The function of any amplifier, including the SSPA (solid-state power amplifier) is to increase or add to the power charge on its input signals. Solid-state amplifiers can amplify signals in the range 30KHz to 300GHz.

SSPA is commonly used in cellular networking and broadcasting systems. Its shape and size can be varied as needed by the circuit topography, especially in satellite communication applications.

SSPA is the most integral device for satellite and broadcasting applications. It performs the crucial function; that of amplifying weak radio frequencies signals-as received by the antennas- to the required amplification level.

In any amplifier, it is the transistors that carries out the bulk of the amplification job. Gallium Arsenide (GaAs) based transistors for SSPA were popular earlier, on account of its quick-replacement feature.

In recent times, however, the transistor based on gallium nitrate (GaN) is primarily used in SSPAs, as it provides improved efficiency without signal loss as compared to GaAs based SSPAs.

Earlier, for L, S, and C band satellite communications, GaN transistor-based SSPA was used. But now, for high frequencies like X, Ku, and Ka frequency bands, advanced GaN-based SSPAs are being used.

In addition, millimeter and microwave applications like radar and electronic warfare also use SSPAs with GaAs and/or GaN transistors.

Further, GaN-based SSPAs can withstand high operating temperatures without degrading any of the output parametric. GaN-based SSPA is said to be the most reliable amplifier on account of its lower maintenance down-time and savings on OPEX cost.

Raditek Inc provides SSPA covering the range 30KHz to 90GHz.  See the Raditek Inc website.

A Band pass filter (BPF) is used to block the unnecessary frequencies and allow only the required frequencies to pass further into a system, appliance, or application. An integrated system decides the requisite resonant frequencies and the unnecessary frequencies get removed with digital or a band pass filter.

In essence, the band pass allows only those signals that are required by the transmission parametric Signals outside of the specified band is attenuated but not completely rejected, which is termed as “roll-off”.

The pass filters help to keep such roll-offs to be as narrow as possible so that it performs as close to the designed parameters. This function prevents the wireless stations from a mix-up of frequencies resulting in a detrimental outcome.

Filters are divided into four groups, defined by their relative cut-off frequency values-High-pass, Low-pass, band-pass and band-stop filters.

Among the above groups, a band pass filter has two categories – Active and passive band pass filters. Active BPF uses active components like transistor and Op-Amp for filtering electronic signals and the passive BPF uses passive components like resistors, inductors, and capacitors to generate a frequency band.

Active BPF is highly effective in dealing with the very low frequencies-close to 0 Hz and yields a very high gain, however, is unsuitable for very high-frequency applications. Passive BPF is of utmost usefulness for the 100Hz to 300MHz frequency range.

Band pass filter is used in applications like power supplies, audio electronics, radio communications, and lighting equipment.

All types of filters are available from Raditek Inc. examples can be seen on the Raditek website.

Microwave amplifiers are devices that boost the voltage or power of the radio frequency that is fed into it from various sources like the antenna and or from other systems.

Microwave amplifiers are a solid-state RF device that provides gain, stability, power, linearity and noise reduction to the input signal and amplifies it as per the set parameters.

Solid-state amplifier systems use transistors that either have Gallium Arsenide (GaAs) or Gallium Nitrate (GaN), which is responsible for the actual amplification of the input signal. GaAs transistor has the best linearity and the GaN transistor has the best efficiency.

A microwave amplifier is a very crucial, critical, and integral device that handles a frequency range from 1 to 100GHz.

And therefore it extensively used in electromagnetic compatibility systems (EMC), Defense systems, medical and diagnostic systems, lab and field testing appliances and point to point microwave link systems.

Microwave amplifiers are fundamental devices in modern-day electronics and are a part of all electronic devices that deal have to deal with the electronic audio/video communications.

There are various types of microwave amplifiers and that includes 1) The Gyrotron, 2) The Klystron and 3) the Amplitron-also is known as Crossed-Field Amplifier (CFA) or Platinotron.

Microwave amplifiers are prone to heating up and hence amplifiers made by reputed companies have a robust built-in state of art cooling systems like the convection cooling heat sink or forced air cooling apparatus and for ultra-high power amplifiers, water cooling systems are also used.

See the Raditek website.

Coupler coaxial is a very basic microwave device used in almost all the microwave applications and systems. It is widely used in the telecommunication sector, test gadgets, instruments and in commercial applications like medium-power transmitters, aerospace industry and military communication systems.

While the splitter degrades signals (3dB), coupler coaxial, on the other hand dissipates it to the extent of only 0.5dB.

There are different types of coaxial couplers BNC, MCX, N-type, F-type, SMT, UHF, TNC-SMC, and a few other N-types which are high-performance couplers used in multiple applications mentioned above.

