A

Amplifier Class A

Most microwave and millimeterwave amplifiers are Class A amplifiers. Class A amplifiers have a fixed forward bias. When Class A amplifiers operate below the compression point, the RF signal swing is uniformly above and below the quiescent DC bias set point and well within the linear region of the transistor. Therefore, Class A amplifiers have high linearity and low efficiency.

Amplifier Class C

Class C amplifiers are not DC forward biased. The current of the drain flows over less than 50% of the RF input cycle. Class C amplifiers have a very limited dynamic range and poor linearity. However, they have high efficiency and are widely used in extremely high power applications.

Anechoic Chamber

The anechoic chamber environment allows antenna pattern and radiation characteristic measurements "Over the Air" without reflections or ambient radio signal interference. Anechoic chamber is usually built inside a large faraday cage with radio wave absorbers in the interior.

Antenna Beamwidth

Beamwidth refers to the width of the antenna’s main lobe. The terms “3 dB beamwidth” and “half power beamwidth” are often used to define an antenna’s main lobe beamwidth and are often simply referred to as “beamwidth” for short.

Antenna Boresight

An antenna boresight, which is also referred to as an electrical boresight, is the optical axis or the direction of maximum gain of a directional antenna.

Antenna Cross Polarization

Cross polarization is the radiation orthogonal to the desired polarization.

Antenna Directive Gain

Directive gain, which is also referred to as antenna gain, is directly related to the antenna’s directivity and efficiency. It is the ratio of the radiation intensity in one intended direction to the total power input into the antenna and is measured in dB.

Antenna E-Plane and H-Plane

E-Plane is any plane that contains the electrical field and the direction of maximum radiation from a linearly polarized antenna. H-Plane isany plane that contains the magnetic field and the direction of maximum radiation from a linearly polarized antenna.

Antenna Far Field

Far field is the point where the angular field distribution or the antenna pattern is independent of the distance from the antenna. Eravant provides an antenna range far field calculator here.

Antenna Front to Back Ratio

Front to back ratio refers to the ratio of directivity of an antenna to its rear directive gain.

Antenna Near Field

Near field is the point where the angular field distribution or the antenna pattern is dependent on the distance from the antenna. Eravant provides an antenna range near field calculator here.

Antenna Pattern

An antenna pattern, which is also referred to as a radiation pattern, is the antenna’s desired performance as a function of the azimuth and elevation directions. It is an angular graphic display of the radiation properties or a field distribution of the antenna and is plotted with either Cartesian or polar coordinates.

Antenna Side Lobes and Side Lobe Level

Side lobes are radiation lobes that occur in addition to the main lobe. The side lobe level is the relative power level of any side lobe carrying to its main lobe and is measured in dBc.

Anti-cocking

Anti-cocking often refers to the waveguide flange structure that is designed to prevent the misalignment of mating surfaces, in which two mating surfaces are not touching at all points. The anti-cocking flange is designed and offered for this particular purpose. The benefits of anti-cocking are highlighted here in our blog.

Aperture Antenna

An aperture antenna features an opening in a surface that is designed to radiate. Most microwave and millimeterwave antennas are aperture antennas. Examples of aperture antennas are slot antennas, horn antennas, lens antennas, array antennas and reflector antennas.

Aperture Efficiency

Aperture efficiency is the ratio of the effective radiating area of an antenna to its physical aperture area. Several elements of the antenna can affect its aperture efficiency. In a feed-and-reflector combination antenna, 5 separate components, 1) the illumination efficiency, 2) the spillover, 3) the phase efficiency, 4) the cross-polar efficiency and 5) the surface error efficiency, contribute to the aperture efficiency.

Array Antenna

An array antenna is an antenna that is comprised of multiple radiation elements, which are configured and connected to produce a directional radiation pattern. Array antennas are offered here.

Attenuator Phase Stability

Phase stability is used to measure the phase variation of an electrical attenuator while the attenuation values are adjusted. High phase stability attenuators are designed to achieve a near constant phase during attenuation adjustments.

