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Glossary
Technical terms and jargon are abundant in our industry. Below is a short list of technical terms and definitions we use at Rakon.
Crystal Filter
A filter that allows only the desired frequency to pass through to the output.
Crystal (X) / Crystal resonator (Xtal)
At the heart of XOs, VCXOs, TCXOs and OCXOs are quartz crystals (X), which are designed to resonate with electrical stimulation using the piezoelectric effect.
Crystal Oscillator (XO)
Generally, XOs are lower in cost than TCXOs as they do not have temperature compensation. They are simply quartz crystals combined with basic oscillation circuitry. XOs can offer high frequencies with low performance. They are typically used in telecommunication networks and other broadband applications.
Crystal Micro-Electro-Mechanical System (XMEMS®)
Rakon’s advanced quartz-based resonator technology. It is made with Rakon’s NanoQuartz™ microfabrication process, delivering unprecedented resonator and oscillator performance.
Distribution Amplifier
A device that accepts a single input signal and provides the same signal characteristics to multiple isolated outputs.
Digital Pulse Compression Subsystems (DPCSS)
Digital Pulse Compression Subsystems (DPCSS) use high speed digital processing, enabling significantly improved overall system performance. They can be used as a replacement of existing SAW-based pulse expanders or compressors to overcome device obsolescence or enhance radar performance.
Frequency: Nominal Frequency (Fn) and Output Frequency (fo)
Nominal Frequency (Fn)
The Nominal Frequency (Fn) is the specified reference output frequency of a Rakon crystal, oscillator, filter, equipment, or subsystem. It represents the intended operating frequency defined under nominal electrical, environmental, and operating conditions. Fn is used as the baseline for specifying and assessing frequency tolerance, stability, and accuracy, ensuring reliable performance in demanding system‑level applications.
Output Frequency (fo)
The Output Frequency (fo) is the actual frequency delivered by the device during operation. In RF and frequency‑and‑timing applications, fo denotes the realised output frequency corresponding to the nominal frequency, accounting for manufacturing tolerances, operating conditions, ageing, and environmental influences.
Femtocell
A small cellular base station that plugs into an existing internet connection and provides strong mobile signal in the home. (See also small cells definition).
Frequency Generation Unit (FGU)
A complete subsystem that provides up to 48 outputs from the same ultra stable reference oscillator.
Frequency Multipliers
Frequency Multipliers are narrowband systems dedicated to specific input frequencies to optimise sub-harmonics filtering. Their excellent phase noise performance makes them ideally suited to high-frequency applications in any environment
High reliability (Hi-Rel)
In some industries reliability and high precision performance are critical. Rakon’s high reliability solutions are found in space, defence and industrial applications which require the most stringent performance criteria.
High Stability Temperature Compensated Crystal Oscillator
High Stability TCXOs are used in high volume, high performance markets such as mobile phone devices where small oscillator size is important. High Stability TCXOs have a typical performance of 0.5 parts per million (ppm) over wide temperature ranges. They are available in sizes as small as 2.0 x 1.6 mm.
Oscillator
A circuit or device that generates a repetitive electric signal and consists of a resonator and electronic components.
Oven Controlled Crystal Oscillator (OCXO)
OCXOs are used in applications where precise reference clocks are needed to secure high volume data traffic. Stabilities can be as tight as less than 1 part per billion (ppb). OCXOs are generally more expensive, physically larger and consume more power than a TCXO.
Oven Controlled SAW Oscillator (OCSO)
An oven controlled oscillator using Surface Acoustic Wave (SAW) technology instead of a quartz crystal.
ppm, ppb and ppt
ppm, ppb, and ppt are units used to describe very small frequency errors relative to a nominal (reference) frequency. Instead of showing the error in hertz (Hz), they express it as a very small fraction of the intended frequency.
• ppm (parts per million) = 10⁻⁶
• ppb (parts per billion) = 10⁻⁹
• ppt (parts per trillion) = 10⁻¹²
These units make it easy to compare frequency accuracy and stability across different operating frequencies.
Example: A 1 Hz error equals:
• 1 ppm at 1 MHz
• 1 ppb at 1 GHz
• 1 ppt at 1 THz
ppm, ppb, and ppt are commonly used to specify frequency performance such as tolerance, stability (short- and long term), temperature effects, ageing, and holdover in filters, crystal resonators, oscillators, clocks, timing systems, and related equipment.
Phase-locked Oscillator (PLO)
Phase-locked oscillators (PLO) are frequency sources that deliver a signal of high spectral purity. Integrated stable reference is the key building block of PLOs, enabling a better close-in phase noise and achieving a lower noise floor. PLOs are generally used in communication and radar applications.
Small cells
A small, lower cost, cellular base station, typically installed on lamp posts which provides a limited area coverage compared to conventional (macro)base stations. Small cells are expected to reduce the need for macro stations.
Smart Wireless Device (SWD)
A portable device with added data functionality such as internet access, computing and video capability. Examples include smart phones and tablets.
Surface Acoustic Wave Resonator (SAW)
At the heart of SAW oscillators are SAW resonators that use the piezoelectric effect to generate electrically stimulated acoustic waves at a resonant frequency.
Ultra Stable Oscillator (USO)
An extremely stable oscillator used in high-end space and instrumentation applications.
Ultra Stable Temperature Compensated Crystal Oscillator
Many applications demand an even higher level of performance than our high stability TCXOs. Rakon’s Ultra Stable TCXOs can achieve stabilities better than 100 parts per billion (ppb) over temperature.
Voltage Controlled Crystal Oscillator (VCXO)
A VCXO is an oscillator designed to have its oscillation frequency changed significantly by a controlled voltage. Customers using high performing OCXOs for base stations and telecom infrastructure also use many VCXOs at different frequencies as part of their timing network requirements. VCXOs can offer much higher frequencies as well as low noise performance. They are typically used in telecommunication networks.
Voltage Controlled Oscillator (VCO)
A purely electronic oscillator circuit with an adjustable output frequency, without the use of a crystal or SAW resonator.
Voltage Controlled SAW Oscillator (VCSO)
A SAW oscillator with an adjustable output frequency.
XMEMS
Rakon’s advanced quartz-based resonator technology. It is made with Rakon’s NanoQuartz™ microfabrication process, delivering unprecedented resonator and oscillator performance.
XTAL
Short for 'crystal resonator', or 'crystal'.
XO
Generally, XOs are lower in cost than TCXOs as they do not have temperature compensation. They are simply quartz crystals combined with basic oscillation circuitry. XOs can offer high frequencies with low performance. They are typically used in telecommunication networks and other broadband applications.