Product Introduction ...

What is fixed coaxial attenuator?

As the name implies RF attenuators reduce the level of the signal, i.e. they attenuate the signal. An attenuator is effectively the opposite of an amplifier, though the two work by different methods. While an amplifier provides gain, an attenuator provides loss, or gain less than 1. This attenuation may be required to protect a circuit stage from receiving a signal level that is too high. Also an attenuator may be used to provide an accurate impedance match as most fixed attenuators offer well-defined impedance, or attenuators may be used in a variety of areas where signal levels need to be controlled.
There are many used for these RF attenuators and although these may not seem obvious initially when asking what is an attenuator, they are widely used in RF applications.

• Type of attenuators
  Attenuators can be categorized in a number of ways according to their capabilities and the technologies they use – Fixed RF attenuator, Switched RF attenuators and Variable RF attenuators; there are a number of ways in which attenuators can be designed and made - Resistor RF attenuators, PIN diode RF attenuators, and FET RF attenuators. Fixed RF attenuator, as the name implies fixed attenuators have a specific value and this cannot be changed. They may come in a variety of formats from small in-line items in a similar format to connector adaptors to those in small boxes with connectors on the ends to those incorporated within equipment.
• Attenuator specifications
  When designing, purchasing or using an RF attenuator it is necessary to be able to specify it to ensure that an attenuator with the correct performance is obtained. While some of the major specifications are detailed below, for some applications other parameters may need to be specified.
  1. Attenuation:This is the primary specification for an RF attenuator. It is the ratio between the output and the input power levels and is typically quoted in decibels (dB).
  2. Attenuation accuracy:It is often necessary to know the accuracy of the level of the attenuation of the attenuator. Particularly in applications where equipment is being tested, the attenuation accuracy is likely to be important. In these cases a tolerance on the nominal level of attenuation will be given.
  3. Frequency response:The level of attenuation of an attenuator will vary with frequency. This can result from the frequency dependence of the resistors or other components used in the RF attenuator, or where coupling between the input and output may exist as this will be frequency dependent. Some RF attenuators where the absolute level of attenuation is important may be provided with calibration charts measuring the absolute attenuation at different spot frequencies over a frequency band.
  4. Impedance:RF attenuators will be designed for use in systems with a given characteristic impedance. 50 ohms is the most common, although 75 ohms is also used, and it may be possible to obtain RF attenuators with other impedance values should the need arise.
  5. Power dissipation:In order to reduce the signal level, RF attenuators dissipate or absorb the unwanted power. For many small signal applications, power dissipation is not an issue, but for other applications where signal levels are higher, it is necessary to ensure that the RF attenuator will satisfactorily be able to handle the power levels anticipated. Power capabilities for RF attenuators may be quoted in Watts (or mill watts) or as dBW - decibels relative one Watt (or dBm - decibels relative to a mill watt).
  6. Mechanical details of the attenuator:The mechanical details may include aspects such as the size and weight. The connectors may be included in this area of the attenuator specification.
  7. Environmental details:Many applications for attenuators are for use within benign conditions such as a laboratory environment. Environmental conditions would not be an issue. However for some applications it is possible that an environmental is required to detail factors such as vibration, temperature, humidity and the like.
• Attenuator Applications
  RF attenuators are used in a wide variety of applications in RF circuits. They are a key building block used in many areas of RF design:
  1. Reduce signal level:The basic concept behind an attenuator is to reduce the signal level. This can be required to control levels within a circuit to keep them within the required range.
  2. Improve impedance match:By its very nature an impedance matched RF attenuator will improve the impedance match. This can be very useful when driving RF mixers that are match sensitive and their performance will be degraded if a poor match is seen.
  3. Variable level control:RF attenuators can be used for level control on the output of items such as signal generators. It is far better to be able to generate an accurate fixed level from the basic generator and then used switch attenuators to reduce the signal to the required level.
  RF attenuators are used widely within RF circuits for a variety of reasons.

What is RF termination?

Also known as RF loads and dummy loads
An RF Coaxial Termination is a passive 1-port interconnect device, which provides a resistive power termination to properly terminate the output port of a device under test (DUT) or to terminate one end of an RF test cable. These devices can be used in the field, to possibly terminate the unused port of a multiport RF coaxial switch or of a directional coupler. Mainly, however, these impedance termination devices are used in various factory or laboratory Test & Measurement applications.
RF Coaxial Terminations are available in various power ratings and in a wide variety of standard coaxial connector types (e.g., N, SMA, BNC). They can also provide a variety of impedances, such as a short-circuit termination. More typically, however, these terminations provide a “matching impedance”–either 50 Ω or 75 Ω–to match the characteristic impedance of a particular coaxial cable or transmission system. Some RF Coaxial Terminations include a heat sink to dissipate substantial RF power (up to its rated power value). Specific attributes which are important in selecting the right RF Coaxial Termination for your application include the Series for the coaxial connector type (N, SMA, BNC, etc.), its Gender (Male or Female), and its nominal Impedance value, in Ohms (50 or 75Ω).

• Termination Specifications
• Termination Applications
• What are the advantages of Amphars/Nanjing’s terminations?

What is RF adapter?

• RF Adapters Specifications
• Adapters Applications
• What are the advantages of Amphars/Nanjing’s adapters?

  We offer a full gender family of straight and right-angle adapters in different connector options, to cover applications ranging from DC–65 GHz. These adapters come standard in a passivated stainless steel body with a captivated Beryllium Copper center conductor to ensure mating repeatability. In addition, options such as gold-plated housing or no captivated center conductor are also available to fit the desired application. All of our adapters are 100% tested to ensure optimum performance over their respective frequency range.
  We offer a full gender family of straight and right-angle adapters in different connector options, to cover applications ranging from DC–65 GHz. These adapters come standard in a passivated stainless steel body with a captivated Beryllium Copper center conductor to ensure mating repeatability. In addition, options such as gold-plated housing or no captivated center conductor are also available to fit the desired application. All of our adapters are 100% tested to ensure optimum performance over their respective frequency range.