Attenuator, Analog Controlled

Analog controlled attenuators have attenuation values that are continuously controlled by the applied current. Analog controlled attenuators are offered here.

Attenuator, Digitally Controlled

Digitally controlled attenuators have attenuation values that are digitally controlled by the bits. For example, if the attenuation range is 64 dB and the bit size is 6, the attenuation step size is 1 dB. Digitally controlled attenuators are offered here.

Attenuator, Electrical

Electrical attenuators are used to control signal levels and are offered with either analog or digital controls. Electrical attenuators are offered here.

Attenuators

Fixed and level setting attenuators are constructed with an E-plane resistive insert in the rectangular waveguide. The insertion loss of these attenuators is dependent on the frequency. The standard attenuation values for fixed attenuators are 3, 6, 10, 20 and 30 dB, and the attenuation range of level setting attenuators is adjustable from 0 to 30 dB via a micrometer. Fixed and level setting attenuators are typically used for signal attenuation when accuracy is not a focus.

Direct reading and programmable attenuators are constructed with a precision, resistive rotary vane in a circular waveguide. The operating mode of the attenuators is the circular waveguide, TE11 mode. Unlike fixed and level setting attenuators, the attenuation value and phase shift of these attenuators are independent of the frequency. The direct reading attenuator uses a large scale dial to indicate the attenuation value, making this attenuator ideal in waveguide systems when a broadband direct reading of attenuation or a standard for system calibration and instrumentation is required. The programmable attenuator is designed for both manual and computerized operations. While the toggle switch and LED indicator on the front panel are used for manual operations, an IEEE-488 or RS-232 interface on the back panel is used for automatic controls. The programmable attenuator is ideal in ATE systems where the attenuation is controlled remotely via a computer interface.

Fixed, level setting, direct reading and programmable waveguide attenuators are offered here.

Axial Ratio

Axial ratio is a measure of the circularly polarized field of an antenna or the ratio of two orthogonal components of an E-field. A perfectly circularly polarized antenna has an axial ratio of 1 or 0 dB.

B

Bias

Bias in the microwave industry is refers to the DC supply which provides a steady current or voltage that supports a circuit for RF operation.

C

Circulator

A circulator, in principle, can have many ports, but the three-port Y junction circulator is the most commonly used in the industry. Circulators have low insertion loss in the forward direction (port 1 -> port 2 -> port 3) and high isolation in the reverse direction (port 3 -> port 2 -> port 1). Circulators are mainly used as a duplexer in radar and communication systems where a single antenna is shared for both the transmitter and receiver channels. Circulators are a ferrite device, which is referred to as a non-reciprocal device. Circulators are offered here.

Circulator, Drop-in

Drop-in circulators are non-reciprocal, ferrite-based devices with tabs as their input and output ports for easy subassembly and module circuit integration. The characteristic port impedance of these circulators is 50 Ω.

Circulator, Full Waveguide Band

Full waveguide band circulators are cavity-type, non-reciprocal, ferrite-based devices. They have the same mechanical configuration as waveguide junction isolators, but cover full waveguide bands. For example, a Ka-band full waveguide circulator has an operating bandwidth of 26.5 to 40 GHz, which covers the full WR-28 frequency range. Full waveguide band circulators are offered here.

Circulator, Microstrip Line

Microstrip line circulators are non-reciprocal, ferrite-based devices that have a thin film circuit printed on a ferrite substrate and a magnet placed on the junction to move the signal in a forward direction. The devices have two mechanical configurations substrate only and substrate on carrier. The characteristic port impedance of these circulators is 50 Ω.

Circulator, Waveguide Junction

Waveguide junction circulators are cavity-type, non-reciprocal, ferrite-based devices. The signal circulation occurs in the center of the “Y” junction, where a ferrite puck is placed, and a uniform magnetic field is formed by a pair of magnets. The RF interface ports are waveguides. Waveguide junction circulators are offered here.

