SSPA stands for a solid-state power amplifier. This is one among the two types of microwave amplifier, the other one being traveling wave tube amplifier-TWTA.

Amplifiers come in varied shapes and sizes, especially in the satellite communication sector. Whether it is SSPAs, vacuum-tube amplifiers, magnetic amplifiers or negative resistance amplifiers, all have their inherent usefulness and drawback or inapplicability, basis their utilization.

Irrespective of the types of amplifiers, it is the most important component which makes satellite communications possible by enhancing the power of radio frequencies received by antennas.

An SSPA system based on Gallium Arsenide (GaAs) is in use for over 4 decades now and are popular.

However, Gallium Nitrate (GaN) based SSPA was first designed by the department of defense, in 2000 and were used for improvised explosion device-IED-jammers in Iraq.

Commercial use of Gallium Nitrate (GaN) based SSPA, initially, was developed for low-frequency L, S and C band satellite communications. Now, it is also been used for higher frequencies like X, Ku, and Ka frequency bands.

SSPA based on GaAs and GaN transistors are used for microwave and millimeter-wave electronics purposes like satellite, radar, communications and electronic warfare systems.

The temperature is a crucial aspect of SSPA’s performance, Gallium Nitrate-GaN-based SSPA can perform better, without degradation, as compared to a GaAs SSPA.

Gallium Nitrate based SSPA is voted to be the most intrinsically reliable SSPA compared to other amplifiers, as it has a reduced maintenance down-time that results in OPEX cost saving.

Many GaAs and GaN SSPA can be found on the Raditek website.

It is a modern-day technological miracle that we are able to receive crisp pictures, clear sound in our television sets, from satellites, orbiting thousands of miles up in the space.

The electronics that made this possible is a wonderful weather-proof device called the LNB-Low noise block downconverters.

Low noise block downconverters-known as LNB-is a receiving device that is installed on the DTH dish antenna used for TV reception.

Satellite signals become very weak during the time it travels over 22000 miles to reach a dish antenna. The “dish” part of an antenna works like a lens that focuses most possible signals on LNB and therefore the curvature on the dish.

LNB receives low-level microwave frequency beamed by the satellite that is projected by the dish antenna, amplifies it, down converts the signals to a lower frequency band and sends them through a cable to a receiving set in an apartment or a building.

Therefore, the LNBs perform two functions-1) that of an amplifier and 2) and that of the down converter of super-high satellite signals to a lower frequency conducive for TV reception.

Both these functions are important to deliver the signal through a regular cable.

However, it is found that only older satellite dishes used LNBs. The newer and the modern versions of dish antennas use a more compact LNBF-Low Noise Block Downconverters plus Freedom.

As the industry has totally shifted to the use of LNBFs so much so that they don’t even highlight the “F”-for freedom-anymore. LNBFs have completely replaced the LNBs.

The power splitter is used, mostly in radio technology. Radio Frequency (RF) power splitters are used to split or divide a single frequency line into several lines or pathways.

When the power splitters are used the other way round, it turns into a combiner where it combines more than one frequency line into a single line. Therefore, this power splitter is also a combiner. It is a reciprocal device.

Types of Power Splitters / Combiners: There are two types of power splitter/combiner.

1)  Resistive Power Splitter: These power splitters use resistors hence they are able to maintain the required impedance of the system. The use of resistors introduces a loss above the loss caused by splitting. However, it provides credible performance over a broad range of frequencies and maintains the required impedance match.

2)  Hybrid Power Splitter: These power splitters use transformers which result in a low level of power loss due to the splitting action. The major loss in this type of splitters is the loss that arises out of the splitting process as the same signal is shared a number of outputs.

Different types of power splitter/combiners are available in the trade, for example that can be used to split and/or combine signals in any ratio by selecting the correct values of the components used in their configuration.

There is some inherent power loss with the insertion of splitters/combiners in any system as no component is totally loss-free. These losses cannot be calculated in absolute numbers; however, it can be minimized.

A Phase Lock Oscillator or PLO as referred to in the electronic parlance, utilizes state-of-the- art planar circuits, three-terminal devices and dielectric resonator technology to generate high-quality microwave signals at lower frequencies. Other devices like frequency multipliers, amplifiers and filters are used to extend the low frequencies for higher frequency requirements

A standard Phase Lock Oscillator covers the frequency range of 2 to 110GHz and offers both internal and external reference options. Frequency stability and phase noise is subject to the oscillator reference type.

The vital function of a Phase Lock Oscillator is to generate an output signal whose phase is related to the input signal.