Electronic engineers across the global are replacing the bulky cable assemblies with the simple board to board coupler coaxial that can handle the power load of 100w which reduces the weight and space utilized.

These days, micro coaxial couplers are available for various applications which are suitable for 10GHz and are 30% smaller in size to their predecessors.

Then there are directional coaxial couplers that are suitable to cover frequency bands from 0.25-40.0 GHz in multi-octave and octave band configurations.

In addition to the above types of coaxial couplers there are coaxial waveguide couplers, Ka and Ku Band coaxial couplers.

In certain applications, it becomes necessary to connect the transmission lines coming from the coupler coaxial to strip transmission lines. For this purpose, advanced coaxial couplers and connectors are now available which compensate for the impedance mismatch and phase shift.

Such an adaptable convertibility allows for interchangeability of couplers and connectors for further tasks without disconnecting the lines.

See the Raditek website.

A phase lock oscillator is available in various architectures having different properties. Its basic function is to generate periodic signals. The phase comparator in the circuitry then compares the phase of these periodic input signals and adjusts the oscillator, if needed, to keep the input and the output phases matched. The locked input and output phases ensure that the input and output frequencies are in sync. Besides keeping input/output frequencies in sync, a phase lock oscillator is also used to track the input frequency or to generate an output frequency in multiples of the input frequency. Phased lock oscillators are used extensively for computer clock synching, demodulation, and frequency synthesis-generate stable frequency at the output level as calibrated by the design parameters warranted by the application circuitry. These properties of the PLO are helpful to demodulate calibrated frequency signals, recover needed frequencies from a communication system. Phase lock oscillator is also used to distribute accurately timed pulses in digital circuits like microprocessors. No wonder that the PLO is widely used in radio, telecommunications, computers, and electronic applications. An integrated circuit provides a single phase lock oscillator block and this technique is used in most of the modern electronic devices that handle output frequencies ranging from a fraction of hertz to gigahertz. A PLO is a dynamic low noise frequency source which is available in different configurations that are adapted to different applications and its internal as well as the external environments. A full range can be seen on the Raditek website.

The magic of crisp and clear television images and sound has to be attributed to LNB-Low noise block down converter.

LNB device is mounted on satellite dish which collects and reflects radio waves beamed down by the satellite, approximately twenty-two thousand miles away, and converts it into a signal that could be sent to a receiver placed in a building or an apartment, with the help of a coaxial cable.

Low noise block converter is exposed to elements of nature and therefore configured to withstand extreme weather conditions and maintain its functional integrity.

Two crucial functions of an LNB:

Firstly, it works as a low noise amplifier which receives feeble satellite signals and amplifies to the calibrated extent.

And secondly, it converts the super high satellite frequencies and transforms it into lower frequencies. These two functions convert satellite signals into images and sounds for television and computers.

Originally satellite dishs used an LNB which was a separate unit that was mounted on a satellite dish antenna. However, with the technological advancements in this field, the newer satellite dish antennas use LNBF – “F” denoting the field horn. These are smaller and compact in size.

In an LNB, TV Channel switching is enabled by the shifts in polarity with the help of the exterior motor and the channel.

However, in the case of LNBFs, the voltage going into the horizontal and vertical antenna probes cause a shift in polarity which makes switching channels possible.

A full range can be seen on the Raditek website.

The advent of Gallium Nitrate (GaN) based, scaled-down and miniature models of transistors assisted the development of energy-efficient, environment friendly, less voluminous, and light-weight GaN transistor-based solid-state power amplifier (SSPA) – referred to as SSPA amplifier GaN – with excellent linearity and output power.

SSPA amplifier GaN is the most practical alternative to the traveling wave tube amplifier (TWTA) base amplifier in use earlier. The bulk of the amplification job is carried out by these transistors.

SSPAs are used in various high-power radio-frequency and other applications like transmitters and low noise receiver amplifiers.

GaN-based SSPA is a complete module by itself which can have 75dB high gain. It also can have a communication bus, gain adjustment facility, and a microcontroller.

Being configured in a modular architecture it is pre-disposed to offer ease of repair and replacement. Modular based systems ease the maintenance load and thereby the time required for this activity.

Therefore the SSPA amplifier GaN has a soft fail capability that does not exist in TWTA based power amplifiers.

These amplifiers can have an alpha-numeric control dashboard that displays the performance parameters of the amplifier. Performance data can also be accessed from a remote location using the in-built tele-interface.

The auto-shutdown feature in these SSPAs protects the system from the heat-related damage prevalent in amplifiers.