Coaxial Connector Types

The main coaxial connector types used in higher microwave and millimeterwave frequencies are summarized in the table below. “K” and “V” connectors are trademarks of Anritsu. Their alternative names are 2.92 mm and 1.85 mm connectors, respectively. “SMA” connectors are a trademark of Tyco Electronics, formerly known as Omni Spectra. As shown in our coaxial blog, the inner diameter of the outer conductor is used to name the connector type. For example, the 2.92 mm connector has an outer conductor with a 2.92 mm inner diameter. In addition, the indicated TEM mode operating frequency range for these connectors is wider than industry standard specifications. For example, the K connector’s operating frequency range is listed below as DC to 45.58 GHz, while the industry standard specification is DC to 40 GHz. Eravant also offers a coax calculator to calculate impedance and cut-off frequency.

Coaxial Line

A coaxial line is a transmission line that is comprised of an outer conducting metal tube that encloses and insulates an inner central conducting core. Coaxial lines are primarily used to transmit high frequency signals.

Coaxial Line Characteristic Impedance

The characteristic impedance of a coaxial component operating within the TEM mode is given by Zo = 138/√Ɛr log⁡〖D/d〗(Ω)

Coaxial Line Dominant Mode

The dominant mode of a coaxial line is the TEM mode. The electric and magnetic fields of the TEM mode in a coaxial line is shown on the right. Higher order modes tend to cause excessive loss. A coaxial line’s dominant mode of operation is governed by the diameters of its outer conductor (D) and inner conductor (d) and the dielectric constant (Ɛr) under the following relationship D+d ≤ 2λo/(π√Ɛr). This can be calculated using our coax calculator here.

Conditional Stable

A conditionally stable amplifier may oscillate under certain conditions and a conditional stable oscillator may output different frequency and power under certain conditions.

Conversion Loss

Conversion loss is the ratio of output signal power to input signal power. Conversion loss is measured in decibels when using the formula Conversion Loss =10log(G).

Corner Reflector Edge Length

It is the length of edge of a corner reflector. It can be used to calculate radar cross section of a corner reflector.

Coupling

Coupling is the signal sampling from the main transmission stream to side streams.

D

Detection Sensitivity

Detection sensitivity is the output level of the detected signal versus the input level of the RF power, measured in mV/mW.

Detector, Amplitude

An amplitude detector is used to convert an RF signal to a DC signal. The relationship of the input power and detected output voltage is square root.

Detectors, Waveguide

Waveguide detectors are GaAs beam lead Schottky diode-based detectors that are designed for millimeterwave network analyzer applications to offer a high dynamic range and superior port matching. The RF interface of these detectors is a standard waveguide with an integrated Faraday isolator to improve the port VSWR.

Dielectric Constant

The ratio of the electric permeability of the material to the electric permeability of free space

Directivity

Directivity is a measure of how well the coupler or electrical device isolates two opposite-travelling (forward and reverse) signals. Eravant split-block waveguide couplers, SWD- series, generally provide high directivity up to 40 dB.

Dominant Mode, Rectangular Waveguide

The dominant mode of a rectangular waveguide is TE10 mode. The cut off frequency of the TE10 mode in a rectangular waveguide is C/2a, where "c" is the speed of light and "a" is the width of the waveguide. Eravant provides a rectangular waveguide wavelength calculator to calculate cut off frequency.

E

EIRP

The product of transmitter power and the antenna gain in a given direction relative to an isotropic antenna of a radio transmitter. Normally the EIRP is given in dBi, or decibels over isotropic.

F

Faraday Isolator

A Faraday isolator is constructed based on the Faraday EM field rotation principle. Faraday isolators offer high isolation across full waveguide bands with a superior phase performance. Faraday isolator is a ferrite device, which is referred as a non-reciprocal device.