Different types of Phase Locked Oscillators are available in the trade such as:

• 1. Phase-locked oscillators with digital Phase-lock IC
• 2. Phase-locked oscillators with analog sampling phase detector
• 3. Dual loop phase-locked oscillators
• 4. PLXO – Phase Locked Crystal Oscillator
• 5. PLCRO – Phase locked coaxial resonator oscillator.
• 6. PLDRO – Phase locked dielectric resonator oscillator.
• 7. PLVCO – Phase locked dielectric voltage control oscillator.

Phase locked oscillator must be compatible with other components in the system and must not only operate properly on the “bench” but must also operate suitably in complex electronic systems.

The perfect oscillator signal spectrum would consist of a single line of infinitesimal width. No perfect oscillator has yet been discovered.

A different phase locking circuitry is used basis the customers’ in the cases where customers’ selects 10 MHz or 100 MHz reference and the output frequency is not a multiple of these frequencies.

Raditek Inc. offers the widest and best performance oscillators in the world.

A low noise amplifier is an electronic device that amplifies a very low-power signal without significantly degrading its signal-to-noise ratio.

An amplifier will increase the power of both the signal and the noise present at its input, but the amplifier will also introduce some additional noise.

Low noise amplifiers or LNAs are designed to minimize such additional noise. The amplifier designers are able to bring this noise reduction by using low-noise components, operating points and circuit topologies.

Minimizing additional noise must be in sync with the other design goals such as power gain and impedance match.

For a low noise, high amplification is required for the amplifier in the first stage. And therefore, they are fitted with junction-field-effect transistors (JFETs) and high-electron-mobility transistors (HEMTs). They are driven in a high-current regime which reduces the relative shot noise. It also requires input/output impedance matching circuit to enhance the gain.

Low Noise Amplifier is

A typical LNA will supply a power gain of 100 (20decibles) while reducing the signal to noise ration by less than a factor of two (3 decibel noise figure).

 To optimize the retrieval of the desired signal in the later stages of the circuitry, low noise amplifier is placed close to the signal source and therefore the noise level is reduced by the signal gain created by the LNA.

Low Noise Amplifier, a key component of any radio receiver, helps to restore or enhance the strength of only the desired signals and cut out on the distortions caused by generated by the other signals and/or the circuitry.

Power Splitters are devices used to split a single Radio Frequency (RF) line into one or more output lines. These are passive devices and are used predominantly in the field of radio technology.

These splitters transmit a defined amount of electromagnetic power in a transmission line to a port, enabling the transmitted signal to be used in another circuit.

Latest Power Splitters are built to retain signal strength with any modulation loss. However, multiple output ports on the splitter will decrease the signal strength coming into the splitter.

There are two types of power splitters-

1) Restive Power Splitter – These splitter use resistors that maintain the characteristic impendence, however, the use of resistors introduces the loss above that of the minimum caused by splitting.

2) Hybrid Power Splitter – These splitters use transformers that provide a minimum level of loss.

Power Splitter, when inserted into a circuit, some loss of power will occur as no component is completely loss-less.

• Advantages of a restive power splitter: they use resistors and can be made easily within a circuit.
• A low cost device.

The main disadvantage of a restive power splitter is that signal power loss is over and above the power lost on account of multiple output port.

• The advantages of Hybrid power splitter: Have lower loss of power on splitting.
• It also enables higher levels of performance visa Vis the restive counterpart.

The disadvantages of a Hybrid Power splitter: These use transformers, hence can be more complicated to manufacture. Transformers have a limited frequency range. This limits its overall range of hybrid power splitters.

Raditek offers many types of power splitters on its website.

Block upconverter, also known as (BUC) is used in uplink of satellite signals.

It converts a given band of low frequencies to a higher frequency typically needed for uplink work. Latest block upconverters converts frequencies from L band to S band, C band, x band. KU band and Ka band.

Most block upconverters use phase-lock loop local oscillators-a control system that generates related output signal- that calls for an external 10MHz frequency reference to maintain correct transmit frequency stability.

Block up converter (BUC) is basically used along with the Low Noise block down converter (LNB) which make up for the “transmit” part of the system and the “receiving” part respectively.

Block upconverters used in remote locations have 2 to 4 watts power in Ku Band frequency and 5 watts in C Band.

Block up converters and Low Noise Block converters are used in conjunction in VSAT-very small aperture transmission-systems used for bidirectional internet access via satellite.

BUC or Block upconverters is a block-shaped device that is assembled with an OMT-orthogonal mode transducer-fitted to the feed horn facing the parabolic reflector dish.

Block up converters for airborne applications have to be skillfully designed to meet the strict quality and performance levels of commercial airlines and military sectors. These devices, often, have to perform in the most challenging environments and therefore have to be highly reliable. There is an additional demand on these devices from the airborne industry for requirements like Size, Weight and Power (SWaP). Block Upconverters for have to meet all these stringent requirements in totality.

