, Ka band, and C band. X and S Bands. Previously Up Converters were used but were less efficient as they used to convert 70 MHz intermediate frequency to C band or Ku band.

Many Block Upconverters use phase-locked loop local oscillators. They also require an external 10 MHz frequency reference in order to maintain the exact transmit frequency. The Block Upconverters used in remote locations are usually 2 or 4 W in the Ku band while 5 W in the C band. Usually the engineers send 10 MHz reference frequency on the same feedline as the primary carrier. In case of smaller BUCs direct current (DC) supply is fed over the feedline utilizing an internal DC block.

Generally, the Block Upconverters are used in conjunction with the low-noise block converters (LNB). Since BUC is the up-converting device, it makes up the “transmit” side of the system, on the other hand, LNB is the down-converting device, so it makes up the “receive” side.

VSAT (Very Small Aperture Terminal) system used for bidirectional access via satellite is the perfect example of the utilization of both BUC and LNB.

The BUC is a block-shaped device recognized when assembled with the LNB in association with an OMT (orthogonal mode transducer) to the feed-horn facing the reflector parabolic dish. They also might be rack mounted indoors or not co-located with the dish.

Rotary Joint

An important part of a radar antenna system is the rotary joint-it is used to connect two different parts of RF waveguide. The rotary joint must be capable of transmitting high, microwave power with a minimum loss.

The Rotary Joints can have the following styles of connection between waveguide port and rotational axis:

• U-style: Both waveguide ports at a right angle to the rotational axis.
• L-style: One waveguide port at a right angle and one in line.
• I-style: Both waveguide ports in line.

Advantages of Waveguide Rotary Joint are:

• High power maintaining capacity.
• Wide bandwidth.
• Different configurations.
• Availability of Multi-channel joints.

Types of Waveguide Rotary Joint

• Single channel
• Dual channel
• Multi-channel

Features

• 360° Continuous rotation
• Straight and right-angle ports available
• Low insertion loss
• 1.5– 20 GHz wideband operation

Applications:

• Mechanically scanned antennas
• Automatic test equipment (ATE)
• Axial ratio measurement

Description of Waveguide Rotary Joint

It is commonly used to scan any kind of antennas in radar and radmeter.

Input and Output ports are available in different positions like: io

• Straight to straight,
• Right angle to straight,
• Straight to right angle, and
• Right angle to right angle variations.
• An extended port available on the ends of the rim

Coupling is by means of flange to ensure good electrical and mechanical support, hence low radiation and internal reflection. The flange end of the unit is joined with the mounting disc, while the rotating side is free to move.

Raditek SSPA amplifiers use field-effect transistors to supply amplification at frequencies 1MHz to 96GHz. Solid State Power Amplifier (SSPA) were developed for use in the most sensitive applications, including Satellite Communications (satcom) Airborne, Radars and Terrestrial Communications including HF, VHF, Wi-Fi, microwave and milliwave point to point links

Advantages of SSPA

• High performance
• Reliability
• Cost-effective modes replacement in applications which are currently using Traveling Wave Tube Amplifiers.

RF of the Amplifiers

• A tuned amplifier that amplifies high-frequency signals used in radio communications is called a radio frequency amplifier, or RF amplifier.
• Pre-amplified and several parallel symmetric branches make up the RF input to the solid state power amplifier.
• SSPA combining many parallel amplifier sections results in built-in redundancy because of this distributed design.
• A current sense alarm indication can be monitored and fed to the RF SSPA controller.
• The amplified results of all the symmetric branches are added up in a combing network which routes the resultant high power to the output of the RF SSPA.

SSPA Amplifier GaAs and GaN

• Gallium Arsenide (GaAs) and Gallium Nitrate (GaN) are the basic SSPA amplifiers currently used. • These are the devices that do the actual amplification.
• GaAs has the best linearity whereas GaN has the best efficiency.
• Solid-State devices such as GaAs FETs, IMPATT diodes, Gallium Nitrate GaN IMFETS and many more devices are for Microwave Amplification.

Different models of SSPA Solid State Power Amplifiers

• Modules Family – 1 MHz to 96GHz
• 19″ Rack Mount Family – 1.5 MHz to 18 GHz
• SSPA HF and ISM Bands up to 5 Kilowatts
• Low Noise Amplifier (LNA)

RADITEK INC. Circulator and Isolator Primer

A circulator is a three port device. It is essentially a passive device, but can exhibit some characteristics that make it almost behave as if it were active. An isolator is a two port device having an input and an output, it is simply a circulator whose third port has been terminated.

Circulators and Isolators provide unique transmission paths, allowing RF energy to pass in one direction with little (insertion) loss, but with high loss (isolation) in the other direction.

An isolator can exist as Stripline, Coaxial, Microstrip, or Waveguide type, and can be rated for powers from milliwatts to Megawatts. Raditek can provide superb stripline isolators to 18GHz, and Microstrip to over 100 GHz.

A typical use of a circulator would be as a duplexer, connecting a transmitter to Port 1, antenna to port 2 and receiver to port 3. This provides simultaneous transmission and reception of signals.

A very common use is at the output of a power amplifier. Forward power is passed with a minimal insertion loss. Reverse power resulting from disconnect at the output (removing the connection to antenna), will (with no isolator installed) flow back to the output FET/LDMOS etc. and likely damage or destroy it/them. With the isolator installed, any reflected power will flow into the isolator’s load and be safely dissipated as heat (as long as the load is rated to handle the power, and is properly heat sunk, so that the load temperature stays <100 degree C). The 100 Watt loads and attenuators, for example, will typically derate to 0 Watts dissipation at 150 degree C.

Typical stripline parameters could be 0.25dB insertion loss, 22dB isolation and VSWR on the ports of 1.2:1 over a 5% percentage bandwidth. Size increases for greater bandwidths.

Optionally available are: High performance models for extended temperature (e.g. RI-SS) and very low intermodulation distortion (-U),

The Raditek isolators and circulators are believed to have the best performance in the marketplace, within constraints and compromises of physical size, power, and RF performance.