Ferrite Device

Ferrite devices generally refer to non-reciprocal devices, such as isolators and circulators. These devices use ferrite magnets that cause electrical signals to travel in one direction with minimal loss.

Flicker Noise

A form of electronic noise that dominates at low frequencies or low frequency offsets from an oscillator or a frequency source. 1/f noise is proportional to the inverse of the frequency, i.e. 1/f.

Focal Length

The focal length was initially introduced in the optical system. The focal length is an optical measure of how strongly the system converges or diverges light. It is the inverse of the system's optical power. It was adapted later for microwave antenna with similar measure.

Frequency Accuracy

The difference between the frequency standard and actually measured frequency.

Frequency Extenders

Frequency extenders are designed to extend industry standard, low frequency signal sources or generators to higher millimeterwave frequencies. These extenders offer a low cost means of producing millimeterwave signal sources while preserving the functionality and features that industry standard models offer.

Frequency Modulation Deviation Stability

Frequency modulation deviation stability is used to characterize an electrically tuned oscillator’s frequency tuning sensitivity stability over temperature, which is important for any communication and radar system.

Frequency Multiplier

There are two types of frequency multipliers, active and passive multipliers. Active multipliers involve three terminal devices and require an external DC bias. On the other hand, passive multipliers employ resistive or capacitive devices, such as Schottky diodes or Varactor diodes, eliminating the need for an external bias. Frequency multipliers utilize the nonlinear characteristics of semiconductors to generate and extract the desired harmonic of an input frequency, such as 2x, 3x, etc.

Frequency Pulling

Frequency pulling is used to characterize the load capacity of an oscillator. It is often specified as a frequency change caused by the 360° phase change of a given VSWR load. In general, the smaller the change, the better the oscillator.

Frequency Pushing

Frequency pushing is the change in output frequency of an oscillator caused by bias voltage variation or ΔF/ΔV. It is also referred to as bias tuning.

Frequency Stabilities, Long-term

Long-term frequency stability characterizes the aging process of circuit elements and materials and is usually expressed in terms of parts per million (PPM) per hour, day, week, month or year.

Frequency Stabilities, Short-term

Short-term frequency stability characterizes frequency changes from the nominal frequency that occur over a duration of less than a few seconds and is usually expressed in terms of parts per million (PPM).

Frequency Stability

Frequency stability is the output frequency stability of an oscillator or versus temperature or ΔF/ΔT. It is generally specified in KHz/°C or ppm/°C.

Frequency Switching Time (Hopping Time)

The amount of time from when the command for the next frequency is requested until the time that the synthesizer's output becomes usable and meets the specified requirements

Frequency Tuning Rate

Frequency tuning rate is also referred to as frequency tuning speed or frequency hopping rate. This is used to characterize the frequency changing speed of an oscillator.

Frequency Tuning Sensitivity

Frequency tuning sensitivity is used to characterize the frequency tuning slope of an electrically tuned oscillator.

FSPL (Free-space Path Loss)

Free-space path loss is an attenuation measure of radio energy between the feed points of two antennas that results from the combination of the receiving antenna's capture area plus the obstacle free, line-of-sight path through free space.

G

Gain

Gain is the ratio of the output power to input power. When using G=10log(G), gain is measured in decibels. Small signal gain is the gain in the linear region of an amplifier’s operation, often simply referred to as “gain” in the microwave and millimeterwave industry for simplicity.

Gain Flatness

Gain flatness is the gain variation over a defined frequency range at a fixed temperature, often specified as ±x.x dB.

Gain Stability

Gain Stability is the gain variation versus temperature, often specified as ±x.xx dB/˚C.

H

Harmonic Distortion

Harmonic distortion is the presence of harmonics that change the voltage waveform from a simple sinusoidal to complex waveform. Harmonic distortion is mainly caused by non-linear device operation or feedback in the amplifier circuits. It is generally given as the relative value of harmonic components to its fundamental power level and often specified as –xx dBc.