State-of-the-art versatile SSPA amplifier GaN devices/models are manufactured by Raditek Inc and can handle millimeter frequency bands to 90 GHz and ultra-high power output-from watts to kilowatts. See the Raditek Inc website.

Applications like telecommunication infrastructure, TV broadcasts, global navigation satellite systems, aerospace and defense sector applications require highly precise amplitude and frequency oscillation cycle.

A Rubidium Oscillator is an atomic clock which derives its stability from the intrinsic stability of the rubidium ground state hyperfine resonance. Most rubidium devices will have a frequency offset of less than 0.1 ppb directly “out of the box”. Most rubidium devices will have a frequency accuracy of less than ±0.5 (5E-11) directly “out of the box”.

They are very stable and once they are “calibrated” or “disciplined” using a known good reference (traceable to a primary reference source), they create wonderful telecommunications clocks. They are excellent holdover oscillators (<1.5usec.) because of their stability. For many applications, such as the calibration of the internal OCXO in counters, spectrum analyzers, and communications test systems, this provides more than an order of magnitude margin in every parameter.

The excellent stability also allows the clock to act as a very narrow-band filtering clock. Filter time constants of the order of days can be implemented if the oscillator is a rubidium because of the stability. Therefore it can filter out essentially all accumulated wander on the reference. In contrast, quartz oscillators, even expensive ones, will provide stratum-1 quality holdover only for a few hours.

Rubidium devices also act as excellent firewalls. A rubidium oscillator cannot be made to change its frequency by very much; typically ±2ppb ppm offset at from absolute truth, and therefore cannot be steered very wrong in the event of a reference going “rogue”. The equivalent limit for quartz is about ±0.5ppm at 10MHz.

Our Rubidium oscillators provide cost-effective, compact, and long lasting stable reference signal equipment for precision test and measurement applications, telecommunications, advanced communications, navigation and targeting systems.

Our RMRO-10M-Sf-LN-c5 Low Noise Rubidium Oscillator Module is a sub miniature atomic clock combined with ‘active noise filter’ technology. This rubidium oscillator has 100x less drift than OCXO’s. With short term stability of 2×10‐12/s @ 100s this rubidium oscillator provides significant improvement in performance over other rubidium component.

These and other models are available from the Raditek website.

Microstrip isolator is a radio frequency segregator which is made by applying microstrip technology in which a conductor is separated from the ground plane by a dielectric layer called the substrate. Microstrip lines are used to conduct microwave frequencies.

The isolator’s function is to guard other RF components from excessive signal reflection. Microstrip isolator can be built to cover different frequency ranges from 2.0 to 60 GHz.

Microstrip lines are one-directional transmission paths for RF. The Microstrip isolator captures the reflected power and dissipates it as heat.

The selected isolator path provides negligible insertion loss and excellent isolation for stripline based components and other module integrations. It is a crucial and critical device where port isolation or VSWR is concerned.

When determining the isolator for any purpose it is recommended that one first ascertains the following:

1. – Frequency range of application.
2. – The power load that the isolator would handle.
3. – Insertion loss needed by the system, and
4. – Port to port isolation needed.

Microstrip isolator circuits are used in high-frequency commercial, space, and military applications.

Microstrip technology-based devices are very economical as compared to wave-guide technology-based similar products and is far lighter and compact in dimension.

Microstrip has inherent limitations: low power handling capacity, higher losses, and moreover, it is not an enclosed device and hence prone to radiation.

Raditek offers many types of microstrip isolators on their website.

A circulator is a 3 or 4 port non-reciprocal, Ferro-magnetic, device which transfers the power to other adjacent ports as per the circuitry design.

Circulators allow high power flow which is the microwave energy, only in one direction within the RF circuit. Such circulators can have isolation ratings ranging from 16dB to 22dB.

When one of the 3 or 4 ports is terminated-matched condition-the other ports become isolated in the reverse direction. Therefore and isolator is a circulator with matched terminations.

Circulator high power is made out of ferrite material that exhibits low insertion loss, low power dissipation and high power handling capacity. However, it has several drawbacks such as relatively small bandwidth.

Circulator high power capacity has been used in the microwave and millimeter-wave systems to de-couple the transmitted and received signals. In a continuous wave (CW) radar system, the high-power circulators work as diplexer allowing the transmitter and the receiver to share the same antenna.

There are different types of circulator high power devices, but the popular ones are:

• – High-power drop-in circulator-suitable for VHF to Ku Band @ Kilowatt power
• – The UHF circulators-low-loss circulators with efficient heat transfer.
• – Circulator high power in coaxial and waveguide formats for different circuit designs.
• – High power broadband ferrite circulator-used for air traffic surveillance.

Raditek offersthe widest range of Circulator high power devices available in the electronic industry see the Raditek website.