Raditek offers many types of Block up converters on its website.

Low Noise Amplifiers, also known as (LNA) are an electronic device that amplifies signals of a very low strength from the input source like an antenna where the signals are barely recognizable and need to be amplified with the addition of noise-that without degrading the signal to noise ratio (SNR). LNA’s are designed to minimize the additional noise.

Basic function of a Low Noise Amplifier: Its basic function is to boost the input signal to an appropriate level above the noise floor, so that it can be used for further or additional processing. LNA is the part of an amplifier/receiver that intercepts the incoming signal first hand and therefore plays a vital part in the electronic communication process.

Low Noise Amplifiers use low noise components and circuit topologies. All this is done while keeping in mind the other objectives like power gain and impedance matching.

Well-designed LNAs have a low NF-1 dB, for e.g.-enough to boost the signal-e.g. 10 dB-and a large enough inter-modulation and compression point-IP3 and P1dB-to get the required output from it. Further important specification and parameter of a good LNA is its operating bandwidth, gain flatness, stability, input and output voltage standing wave ratio (VSWR).

LNA should be used keeping it close to the signal source due to which the noise from the subsequent stages of the receiving chain is reduced as a result of signal gain created by the LNA.

The Work done by Low Noise Amplifier enables optimum retrieval of the desired signal in the later stages of the system.

Use of Low Noise Amplifiers:

• – LNA is extensively used in radio communication
• – All electronic testing equipment.
• – It is used in all radio receiving sets of various types.

A full range of LNA’s are available from Raditek website.

Microwave amplifiers are solid state amplifiers in the frequency range of 1 to 100GHz. Microwave amplifiers finds extensive use in Electromagnetic Compatibility systems (EMC), Electromagnetic interference (EMI), Defense systems, Medical and diagnostic systems, laboratory and field testing appliances. Point To Point microwave links.

The characteristics of a microwave amplifier are gain, stability, noise, power, linearity, etc.

Types of Microwave amplifier:

Low noise amplifier (LNA)-It is designed to take very low level signals and amplify it with minimum additional noise.

Power amplifier (PA)-this amplifier takes the already high level signal and further boosts for transmission over lossy medium such as through air.

Linear signal amplifier (LSA)-Linear signal amplifiers are generic amplifiers, sometimes called ‘gain blocks’ that provide signal gain within a system.

Driver amplifier- These amplifiers are good for use in single frequency applications-(continuous wave or CW)-as in synthesizers or as amplifiers for the local oscillator (LO) driving a mixer.

Uses of Microwave amplifiers:

Microwave amplifiers are used for numerous applications as follows:

• • – To generate high power RF.
  • – Radio transmitters
  • – Inter-stage transmitters
  • – Medical amplifiers for cancer treatment
  • – Low-noise amplifiers for receivers
  • – Radar applications

Microwave amplifiers are prone to heat generation and therefore a robust in-built cooling system is an absolute necessity. The availability of this feature on the selected Microwave amplifier is a must.

The Microwave amplifiers as classified and categorized mainly by
1) Their frequency coverage
2) Output power

Magnified output is called “Gain”, “Power gain” or simply “Gain”, which is expressed in terms of decibels (dB)

It is suggested that customers list out their feature and output requirements for a Microwave amplifier and then check the Raditek website. This would help them select the one that suits the best for their application.

BUC stands for ‘Block Up Converter.’ Its main function is to transmit signals to satellites. Users install it to change a low IF frequency signal to higher frequencies for transmission to a satellite.

To select the most appropriate Block Up Converter, you must consider all these parameters.

• – Input: Input in the BUC is the intermediate frequency (IF frequency), which is received by the device to be amplified and up-converted. You must check the range of frequencies it can receive these are typically L band between 950 and 2200MHz.
• – Output: It is the frequency (RF frequency) that is sent out of the satellite after amplification. It is denoted using Frequency bands such as Ka-Band, Ku Band, C Band and X Band, etc.
• – Gain: It is the magnitude raised by the device after amplification. Different types of BUCs have different gains.
• – DC Voltage: It is the voltage that the device requires for operation. It is also different for different BUCs.
• – Connector: You should also check the type of connector. There are a variety of connectors like N-Type or SMA, both Male and Female.
• – LO Frequency: Also check the LO (Local Oscillator) frequency, because it is necessary for the transmission of the correct frequency.
• – Grade: You should also check the grade of the device as there are commonly two grades available, Military and commercial.

Checking all these parameters is easy online as you get a PDF file attached to the picture and description of the product. A wide range of variants are available on the Raditek website and you can find the exact one you need easily. Carefully read the description and place your order at sales@raditek.com.