Harmonic Suppression

Harmonic suppression is the power of undesired harmonics versus the desired harmonic, measured in dBc.

Harmonics

Due to the nonlinear characteristics of semiconductor devices, oscillators, amplifiers, mixers, multipliers, etc. electrical device may generate the desired frequency as well as other undesired frequency components. The harmonics are the integer frequency components of the desired frequency, generally specified in dBc.

I

Impedance

It is the effective resistance of an electric circuit or component to alternating current.

Insertion Loss

Insertion loss is the circuit loss that occurs when signals travel in a forward direction. It is caused by the resistive and dielectric losses of the path.

Intercept Point

The intercept point (IP) is an imaginary point where the slopes of the fundamental, 2nd order intermodulation (IMD) and 3rd order IMD meet. The IP is used to quantify the linearity of power amplifiers. The 3rd order distortion, i.e. the third order intercept (IP3), is widely used to quantify the linearity of microwave and millimeterwave amplifiers.

Iso-adapter

An iso-adapter is a device that provides an interface transition, such as from coaxial to waveguide, or vice versa, as well as port isolation.

Isolation

Isolation is the measure of a ferrite device’s ability to behave non-reciprocally or as an electrical device when signals move in a reverse direction.

Isolator

An isolator is a two-port device. Isolators have low insertion loss in the forward direction (port 1 -> port 2) and high isolation in the reverse direction (port 2 -> port 1). Isolators are mainly used for port isolation to prevent signals from being reflected. Isolator is a ferrite device, which is referred as a non-reciprocal device.

Isolator, Drop-in

Drop-in isolators are non-reciprocal, ferrite-based devices with tabs as their input and output ports for easy subassembly and module circuit integration. The characteristic port impedance of these isolators is 50 Ω.

Isolator, Full Waveguide Band

Full waveguide band isolators are cavity-type, non-reciprocal, ferrite-based devices. They have the same mechanical configuration as waveguide junction isolators, but cover full waveguide bands. For example, a Ka-band full waveguide isolator has an operating bandwidth of 26.5 to 40 GHz, which covers the full WR-28 frequency range.

Isolator, Microstrip Line

Microstrip line isolators are non-reciprocal, ferrite-based devices that have a thin film circuit printed on a ferrite substrate and a magnet placed on the junction to move the signal in a forward direction. The devices have two mechanical configurations substrate only and substrate on carrier. The characteristic port impedance of these isolators is 50 Ω.

Isolator, Waveguide Junction

Waveguide junction isolators are cavity-type, non-reciprocal, ferrite-based devices. The signal circulation occurs in the center of the “Y” junction, where a ferrite puck is placed, and a uniform magnetic field is formed by a pair of magnets. When the third port is terminated with a matching load, the isolator is formed. The RF interface ports are waveguides.

Isotropic Radiator

It is defined as a theoretical point source of electromagnetic or sound waves which radiates the same intensity of radiation in all directions.

L

Limiter Leaking Power

Leaking power is the output power after an electrical limiter is “triggered”, which is when the input power exceeds the desired value.

Limiter Recovery Time

Recovery time is the time it takes for the insertion loss of an electrical limiter to return from the “triggered” stage to 3 dB higher than the normal insertion loss. The shorter the recovery time, the better. The recovery time can range from 100 ns to 2 μs. During the recovery time, the system is “blind”.

Limiter, Electrical

An electrical limiter has a negligible insertion loss when the applied power level is below the threshold. However, its insertion loss will increase dramatically once the applied power level exceeds the threshold. In other words, the limiter’s output power level is independent from the input power once “triggered”. This feature is desirable when over power protection is required, such as for low noise amplifiers or mixers in a communication or radar system.

M

Magnetic Susceptibility

It is a measure of how much a material will become magnetized under an applied magnetic field.

Microphonics

Microphonics is a phenomenon where the oscillator or electrical device transforming mechanical impacts or vibrations into an undesired output frequency or power variation. It is mainly caused by the instability of the device’s mechanical configuration. Microphonics is one of the biggest issues with Gunn and dielectric resonator oscillators, but Eravant has been able to greatly reduce this problem with improved mechanical designs.

Mixer

A mixer is a frequency down-converter that uses the nonlinear characteristics of semiconductor devices, such as Schottky diodes or transistors, to convert high radio frequencies into intermediate frequencies. Three frequency components are generally involved a local oscillator (FLO), a radio frequency (FRF), and an intermediate frequency (FIF). The relationship of these three frequencies is FIF = FRF±FLO. Since the local oscillator is used to pump semiconductor devices into a nonlinear region for harmonic generation, the required LO power is relatively high. For an unbiased mixer, the required LO power is generally around +13 dBm.

Mixer, Balanced

Balanced mixers are mixers that use two or more nonlinear devices and phase-correlating power dividers to reduce the number of mixing products. The number of nonlinear devices alone does not determine whether a mixer is single-balanced or double-balanced. As mentioned, single-ended mixers will produce every possible mixing product. A balanced mixer will reduce mixing products by 50%, and a double - balanced mixer will reduce them by 25%.

Mixer, Harmonic

Harmonic mixers are mixers that utilize a relatively low local oscillator frequency to convert high radio frequencies to intermediate frequencies. Therefore, the higher order harmonics of the local oscillator frequency is used. The resultant IF is shown as FIF = FRF ±nFLO, where n = 2, 3, 4... These mixers have a relatively high conversion loss due to the higher order harmonics used. These mixers are mainly used with phase locked loops and spectrum analyzers.

Mixer, Single-Ended

Single-ended mixers are mixers that share a single port for the RF and LO frequency. These mixers are rich in harmonics and produce every possible mixing product or 100% of nFRF ±mFLO, where n and m are integers. Eravant does not offer this type of mixer.

Mixer, Subharmonically Pumped

Subharmonically pumped mixers are harmonic mixers that use a local oscillator frequency at half its radio frequency. Due to their unique features, subharmonically pumped mixers are widely used in communication and radar systems.

Mixing Products

Due to the nonlinear characteristics of semiconductors, many frequency components are generated in mixer circuits as FIF = nFRF ±mFLO and up-converter circuits as FRF = nFLO ±mFIF, where n and m are integers. These frequency components are called mixing products.

Modulation Depth

Modulation depth is refer to the amount or quantity of deviation a modulating or program signal causes a particular parameter of a carrier signal.

N

Network Analyzer Extenders

Network analyzer extenders are designed to extend industry standard, low frequency vector or scalar network analyzers to higher millimeterwave frequencies. These extenders offer a low cost means of producing millimeterwave network analyzers while preserving the functionality and features that industry standard models offer.

Noise Figure

Noise figure is defined as NF = ((So/No) Signal To Noise Ratio at Output) / ((Si/Ni) Signal To Noise Ratio at Input). When using NF=10log (NF), noise figure is measured in decibels. Noise figure indicates how much the signal is “contaminated” throughout a component or system.

Noise Figure and Gain Test Extenders

Noise figure and gain test extenders are offered to extend noise and gain measuring capabilities to higher millimeterwave frequencies. These extenders are designed to interface with noise and gain test systems that have an input IF of 10 MHz to 1.6 GHz, such as the industry standard Agilent 8970A/B, N8973A and Maury MT 2075B. An external DC power supply is required to power up the extenders.

Noise Sources

Noise sources are silicon IMPATT diode-based, solid-state noise sources. These noise sources implement a high performance diode and propriety circuit design to offer high ENR with extreme flatness across the entire waveguide bandwidth. They are offered with and without integrated Faraday isolators.

Noise, AM

AM noise is the signal’s amplitude fluctuation or jitter due to amplitude modulation.

Noise, PM

PM noise is the signal’s phase fluctuation or jitter due to phase modulation.

O

Oscillator, Fundamental

A fundamental oscillator is an oscillator with an output frequency that is the same as the oscillating frequency, such that there is no frequency dividing and multiplying within the circuits.

Oscillator, Second Harmonic

A second harmonic oscillator suppresses its fundamental oscillating frequency for output and extracts and optimizes the second harmonic of its oscillating frequency for output. Second harmonic oscillators are mainly used at higher microwave and millimeterwave frequencies to expand the device’s operating frequency range.

P

P1dB

P1dB is defined as the output power level of an amplifier when it loses tracking with the input power increase by 1 dB. As a rule of thumb, the IP3 should be 8 to 12 dB higher than the P1dB for carefully designed and fabricated microwave and millimeterwave linear power amplifiers.

Passive Inter-Modulation (PIM)

Passive Inter-Modulation, is a type of signal distortion that is created when two or more carrier frequencies are exposed to non-linear mixing without active devices and is commonly caused by metallic material and workmanship quality of interconnects in a system.

Permittivity

A measure of the electric polarizability of a dielectric material.

Phase Match

A measure of the polarization wave produced by two or more beams of incident radiation in a nonlinear medium, which has the same phase velocity as a freely propagating wave of the same frequency.

Phase Noise

Phase noise is the signal’s phase fluctuation or instability due to phase modulation. It is widely used to describe the characteristic randomness of an oscillator’s frequency stability.

Phase Shifter, Analog Controlled

Analog controlled phase shifters have phase shifting values that are continuously controlled by the applied voltage.

Phase Shifter, Digital Controlled

Digital controlled phase shifters have phase shifting values that are digitally controlled by the bits. For example, if the phase shifting range is 360° and the bit size is 5, the phase shifting step size is 11.25°.

Phase Shifter, Electrical

An electrical phase shifter is a device that can cause a signal phase change when an external voltage is applied. Phase shifters are offered with either analog or digital controls.

Phase Shifters

Waveguide, micrometer-driven phase shifters are offered in this section of the catalog.

Polarization, Left Hand Circular (LHCP)

It is defined as the electric field vector rotates in a left-hand sense with respect to the direction of propagation.

Polarization, Linear

It is the confinement of the electric field vector or magnetic field vector to a given plane along the direction of propagation.

Polarization, Right Hand Circular (RHCP)

It is defined as the electric field vector rotates in a right-hand sense with respect to the direction of propagation.

Power Added Efficiency

Power-added efficiency (PAE) is used to rate the efficiency of a power amplifier. It is defined as PAE = 100*{[POUT]RF – [PIN]RF} / [PDC] It differs from power efficiency, which is defined as η = 100*[POUT]RF / [PIN]DC. However, PAE is very similar to power efficiency when the gain of a power amplifier is sufficiently high.

Power Handling

Power handling is the maximum input power that a device can sustain without being damaged.

Power Handling, Forward

Forward power handling is the power handling capacity of a device when signals travel in a forward direction.

Power Handling, Reverse

Load power handling is the power handling capacity of a device when signals travel in a reverse direction.

Power Stability

Power stability is the output power stability of an oscillator or an electrical device versus temperature or ΔP/ΔT. It is generally specified in dBm/°C.

R

Radar Cross Section (RCS)

Radar cross section (RCS) is a measure of how detectable an object is by a radar system.

Radar, Doppler

Doppler radar is based on the Doppler effect, which is the change in frequency of a moving target’s reflected signal. The shift in frequency or Doppler shift is expressed by the equation Where FRF is the transmitted frequency in Hz C is the speed of light (3 x 108 meter/sec) V is the target’s speed in meters/sec ϴ is the angle between the moving target and radar beam. Two extremes are 1) no Doppler shift when the moving target’s direction and radar beam are perpendicular (ϴ=90°) and 2) Fd = 2 V FRF / C, when the moving target’s direction and radar beam are parallel or ϴ is really small (0 to 10°).

Radar, Doppler Directional

Doppler directional radar is used to measure a moving target’s speed and direction. There are various ways to detect a moving target’s direction. The directional sensors offered are based on a phase detector or I/Q mixer approach.

Radar, FMCW Ranging

Ranging radar is used to measure the distance between a radar and the target. There are several ways to measure a target’s distance. The ranging sensors offered are based on a continuous frequency modulation (FMCW) approach.

Rejection

The phenomenon in waveform signals, where a certain frequency or range of frequencies are lost or removed from a source signal. This is desirable in applications such as filtering where components are designed to stop certain frequencies from passing through the system. The measure of Rejection is usually expressed in decibels (dB).

Return Loss

Return loss (RL) is the ratio of reflected power to incident power at the amplifier’s input and output ports and widely used in the industry to define the degree of a device’s port mismatch. Return loss is measured in decibels. The higher the return loss value, the better the port matching. Click here for Eravant's VSWR/Return Loss Calculator

Roughness Average (Ra)

Roughness Average (Ra) is the arithmetic average of the absolute values of the roughness profile. It is one of the most effective surface roughness measures commonly adopted in engineering which provides a great general description of the height variations on the surface usually presented in micro-meters or micro-inches. In general, Eravant parts have an Ra of 0.8 micro-meters or 32 micro-inches.

S

Spectral Purity

Spectral purity refers to the ratio of signal power to phase-noise sideband power.

Spurious

Spurious are frequency components other than harmonics and the desired frequency, generally specified in dBc.

Switch, Absorptive

Absorptive switches exhibit low VSWR in both “on” and “off” states. In general, these switches offer lower insertion loss and cost less than reflective switches.

Switch, PIN Diode

PIN diode switches are used to electrically direct signals through an applied voltage/current. Various types of switches, such as single pole, single throw (SPST) and single pole, double throw (SPDT), etc. are offered. Both absorptive and reflective switches are widely used in the industry.

Switch, Reflective

Reflective switches only exhibit low VSWR in the “on” state since the “off” state is achieved by shortening the RF signal’s transmission path.

Switching Time

Switching time refers to the “on” time and “off” time. The “on” time begins when a 50% control pulse is applied and ends when 90% of the RF signal is achieved. On the other hand, the “off” time begins when the control pulse drops below 50% and ends when 90% of the RF signal disappears. The switching time is related to the PIN diode and TTL driver.

U

Unconditionally Stable

An unconditionally stable amplifier refers to an amplifier that has no signal output when an input signal is absent regardless of the load, source impedance and operating temperature. An unconditional stable oscillator refers to an oscillator that generates stable signal with same frequency and power all time.

Uni-Guide™

Uni-Guide™ is a trade-marked, patent pending waveguide connector invented by Eravant. Its counterpart is coaxial connectors, such as SMA, 2.92 mm, 2.4 mm, 1.85 mm etc. connectors. Uni-Guide™ products can be found here.

Up-Converter

An up-converter uses the nonlinear characteristics of semiconductor devices to convert intermediate frequencies to higher radio frequencies for transmitting, shown as FRF = FLO ±FIF.

V

VSWR

VSWR stands for Voltage Standing Wave Ratio, which is another way to characterize port mismatch. The relationship between VSWR and return loss is RL = -20*Log[(VSWR-1)/(VSWR+1)] dB. Click here for Eravant's VSWR/Return Loss Calculator

W

Waveguide, Circular

The circular waveguide is a piece of circular hollow metal tube used to carry and guide the microwave signals. Common dominant mode is TE11 mode and low loss mode is TE01 mode.

Waveguide, Rectangular

Rectangular waveguide is a piece of rectangular hollow metal tube used to carry and guide the microwave signals. Its dominant mode is TE10 mode.

Z

Zenith Angle

Zenith Angle is measured from the positive z axis and it describes a conical surface with its apex at the origin.